Evaluation of chest pain in primary care

Shaival J Kapadia, MD FACCBon Secours Heart and Vascular

Institute

A careful history will lead to the…

diagnosis 80% of the time

Medicine is the science of uncertainty and the art of probability

Sir William Osler

Chronic recurrent chest pain

High suspicion for ACS or unstable angina – then ED

Epidemiology of chest pain

• Prevalence varies with population

• Chest pain is the chief complaint in about 1-2% of outpatient visits

• Cause predominantly noncardiac BUT heart disease remains leading cause of death in the US– Musculoskeletal chest pain 36% (costochondritis 13%)– GERD 13%– Angina responsible for 11%, unstable angina or MI only

1.5%– 15% never reach a definitive diagnosis

Origin of chest pain – difficult?

• Various disease processes in variety of organs

• Severity of pain does not correlate with life threatening potential

• Location of pain often does not correspond with source

• More than one disease process may be present

ECG

• Low sensitivity for coronary ischemia

• Only 50% with proven MI have positive initial ECG

• Up to 76% of ACS – normal or nonspecific initial ECG

Cardiovascular Causes

• Ischemic syndromes– ACS– Stable angina– Coronary vasospasm

• Nonischemic syndromes– Aortic dissection– Pericarditis– Myocarditis– Stress induced cardiomyopathy

Chest wall

• Costochondritis– Costovertebral joint dysfunction– Sternalis syndrome– Xiphoidalgia

• Rheumatic diseases• Stress fractures• Metastatic malignancy• Acute chest syndrome (sickle cell crisis)• Herpes zoster (shingles)

Gastrointestinal

• Esophageal– Reflux– Rupture– Spasm– Espophagitis

• Pancreatobiliary– Pancreatitis– Cholecystitis/biliary colic

• PUD

Pulmonary

• Vasculature– Acute pulmonary embolism– Pulmonary hypertension

• Parenchyma– Pneumonia– Cancer

• Airways– Asthma/COPD

• Pleura– Pleuritis– Pneumothorax

Psychiatric

• Anxiety• Depression• Panic attacks• Munchausen

The History

• Quality of pain

• Region or location

• Radiation

• Temporal elements

• Provocation

• Palliation

• Severity

Associated sign and symptoms

• Diaphoresis

• Dyspnea

• Cough

• Syncope

• Palpitations

• Psychiatric symptoms

• Constitutional symptoms

True Diagnosis: “Gold Standard”

a

True positive

D

True negative

C

False negative

B

False positive

Disease present Disease absent

a + b

c + d

b + da + c

Positive

Negative

Sensitivity = a / (a + c)Specificity = d / (b = d)

Positive predictive value = a / (a + b)Negative predictive value = d/ (c + d)

Positive likelihood ratio =a / (a + c)b / (b + d)

Negative likelihood ratio = c / (a + c)d / (b + d)

Likelihood Ratios & Bayes Nomogram

Likelihood ratios (LR) and Bayes’ Nomograms are a useful way of expressing the power of diagnostic tests in increasing or decreasing the likelihood of disease

Characteristics of Chest Pain and the Probability of Cardiac DiseaseCharacteristic Likelihood

RatioChest pain radiating to left 2.0

Chest pain radiating to right 3.0

Chest pain radiating to both 7.0

Pressure, squeezing, aching <2.0

Pleuritic, sharp, stabbing, positional, reproducible pain on palpitation

0.2-0.4

Normal ECG 0.1-0.3

Hypotension 3.0

Presence of 3rd heart sound 3.2

New ST – T elevations 5.7-53.9

Nausea, vomiting, diaphoresis 2.0

Bayes Nomogram

Two methods of estimating the pre-test probability:

• Emergency gut feeling (educated guess) after the history and examination

• Clinical decision rules

Rouan Decision Rule for Myocardial

Infarction• The Rouan Decisoin Rule

reliably predicts which patients with chest pain & a normal or nonspecific ECG are at higher risk for MI

• However, 3% of patients initially diagnosed with a non-cardiac cause of chest pain suffer death or MI within 30 days of presentation

• Patients with cardiac risk factors warrant close follow-up

Clinical Characteristics

Age greater than 60 years

Diaphoresis

History of MI or angina

Male sex

Pain described as pressure

Pain radiating to arm, shoulder, neck or jaw

Score* Risk of MI (%)

0 Up to 0.6

1 Up to 3.4

2 Up to 4.8

3 Up to 12.0

4 Up to 26.0

• One point for each clinical characteristic• NOTE: At no level of risk can MI be completely ruled

out

Summary

• Although diagnostic tests are impressive, they should NOT replace the history and physical examination (H&P)

• Clinical decision rules provide pre-test probability of a disease

• And coupled with H&P drive appropriate testing

What type of stress test should I request?

Dr. Jun Chung

Types of stress test commonly available

Regular – exercise stress – pharmacologic

Stress echo – exercise stress– dobutamine

Stress nuclear– exercise stress– dobutamine – vasodilator

Question #1 : can they exercise

Recommendation

• If patient can exercise and ECG is interpretable, proceed to regular stress test

• If the patient cannot exercise, or ECG is uninterpretable, proceed to imaging stress test

• Often, insurance payors are reluctant to approve imaging stress test as initial test.

Caveat for regular stress test

• Sensitivity 68%, Specificity 77%: Meta-analysis of 147 studies

• Sensitivity 50%, Specificity 90% when corrected for workup bias

• Easy test for young healthy active individuals?

ECG uninterpretable? …proceed to imaging stress test

• ST or T wave abnormality on rest ECG

• LBBB

• Ventricular paced complexes

• Chronotropic incompetence

• Borderline include LVH and RBBB

Uninterpretable ECG

Imaging stress test needed• Exercise stress echo or pharmacologic stress echo

– if reasonably good images obtainable based on body habitus

– Pharmacologic option for stress echo is dobutamine

• Exercise stress nuclear or pharmacologic stress nuclear– Dependent on body habitus– Pharmocologic options include dobutamine and

vasodilator

With uninterpretable ECG in a patient who can exercise…

• Would typically recommend exercise stress echo or nuclear scan over pharmacologic test

If Patient Cannot Exercise

Pharmacologic Options• Pharmacologic echo utilizes dobutamine with

atropine

• Pharmacologic nuclear scan – LBBB, PPM, HTN – Vasodilator – Preferred option– Dobutamine/atropine – only necessary if patient is on

actively wheezing or on methylxanthines*

*If methylxanthines can be be temporarily withdrawn for 72 hours, then would proceed with vasodilator stress

Pharmacology

• Dobutamine: structural similarities to endogenous catecholamines, norepinephrine or epinephrine– Mechanism of action: beta1 stimulation (less alpha1 and

beta2)– Increase chronotropic and inotropic action– Contraindicated with LBBB, ppm,^HR, ^BP

• Atropine • Vasodilators: dipyridamole, adenosine,

regadenoson– Can use in stable COPD w/o active wheezing– Cannot use with active wheezing or methylxanthines

(aminophylline, theophylline, caffeine)

Pros and Cons of Echo and Nuclear

• Echo: – No radiation– No need for expensive equipment– More info than just ischemia, such as pulmonary

pressure change and valve abnormality– Easier to get pre-authorization– Reader dependent?

• Nuclear scan:– Objective, less reader dependent?– Fewer false positives in females– Radiation – Expensive equipment

Chest Pain evaluation after EKG

Stable?Definitive procedure

Can Exercise?

YesNo

Abnormal EKG Normal EKG

Stress Echo

DobutamineStress Echo

Pharm. Nuclear

Stress Nuclear

DobutamineNuclear

Vasodilator**Nuclear

Yes

No

• Pt. with active wheezing

• Pt. taking methylxanthnes*

• LBBB• PPM• HTN• Without

wheezing

If pt. is unable to achieve target HR, test can be easily switched to pharmacologic

If pt. is unable to achieve target HR, test can be changed to Dobutamine if nurse available

Reg. Exercise Stress

Echo vs. Nuclear• Echo favored: if experienced tech and reader,

readily available, no need to wait for dose, no radiation, suspect valvular disease, need pulmonary pressure, less expensive, easier to get prior auth.

• Nuclear favored: more uniform, less subjective, fewer false positives in females, morbidly obese

• Methylxanthines-aminophylline, theophylline, caffeine• Vasodilator-dipyridamole, adenosine, regadenoson (Lexiscan)

If patient has LBBB, PPM or uncontrolled HTN recommend vasodilator nuclear

#1

• 27yo teacher with exertional chest pains, and family history of CAD

• Normal exam • Normal ECG

#2

• 64yo health club owner with exertional chest pains, tobacco use, HTN and family history

• Normal exam • Normal ECG

#3

• 57yo MD with new onset exertional chest pains. No risk factors.

• Normal exam• Chronic LBBB

#4

• 48yo shipyard worker with exertional chest pain, obese, tobacco, hypertension and hyperlipidemia

• Normal exam• LVH

#5

• 72yo farmer with exertional chest pains. COPD, current tobacco, HTN, hyperlipidemia

• Active wheezes• Barrel chested• RBBB