Effects of lipid-lowering therapy on total and coronary mortality

The results of several lipid-lowering randomized trials were released during the past year. The Scandinavian Simvastatin Survival Study has contributed significantly to the understanding of lipid-lowering on all-cause and coronary mortality outcome. An approximate 25% net difference in cholesterol between the simvastatin and placebo group produced a 30% reduction in total mortality in the simvastatin group (P < 0.01). No increase in noncardiovascular mortality or nonfatal diseases was observed. Although angiographic trials that study atherosclerosis are not designed to show the effect on clinical outcome, several new trials such as the Asymptomatic Carotid Artery Progression Study, the Multicentre Anti-Atheroma Study, the Canadian Coronary Atherosclerosis Intervention Trial and the Stanford Coronary Risk Intervention Project all add information that is consistent with the results from the Scandinavian Simvastatin Survival Study. The meta-analysis of randomized cholesterol-lowering trials also indicates that no excess of all-cause mortality is present when the degree of cholesterol reduction and treatment modality is adjusted. It is probable that the excess mortality from noncardiovascular causes found in unadjusted analyses is due to specific effects of hormones and fibrate drug treatments to reduce cholesterol. It is concluded that the lipid hypothesis is confirmed more solidly than ever before.