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

Aims To analyse (1) the prognostic importance of clinical findings and lipids in patients with a previous myocardial infarction and (2) the relative and absolute benefit of simvastatin in patients at low, medium and high predicted 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 study only deals with those 3525 patients who had a previous myocardial infarction. End-points comprised coronary death, definite and probable hospital verified myocardial infarction, and resuscitated cardiac arrest. Because there 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=0.023), 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 corresponding 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 significantly to prediction. The relative benefit from simvastatin treatment was independent of predicted risk, but the absolute benefit increased from low to high risk.