Perioperative Cardiovascular Evaluation for Non-Cardiac Surgery

Dr Nor Hidayah Zainool Abidin

Outlines

I. Clinical AssessmentII. Preoperative Evaluation

I. General approach to patientII. Perioperative Beta blocker therapy

III. Disease specific approachesIV. Management of patient with PCIV. Management of patient with pacemaker /

ICDVI. Intraoperative and postoperative

management

Introduction

• Determine the stability of pt cardiovascular status --> optimal medical condition?

• Recommend the changes in medications, suggest preoperative test or procedure, propose higher level of peri operative care

Clinical Assessment

• Functional capacity can be expressed as metabolic equivalents (METs)

• The metabolic equivalent, or MET= the ratio of a person's working metabolic rate relative to the resting metabolic rate

• 1 MET = 3.5ml O2 equivalant/kg/min = resting O2 consumption

Estimated Energy Requirements for Various Activities

Can You… Can You…

1 Met Take care of yourself? 4 Mets Climb a flight of stairs or walk up a hill?

Eat, dress, or use the toilet? Walk on level ground at 4 mph (6.4 kph)?

Walk indoors around the house?

Do heavy work around the house like scrubbing floors or lifting or moving heavy furniture?

Walk a block or 2 on level ground at 2 to 3 mph (3.2 to 4.8 kph)?

Participate in moderate recreational activities like golf, bowling, dancing, doubles tennis, or throwing a baseball or football?

4 Mets Do light work around the house like dusting or washing dishes?

≥ 10 Mets

Participate in strenuous sports like swimming, singles tennis, football, basketball, or skiing?

MET indicates metabolic equivalent; mph, miles per hour; kph, kilometers per hour. *Modified from Hlatky et al,11 copyright 1989, with permission from Elsevier, and adapted from Fletcher et al.12

METs classification

– excellent (greater than 10 METs)– good (7 to 10 METs)– moderate (4 to 6 METs)– poor (less than 4 METs)– unknown.

• Perioperative cardiac and long-term risks are increased in patients unable to meet a 4-MET demand during most normal daily activities.

activities < 4 METs• slow ballroom dancing• golfing with a cart• playing a musical instrument• walking at a speed of approximately 2 to 3 mph.

Active cardiac conditions

Condition Examples

Unstable coronary syndrome Unstable or severe angina

Decompensated HF ( NYHA class IV, worsening or new onset HF)

Significant arrythmias

- Symptomatic bradycardia - Newly recognized ventricular tachycardia

Mobitz II atrioventricular block Third-degree atrioventricular heart block Symptomatic ventricular arrhythmias Supraventricular arrhythmias (including atrial fibrillation) with uncontrolled ventricular rate (HR greater than 100 beats per minute at rest)

Valvular heart disease

- Symptomatic mitral stenosis (progressive dyspnea on exertion, exertional presyncope, or HF)

Severe aortic stenosis (mean pressure gradient greater than 40 mm Hg, aortic valve area less than 1.0 cm2, or symptomatic)Symptomatic mitral stenosis (progressive dyspnea on exertion, exertional presyncope, or HF)

Estimation of clinical cardiac risk

1. Ischemic heart disease – history of MI– history of positive treadmill test– use of nitroglycerin – current complaints of chest pain thought to be secondary to coronary ischemia– ECG with abnormal Q waves)

2. Congestive heart failure– history of heart failure– pulmonary edema– paroxysmal nocturnal dyspnea– peripheral edema, bilateral rales, S3– chest radio- graph with pulmonary vascular redistribution

3. Cerebral vascular disease – history of transient ischemic attack or stroke

4. High-risk surgery – abdominal aortic aneurysm or other vascular, thoracic, abdominal, or orthopedic surger

5. Preoperative insulin treatment for diabetes mellitus• Preoperative creatinine greater than 2 mg per dL.- risk factor for

postoperative renal dysfunction

Goldman Cardiac Risk factors

factors points

third heart sound (S3) 11

Elevated Jugulovenous pressure 11

Myocardial infacrtion in the pst 6 months 10

ECG: premature arterial contraction or any rhythm other than sinus

7

ECG shows> 5 premature ventricular contractions per minute 7

Age > 70 years 5

Emergency procedure 4

Intra-thoracic, intraabdominal or aortic surgery 3

Poor general status, metabolic of bedridden 3

scores incidence of death

incidence of cardiovascular complications

> 25 56% 22%

< 26 4% 17%

< 6 0.2% 0.7%

Minor predictors

• advance age > 70yo

• abnormal ECG (LV hyperthrophy, LBBB, ST-T abnormalities)

• rhythm other than sinus

• uncontrolled systemic hypertension

might lead to higher suspicion of CAD - not been proven independantly increase perioperative risk

15

RISK INDICES :

1) ASA.

2) NYHA

3) Goldman ( 1977).

4) Detsky (1997 ).

5) ACC / AHA ( Updated in 2007 ).

6) Lee ( 1999 ).

Clinical Assessment

Perioperative Medical Therapy

• Perioperative Beta-Blocker Therapy– titration to maintain tight heart rate control should

be the goal.

Benefits of B-Blocker

• effective modulation of severe blood pressure fluctuations reduction in the number and duration of perioperative coronary ischemic episodes.

• decrease the incidence of postoperative atrial fibrillation

• can reduce the incidence of arrhythmias during the perioperative period

• can reduce mortality and the incidence of cardiovascular complications

Preoperative evaluation

• cardiac/ comorbids disease --> high surgical risk category

• serious cardiac conditions

• pacemaker or ICD

• risk factors --> increase cardiovascular risk

• medications

• functional capacity

• History• Physical Examination• Basic investigation• Further evaluation

– non invasive test• ECHO• Holter ECG• Exercise stress test• Dobutamine stress test

– invasive test• radionuclide scan• coronary angiography

Disease-Specific Approaches

• A. Coronary Artery Disease• B. Hypertension• C. Valvular Heart Disease

– aortic stenosis– mitral stenosis– atrial fibrillation (risk of thromboembolism)– prostetic valve disease (SBE prophylaxis)

Coronary artery disease

• 1) What is the amount of myocardium in jeopardy?

• 2) What is the ischemic threshold, that is, the amount of stress required to produce ischemia?

• 3) What is the patient’s ventricular function?• 4) Is the patient on the optimal medical regimen?

Hypertension

• Stage 1 or stage 2 hypertension – is not an independent risk factor for perioperative

cardiovascular complications– no benefit of delaying surgery

• antihypertensive medications should be continued during the perioperative period.

• avoid withdrawal of beta blockers because of potential heart rate or blood pressure rebound

Stage 3 Hypertension

• exaggerated intraoperative blood pressure fluctuation + ECG evidence of myocardial ischemia in patients

• more likely to develop intraoperative hypotension

time for optimization of drugs effects vs the risk of delaying the surgical procedure

without significant cardiovascular comorbidities can proceedwith surgery despite elevated blood pressure on the day of surgery

Valvular heart disease

• Aortic stenosis• elective noncardiac surgery should generally be

postponed• require aortic valve replacement

– mortality risk of approximately 10%.• associated with an increased risk of acute MI

Mitral stenosis• increases the risk of HF.• Preoperative surgical correction of mitral valve

disease is not indicated before noncardiac surgery.

• mild or moderate– ensure control of heart rate during the perioperative

period, because the reduction in diastolic filling period that accompanies tachycardia can lead to severe pulmonary congestion.

• severe stenosis– balloon mitral valvuloplasty or open surgical repair before

high-risk surgery

• Aortic regurgitation– volume control and afterload reduction

• not benefited with slow heart rates

• mitral regurgitation– 2 most common

• mitral valve prolapse that results from myxomatous degeneration

• functional mitral regurgitation that complicates post infarction LV remodeling.

• premedications• anticoagulant management

– risk of thromboembolism without anticoagulation is high

• antibiotics prophylaxis– surgery that may result in bacteremia

Subacute Bacterial Endocarditis (SBE) Prophylaxis

• Prosthetic cardiac valve• Previous bacterial endocarditis even in the

absence of heart disease. • Most congenital cardiac malformations. • Rheumatic/acquired valvular dysfunction. • Hypertrophic cardiomyopathy• Mitral valve prolapse with valvular regurgitation.

Not recommended• Innocent cardiac murmurs without structural heart

disease. • Isolated secundum atrial septal defect. • Surgical repair without residual beyond 6 months for the

following: – Secundum atrial septal defect– Ventricular septal defect – PDA– Previous CABG

• Mitral valve prolapse without valvular regurgitation. • Cardiac pacemakers and implanted defibrillators.• Previous rheumatic fever without valvular dysfunction.

Standard Oral Regimen

Amoxicillin2 gm orally 1 hr before procedure

None after initial dose.

For those allergic to Amoxicillin or Penicillin, use either Erythromycin or Clindamycin

Erythromycin Erythromycin Ethylsuccinate 800 mg orally or

Erythromycin sterate 1.0 gm orally, 2 hrs before the procedure.

Clindamycin 300 mg orally, 1 hr before the procedure

Drug Dosing Regimen*

For patients unable to

take oral medications

AmpicillinIV or IM administration,

2 gm, 30 min before the procedure.

Ampicillin, Amoxicillin and

Penicillin allergic patients

unable to take oral medications

ClindamycinIntravenous administration, 300 mg 30 min

before the procedure.

Alternate Prophylactic Regimens: Dental, Oral, or Upper Respiratory Tract Procedures in Patients Who Are at Risk

Drug Dosing Regimen*

Patients considered at

high risk and not candidates for

standard regimens

Ampicillin, Gentamicin,

or Amoxicillin

IV or IM administration of

Ampicillin, 2 gm,

plus Gentamicin, 1.5 mg/kg (not to exceed 120 mg),

30 min before procedure;

followed by Amoxicillin 1.5 g, orally 6 h after initial dose.

Ampicillin, Amoxicillin and

Penicillin allergic patients

considered

at high risk

Vancomycin plus

Gentamicin

IV administration of Vancomycin 1.0 g over 1 hour,

plus Gentamicin 1.5 mg/kg IV/IM (not to exceed 120 mg),

complete injection/infusion within 30 minutes of starting

the procedure: no repeat dose is necessary.

Proposed approach to the management of patients with previous percutaneous coronary intervention (PCI) who require noncardiac surgery

premature discontinuation of dual antiplatelet therapy markedly increases the risk of

stent thrombosis and death and/or MI

PCI- Ballon Angioplasty

• Delaying surgery for at least 2 to 4 weeks after balloon angioplasty to allow for healing of the vessel injury at the balloon treatment site

PCI Bare metal stent

• thrombosis is most common in the first 2 weeks

• rarely more than 4 weeks after stent placement

• A thienopyridine (ticlopidine or clopidogrel) + Aspirin (4 weeks)

PCI: Drug-Eluting Stents

• locally deliver antiproliferative drug - rapamycin/paclitaxel --> reduce restenosis to near zero within the stent

• therefore preferred revascularization option in IHD

• Delayed endothelial healing in the region of DES -->risk of subacute stent thrombosis

• continue aspirin and clopidogrel for 1 yr

• If thienopyridines must be discontinued before major surgery, aspirin should be continued and the thienopyridine restarted as soon as possible.

• warfarin, antithrombotics, or glycoprotein IIb/ IIIa agents --> ? reduce the risk of stent thrombosis after discontinuation of oral antiplatelet agents (NO EVIDENCE)

Proposed approach to the management of patients with previous percutaneous coronary intervention (PCI) who require noncardiac surgery

Intraoperative Electromagnetic Interference With Implanted Pacemakers and ICDs

• device evaluation within 3 to 6 months before operation

• This evaluation should include – the type of device, – pacemaker dependent for antibradycardia

pacing • indication for device placement

– device programmed settings and battery status.

• whether the patient is pacemaker dependent, • whether the pacemaker has unipolar or bipolar

leads, • whether the electrocautery is bipolar or unipolar • the relative distance from and orientation of the

electrocautery relative to the pacemaker and pacemaker lead.

Factors that influence adverse interactions

Electrocautery effects

• temporary or permanent resetting to a backup, reset, or noise reversion pacing mode

• temporary or permanent inhibition of pacemaker output

• an increase in pacing rate due to activation of the rate-responsive sensor

• ICD firing due to activation by electrical noise• myocardial injury at the lead tip that may cause

failure to sense and/or capture.

Management1.bipolar electrocautery system2.short and intermittent bursts, lowest possible

energy levels3.max distance4.placement of the ground patch in a

position(unipolar cautery) so as to minimize current flow

5.emergency cardioversion--> the paddles should be placed as far from the implanted device --> perpendicular to the orientation of the device leads

Intraoperative Management

• perioperative plan --> Intraoperative management

• intraoperative monitoring

• postoperative monitoring

• ventilation

• analgesia

• perioperative use of anticoagulants or antiplatelet agents.

Post operative management

• post operative monitoring

• continue supplemental Oxygen

• repeat 12 lead ECG

• close observation for at least 72 hrs - reinfarction rate is highest in POD3

Conclusion

Thorough history• Detailed physical examination• Judicious use of tests• Categorize patients into low, intermediate & high

risk category .• Combine preop assessment with periop risk

reduction strategies & optimize medical treatment to improve outcome.

careful teamwork and communication between surgeon, anesthesiologist

the patient’s primary caregiver