Risk stratification and Risk stratification and secondary prevention following secondary prevention following

acute myocardial infarctionacute myocardial infarction

In-Ho ChaeDepartment of Internal Medicine

Seoul National University Hospital

Seoul National University Hospital

CAD – risk stratification in general

Symptom Past medical history Physical finding Rest 12-lead ECG Echocardiography Stress test

Exercise treadmill test Dipyridamole Tl/MIBI-Tc myocardial SPECT Dobutamine stress EchoCG

Myocardial enzyme

Seoul National University Hospital

Risk at initial presentation of AMI

Clinical parameters Female Old age ( >70 yrs) DM Prior angina pectoris or previous MI

EKG Anterior wall MI Inferior wall MI with RV infarction ST change: multiple leads or high sum High grade block: > type 2 Morbitz, IVCD

Seoul National University Hospital

Risk factors at initial presentation

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Risk during hospital course

Recurrent ischemia Postinfarction angina

Reinfarction Silent ischemia

ECK change Holter monitoring

Non-Q-wave AMI Initial manif.: non-ST or ST elevation ACS Same as Q-wave AMI

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Risk at hospital discharge

Prognostic factors for short- & long-term survival Resting LV function Residual ischemic myocardium Susceptibility to serious ventricular arrhythmia

Ventricular ectopic activity, electrical instability Patency of infarct-related artery Dx; EchoCG, stress test, EKG, CAG, etc

Seoul National University Hospital

High risk following AMI

Consider aggressive management Recurrent ischemia at rest CHF or LV EF < 40% Sustained VT or VF >48 h post-MI

Not high risk Stress test: exercise ECG, RI scan

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Echocardiography following AMI

Evaluating Infarct size Regional wall motion abnormality Global LV function Complication: MR, aneurysm, thrombi,

pericardial effusion Stress test

Dobutamine stress EchoCG: viability test

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Stress test following AMI

Predischarge test for uncomplicated AMI Risk stratification of post-MI: prognosis Functional capacity Efficacy of current medication

Image: ECG, radionuclide scan, EchoCG Stress: exercise, vasodilator, dobutamine

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Exercise ECG following AMI

Before discharge Submaximal exercise (5 mets): 4-6 days Symptom-limited exercise: 10-14 days

Early after discharge 14-21 days

Late after discharge 3-6 weeks after AMI Low risk or inadequate test at discharge

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Myocardial SPECT following AMI

RI Scan > exercise ECG Pre-excitation Pacemaker rhythm LBBB or LVH >1mm ST change in resting ECG

RCA lesion

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Assessment for electrical instability

High risk of sudden cardiac death after AMI QT dispersion: variability of QT interval Holter: ventricular arrhythmia EPS Signal-averaged ECG: delayed fragmented conductio

n Heart rate variability: beat-to-beat variability of RR in

terval Baroreflex sensitivity

Seoul National University Hospital

Seoul National University Hospital

Secondary prevention of AMI

Life style modification Lipid modification Antiplatelet agent ACE inhibitor Beta-adrenoreceptor blocker Antiarrhythmic Anticoagulant, nitrate, calcium antagonist Hormone replacement therapy

Seoul National University Hospital

Life style and lipid modification

Stop smoking Blood pressure control Lipid risk

LDL > 100 mg/dl HDL < 40 mg/dl Statin: 30-40% reduction of cardiac mortality

CARE, 4S Niacin or gemfibrozil : TG & HDL !!

Seoul National University Hospital

Cardiovascular drugs -1

Antiplatelet agents 25% reduction of recurrent infarction, stroke, vascul

ar death Aspirin, clopidogrel >> ticlopidine

ACE inhibitor Prevent ventricular remodeling Decrease recurrent ischemia, arrhythmia, CHF Ix; CHF, EF < 40%, RWMA

Seoul National University Hospital

Cardiovascular drugs -2

Beta blocker 20% reduction of long-term mortality Early therapy < 6 hr of AMI

Calcium channel blocker Not routine Contraindication of beta blocker:

asthma etc- diltiazem, verapamil

Nitrate Not routine

Seoul National University Hospital

Cardiovascular drugs -3

Anticoagulants Not routine; even combination with aspirin Ix: DVT, PTE, mural thrombi, large RWMA, Af, Hx of e

mbolic CVA Hormone replacement therapy

Not indicated in secondary prevention: HERS Can be continue in case of primary prevention

Antioxidant Not indicated

Seoul National University Hospital

Cardiovascular drugs –4

Antiarrhythmic therapy Class I: no role Calss II: beta blocker – beneficial Class III

D,I-sotalol: possible benefit Dexsotalol: increase incidence of arrhythmia Amiodarone: reduce mortality

Class IV DHP - Nifedipine: maybe harmful ? Non-DHP diltiazem: beneficial

Seoul National University Hospital

Drugs for secondary prevention of AMI

Aspirin Statin Beta blocker ACE inhibitor Proper antiarrhythmics as indicated

Life style modification