Risk factors for a major coronary event after myocardial infarction in theScandinavian Simvastatin Survival Study (4S) - Impact of predicted risk onthe benefit of cholesterol-lowering treatment

Aims To analyse (1) the prognostic importance of clinical findings and lipi ds in patients with a previous myocardial infarction and (2) the relative a nd absolute benefit of simvastatin in patients at low, medium and high pred icted risk. Methods The 4S was a double-blind, randomized, clinical trial of long-term treatment with simvastatin or matching placebo in patients with myocardial infarction or angina pectoris, serum total cholesterol 5.5-8.0 mmol. l(-1), and serum triglycerides less than or equal to2.5 mmol.l(-1). The present s tudy only deals with those 3525 patients who had a previous myocardial infa rction. End-points comprised coronary death, definite and probable hospital verified myocardial infarction, and resuscitated cardiac arrest. Because t here were few women the primary analyses were performed among men. Results A Cox model analysis in the placebo group identified the following independent predictors of coronary events: a history of hypertension (P=0.0 23), diabetes (P=0.0001), smoking after the myocardial infarction (P=0.010) , total cholesterol (P=0.020), and HDL cholesterol (P=0.062). The relative reduction of risk by simvastatin treatment in patients: at]OM., medium and high predicted risk was 38%. 39% and 42%, respectively, but the correspondi ng absolute benefit pet 100 patients treated for 6 years increased from 7.9 to 16.2. Conclusion In addition to serum lipids, clinical variables contributed sign ificantly to prediction. The relative benefit from simvastatin treatment wa s independent of predicted risk, but the absolute benefit increased from lo w to high risk.