Meeting (need) and demand for Urgent Angiography in ACS ... · PDF file- 2 - Meeting (need)...

Meeting (need) and demand for Urgent Angiography in ACS Patients in the Greater Manchester and Cheshire Cardiac Network A Report of the findings of a pilot Study 2008

Dr G Cook Mr D Havely Mr P Rishton Ms H Iles-Smith Dr P Lewis Dr F Fath-Ordoubadi

Clinical Effectiveness Unit Stockport NHS FT and Departments of Cardiology Stockport NHS FT and Central Manchester

With special thanks to the 4 hospital sites and cardiology departments that contributed to this study

- 1 -

Acknowledgements Special thanks to the 4 Hospital Trusts Wrightington Wigan and Leigh Leighton Hospital Crewe Tameside General Hospital Stepping Hill Hospital And Drs Sanjay Arya Consultant Cardiologist Joanna Trelawny Sundeep Puri Their cardiology departments and teams and in particular Helen Titu & Rebacca Keld Wigan Hugh Roberts Crewe Helen Gallery Helen Goodwin Richard Baugh Tameside

Author contact details Gary Cook MB ChB LLB MRCP FFPH Consultant Epidemiologist Department of Epidemiology Willow House Stepping Hill Hospital Stockport NHS FT 0161 419 5985 [email protected] 30th October 2009

- 2 -

Meeting (need) and demand for Urgent Angiography in ACS Patients in the Greater Manchester and Cheshire Cardiac Network Contents 1. Executive Summary

1.1 Summary and Conclusions 1.2 Chest Pain 1.3 Non Chest Pain 1.4 General observations 1.5 Recommendations 1.6 Summary of Key Observations 1.7 General Observations 1.8 Chest Pain 1.9 Non Chest Pain 1.10 Regression model 1.11 Estimating need

2. Background 3. Aims of the project 4. Defining need and demand for Urgent Angiogram 5. Method

5.1Variations 5.2Case definition: 5.3 Inclusion Criteria 5.4 Exclusion Criteria 5.5 Consent and Research Ethics 5.6 Analysis 5.7 Extrapolation of findings to a population base 5.8 Regression Analysis

6 Results 6.1 Regression Analysis 6.2 Application to an estimated population base

7. Strengths and Weaknesses of The Study Method 8 Summary, Conclusions and Discussion

8.1 Chest Pain 8.2 Non Chest Pain

10 Appendix 10.1 Appendix 1 Referral Data for Chest Pain and Non Chest Pain Cases 10.2 Appendix 2 Regression Model Predictors and Outputs 10.3 Appendix 3 Estimating met and unmet need/demand for urgent angiogram for UA/NSTEMI by population.

11. References

- 3 -

Meeting (need) and demand for Urgent Angiography in ACS Patients in the Greater Manchester and Cheshire Cardiac Network

1. Executive Summary

This study was commissioned by the Greater Manchester and Cheshire Cardiac Network with the following aims:

• To address the question of who is being considered for urgent angiogram and whether we are identifying need and meeting demand adequately?

• To provide an estimate of the burden of category B and C non-ST elevation ACS cases requiring transfer for in-patient angiogram in the Greater Manchester and Cheshire Cardiac Network.

Four hospitals (Crewe, Stockport, Tameside and Wigan) were selected as a purposive sample, representing a mix of hospitals and populations ranging between high and low referrers for urgent angiogram, to participate in the study. Patients to be studied were those admitted to hospital as an acute medical emergency with a suspected Acute Coronary Syndrome (Unstable Angina and Non ST elevated MI). They were identified initially on the basis of having had a blood test for Troponin on admission. This test is used primarily as part of a strategy to rule out acute myocardial infarction in patients presenting with chest pain but without obvious ST elevation on ECG. Those fitting the urgent referral categories B and C enter a referral pathway for urgent angiogram. However, Troponin is also measured in patients in the absence of chest pain but whose presentation and ECG changes may indicate acute myocardial ischaemia. Some of these patients might also benefit from referral for urgent angiogram. However they do not fit the chest pain triage strategy. These non chest pain patients were identified and included in this study. The study itself collected data on a rotating monthly basis. Each hospital contributed patients over a total of 90 days within a 12 month period. The detailed analysis is in the main part of the report but the key observations are summarised below.

1.1 Summary and Conclusions

730 cases1 of possible ACS were hospitalised over 90 days at each of the four hospitals, of which 476 (65%) were chest pain and 254 (35%) non chest pain presentations. This would be equivalent to almost 3000 in a year.

1 This study is based on cases or hospitalised events rather than individual patients, some patients may have appeared more than once.

- 4 -

1.2 Chest Pain

Only the 476 (65%) chest pain cases fell within the current triage system for urgent referral for angiogram. They were more likely to receive the full panoply of antithrombotic therapy, There is little difference between hospitals in the prescribing of anti-platelet treatment. However, there is room for improvement either by increasing the percentage of cases receiving appropriate treatment and or by making it clear why those not treated are exceptions. The majority (80%) of these cases are referred to cardiology, 42% for angiogram and over half for cardiac rehabilitation.

Overall 46% of chest pain cases were categorised as a having need or generating demand for urgent referral for angiogram of which 83% were referred hence representing need/demand met. A further 34% of these cases may have warranted more urgent referral. Cases in this group were a mix of patients who, for example, refused or declined invasive treatment, had other more urgent medical issues for stabilisation or were passed onto an elective out patient pathway for further assessment including stress testing. In 20% of chest pain cases circumstances militated against referral i.e they had serious other co-morbidities and there was no demand. There appears a need to develop the application of a triage system that takes into account the risks and benefits more explicitly and in a much more structured and standardised way. Where angiogram was performed it was more likely in younger, mobile and self caring males. Such cases were more likely to have higher troponins and lower creatinine values, higher blood pressure, fewer ECG changes and more likely to have confirmed ACS diagnosis and to have received the full range of anti-platelet therapy. Cases in the Probable Urgent Angiogram Not Done group show similarities to the met demand group although marginally older and more likely to be female re-inforcing the notion that some if not all of these cases may truly represent an unmet need group. Over half of the total chest pain presentation cases were codified by the research nurse as potential category B cases based on the referral guideline criteria as assessed at day 1-2. Only 117 (45%) of these had an angiogram, they accounted for almost two thirds of the angiogram cases done. The remainder were codified as C or other. The crude application of the B & C category was not that useful in this study without the addition of a full and explicit risk benefit assessment. It is understood that the referral algorithm is under review; this would be timely given the recent NEJM article on the optimal management of ACSi. The analysis of Primary ICD 10 codes on PAS showed that for chest pain cases

• 43% were codified as STEMI ( if correctly coded as such should they have been entered on a different pathway?) and

o of these 52% had an urgent angiogram. • A further 30% were codified as NSTEMI or Angina

o of which a third had an urgent angiogram • The remaining 26% had a range of other diagnoses in particular R or symptom

codes o of which one fifth underwent urgent angiogram.

- 5 -

The accuracy of clinical coding remains a problem and is of critical importance if used as a basis for benchmarking hospital performance in these areas by Dr Foster for example. 1.3 Non Chest Pain

The remaining 254 (35%) cases were admitted with non chest pain presentations. This feature was heavily influenced by clinical practice in Stockport where more older cases with these types of presentation in particular were routinely tested for troponin and drawn into the study population. These tests and subsequent admissions were not part of a systematic triage system as is in place for chest pain and this raises the question whether there should be such a system.

Just over half of non chest pain cases are referred to cardiology, 12% are referred for urgent angiogram and a third for cardiac rehabilitation. Approximately16% of non chest pain cases were identified as having a need for urgent referral for angiogram of which 59% had been referred and hence the demand met. However the majority of this met demand emanated from Stockport. A further 46% of non chests pain cases were deemed to be requiring of further assessment with a view to less urgent angiogram although not all (un-quantified proportion) of these cases would necessarily have been referred. In 38% of non chest pain cases the circumstances militated against referral i.e. there was no need. The value of routine Troponin testing in non chest pain presentations and the feasibility of a non chest pain triage system should be further considered. Although not presented here there are concerns about the interpretation of low level troponin when measured in some patients . 1.4 General observations

Stockport admits on average an older population of cases and fewer cases with chest pain. Tameside tends to have younger cases and a higher proportion of current smokers. It is noted that the prevalence of smoking is highest in the younger age groups. This should be of no surprise as their life expectancy is curtailed and current smokers would not normally be expected to live to be 75 and older. Tameside in addition has the legacy of a cigarette manufacturing industry in its midst. Extra attention should be given to smoking cessation in these younger hospitalised patients.

It is possible to apply the findings of this study to estimate met and unmet need/demand for hospitalised chest pain cases. It was out with the study to identify unmet need remaining in the community.

In summary it was estimated that hospitalisation rates of troponin tested suspected UA/NSTEMI cases was 42 per 10,000 population aged 30 years plus. The rate for those with chest pain presentation was 27 and non chest pain 15 per 10,000. In

- 6 -

respect of chest pain cases 11 per 10,000 underwent urgent angiogram but upto a further 11 per 10,000 may warrant urgent angography. For non chest pain cases about 1 per 10, 000 had angiogram although the potential demand may be as high as 20 per 10,000. It is worth reflecting that these are unadjusted rates and include high rates for the very elderly. Further work is required to better understand the need/demand in this group before adopting values like these to estimate future need/demand.

1.5 Recommendations

1. Confirm up to date and explicit triage, risk benefit assessment (including explicit criteria on who would or would not benefit from different types of treatment strategies) , and clarify treatment options and angiogram referral pathways for Chest Pain - UA/NSTEMI ACS cases for optimal management

2. Seek to roll out and train all GM Network Trusts to adopt the optimal management pathway with standards for chest pain cases

3. Re-audit the optimal management against agreed standards in 2010/11

4. Review the appropriateness and application of the optimal management plan to cases with a non chest pain presentation and those aged 85 or more

5. In order to refine the estimates for unmet need/demand re-review those cases who fell into the potential demand categories for both chest and non chest pain cases to clarify the true number that would be considered appropriate for referral

6. In light of other published material together with the output from the above develop more robust estimates of unmet need/demand to project future catheter laboratory requirements

7. Utilise this cohort of cases to follow-up 6-12 month outcomes and survival. Some additional support would be required.

- 7 -

2. Summary of Key Observations

2.1 General Observations 730 cases of possible ACS were hospitalised across the four hospitals over a 90 day period of which 476 (65%) were chest pain and 254 (35%) non chest pain presentations. This would be equivalent to almost 3000 in a year. There were significant differences between hospitals with respect to the average age of hospitalised cases. Stockport admitted on average an older population and Tameside a younger group. Stockport had the lowest percentage of cases presenting with chest pain. There is a higher proportion of current smokers amongst Tameside’s cases. There are is in use differing Troponin kits and decision limits values. The differing decision limits used in this study resulted in 44% of Tameside’s cases being classed as negative compared with around 22% or less for the other 3 hospitals. Crewe generated the highest percentage positive. Overall 83% (range 72%-89%) of the cases had a 5 day diagnosis of NSTEMI or Unstable Angina. Cases who present with chest pain whether or not the 5 day diagnosis was NSTEMI/UA were more likely to receive anti-platelet treatment than those with non chest pain. Generally there is little difference between Trusts in the prescribing of anti-platelet treatment; the majority of chest pain and or NSTEMI/UA cases are treated. A smaller percentage of non chest pain cases are treated with antithrombotics and they are prescribed fewer drugs. There is greater variation between hospitals in this practice, with Stockport more likely to prescribe in the non chest pain group and Tameside the least likely. Both Crewe and Stockport are more likely to prescribe in older cases. Overall 80% of chest pain cases are referred to cardiology compared with just over half of non chest pain cases. 42% of chest pain cases are referred for urgent angiogram compared with 12% of non chest pain cases. Over half of chest pain cases are referred to cardiac rehabilitation compared with a third of non chest pain cases. NSTEMI and UA cases along with other cardiac diagnoses are most likely to be referred for all three services compared with other non cardiac. Younger cases are also more likely to be referred compared with the elderly. Crewe on the other hand tends to refer the least for angiography but the most to cardiac rehabilitation.

- 8 -

Overall 46% of cases with chest pain were identified as having a need for urgent referral for angiogram (Urgent and Probable Urgent) of which 83% were referred hence representing met need/demand. A further 34% of chest pain cases were assessed with a view to less urgent angiogram, although some may have warranted more urgent referral.. In 20% of chest pain cases circumstances mitigated against referral i.e there was no demand. Approximately16% of non chest pain cases were identified with a need for urgent referral for angiogram 59% of which had been referred and demand met. However the majority of this met demand emanated from Stockport. 46% of non chest pain cases were deemed as requiring further assessment with a view to less urgent angiogram although not all (un-quantified proportion) of these cases would necessarily be referred. In 38% of non chest pain cases the circumstances mitigated against referral i.e. there was no need. 2.2 Chest Pain

Chest pain cases where angiogram was performed were more likely to be younger and male, more mobile and self caring, to have higher troponins and lower creatinine values, higher blood pressure, fewer ECG changes and more likely to have confirmed ACS diagnosis and to have received the full range of anti-platelet therapy, to have been referred to cardiology and cardiac rehabilitation and least likely to have died compared with those in the other groups especially the no angiogram group. Cases in the Probable Urgent Angiogram Not Done group show similarities to the met demand group although marginally older and more likely to be female re-inforcing the notion that these cases in particular may truly represent an unmet need group. Of the total chest pain presentation cases:

• over half were codified by the research nurse as potential category B cases based on the referral guideline criteria as assessed at day 1.

o Only 117 (45%) of these had an angiogram, they accounted for almost two thirds of the angiogram cases done.

o Approximately one third of the remaining cases fell into categories of need where urgent referral may have been appropriate.

• The remaining half of chest pain cases were category C and other, o 66 (30%) had an urgent angiogram contrary to the referral guideline.

However, of those not undergoing urgent angiogram they fell into potential categories of need for urgent angiogram.

The analysis of Primary ICD 10 codes on PAS showed that for chest pain cases:



- 9 -


codes of which one fifth underwent urgent angiogram; 2.3 Non Chest Pain

Of the 254 non chest pain cases 41 (16%) were deemed eligible for urgent referral based on either the fact of actual referral or by the retrospective application of the rule that Troponin elevation and ECG indication is sufficient cause even in the absence of chest pain. Of those deemed eligible 23 (56%) actually underwent angiogram; it is worth noting that the majority 16 (70%) were Stockport cases. The remaining 18 (44%), that is 7% of this non chest pain group overall, may represent unmet need. A further 116 (46%) were deemed as possibly requiring angiogram but were managed in other ways or electively. Stockport contributed almost half the cases in this group. Ninety seven cases (38%) were thought to be too ill or frail to benefit from referral for angiogram. The group of non chest cases who underwent angiogram were more likely to be young, male, with fewer comorbidities, greater mobility and to be more self caring. They tended to have lower creatinine, fewer ECG changes and then to have received anti-thrombotic therapy and to be referred to cardiology. They also had a lower in hospital mortality rate. The majority of these difference were statistically significant. In contrast those on the probable and possible referral group were older and predominantly female. However the latter observation may not be surprising given the predominance of females in the older age groups. Finally the group considered too frail and ill to benefit had an in-hospital mortality of 37% compared with 7% or less for the others. Of the non chest pain presentation cases:

� almost two thirds were codified by the research nurse as potential category B cases based on the referral guideline criteria as assessed within first 48 hours.

o Only 11 (7%) of these had an angiogram, they accounted for almost half of the angiogram cases done.

o Over half (54%) of the remaining category B cases fell into categories of unmet need/demand where urgent referral may have been appropriate.

� One third of non chest pain cases were category C or other, o of which 12 (13%) had an urgent angiogram. However, almost half of

those not undergoing urgent angiogram in this category may have warranted urgent referral.

Interestingly, of non chest pain cases overall:

� 90 (35%) were codified as STEMI on PAS using ICD 10 codes o of which 11 (12%) had an urgent angiogram.

� 38 (15%) were codified as NSTEMI or Angina o of which 5 (13%) had an urgent angiogram

� The remaining 126 (50%) had a range of other diagnoses in particular non medical, other cardiac and symptom codes.

- 10 -

o 7 cases with these other codes underwent urgent angiogram. 2.4 Regression model

The following previously identified factors were significant predictors within the model of whether or not need was met: Previously Identified factors are significant predictors within the model:

• Age – Increasing age associated with lesser likelihood of urgent angiogram

being done • Gender

– Being female is associated with lesser likelihood of urgent angiogram being done

• Trust – Crewe is associated with lesser likelihood of urgent angiogram being

done Additional predictors added to the model:

• Troponin – Positive/Borderline is associated with greater likelihood of urgent

angiogram being done • Presenting Complaint

– Chest Pain is associated with greater likelihood of urgent angiogram being done

• Previous Medical History – CABG associated with lesser likelihood of urgent angiogram being

done Deprivation Analysis of Crewe data indicated that cases from the lower socio-economic strata were least likely to be accessing urgent angiography. 2.5 Estimating need Need was estimated by applying the study data to estimated catchment populations stratified by age, sex, and Index of Multiple Deprivation quintile. There is an obvious rising trend in hospitalisation rates with increasing age for all trusts, but with variation between trusts for specific age groups. Stockport has a particularly high rate of troponin tested hospitalised chest pain cases in the over 85 year olds. Stockport has the highest hospitalisation rate for chest pain in females of all trusts but Tameside is not far behind, For male cases Tameside has the highest crude 30 year plus rate of hospitalisation for this group of cases followed by Stockport. Crewe and Wigan are alike but about 25% lower.

- 11 -

The majority of the hospitalised chest pain cases for those in the age group 30-64 underwent urgent angiogram, the rates range 1.2 per 10,000 in Crewe to 2.9 per 10,000 in Tameside. Non chest pain presentation is predominantly a feature of older people. The hospitalisation rate of troponin tested cases rising from 1.2 per 10,000 at 55-59 to 44.4 per 10,000 by 85+. There is considerable variation between Trusts in the actual age specific rates and Stockport has a hospitalisation rate of 81.4 per 10,000 in the age group 85 plus that is more than 2-3 times the rates of the other three trusts.

In summary it was estimated that hospitalisation rates of troponin tested suspected UA/NSTEMI cases was 42 per 10,000 population aged 30 years plus. The rate for those with chest pain presentation was 27 and non chest pain 15 per 10,000. In respect of the chest pain cases 11 per 10,000 underwent urgent angiogram but upto a further 11 per 10,000 may warrant urgent angography. For non chest pain cases about 1 per 10, 000 had angiogram although the potential demand may be as high as 20 per 10,000. It is worth reflecting that these are unadjusted rates and include high rates for the very elderly. Further work is required to better understand the need/demand in this group before adopting values like these to estimate future need/demand.

- 12 -

Meeting (need) and demand for Urgent Angiography in ACS Patients in the Greater Manchester and Cheshire Cardiac Network

3. Background

The term acute coronary syndrome (ACS) refers to a spectrum of acute clinical presentations of coronary artery disease caused predominantly by atherosclerotic plaque rupture, leading to thrombus formation and coronary vasoconstriction. These patho-physiological changes result in variable degrees of coronary artery occlusion and myocardial damage. The resultant clinical spectrum of acute coronary syndrome may range from cases with transient reductions in myocardial blood flow with minimal or no myocardial injury, to those with persistent and complete coronary artery occlusion with large areas of jeopardised myocardium, prone to irreversible damage.

For therapeutic and prognostic reasons, it is important to determine whether the patient with prolonged cardiac chest pain has an open or closed coronary artery and fortunately this can be guided by ST-segment changes on the ECG. The presence of ST-segment elevation is highly suggestive of a completely occluded coronary artery with impending irreversible myocardial damage, whereas the absence of ST-segment elevation usually suggests that the artery is open, but significantly narrowed by clot formation. Consequently, acute coronary syndrome has been broadly divided into 2 categories: ST elevation myocardial infarction (STEMI) and non-ST elevation acute coronary syndrome (NSTEMI/ACS). The importance of this distinction lies in the differing therapeutic approaches to these two separate clinical entities. Cases with STEMI require immediate reopening of the occluded coronary artery with aspirin and either thrombolytic therapy or percutaneous coronary intervention.

In contrast, those who have a NSTEMI/UA do not benefit from thrombolytic therapy, but require initial anti-platelet and anti-ischaemic drug therapy followed by appropriate triage for in-patient coronary angiogram and revascularisation. It has been shown that cases with NSTEMI/UA, who have a positive troponin or ECG changes, who are treated by an invasive strategy of mandatory inpatient coronary angiogram and revascularisation have a markedly lower event rate than those treated conservatively (ref).

In 2003 the Greater Manchester and Cheshire Cardiac Network (GMCCN) ratified new guidelines for the transfer of cases with non- ST elevation ACS, to the tertiary centres (MRI and Wythenshawe), for angiogram.

In brief the guideline is:

Category A (transfer within 24 hours)

• Refractory or recurrent ischaemia • Haemodynamic instability • Important ventricular arrhythmia (VT and VF)

Category B (transfer within 72 hours)

• Troponin T > 0.1 • ST depression >1mm in at least 2 leads on admission

Category C (transfer within one week)

• Positive troponin T <0.1 and

- 13 -

� history of previous PCI; � ongoing symptoms; � left ventricular dysfunction; or � positive exercise test in stages I and II

Typically cases present with chest pain as a predominant symptom the nature of which raises a high degree of suspicion of an underlying STEMI or NSTEMI/ACS. Cases would be entered onto a chest pain protocol. As part of the assessment and investigation a serum troponin measurement would be performed, typically at 12 hours post onset of symptoms, to rule out myocardial cell damage. Cases with a clear STEMI would not normally warrant a troponin test but it is often done. A positive result is indicative of myocardial cell damage and in the majority of cases is probably due to an acute ischaemic event. Interpretation is done in light of patient history, ECG findings and clinical assessment. Elevated troponin may occur in a number of other situations including Chronic Renal Disease, Heart Failure, Cardio-myopathies and infective conditions affecting the heart. A negative result also must be interpreted in light of symptoms and ECG, as unstable angina can present a picture of continuing chest pain, with abnormal ECG patterns but negative troponins. The above triage and referral process has been predicated on the chest pain presentation as have the subsequent treatment protocols. Some cases with STEMI or NSTEMI/ACS may present with acute breathlessness or collapse and not the typical chest pain scenario.

All hospitals have introduced troponin as a blood test in this scenario however there are two types troponin T and I. They use different assay systems and have different decision limits. troponin I in particular has more varied systems and different assays have been implemented across some North West hospitals whereas T tends to be standardised to the same assay system. The use of troponins is increasingly being used in cases who present with non-chest pain symptoms, perhaps predominantly for rule out of acute myocardial ischaemia but there is a belief that the test is being used as more of a general screening test in unwell cases. These extended uses create some interpretation difficulties especially in older cases with multiple co-morbidities.

There has been a growth in facilities for angiogram and early intervention for cases with STEMI or NSTEMI/ACS across Greater Manchester in the past 5-10 years. Despite this growth there is a perception that the need for this service among cases with NSTEMI/ACS is not being met fully. Referral patterns for angiogram vary quite considerably by hospitals although these figures are not easily adjusted for differences in underlying population size or disease patterns. With these concerns in mind this project, supported by the GM&C Cardiac Network, seeks to identify such cases and current patterns of met and unmet need and demand within the hospitalised population.

4. Aims of the project

To provide an estimate of the burden of categories B and C non-ST elevation ACS requiring transfer for in-patient angiogram in the Greater Manchester and Cheshire Cardiac Network. To address the question who is being considered for urgent angiogram and whether we are identifying need and meeting demand adequately?

- 14 -

4.1 Defining need and demand for Urgent Angiogram

For the purposes of this report need and demand and the subsets of met and unmet components are illustrated by the following chart (taken from Barker & Rose Epidemiology in Medical Practice 2nd Edition 1979 Churchill Livingstone :London)

This model as applied to this study of the need for urgent referral for angiogram among cases with confirmed ACS (NSTEMI and Unstable Angina in category B&C) would create the following patient groups:

Unperceived unmet need would represent those cases with ACS who do not present to hospital, some may die others may present later but the number is difficult to quantify and is not being estimated in this project. This category would also include hospitalised cases in whom an ACS diagnosis was missed. Perceived unmet need will be those cases with confirmed ACS who were not referred for urgent angiogram. They may have been overlooked or established in an alternative or less urgent treatment pathway. Unmet need where the demand is recognised will be those cases for whom urgent referral was requested but not met (this could include those cases who were delayed but eventually transferred but might also include some cases entered onto a less urgent pathway). Met need and met demand represent those cases with confirmed ACS undergoing urgent angiogram in a timely fashion. Demand surplus to needs would be the overdiagnosis of ACS and those undergoing angiogram who end with a negative result. We should also recognise that there is a group of cases who have confirmed ACS but for whom urgent angiogram would not be beneficial or in their interest, the potential for harm outweighs the benefit. Such cases would include the very frail, those with

demand

Demand surplus to need

Unmet need Met need

Met demand

Need for health services

Perceived Unperceived

Consumption of health services

Ineffective treatment Unnecessary

investigations Unmet

- 15 -

complex heart disease and active comorbidities such as cancer or extensive peripheral vascular disease, severe dementia and renal failure. 5. Method This is a prospective study involving four district general hospital sites that were selected purposefully from within the Greater Manchester and North Cheshire Cardiac Network. They included :

1. Stockport NHS Foundation Trust (Stepping Hill Hospital)

2. Mid Cheshire Hospitals NHS Trust (Leighton Hospital)

3. Wrightington, Wigan and Leigh NHS Trust (Royal Albert Edward Infirmary)

4. Tameside and Glossop Acute Services NHS Trust (Tameside General Hospital)

They represent a mix of populations varying in degrees of affluence and life expectancy, use and provision of hospital services and access to and use of angiogram or tertiary facilities. One site, Wigan, has an established Cardiac Catheter laboratory in addition to access to tertiary centres. A second site Stockport had recently established a Cardiac Catheter Laboratory but it was not in use for these cases. This latter hospital and the other two sites refer cases to tertiary centres. A sample size calculation was not done. This was an empirical study based on case ascertainment within a given time frame and available resource for the study. A trained cardiology nurse undertook the data collection for each hospital. He identified relevant cases over a 4 week cycle at each of the four different sites on three separate occasions in rotation over a 13 month period. On 4 occasions the 4 week cycle was interrupted for short periods of up to two weeks due to holiday or illness or the absence of support staff at specific sites accounting for the extra month of data collection. Having a blood test for serum troponin was the trigger for the first step in identifying cases for possible inclusion in this study. This approach is predicated on the common policy that all emergency medical cases with chest pain or other symptoms suggestive of underlying ACS or cardiac cause would have such a blood test, ideally at 12 hours from the onset of the symptoms. Lists of cases who had had this test were either generated in paper form on a daily basis by the laboratories directly or by the nurse accessing the computerised laboratory database. Account was taken of the variation between hospitals with regard to the different tests and regimes and configuration of local services. No hospital had a universal IT system that linked laboratory and admission data. Case ascertainment was supplemented by scrutinising admission lists on emergency admission units and other wards or departments where appropriate. For example point of care testing was used in one ED department necessitating scrutiny of ED records although only cases who were admitted were eventually included as they were subjected to a 12 hour troponin test. Patient details were checked against hospital Patient Administration Systems to confirm type and date of admission and co-incidence of date of admission with the date of the troponin sample. The researcher contacted all wards on a daily basis (Monday to Friday) to identify all cases newly admitted with chest pain and / or cardiac-related breathlessness / collapse together with ECG changes or troponin T elevation. Cases presenting over the weekend were picked up on Mondays.

- 16 -

5.1 Variations During the first month of data collection at Stepping Hill Hospital (July 2007) the Pathology department ran the gather programme and sent only the troponin results 0.03ng/ml and above. The cases of ACS with troponin negative features were identified in the emergency areas by research nurse without the use of this list, a further check using HES data was carried out to identify any other missing cases. 5.2 Case definition

Cases with a primary working diagnosis of ACS (NSTEMI and Unstable Angina) within , categories B or C and either troponin positive or negative.

NSTEMI Chest pain, ischaemic ECG and troponin greater than 0.1 Unstable Angina Ongoing chest Pain, dynamic ischaemic ECG plus or minus detectable troponin 5.3 Inclusion Criteria Cases admitted as medical emergencies with negative or positive troponin test results within the first 48 hours of admission and diagnosed with either suspected or confirmed acute coronary syndrome regardless of presenting complaint. Once reviewed by medical team, and confirmed as ACS/NSTEMI they were included in the study and their progress followed. Not all cases are immediately diagnosed as ACS/NSTEMI therefore many cases were monitored for up to 5 days until a definite diagnosis was given. All other cases with working diagnosis or non-specific diagnosis even after consultant ward round were considered for inclusion. 5.4 Exclusion Criteria

• Cases with confirmed diagnosis of ST elevated myocardial infarction (STEMI) as stated in the notes and demonstrated by ECG change;

• Category A cases that were listed and transferred for in-patient angiogram prior to the

researcher reviewing the case notes;

• Cases with an alternative diagnosis or ‘non cardiac diagnosis’ such as Pulmonary Embolus (confirmed by VQ / CTPA) that explains elevated troponin and symptoms and was clearly stated in the notes within the first 24-48 hours of admission;

• Cases who were an in-patient for longer than 48 hours, (a mix of surgical, orthopaedic and longer stay medical cases), at the time the first sample was sent even though an ACS diagnosis was being considered. It was felt that such cases would be less likely or ineligible for referral and small in number. The effort required to adequately scrutinise them was also felt to be beyond on the scope of this study;

• Non-emergency cases and other routine blood test requests for example from outpatients, waiting list and list admissions for surgery and those from general practice were removed;

- 17 -

• Cases who were discharged from the A&E dept. Data concerning basic demographics and risk factors, presenting complaint and co-morbidities, ECG findings, initial diagnosis and treatment, the act of referral to cardiology and for angiogram and to cardiac rehabilitation, or reasons for non referral were extracted from the patient’s medical record onto the data collection proforma (is available on request). Cases notes were checked to confirm a five day diagnosis as being one within the following 4 categories NSTEMI, Unstable angina (ACS), Other Cardiac, or Non Cardiac. Those cases where senior review had indicated a diagnosis of “query” or “suspected” cardiac cause and were being treated as such were monitored until a diagnosis of ACS was made by the clinical team and documented in the case note. Cases were then added to that category. Many cases were treated as suspected ACS from admission and also many of those cases who were admitted with LVF, AF or SVT were often documented as a “Query Ischaemic” cause, these cases were included at this stage if they received anti-platelet and or anti-ischaemic treatment in addition to their treatment for AF or LVF. The case notes of included cases were re-reviewed up until discharge to complete data capture for all data items on the proforma from admission through to discharge. Inpatient deaths were noted along with the date of death. The ICD 10 discharge diagnoses as recorded on the Hospital Episode System were also logged retrospectively. Additional deaths that occurred post discharge and were logged on PAS were also noted. These subsequent deaths were entered as “Death after discharge”. Cases transferred to the tertiary centres (MRI or Wythenshawe Hospital) were further tracked on the CATS system (the GMCCN referral system) to identify the date of Angiogram and any subsequent treatment procedures (angioplasty and/or stent insertion). Following discharge the ICD 10 codes for each patient episode on discharge were identified on PAS and added to the data collection proforma. The reasons why cases were not referred for urgent angiogram, where explicitly documented in the case record, were identified and recorded on the database. If there was no explicit documented reason for non referral the research nurse identified and recorded a potential reason for non referral based on his scrutiny and interpretation of the medical record and the following guidance. Non referral was justified if there was evidence of inter-current problems such as sepsis and acute infections (eg pneumonia), renal failure, low haemoglobin, severe peripheral vascular disease. In addition cases with documented evidence of confusion and or dementia were deemed not capable of consenting for an urgent procedure. Cases who would have difficulty in laying flat and managing airways eg spondylosis and COPD were also considered as inappropriate referrals. The presence of stroke particularly haemorrhagic stroke, active cancer, a poor prognosis, a high degree of dependency or frailty, or having a Do Not Resuscitate order in place, or the receiving of palliative care was deemed to imply an inappropriate case for referral. Some chronic heart failure cases and cases with known valvular heart disease were also excluded. Cases with stable angina were not referred urgently but presumed to be entered onto a outpatient pathway for non urgent assessment. These guidelines for the study were based on current clinical practice. A proforma was used to facilitate data collection (see Appendix B)

- 18 -

5.5 Consent and Research Ethics A submission to Bolton Ethics Committee gave approval to the project confirming that informed consent for collecting data from the case notes of hospitalised cases did not warrant individual patient consent. No clinical use was to be made of the data and there was no influence on subsequent management except in the exceptional circumstance where an elevated troponin was recorded and/or the research nurse identifies non-ST elevation ACS for a patient and it appeared that it had been overlooked by the clinical team. On the one occasion this happened the project team drew the result to the attention of the lead clinician for that patient and the patient was recalled.

Table 1 Troponin Measurement Systems by Hospital Trust Testing Time Analyser Testing Kit Comment Crewe Troponin I Tosoh AIA 600

to Immulite 2500 since Jan 08

Stockport Troponin T Roche Modular E 170

Generation 2 Gen 1 to Gen 2 from October 2007

Tameside Troponin I Beckman-Coulter DCI880I

ACCU-I In use consistently

Wigan Troponin T Roche Modular E 170

Generation 1 Unchanged for 12 months

Table 2 Troponin Decision limits ��

��

��

Crewe �� Stockport �� !�� Tameside �� Wigan �� !�� For the purposes of this study the Troponin Values were grouped as in the Table above. 5.6 Analysis Data was first entered in a database and subsequently output to a spreadsheet and SPSS version 16 for analytical purposes. Chi square, and other simple statistical tests were applied to the comparative data in addition a step wise regression analysis was carried out in SPSS (Dan to add) A descriptive analysis of data presents a number of comparative figures by hospital site for the various data items such as age, sex, gender, presenting complaint etcetera.

- 19 -

The categories of met and unmet demand and of unmet need are dealt with as follows: The various reasons for non referral were grouped into broad sub categories as outlined in the Table 3 below. These sub-categories were further grouped into 4 main categories reflecting met and unmet demand and unmet need (or potential demand) and finally no demand. Table 3 Categories of Non Referral for Angiogram Sub-categories of Reasons for Non Referral Reasons for Non Referral for Angiogram Awaiting CABG surgical intervention Known Coronary artery disease (1) Previous assessment and on CABG list

Decision to treat medically (4)

Cases in whom an active decision to treat medically for reasons such as negative investigations, stable angina, high risk for intervention, cardiology assessment, other cardiac diagnosis

Difficult procedure doubtful benefit (4) Cases with severe peripheral vascular disease

DNAR Too Unwell Frail (4)

Cases who had active cancer or other life limiting illness, and or had a DNAR order, who were too unwell or frail to cope with investigation

Elective OPD ETT and or elective angiogram (3)

Another group of cases who were treated medically initially but were being actively followed up with a view to elective referral for angiogram

No Reason for non referral (2) There was no discernable reason for non urgent referral

Not accepted by Tertiary centre (4) On discussion or arrival patient was declined by tertiary centre

Other cardiac diagnosis (4) Viral myocarditis, insertion of AICD

Other non cardiac diagnosis (4) Chest infection, PE, Anaemia, Bleeding, COPD etcetera

Patient Died (4) Cases who died before a transfer decision or before angiogram could be done

Patient Refusal Choice (3)

Patents who refused to undergo angiogram or elected to undergo medical management following discussion with clinician

Previous Angiogram (3) Patient had had a previous angiogram Psychiatric patient (3) Patient under psychiatric treatment Private referral (1) Cases who requested private care

Unfit for urgent angiogram but who might be referred later (3)

Cases whose medical state precluded urgent referral but once stabilised might be referred urgently or electively

Numbers represent allocation of sub categories to demand/need main category (group 1 also includes those cases referred for NHS angiogram that are not shown above). The unmet need that has not presented to hospital is an unknown quantity. There was no further consideration given to identifying this group for logistical reasons and was considered outside the scope of this project. For the purpose of this analysis the summated categories 1-4 referred in the Table 3 above are defined as follows : 1 Met (Need) Demand for immediate or urgent referral for angiogram (where angiogram completed or on CABG waiting list, referred to the private sector), it is

- 20 -

worth noting that within this group there will be some events that may be identified as demand surplus to need for example cases with normal angiograms may fall into this category), equivalent to Urgent angiogram done; 2 Apparent Unmet (Need) Demand for immediate or urgent referral for angiogram in cases who had no good reason for not being referred including those cases in whom there was no reason for non referral (this is part of the unmet need), equivalent to Urgent Angiogram Probably Indicated but Not Done 3 Potential Unmet (Need) Demand for delayed referral following further assessment (those cases sent for outpatient ETT or further assessment and or elective angiogram, those cases deemed unfit for urgent angiogram but who might be referred later following stabilisation of reversible or controllable clinical reasons, psychiatric cases, cases who had had a previous angiogram, cases under psychiatric treatment, cases requesting medical treatment or declining immediate referral or requesting private care (this may be perceived or unperceived unmet need), equivalent to Angiogram Possibly Indicated; 4 No (Need) Demand for immediate or delayed referral for angiogram in cases where an active decision to treat medically for reasons such as negative investigations, stable angina, high risk for intervenion, cardiology assessment and decision, and for other cardiac diagnosis, or in cases where there was a ‘do not resuscitate order’, cases who were deemed too frail or unwell and near end of life or had active cancer or would not benefit such as those with extensive peripheral vascular disease and those declined by tertiary centre, non cardiac diagnosis or those cases who died, equivalent to Angiogram not done or contra-indicated. Tabulations and flow charts based on these angiogram categories are presented in later tables and charts. 5.7 Extrapolation of findings to a population base The data collected, together with an estimate of catchment population for each of the 4 trusts involved, were used to generate hospitalisation rates for cases matching the project inclusion criteria. The catchment population estimates were based upon population data, stratified by age, sex, and IMD score, and emergency admission data based on Hospital Episode Statistics. Population data provided by Tom Hennel of the Public Health Department, Department of Health Government Office North West. HES data provided by Stockport PCT. Application of study data these figures should provide estimates of the underlying levels of need and of met and unmet need and demand.

Evidence of differences in clinical practice and access based on deprivation, age and gender will be explored. 5.8 Regression Analysis The stepwise regression analysis will examine what factors are more or less likely to have influenced access to angiogram.

- 21 -

6. Results 730 hospitalised patient events of possible acute coronary syndrome were identified from the 4 trusts for the equivalent period of 3 months (in actuality 84 days). Of these 476 (65%) presented with chest pain and the remainder 254 (35%) with non chest pain presentations including breathlessness or collapse. Demographic information and other descriptive statistics by Trust are presented in Table 4. Table 4 Hospital and Population Descriptors Crewe Stockport Tameside Wigan All Population Served† 280,000 350,000 250,000 300,000 1,180,000 Estimated Catchment Population†† 254,000

*** 250,000 222,000 266,000 992,000

Total Number of Beds 548 827 535 758 2668 Total Number of Medical Beds 276 452 225

Not to hand

Deprivation Index 13.6 12 34.5 31.6 % Adult Smokers 25.3% 21.5% 30.3% 26.1% Deaths from Smoking Per ??? pop 221.3 226.6 309.1 277.8 SMR Early Deaths Heart Disease & Stroke 89.8 86.8 119.9 115.7 Male/Female Life Expectancy (years) 76.9/80.7 77.1/81.9 74.9/79.8 75.3/79.6 Total Number of CTnT tests* (Crude Test Rate per 1000 population served)

1176 (4.2)

2727 (7.8)

1255 (5.0)

824 (2.7)

5982 (5.1)

Total Number excluded as ineligible 626 187 Number of cTnT results where records scrutinised 2101 637 Number of hospitalised cases kept in study 138 282 168 142 730 † Based on hospitals’ estimates †† Catchment population estimates based on GONW population, and HES emergency medical admission data *some cases have more than 1 cTnT for their admission this is not accounted for in the total number of cTnT tested cases, in addition. **The first month numbers cTnT results is only for +ve results and excludes point of care testing in ED . *** Does not include North Derbyshire segment of catchment population.

- 22 -

Table 2 Hospital Sample Demographics Crewe Stockport Tameside Wigan All P Value

Number 138 282 168 142 730

Mean Age and Range (years)

74 38-98

76.5 36-102

70 18-101

73 34-97

74 18-102

<0.001

% Aged 85+ 21.0% 29.8% 13.7% 20.4% 22.6% 0.001 % Male 59% 56% 53% 65% 58% 0.215 %Admitted from Home 79% 86% 86% 89% 85% 0.127 Admitted through A&E 83% 82% 90% 85% 85% 0.083 Prior Mobility and Use of Aids

Unaided 63% 60% 78% 61% 65% 1 -2 Stick 15% 18% 8% 13% 14%

Frame/Wheelchair/bedbound 12% 15% 5% 4% 10%

Not Known/Recorded 10% 7% 8% 21% 11%

<0.001

Observations The overall mean age was 74 years. There are highly significant differences between trusts with respect to age of their cases. Stockport has an older population of recruited cases with those over 85 comprising twice the proportion that they do in Tameside, which has the youngest population. Although Wigan has proportionally more males this is not significant. Stockport has a higher proportion of cases who require the use of mobility aids with Tameside having the lowest; this most probably reflects the age patterns of the samples. Data in aids and mobility was least well recorded in Wigan. Table 5 Clinical Feature Principle Presenting Complaint Crewe Stockport Tameside Wigan All

P Value

Non chest pain 27% 44% 32% 27% 35% Chest pain 73% 56% 68% 73% 65%

<0.001

Mean Number of Comorbidities 1.3 1.4 1.1 1.3 1.3 0.042 % Any prior CABG/PCI//PPM intervention 14% 20% 18% 19% 18% 0.554 % Any Previous MI or IHD 55% 59% 51% 61% 56% 0.271 Risk Factors

Smoking 14% 13% 24% 18% 17% 0.010 Hypercholesterlaemia 10% 16% 17% 13% 14% 0.332

FH IHD 14% 15% 15% 16% 15% 0.979 All Ages Mean Systoloic BP 136 139 141 136 138 0.375 All Ages 86 90 88 85 88

- 23 -

Observations Table 5 shows a highly statistically significant variation in the percentage of cases, that were either troponin tested or for whom an ACS diagnosis was considered, that presented with chest pain as the principle symptom. Across the 4 Trusts Stockport had the lowest percentage of chest pain presentations . The other three trusts were much more alike. Stockport cases have significantly more co-morbidities compared with Tameside in particular. There was no significant difference in the percentage of cases with a previous cardiovascular disease history. In respect of risk factors there is a higher proportion of current smokers amongst Tameside’s cases. Table 6 Troponin Results by Trust Trust (troponin Type) p

Troponin_Range Crewe (I)

Stockport (T)

Tameside (I)

Wigan (T)

Grand Total

Undetected or Negative

11 (8%) 32 (11%) 6 (4%) 28 (20%) 77 (11%)

Detectable _Neg 7 (5%) 33 (12%) 68 (40%) 3 (2%) 111 (15%) Borderline 42 (30%) 83 (29%) 37 (22%) 34 (24%) 196 (27%) Positive 78 (57%) 134 (48%) 57 (34%) 77 (54% 346 (47%)

Grand Total 138

(100%) 282

(100%) 168

(100% 142

(100%) 730

(100%) <0.001

Observations There are some difficulties in comparing the distribution of Troponin result categories, particularly in deciding cut-off values for negative and detectable negative. Crewe and Tameside have differing Troponin I Kits and cut-offs in use. Crewe also used point of care testing in the emergency department and these cases were not included. We have unilaterally forced their results into the above categories. Of the cases tested 44% of Tameside’s cases would be classed as negative compared with around 22% or less for the other 3 Trusts. Crewe has generated the highest percentage positive. Table 7 Principle 5 Day Diagnosis by Trust Trust p Troponin_Range Crewe Stockport Tameside Wigan Grand Total NSTEMI 66 (48%) 115 (41%) 73 (43%) 43 (30%) 297 (41%) Unstable Angina 51 (37%) 134 (48%) 63 (38%) 60 (42%) 308 (42%) Other Cardiac Diagnosis 12 (9%) 15 (5%) 17 (10%) 18 (13%) 62 (8%)

Non-Cardiac Diagnosis 9 (7%) 18 (6%) 15 (9%) 21 (15%) 63 (9%)

Grand Total 138 (100%)

282 (100%)

168 (100%

142 (100%) 730 (100%)

0.003

Observations

- 24 -

Overall 83% (range 72%-89%) of these cases had a 5 day diagnosis of NSTEMI or Unstable Angina. Table 8 Preliminary Anti-platelet Triple Treatment (numbers and percentages) by Presenting Complaint, Age and Diagnosis Preliminary Treatment with Triple antiplatelet Crewe Stockport Tameside Wigan All

P Value

By Presenting Complaint

Mean Number of Drugs Prescribed per Case

Chest Pain 2.4 2.5 2.7 2.6 2.5 0.170 Non Chest Pain 1.4 1.8 0.8 1.4 1.5 <0.001 Percent No Anti-platelet Treatment at all Chest Pain 10% 8% 7% 12% 9% 0.473 Non Chest Pain 35% 24% 63% 44% 37% <0.001 By Age Percent No Anti-platelet Treatment at all Age Less than 55 years n=77

7% 12% 3% 8% 6% 0.668*

Age 55-74 years n=282

19% 8% 17% 13% 13% 0.176

Age 75+ years 16% 19% 41% 30% 25% 0.001 By Diagnsotic Group

Percent No Anti-platelet Treatment at all

NSTEMI/UA 16% 14% 22% 10% 16% 0.057 Other Cardiac 17% 27% 35% 50% 34% 0.257* Non Cardiac 22% 17% 33% 48% 32% 0.193* Table 9 Principle 5 Day Diagnosis and Treatment with Anti-platelet Therapy

Presenting Complaint and Mean Number of anti-platelet drugs

Principle Diagnosis upto 5 days Chest Pain Non Chest Pain Grand Total NSTEMI/UA 2.6 1.5 2.2 Non-Cardiac Diagnosis 2.0 1.2 1.6 Other Cardiac Diagnosis 2.4 1.3 1.7 Grand Total 2.5 1.5 2.1

Observations Cases who present with chest pain whether or not the 5 day diagnosis was NSTEMI/UA were more likely to receive anti-platelet treatment than those with non chest pain. There was no significant difference between Trusts in the prescribing of anti-platelet treatment; the majority of chest pain and or NSTEI/UA cases are treated. A smaller percentage of non chest pain or other diagnostic groups are treated but they are prescribed fewer drugs. There is significant variation between Trusts in this latter group, with Stockport significantly more likely to prescribe in the non chest pain group and Tameside the least likely. Both Crewe and Stockport are more significantly likely to prescribe in older cases.

- 25 -

Table 10 Referral for Cardiology, Cardiac Rehabilitation and Angiogram by Trust and Presenting Complaint Referral for Cardiology, Cardiac Rehabilitation and Angiogram Crewe Stockport Tameside Wigan All

P Value

By Presenting Complaint

Referral to Cardiology

Chest Pain 76% 78% 79% 85% 80% 0.389

Non Chest Pain 57% 52% 65% 56% 56% 0.502 Age Less than 55 years n=77

100% 88% 82% 100% 90% 0.518*


81% 88% 87% 84% 85% 0.640

Age 75+ years 57% 53% 59% 67% 57% 0.271 NSTEMI/UA 74% 69% 81% 87% 76% 0.002 Other Cardiac 75% 53% 71% 72% 68% 0.584* Non Cardiac 22% 44% 20% 33% 32% 0.441* Referral Angiogram Chest Pain 27% 44% 43% 52% 42% 0.002 Non Chest Pain 5% 16% 13% 3% 12% 0.074* Age Less than 55 years n=77

36% 65% 56% 75% 57% 0.203


32% 56% 40% 52% 46% 0.014

Age 75+ years 9% 14% 17% 20% 15% 0.342 NSTEMI/UA 23% 35% 40% 51% 37% <0.001 Other Cardiac 17% 13% 0% 0% 6% 0.333* Non Cardiac 0% 6% 7% 10% 6% 0.937* Referral Cardiac Rehabilitation Chest Pain 67% 46% 53% 50% 53% 0.008 Non Chest Pain 59% 27% 35% 26% 33% 0.002 Age Less than 55 years n=77

64% 59% 59% 58% 60% 0.986*


77% 51% 46% 47% 54% 0.001

Age 75+ years 55% 28% 42% 36% 37% 0.001 NSTEMI/UA 74% 42% 57% 57% 54% <0.001 Other Cardiac 33% 7% 6% 11% 13% 0.123* Non Cardiac 0% 6% 0% 0% 2% 0.609* Observations Overall 80% of chest pain presentation cases are referred to cardiology compared with just over half of non chest pain cases. 42% of chest pain cases are referred for urgent angiogram compared with 12% of non chest pain cases, and over half of chest pain cases are referred to cardiac rehabilitation compared with a third of non chest pain

- 26 -

cases. NSTEMI and UA cases along with other cardiac diagnoses are most likely to be referred for all three services compared with non chest pain. Younger cases are also more likely to be referred compared with the elderly. Crewe on the other hand tends to refer the least for angiogram but the most to cardiac rehabilitation. Estimating Met and Unmet Demand for Urgent and Elective Angiogram Referral The four categories of demand defined previously as:

� Met Demand (Urgent Angiogram Done) � Unmet Demand (Urgent Angiogram Probably Indicated but Not Done) -

where there was probably a case for urgent referral � Potential Unmet Demand (Angiogram Possibly Indicated) where an

angiogram may or may not be necessary and may be done as an elective procedure

� and No Demand (Angiogram not or contra-indicated) in cases whose condition or prognosis as such means that the investigation would be futile.

The attribution of the hospitalised cases to these categories are presented by principle presenting complaint either chest pain or non chest pain (which includes breathlessness, collapse and other). Table 11A Distribution of Numbers of Cases by Trust according to Type of Demand for Chest Pain Presentation Only

Trust

Urgent Angiogram

Done

Urgent Angiogram Probably Indicated

but Not Done

Angiogram Possibly Indicated Elective

Angiogram not

done/contra- indicated All

P value

Crewe 31 14 34 22 101 Stockport 56 10 58 34 158 Tameside 49 7 37 21 114

Wigan 47 6 33 17 103

0.229

All Trusts 183 37 162 94 476

Met Demand Unmet

Demand

Potential Unmet

Demand No Demand

Table 11A shows 220 (46% range 39-49% by Trust) cases with chest pain where there is need for urgent referral for angiogram (Urgent and Probable Urgent) of which 183 (83% (range 69% to 89% by Trust)) had been referred representing met demand. The number of cases overall requiring further assessment with a view to less urgent angiogram was 162 (34% - range 32-37%) (although some may have warranted more urgent referral). There were 94 (20% - range 17-22%) cases where the circumstances mitigated against referral i.e there was no demand. Total Demand for Urgent Angiogram equates to Met Demand and Unmet Demand

- 27 -

Table 11B Proportion of Cases by Trust according to Type of Demand

Chest Pain Presentation

% Cases of Met

Demand for

Urgent Angio

% Total Urgent

Demand for

Angio Met

% Cases with Potential unmet Demand for less urgent referral

% hospitalised Cases with possible ACS not requiring angiogram

Trust Crewe 31% 69% 34% 22%

Stockport 35% 85% 37% 22% Tameside 43% 88% 32% 18%

Wigan 46% 89% 32% 17% All Trusts 38% 83% 34% 20%

% Cases of Met Demand for Urgent Angiogram = Met Demand/ All Chest Pain Cases*100 % Total Urgent Demand for Angiogram Met = Met Demand/ Met Demand + Unmet Demand*100 % Cases with Potential unmet Demand for less urgent referral = Potential Unmet Demand/ All Chest Pain Cases*100 % hospitalised Cases with possible ACS not requiring angiogram = No Demand/ All Chest Pain Cases*100 Table 12A Number of Cases by Trust according to Type of Demand for Cases with Non Chest Pain Presentation

Trust

Urgent Angiogram

Done


but Not Done


Angiogram not


Crewe 1 5 17 14 37 Stockport 16 6 54 48 124 Tameside 6 3 25 20 54

Wigan 4 20 15 39

<0.001 (sparse

but should be OK)

All Trusts 23 18 116 97 254 Table 12A shows 41 (16% range 5-18%) cases with non chest pain where there is need for urgent referral for angiogram of which 23 (59%) had been referred and the demand met (ranging from 0% to 73% by Trust, see Table 12B second column). The number of cases overall requiring further assessment with a view to less urgent angiogram was 116 (46% range 46-51%) although not all (un-quantified proportion) of these cases would necessarily be referred. There were 97 (38% range 38-39%) cases where the circumstances mitigated against referral i.e. there was no need

- 28 -

Table 12B Distribution of Numbers of Cases by Service and Clinical Criteria according to Type of Demand for Cases with Non Chest Pain Presentation

Trust

% Cases of Met

Demand for

Urgent Angio

% Total Urgent

Demand for

Angio Met

% Cases with Potential unmet Demand for less urgent referral

% hospitalised Cases with possible ACS not requiring angiogram

Crewe 3% 17% 46% 38% Stockport 13% 73% 44% 39% Tameside 11% 67% 46% 37%

Wigan 0% 0% 51% 38% All Trusts 9% 56% 46% 38%

% Cases of Met Demand for Urgent Angio = Met Demand/ All Non Chest Pain Cases*100 % Total Urgent Demand for Angio Met = Met Demand/ Met Demand + Unmet Demand*100 % Cases with Potential unmet Demand for less urgent referral = Potential Unmet Demand/ All Non Chest Pain Cases*100 % hospitalised Cases with possible ACS not requiring angiogram = No Demand/ All Non Chest Pain Cases*100

- 29 -

Table 13 Distribution of Numbers of Cases by Service and Clinical Criteria according to Type of Demand in respect of Chest Pain Presentation

Chest Pain Presentation

Urgent Angiogram

Done


but Not Done


Angiogram not


Number of Cases 183 37 162 94 476

Mean Age (Range) years

64 (34-89)

75 (51-93)

72 (37-96)

78 (19-102)

70 (19-102)

<0.001

Percent Female 28% 51% 36% 47% 36% 0.003 Troponin Range

Undetectable 13% 19% 20% 13% 16% Detectable_Negative 8% 11% 14% 15% 12%

Borderline 20% 27% 28% 34% 26% Positive 59% 43% 38% 38% 46%

0.006

Mean Number of Comorbid Factors 0.9 0.9 1.4 1.5 1.2

<0.001

Mean Systolic Blood Pressure 141 143 139 134 139 0.037 Mean Creatinine 93 105 119 116 107 0.003 Mean No of ECG changes 1.1 1.4 1.3 1.3 1.2 0.036 Percent Not receiving anti thrombotic treatment 4.4% 13.5% 8.6% 14.9% 8.6%

0.018

Mean Number of Drugs (LMWH/Asp/Clop) received 2.7 2.3 2.5 2.2 2.5

<0.001

Previously Fully Mobile 87% 54% 75% 50% 73%

<0.001

Previously Self Caring 98% 100% 96% 83% 95%

<0.001

Percent 5 Day Diagnosis UA or NSTE MI 98% 92% 83% 77% 88%

<0.001

Percent referred to Cardiology 98% 62% 73% 62% 80%

<0.001

Percent Referral angiogram 93% 5% 12% 9% 42%

<0.001

Percent Referral cardiac rehabilitation 83% 49% 38% 23% 53%

<0.001

Percent Death in Hospital 0% 0% 3.7% 19.1% 5.0%

<0.001

Percent Readmission within 28 days of discharge 2.2% 2.7% 8.0% 2.1% 4.2%

0.030

Observation

- 30 -

In those chest pain cases where angiogram was performed they were more likely to be younger and male, be more mobile and self caring, to have higher troponins and lower creatinine values, higher blood pressure, fewer ECG changes and more likely to have confirmed ACS diagnosis and to have received the full range of anti-platelet therapy, to have been referred to cardiology and cardiac rehabilitation and least likely to have died compared with those in the other groups especially the no angio group. Cases in the Probable Urgent Angiogram Not Done group show similarities to the met demand group although marginally older and more likely to be female re-inforcing the notion that these cases in particular may truly represent an unmet need group. Table 14 Chest Pain Met and Unmet Need/Demand according to Category

Category

Urgent Angiogram

Done


but Not Done


Angiogram not done/contra- indicated All

P value

B 117 (64%) 18 (49%) 75 (46%) 48 (51%) 258

(54%)

C + Other 66 (36%) 19 (51%) 87 (54%) 46 (49%) 218

(46%) <0.001

Grand Total 183

(100%) 37

(100%) 162

(100%) 94

(100%) 476

(100%) Observation Over half of the total chest pain presentation cases were codified by the research nurse as potential category B cases based on the referral guideline criteria as assessed at day 1. Only 117 (45%) of these had an angiogram, they accounted for almost two thirds of the angiogram cases done. Approximately one third of the remaining cases fell into categories of need where urgent referral may have been appropriate. The remaining half of chest pain cases were category C and other, 66 (30%) had an urgent angiogram contrary to the referral guideline. However, of those not undergoing urgent angiogram they fell into potential categories of need for urgent angiogram.

- 31 -

Table 15 Number of Cases with Chest Pain Presentation according to Primary ICD 10 Diagnostic Code

Chest Pain ICD 10 Primary Code3

Urgent Angiogram

Done


but Not Done


Angiogram not


Other Medical 1 8 13 22 Other Cardiac 5 2 12 9 28 Angina NSTEMI 50 15 55 25 145 STEMI 106 16 53 30 205 Other Symptom Code 12 3 30 12 57 Uncoded 9 1 4 5 19 Total 183 37 162 94 476 Observation Interestingly 205 (43%) cases overall were codified as STEMI on PAS using ICD 10 codes of which 106 (52%) had an urgent angiogram. 145 (30%) were codified as NSTEMI or Angina of which 50 (34%) had an urgent angiogram The remaining 126 (26%) had a range of other diagnoses in particular symptom codes of which 27 (21%) underwent urgent angiogram. Table 16 Number of Cases with Chest Pain Presentations according to Primary ICD 10 Diagnostic Code and Readmission in 28 Days

Chest Pain ICD 10 Primary Code

Urgent Angiogram

Done


but Not Done


Angiogram not


Uncoded 1 1 Other Medical 2 2 Other Cardiac 4 4 Angina NSTEMI 4 4 8 STEMI 1 1 2 Other Symptom 1 2 2 5 No Readmission 179 35 149 91 454 183 37 162 94 476

- 32 -

Observation Of the initial chest pain cases 4 (2%) undergoing angiogram were readmitted to the initiating DGH within 28 days, all 4 were logged as a further ACS episode. One (3%) non ACS re-admission was noted among the probable group, whereas 13 (8%) of which 5 (3%) were ACS including one STEMI. 3 (3%) futile cases were readmitted including 1 STEMI.

- 33 -

Non Chest Pain Presentation Table 17 Distribution of Numbers of Cases by Service and Clinical Criteria according to Type of Demand for Non Chest Pain Presentation

Category

Urgent Angiogram

Done

Urgent Angiogram Probably

Indicated but Not Done


Angiogram not


P Value

Number of Cases 23 18 116 97 254

Mean Age (Range) years

70 (47-83)

83 (66-101)

80 (50-100)

82 (45-101)

80 (45-101)

<0.001

Percent Female 22% 67% 54% 58% 54% 0.010 Troponin Range

Undetectable 9% 0% 0% 0% 1% Detectable_Negative 9% 11% 4% 6% 6%

Borderline 48% 33% 41% 38% 40% Positive 35% 56% 55% 56% 54%

0.008

Mean Number of Comorbid Factors 1.2 1.2 1.5 1.7 1.5 0.144 Mean Systolic Blood Pressure 139 146 132 139 139 0.193 Mean Creatinine 88 107 133 136 128 0.080 Mean No of ECG changes 1.4 1.8 1.7 1.5 1.6 0.094 Percent Not receiving anti thrombotic treatment 8.7% 22.2% 42.2% 40.2% 37.0%

0.010

Mean Number of Drugs (LMWH/Asp/Clop) received 2.3 1.7 1.3 1.4 1.5 0.004

Previously Fully Mobile 78% 56% 51% 40% 50% 0.010

Previously Self Caring 96% 89% 79% 67% 77% 0.009

Percent 5 Day Diagnosis ACS or

NSTE MI 100% 56% 71% 72% 73% 0.149 Percent referred to Cardiology 96% 33% 61% 45% 56%

<0.001

Percent Referral angiogram 87% 0% 5% 4% 12%

<0.001

Cardiac rehab 78% 44% 28% 26% 33% <0.001 Percent Death in

Hospital 4.3% 0.0% 7.8% 37.1% 18.1% <0.001

Percent

Readmission within 28 days of discharge 4.3% 5.6% 6.9% 1.0% 4.3% 0.216

- 34 -

Observation Of the 254 non chest pain cases 41 (16%) were deemed eligible for urgent referral based on either the fact of actual referral or by the retrospective application of the rule that Troponin elevation and ECG indication even though in the absence of chest pain. Of those deemed eligible 23 (56%- it is worth noting that the majority 16 (70%) were Stockport cases) actually underwent angiogram. The remaining 18 (44%; 7% of this non chest pain group overall) may represent unmet need. A further 116 (46%) were deemed as possibly requiring angiogram but were managed in other ways or electively. Stockport contributed almost half the cases in this group. Ninety seven cases (38%) were thought to be too ill or frail to benefit from referral for angiogram. The group of non chest pain cases who underwent angiogram were more likely to be young, male, with fewer comorbidities, greater mobility and to be more self caring. They tended to have lower creatinine and fewer ECG changes and then to have received anti-thrombotic therapy and to be referred to cardiology. They also had a lower in hospital mortality rate. The majority of these differences were statistically significant. In contrast those on the probable and possible referral group were older and predominantly female. However the latter observation may not be surprising given the predominance of females in the older age groups. Finally the group considered too frail and ill to benefit had an in-hospital mortality of 37% compared with 7% or less for the other groups. Table 18 Non Chest Pain Met and Unmet Need/Demand according to Category

Category

Urgent Angiogram

Done

Urgent Angiogram Probably

Indicated but Not Done

Angiogram Possibly

Indicated Elective

Angiogram not done/contra- indicated All

P Value

B 11 (48%) 12 (67%) 76 (66%) 62 (64%) 161

(63%)

C+Other 12 (52%) 6 (33%) 40 (34%) 35 (36%) 93

(37%) <0.001

Grand Total

23 (100%)

18 (100%)

116 (100%)

97 (100%)

254 (100%)

Observation Almost two thirds of the non chest pain presentation cases were codified by the research nurse as potential category B cases based on the referral guideline criteria as assessed at day 1. Only 11 (7%) of these had an angiogram, they accounted for almost half of the angiogram cases done. Over half (54%) of the remaining category B cases fell into categories of need where urgent referral may have been appropriate. One third of non chest pain cases were category C and other, of which 12 (13%) had an urgent angiogram. However, almost half of those not undergoing urgent angiogram in this category may have warranted urgent referral.

- 35 -

Table 19 Number of Cases with Non Chest Pain according to Primary ICD 10 Diagnostic Code

Non Chest Pain ICD 10 Primary Code3

Urgent Angiogram

Done


but Not Done


Angiogram not


Other Medical 1 2 17 32 52 Other Cardiac 6 32 8 46 Angina NSTEMI 5 3 17 13 38 STEMI 11 8 35 36 90 Other Symptom 3 9 3 15 Uncoded 2 6 5 13 Total 23 18 116 97 254 Observation Interestingly 90 (35%) of non chest pain cases overall were codified as STEMI on PAS using ICD 10 codes of which 11 (12%) had an urgent angiogram. 38 (15%) were codified as NSTEMI or Angina of which 5 (13%) had an urgent angiogram The remaining 126 (50%) had a range of other diagnoses in particular non medical, other cardiac and symptom codes. 7 cases with these other codes underwent urgent angiogram.

- 36 -

Table 20 Number of Cases with Non Chest Pain according to Primary ICD 10 Diagnostic Code for Readmission in 28 Days Episode

Chest Pain ICD 10 Primary Code3

Urgent Angiogram

Done


but Not Done


Angiogram not

/contra- indicated All

Uncoded Other Medical 3 1 4 Other Cardiac 1 1 2 Angina NSTEMI 2 2 STEMI Other Symptom 1 1 2 No Readmission 22 17 109 96 244 Total 23 18 116 97 254 Observation Of the non chest pain cases undergoing angiogram 1 (4%) was readmitted to the initiating DGH within 28 days, this case was coded as other cardiac. Eight re-admissions were noted among the probable and possible groups, of which 2 were coded as Angina or NSTEMI.

- 37 -

6.1 Regression Analysis The method and results of the step wise regression analysis applied to this data is available in appendix 2. The following previously identified factors were significant predictors within the model of whether or not need was met:










done

- 38 -

6.2 Application to an estimated population base

See also Appendix 3 Chest Pain Chart 1 Hospitalisation Rate of Troponin Tested Chest Pain cases with Suspected or Confirmed NSTEMI/UA per 10k population by aggregated Age Groups and Trust stacked by Demand category (3 Month Period)

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

30 to64

65 to74

75 to84

85 up 30 to64

65 to74

75 to84

85 up 30 to64

65 to74

75 to84

85 up 30 to64

65 to74

75 to84

85 up

Crewe Stockport Tameside Wigan

Rat

e pe

r 10

,000

Angiogram Not Appropriate per 10kUrgent Angiogram Not Done per 10kPossible Urgent Angiography per 10kUrgent Angiogram Done per 10k

Observation The majority of the hospitalised chest pain cases for those in the age group 30-64 underwent urgent angiogram, the rates range 1.2 per 10,000 in Crewe to 2.9 per 10,000 in Tameside. The rates for those aged 65-74 and 75-84 undergoing urgent angiogram although higher represented a lower proportion of the overall hospitalisation rate for that age span. The rates were similar across the Trusts between 4-7 per 10,000. In these middle age groups a further 4-12 per 10,000 might represent potential unmet need/demand. No cases in the in the 85+ in Crewe or Tameside underwent urgent angiogram compared with 2 per 10,000 in Stockport and 7.4 per 10,000 in Wigan. Both Wigan and Stockport (especially) have high overall hospitalisation rates for this oldest age group and the potential unmet need/demand for urgent angiogram could be as high as 15-20 per 10,000 population.

- 39 -

Non Chest Pain Within appendix 3 there are additional tables. The summary features are about 1 per 10, 000 had angiogram although the potential demand may be as high as 20 per 10,000. It is worth reflecting that these are unadjusted rates and include high rates for the very elderly. Further work is required to better understand the need/demand in this group before adopting values like these to estimate future need/demand.

7. Strengths and Weaknesses of The Study Method The method of identifying only those cases having had a troponin blood test on admission may have omitted those who present with chest pain and are not tested (but who may have been admitted and tested later). It also drew in cases who did not present with chest pain and did not fit within the chest pain triage algorithm. However, the decision to adopt the troponin test entry was pragmatic based on the available resources to trackdown possible cases. It was a simple task to generate the list of troponin tested cases and an assumption was made that few cases would be missed. Furthermore it would be possible to identify missing cases at a future date by comparing these admissions with the respective hospital PAS database not withstanding problems with ICD 10 coding. The rolling monthly sampling framework was a second pragmatic decision to collect a large enough representative sample for a snapshot of a full 12 month period and to account for possible seasonal variation. Resources did not permit a full 12 months month by month data collection in each of the four trusts. A further limitation was the extent of the clinical follow-up based on scrutiny of the notes which was limited to 5 days and observation reliant on what was documented. In relation to this the research nurse did not review sequential ECGs and document any dynamic changes. This may have further limited the identification of some cases it was assumed that this would have been documented in any case. The allocation of cases to the various need/demand categories was based on what decisions were explicitly documented in the notes and in a percentage of cases the research nurse’s interpretation of the clinical observations and use of the implicit guidance on what types of cases would not be referred. The resulting unmet need/demand cases were therefore a mixed group with assumptions made about their need for referral for angiogram. Confidence intervals need calculating and the effect of troponin testing in the non chest pain cases and the influence of practice in Stockport needs further evaluation.

- 40 -

8 Summary, Conclusions and Discussion

730 cases2 of possible ACS were hospitalised over 90 days at each of the four hospitals, of which 476 (65%) were chest pain and 254 (35%) non chest pain presentations. This would be equivalent to almost 3000 in a year.

8.1 Chest Pain

Only the 476 (65%) chest pain cases fell within the current triage system for urgent referral for angiogram. They were more likely to receive the full panoply of antithrombotic therapy, There is little difference between hospitals in the prescribing of anti-platelet treatment. However, there is room for improvement either by increasing the percentage of cases receiving appropriate treatment and or by making it clear why those not treated are exceptions. The majority (80%) of these cases are referred to cardiology, 42% for angiogram and over half for cardiac rehabilitation.

Overall 46% of chest pain cases were categorised as a having need or generating demand for urgent referral for angiogram of which 83% were referred hence representing need/demand met. A further 34% of these cases may have warranted more urgent referral. Cases in this group were a mix of patients who, for example, refused or declined invasive treatment, had other more urgent medical issues for stabilisation or were passed onto an elective out patient pathway for further assessment including stress testing. In 20% of chest pain cases circumstances militated against referral i.e they had serious other co-morbidities and there was no demand. There appears a need to develop the application of a triage system that takes into account the risks and benefits more explicitly and in a much more structured and standardised way. Where angiogram was performed it was more likely in younger, mobile and self caring males. Such cases were more likely to have higher troponins and lower creatinine values, higher blood pressure, fewer ECG changes and more likely to have confirmed ACS diagnosis and to have received the full range of anti-platelet therapy. Cases in the Probable Urgent Angiogram Not Done group show similarities to the met demand group although marginally older and more likely to be female re-inforcing the notion that some if not all of these cases may truly represent an unmet need group. Over half of the total chest pain presentation cases were codified by the research nurse as potential category B cases based on the referral guideline criteria as assessed at day 1-2. Only 117 (45%) of these had an angiogram, they accounted for almost two thirds of the angiogram cases done. The remainder were codified as C or other. The crude application of the B & C category was not that useful in this study without the addition of a full and explicit risk benefit assessment. It is understood that the referral algorithm is under review; this would be timely given the recent NEJM article on the optimal management of ACSi. 2 This study is based on cases or hospitalised events rather than individual patients, some patients may have appeared more than once.

- 41 -

The analysis of Primary ICD 10 codes on PAS showed that for chest pain cases




codes o of which one fifth underwent urgent angiogram.

The accuracy of clinical coding remains a problem and is of critical importance if used as a basis for benchmarking hospital performance in these areas by Dr Foster for example. 8.2 Non Chest Pain

The remaining 254 (35%) cases were admitted with non chest pain presentations. This feature was heavily influenced by clinical practice in Stockport where more older cases with these types of presentation in particular were routinely tested for troponin and drawn into the study population. These tests and subsequent admissions were not part of a systematic triage system as is in place for chest pain and this raises the question whether there should be such a system.

Just over half of non chest pain cases are referred to cardiology, 12% are referred for urgent angiogram and a third for cardiac rehabilitation. Approximately16% of non chest pain cases were identified as having a need for urgent referral for angiogram of which 59% had been referred and hence the demand met. However the majority of this met demand emanated from Stockport. A further 46% of non chests pain cases were deemed to be requiring of further assessment with a view to less urgent angiogram although not all (un-quantified proportion) of these cases would necessarily have been referred. In 38% of non chest pain cases the circumstances militated against referral i.e. there was no need. The value of routine Troponin testing in non chest pain presentations and the feasibility of a non chest pain triage system should be further considered. Although not presented here there are concerns about the interpretation of low level troponin when measured in some patients . The analysis above has highlighted a number of differences between these four trusts in respect of the nature of the population being admitted, their level of risk, the use of tests (such as troponin) and referral to specialist cardiology services and for urgent angiogram. There are marked variations in clinical practice, with Stockport in particular appearing to have extended the use of Troponin outside the triage of chest pain cases. Stockport is testing a higher number of its hospitalised older cases with and without chest pain as a principle symptom.

- 42 -

From the viewpoint of cases presenting with chest pain the majority, over 90%, receive anti-thrombotic therapy and prescribing practice is similar across all four Trusts. There is some variation in onward referral for cardiac rehabilitation3 and angiogram in particular. About 40% of this category of patient are referred for urgent angiogram representing met demand. An additional similar proportion may warrant urgent referral and these patients may be categorised as unmet demand. However, it would appear that other investigation and treatment strategies had been invoked for locally recognised clinical reasons. These reasons, such as referral for outpatient management, may or may not be justified. Refusal by the patient may represent patient choice if properly informed. Nonetheless if all these cases were assessed as legitimate urgent referrals then demand would almost double from where it is now. It may be advisable to re-review the suggested probable cases to clarify what proportion of them would truly fit an urgent care referral pathway. On the other hand cases presenting with non chest pain symptoms present a different set of challenges. There is considerable variation in the numbers identified by the different hospitals exemplified by the propensity of Stockport to have tested more older people in particular. There is much lower application of antithrombotic treatment with fewer drugs used. A few (12% of cases overall) are referred for urgent angiogram. However on the face of it would appear that a further 20% of these patients might be considered for urgent angiogram. Many of these are elderly cases. Before making a clear statement about possible referral it would also be sensible to re-review these cases with a small panel of clinicians to make a judgement on the suitability of referral. The 2003 ACS Greater Manchester guidelines referral guidelines have been under review during this study. The application of these guidelines and categories B & C does not on the face of it appear to have been that useful in selecting out cases who warranted urgent referral. Category B application of its own included cases who probably ought to have been referred but weren’t and but also those who would not be referred. What is clear is that these cases are not all are subjected to a well documented rigorous and explicit standardised assessment of their potential to benefit from urgent referral for angiogram. This may be with or without intervention but taking into account potential survival and quality of life . There would be value in establishing the outcomes for this cohort of patients at 6 and 12 months. 8.3 A Revised Algorithm The management of acute coronary syndrome (unstable angina and non-Q-wave acute myocardial infarction) has evolved over recent years with the adoption of an early invasive strategy as opposed to a conservative medical treatment model. The evidence to support such a strategy comes from a few RCTs such as FRISC IIii,iii TACTICS-TIMI 18iv,v and RITA 3vi.

3One Trust with a low apparent referral rate for cardiac rehabilitation suggests on review that referral is incompletely documented in the patient record because separate cardiac rehabilitation records are kept.

- 43 -

The approach is predicated on the chest pain presentation and the factors for consideration have been helpfully summarised in a recent NEJM editoriali. The key elements or steps are: Initial assessment of risk of a future cardiac ischaemic event and of potential risk of bleeding from likely treatment. The initial evaluation of cases with ACS should consider the risk of death, myocardial infarction and recurrent ischaemia in the ensuing period of days and months and weigh this against the risk of bleeding complication from the either medical os invasive treatment. Two risk score algorithms the Trombolysis in Myocardial Infarction (TIMI) and the Global Registry ofAcute Coronary Events (GRACE) see table below. TIMI GRACE Age >65 Age 3 or more risk factors for atherosclerosis Killip class (severity of heart failue with

myocardial infarction Known coronary heart disease Systolic arterial pressure 2 or more episodes of anginal chest pain in 24 hours prior to hospitalization

ST-segment deviation

The use of aspirin in the 7 days before hospitalization

Cardiac arrest during presentation

ST-segment deviation of 0.05mV or more Elevated serum markers for myocardial necrosis (troponin or CKMB)

High Risk 3 or more of above 7 Low risk 2 or less Prognostic Time next 14 days after hospitalization ( Death, MI, recurrent ischaemia)

Prognostic Time next 6 months after hospitalization ( Death, MI, recurrent ischaemia)

There should be a cautious interpretation of the presence of cardiac markers as it is well known that myocardial necrosis is caused by disorders other than coronary artery disease (PE, decompensated heart failure, severe hypertension, tachycardia, anaemia and sepsis). One might go further and re-iterate the need for appropriate use and timing of such tests. The more indiscriminate use in all acute medical admissions may be counterproductive and a waste of scarce resources. In addition a patient’s general medical and cognitive status, anticipated life expectancy, personal preference, and their risk of treatment-related complications should be evaluated.

- 44 -

Female sex, older age, renal insufficiency, low body weight, tachycardia, high or low systolic arterial pressure, low haematocrit and a history of diabetes predict an increased risk of major bleeding. Bleeding risk tools are available.4 Once risk is established an appropriate treatment regime can be implemented. The treatment is optimal when the intensity of therapy, both medical and non medical is tailored to the cases future risks of cardiac event or bleeding. Our study indicates the application of these assessments is incomplete and poorly documented. Neither TIMI nor Grace were routinely calculated. Undoubtedly decisions were base on implied assessment applied to a variable extent associated with individual or team clinical judgement. The assessment of unmet need/demand in the chest pain group suggests a shortfall in recognising all cases who might benefit for referral for urgent angiogram. The numbers of unmet need/demand may be as high as that of current activity. It would however be inappropriate to take the figures presented here without first reviewing further those patients who we think should have been referred but weren’t. At a recent cardiology meeting these issues were aired and it was agreed that a review of the cases should be carried out. The resource to enable this needs to be made available. It was also felt that the follow-up of this cohort for outcomes at 6-12 months would add further insight. Some additional resource would be required for this exercise. The variation in clinical practice as exemplified by Stockport’s wider application of Troponin warrants further assessment. In considering potential health inequalities we need a better understanding of how any policy we introduce would apply to both non chest pain patients and the very elderly. There is some evidence that older people are more likely to have elevated troponins and given the greater likelihood of the other non acute ischaemia causes of elevated troponin there is a risk of inappropriate labelling of patients as having an ACS. Furthermore there is anecdotal evidence of adverse events such as bleeding arising from the prescribing of clopidogrel especially in the elderly. Any proposed expansion of services would need to be mindful of the recent credit crunch and future availability of new resources. There will need to be much closer scrutiny of costs and benefits. Trusts themselves will have greater responsibilities to scrutinise their current clinical practices to drive out waste and inefficiency. There are other concerns related to ICD 10 coding practices that warrant further consideration.

9. Recommendations

1. Confirm up to date and explicit triage, risk benefit assessment (including explicit criteria on who would or would not benefit from different types of treatment strategies) , and clarify

4 www.crusadebleedingscore.org

- 45 -

treatment options and angiogram referral pathways for Chest Pain - UA/NSTEMI ACS cases for optimal management

2. Seek to roll out and train all GM Network Trusts to adopt the optimal management pathway with standards for chest pain cases

3. Re-audit the optimal management against agreed standards in 2010/11

4. Review the appropriateness and application of the optimal management plan to cases with a non chest pain presentation and those aged 85 or more

5. In order to refine the estimates for unmet need/demand re-review those cases who fell into the potential demand categories for both chest and non chest pain cases to clarify the true number that would be considered appropriate for referral

6. In light of other published material together with the output from the above develop more robust estimates of unmet need/demand to project future catheter laboratory requirements

7. Utilise this cohort of cases to follow-up 6-12 month outcomes and survival. Some additional support would be required.

- 46 -

10. Appendix 10.1 Appendix 1 Referral Data for Chest Pain and Non Chest Pain Cases Appendix 1 shows the overall numbers of cases by Trust with the reasons for no referral for urgent angiogram Reasons for non referral for urgent angiogram in cases presenting with Chest Pain

Referral Outcome Crewe Stockport Tameside Wigan Grand Total

Awaiting CABG surgical intervention Known Coronary artery disease 3 3 6 Decision to treat medically 12 17 10 8 47 Difficult procedure doubtful benefit 1 1 2 DNAR Too Unwell Frail 6 8 2 2 18 Elective OPD ETT and or elective angiogram 14 21 12 8 55 No Reason for non referral 11 6 4 3 24 Not accepted by Tertiary centre 1 1 2 Other cardiac diagnosis 1 1 2 Other non cardiac diagnosis 3 3 6 6 18 Patient Died 1 4 2 3 10 Patient Refusal Choice 6 8 4 18 Previous Angiogram 2 7 5 5 19 Psychiatric patient 1 1 2 Private referral 2 2 Referred for angiogram and done 26 53 49 47 175 Unfit for urgent angio but who might be referred later 19 27 14 16 76 Total 101 158 114 103 476

- 47 -

Reasons for non referral for urgent angiogram in cases presenting with Non Chest Pain

Referral Outcome Crewe Stockport Tameside Wigan Grand Total

Awaiting surgical intervention Known Coronary artery disease 2 2 4 Decision to treat medically 1 8 5 4 18 Difficult procedure doubtful benefit 2 1 3 DNAR Too Unwell Frail 9 21 4 4 38 Elective OPD ETT and or angio 3 2 1 2 8 No Reason for non referral 5 6 3 2 16 Not accepted by Tertiary centre 1 1 Other non cardiac diagnosis 1 8 2 5 16 Patient Died 2 2 2 2 8 Patient Refusal Choice 3 3 6 Previous Angiogram 4 4 Private referral 1 1 Referred for angiogram and done 1 13 4 18 Unfit for urgent angio but who might be referred later 15 51 27 20 113 Total 37 124 54 39 254

- 48 -

10.2 Appendix 2 Regression Model Predictors and Outputs Outcome:

– Met Demand: +ve – Unmet Demand: -ve – Possible Unmet Demand: excluded – Not Appropriate: excluded

Predictors Block 1: ENTER (The following variables were forced into the model)

– Trust (category variable with 4 values) – Age (numeric variable) – Gender (1 binary variable) – Troponin_Range (category variable with 3 values) – Chestpain_Presentation (1 binary variable) – Co-morbidities (7 binary variables) – Number_Co-morbidities (numeric variable) – Previous_Medical_Conditions (4 binary variables) – Cardiac_Risk_Factors (3 binary variables) – Systolic_BP (numeric variable) – Pulse_Rate (numeric variable) – Killip Score (category variable with 3 values) – Creatinine (numeric variable) – ECG_Feature (8 binary variables) – IMD_2007_Score (numeric variable)

In total this gives a total of 37 degrees of freedom to the model with 255 cases included Table Logistic Regression Output for Met vs. Potential and Unmet Need

Significant Predictor p Odds ratio (95% confidence interval)

Age <0.001 0.842 (0.788 to 0.901) Trust(1) 0.037 0.190 (0.040 to 0.905) Gender(1) 0.004 0.186 (0.060 to 0.580) Trop_Grp(1) 0.017 7.516 (1.430 to 39.500) Trop_Grp(2) 0.008 7.043 (1.681 to 29.505) Present_ChestPain 0.034 5.106 (1.133 to 23.012) ECG_T_wave_changes 0.022 0.291 (0.101 to 0.840) Prev_MHx_CABG 0.019 0.110 (0.017 to 0.698) Risk_Factors_IHD_Smoking 0.009 0.138 (0.031 to 0.614) Creatinine_level 0.075 0.984 (0.966 to 1.002)

- 49 -

Previously Identified factors are significant predictors within the model:










done –

- 50 -

10.3 Appendix 3 Estimating met and unmet need/demand for urgent angiogram for UA/NSTEMI by population. The more detailed results from the estimation of the Potential Unmet Demand for Urgent Angiogram in Hospitalised Cases with Suspected ACS across Four North West Trusts for an equivalent 3 month period is presented below. Results From the 730 cases originally identified 671 were matched to a geographic area within the catchment populations and formed the basis of this further analysis. The 59 excluded cases mostly related to the North Derbyshire High Peak catchment area served by Stockport. It was not possible to access information on this catchment area. 438 of the 671 cases were chest pain presentations and all but 1 were aged 30 years or more. The catchment population data for chest pain are presented for the 437 cases. The remaining 233 cases were non chest pain and for the sake of completion they are included in a separate analysis. The following tables indicate the number of cases by age group and trust and are related to the respective age specific catchment populations. Age specific , crude all age and age and sex standardised hospitalisation rates have been calculated per 10,000 population for a three month period. The figures should be multiplied by a factor of 4 to give an approximate annual figure. Chest Pain Presentation This first section presents figures for chest pain presentation cases. Table 1 Age Specific Hospitalisation Rate for Cases Presenting with Chest Pain and undergoing a Test for Troponin per 10,000 Catchment Population by Trust Trust Age Band Crewe Stockport Tameside Wigan Total 30 to 34 0 0 0 0.5 0.1 35 to 39 1 0.5 1.1 0 0.6 40 to 44 1 1.5 2.2 1 1.4 45 to 49 2.3 0.6 6.7 1.7 2.7 50 to 54 3.1 5 11.2 2.4 5.2 55 to 59 2.8 3.5 7.4 6.8 5.1 60 to 64 6.2 9.8 11.3 10.7 9.5 65 to 69 10.9 14.1 9.3 11.5 11.6 70 to 74 17.5 18.5 15.5 9.8 15.3 75 to 79 8.4 25.6 20.5 11.9 16.6 80 to 84 27.7 14.2 26.2 17.9 21.3 85+ 33.9 59.5 20.1 42 39.9 Total 5.9 7.9 7.9 6 6.9

Observation

- 51 -

There is a clear rising trend in hospitalisation rates with increasing age for all trusts with variable rates between trusts for specific age groups. Stockport has a particularly high rate of troponin tested hospitalised chest pain cases in the over 85 year olds. Table 2 Gender Specific Hospitalisation Rates for Cases Presenting with Chest Pain and undergoing a Test for Troponin per 10,000 Catchment Population aged 30 years+ Trust Sex Crewe Stockport Tameside Wigan Total Female 3.8 6.4 5.5 3.5 4.8 Male 8.2 9.6 10.6 8.6 9.2 Total 5.9 7.9 7.9 6.0 6.9

Table 2 indicates that for females Stockport has the highest hospitalisation rate for chest pain of all trusts but Tameside is not far behind, the catchment population for Tameside is lower and explains why the rate is higher give the lower actual number of admissions, For male cases Tameside has the highest crude 30 year plus rate of hospitalisation for this group of cases followed by Stockport. Crewe and Wigan are similar but about 25% less. Chart 1 Actual and Standardised Rates for Hospitalised Chest Pain Cases Investigated for Query ACS by Trust per 10,000 Catchment Population aged 30+ years

5.9

7.9 7.9

6.05.8

7.68.1

6.1

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

Crewe Stockport Tameside Wigan

Actual Rate

Standardised Rate

*see Appendix for source of values Table 3 Categories B, C and Other

- 52 -

Trust Crewe Stockport Tameside Wigan Total Total Category_B 57 72 43 60 232 Total Category_C 0 0 0 0 0 Total Category_Other 40 57 67 41 205

Chart 2 Rates for Hospitalised Chest Pain Cases Investigated for Query ACS by Category and Trust per 10,000 Catchment Population aged 30+ years

3.5

4.4

3.13.5

3.7

2.4

3.5

4.8

2.4

3.2

0

1

2

3

4

5

6

Crewe Stockport Tameside Wigan Grand Total

Cat B per 10kCat OTHER per 10k

- 53 -

Table 4 Age Specific Hospitalisation Rate for Cases Presenting with Chest Pain and undergoing a Test for Troponin and allocated to Category B per 10,000 Catchment Population over a Three month Period Trust Age Band Crewe Stockport Tameside Wigan Total 30 to 34 0 0 0 0.5 0.1 35 to 39 1 0 0 0 0.3 40 to 44 1 0.5 0.6 1 0.8 45 to 49 0.6 0 1.3 0.6 0.6 50 to 54 1.2 3.8 6.7 1.2 3.1 55 to 59 1.1 1.8 2 3.1 2 60 to 64 3.5 6 3.5 6.3 4.9 65 to 69 5.9 7.5 3.1 6.9 6 70 to 74 12.3 6.8 7.8 4.9 7.9 75 to 79 1.2 14 9.5 7.9 8.1 80 to 84 19.5 7.9 10.1 16.1 13.5 85 up 23.3 41.7 10 22.2 25.3 All Age Bands 3.5 4.4 3.1 3.5 3.7

Table 5 Age Specific Hospitalisation Rate for Cases Presenting with Chest Pain and undergoing a Test for Troponin and allocated to C or Other Category per 10,000 Catchment Population over a Three month Period Trust Age Band Crewe Stockport Tameside Wigan Total 30 to 34 0.0 0.0 0.0 0.0 0.0 35 to 39 0.0 0.5 1.1 0.0 0.4 40 to 44 0.0 1.0 1.7 0.0 0.6 45 to 49 1.7 0.6 5.4 1.2 2.1 50 to 54 1.8 1.3 4.5 1.2 2.1 55 to 59 1.7 1.8 5.3 3.7 3.0 60 to 64 2.8 3.8 7.8 4.4 4.5 65 to 69 5.0 6.6 6.2 4.6 5.6 70 to 74 5.1 11.7 7.8 4.9 7.4 75 to 79 7.2 11.6 11.1 4.0 8.4 80 to 84 8.1 6.3 16.1 1.8 7.8 85 up 10.6 17.9 10.0 19.8 14.6 Total 2.4 3.5 4.8 2.4 3.2

- 54 -

Table 6 Actual Age Specific Values for Cases Presenting with Chest Pain and undergoing a Test for Troponin and Estimated Catchment Populations by Trust for a Three Month Period Trust Age Band Data Crewe Stockport Tameside Wigan Total 30 to 34 Chest Pain Cases 0 0 0 1 1

Estimated Catchment Population 16731 16382 15229 18708 67051

35 to 39 Chest Pain Cases 2 1 2 0 5




















85 up Chest Pain Cases 16 30 8 17 71


Total Number of Cases 97 129 110 101 437 Total Catchment Population 164440 162467 138820 169516 635243

- 55 -

Expected Age Specific Values for Cases Presenting with Chest Pain and undergoing a Test for Troponin and Estimated Catchment Populations by Trust for a Three Month Period Trust Age Band Data Crewe Stockport Tameside Wigan 30 to 34 Expected Chest Pain Cases 0 0 0 0.9

Estimated Standard Catchment Population 16762.7 16762.7 16762.7 16762.7

35 to 39 Expected Chest Pain Cases 1.96 1 2.2 0


40 to 44 Expected Chest Pain Cases 1.93 2.94 4.4 1.94


















85 up Expected Chest Pain Cases 15.07 26.48 8.93 18.69


92.69 120.59 128.82 96.86 158810.7 158810.7 158810.7 158810.7 Age Std Rate 93 121 129 97

A separate age – sex adjustment has been carried out which produced values total expected numbers for the respective Trusts as follows 92, 121, 129, 98. These latter values were included in the chart in the main body of the text.

- 56 -

Actual Age Specific Values for Cases Presenting with Chest Pain and undergoing a Test for Troponin and labelled as Category B and Estimated Catchment Populations by Trust for a Three Month Period Trust Age Band Data Crewe Stockport Tameside Wigan Total 30 to 34 Chest Pain Cases Category B 0 0 0 1 1


35 to 39 Chest Pain Cases Category B 2 0 0 0 2




















85+ Chest Pain Cases Category B 11 21 4 9 45


Total Cases 57 72 43 60 232 Total Population 164440 162467 138820 169516 635243

- 57 -

Actual Age Specific Values for Cases Presenting with Chest Pain and undergoing a Test for Troponin and labelled as Category Other and Estimated Catchment Populations by Trust for a Three Month Period Trust Age Band Data Crewe Stockport Tameside Wigan Total 30 to 34 Chest Pain Cases non B or C 0 0 0 0 0


35 to 39 Chest Pain Cases non B or C 0 1 2 0 3




















85+ Chest Pain Cases non B or C 5 9 4 8 26


Total Cases 40 57 67 41 205 Total Population 164440 162467 138820 169516 635243

- 58 -

Chest Pain by Deprivation Rank and Trust Trust Deprivation Rank Data Crewe Stockport Tameside Wigan

Grand Total

1 Number of Cases 30 34 5 2 71

Total Catchment Population 59584 50650 6640 3622 120497







5 Number of Cases 17 24 47 35 123


Total Number of Cases 97 129 110 101 437 Total Catchment Population 164440 162466.6 138820 169516.2 635242.83

- 59 -

Non Chest Pain Non Chest Pain

Sum of Incidence per 10,000 Trust

Age Band Crewe Stockport Tameside Wigan Grand Total

30 to 34 0.0 0.0 0.0 0.0 0.0 35 to 39 0.0 0.0 0.0 0.0 0.0 40 to 44 0.0 0.0 0.6 0.0 0.1 45 to 49 0.0 0.6 0.7 0.6 0.4 50 to 54 0.0 0.0 0.0 0.0 0.0 55 to 59 0.6 1.8 2.7 0.0 1.2 60 to 64 0.0 3.8 1.7 0.6 1.5 65 to 69 5.9 7.5 2.1 3.1 4.7 70 to 74 3.1 14.6 9.1 2.0 7.1 75 to 79 7.2 10.5 11.1 10.6 9.7 80 to 84 11.4 42.7 26.2 14.3 23.9 85 up 25.4 81.4 37.7 27.2 44.4

Grand Total 2.2 6.8 3.7 2.1 3.7 Observation Non chest pain presentation is predominantly a feature of older people the hospitalisation rate of troponin tested cases rising from 1.2 per 10,000 at 55-59 to 44.4 per 10,000 b y 85+. There is considerable variation between Trusts in the actual age specific rates and Stockport has a hospitalisation rate of this class of cases of 81.4 per 10,000 aged 85 plus that is more than 2-3 times the rates of the other three trusts.

- 60 -

Non Chest Pain Presentation

- 61 -

- 62 -

Combined Chest and Non Chest Pain Crude Hospitalisation Rates of Troponin Tested Cases of suspected UA/NSTEMI by Presentation and Type of Need or Demand per 10,000 population per year

Urgent Angiogram Done per

10k

Possible Urgent

Angiogram per 10k

Urgent Angiogram Not Done per 10k

Angiogram Not

Appropriate per 10k All

Chest Pain 10.5 5.1 6.4 5.5 27.5 Non Chest pain 1.2 5.1 2.8 5.6 14.7 All Cases 11.7 10.2 9.2 11.1 42.2

Crude Hospitalisation Rates of Troponin Tested Cases of suspected UA/NSTEMI by Presentation and Type of Need or Demand per 10,000 population per year

0.0

2.0

4.0

6.0

8.0

10.0

12.0

Urgent Angiogram Done per10k

Possible Urgent Angiographyper 10k

Urgent Angiogram Not Doneper 10k

Angiogram Not Appropriate per10k

Rat

e p

er 1

0,00

0 p

er y

ear

Chest PainNon Chest pain

Observation The hospitalisation rates by catchment population aged 30 years plus of troponin tested suspected UA/NSTEMI cases by need/demand category are shown in the above table. Overall it was estimated that there were 42 per 10,000 population aged 30 years plus. The rate for those with chest pain presentation was 27 and non chest pain 15 per 10,000. In respect of chest pain cases 11 per 10,000 underwent urgent angiogram but upto a further 11 per 10,000 may warrant urgent angography. For non chest pain cases about 1 per 10, 000 had angiogram although the potential demand may be as high as 20 per 10,000. It is worth reflecting that these are unadjusted rates and include high rates for the very elderly. Further work is required to better understand the need/demand in this group before adopting values like these to estimate future need/demand.

- 63 -

Non Chest Pain

Trust

Age Band Data Crewe Stockport Tameside Wigan Grand Total

Number of Cases 0 0 0 0 0 30 to 34 Catchment Population Estimate 16731 16382 15229 18708 67051











Number of Cases 12 41 15 11 79 85 up Catchment Population Estimate 4721 5038 3982 4045 17787

Total Number of Cases 36 110 52 35 233

Total Catchment Population Estimate 164440 162467 138820 16951

6 635243

- 64 -

11. References i Hillis LD Lange RA Optimal Management of Acute Coronary Syndromes NEJM 2009 360;21:2237-2240 ii Invasive compared with non-invasive treatment in unstable coronary artery disease: FRISC II prospective randomised multicentre study. Lancet 1999 354 708-715 iii Wallentin L et al for the FRISC II Investigators. Outcome at 1 year after an Invasive compared with non-invasive treatment in unstable coronary artery disease: FRISC II prospective randomised multicentre study. Lancet 2000 356 9-16 iv Morrow D A et al Ability of minor elevations of Troponins I and T to predict benefit from an early invasive strategy in patients with Unstable Angina and non-ST elevation myocardial infarction JAMA 2001 286 (19) 2405-2412 v Cannon C P et al Comparison of early invasive and conservative strategies in patients with unstable coronary syndromes treated with the glycoprotein IIb/IIIa inhibitor Tirofiban NEJM 2001 344 (25) 1879-1887 vi Fox KA et al Interventional versus conservative treatment for patients with unstable angina or non-ST-elevation myocardial infarction: the British Heart Foundation RITA 3 randomised trial Lancet 2002 360 743-751

Meeting (need) and demand for Urgent Angiography in ACS ... · PDF file- 2 - Meeting (need)...

Documents

Transcript of Meeting (need) and demand for Urgent Angiography in ACS ... · PDF file- 2 - Meeting (need)...