Prevention of sudden death in survivors of myocardial infarction: a decision analysis approach.
During the first year after myocardial infarction, 5% to 15% of patients die, and the majority of deaths occur suddenly. Highly efficacious therapy, such as the implantable cardioverter-defibrillator, may reduce the chance of sudden death, but broad application is limited by associated risks. Hence, attempts to identify patients at high risk so they can receive therapy are desirable. Subgroups with high or low sudden death risks can be identified based on left ventricular function. Further risk stratification using programmed electrical stimulation and the signal-averaged ECG has been advocated, but the best strategy is unknown. Using a decision analysis model, we compared the 1-year survival rates in survivors of myocardial infarction treated with the implantable cardioverter-defibrillator either empirically or based on screening with the signal-averaged ECG and programmed electrical stimulation. The best strategy for selecting patients for therapy depended on the pre-therapy sudden death risk. For patients at low risk, such as those with well-preserved ventricular function, antiarrhythmic therapy selected with screening tests or given empirically increased both the mortality rate resulting from the adverse effects of therapy and the excellent survival rate without therapy. In the moderate-risk population, both empiric and stratified approaches reduced mortality, but stratification substantially limited the number of patients receiving unnecessary therapy. In the high-risk population, empiric treatment achieved the best survival rate, and screening resulted in only a small reduction in the number of patients treated unnecessarily.(ABSTRACT TRUNCATED AT 250 WORDS)
Middlekauff
H R
HR
Division of Cardiology, UCLA School of Medicine 90024-1679.
Stevenson
W G
WG
Tillisch
J H
JH
D002304:Cardiac Pacing, Artificial; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D003661:Decision Support Techniques; D004554:Electric Countershock / Q000295:instrumentation*; D004562:Electrocardiography / Q000379:methods; D006801:Humans; D009203:Myocardial Infarction / Q000401:mortality*; D011237:Predictive Value of Tests; D019736:Prostheses and Implants; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted