Primary prevention of cardiovascular diseases with statin therapy - A meta-analysis of randomized controlled trials

Background: While the role of hydroxymethyl glutaryl coenzyme A reductase inhibitors (statins) in secondary prevention of cardiovascular ( CV) events and mortality is established, their value for primary prevention is less clear. To clarify the role of statins for patients without CV disease, we performed a meta-analysis of randomized controlled trials (RCTs). Methods: MEDLINE, EMBASE, Cochrane Collaboration, and American College of Physicians Journal Club databases were searched for RCTs published between 1966 and June 2005. We included RCTs with follow-up of 1 year or longer, more than 100 major CV events, and 80% or more of the population without CV disease. From each trial, demographic data, lipid profile, CV outcomes, mortality, and adverse outcomes were recorded. Summary relative risk (RR) ratios with 95% confidence intervals (CIs) were calculated using a random effects model. Results: Seven trials with 42 848 patients were included. Ninety percent had no history of CV disease. Mean follow-up was 4.3 years. Statin therapy reduced the RR of major coronary events, major cerebrovascular events, and revascularizations by 29.2% ( 95% CI, 16.7%-39.8%) (P < .001), 14.4%( 95% CI, 2.8%-24.6%) (P =. 02), and 33.8% ( 95% CI, 19.6%-45.5%) ( P < .001), respectively. Statins produced a nonsignificant 22.6% RR reduction in coronary heart disease mortality ( 95% CI, 0.56-1.08) ( P =. 13). No significant reduction in overall mortality ( RR, 0.92 [ 95% CI, 0.84-1.01]) (P =. 09) or increases in cancer or levels of liver enzymes or creatine kinase were observed. Conclusion: In patients without CV disease, statin therapy decreases the incidence of major coronary and cerebrovascular events and revascularizations but not coronary heart disease or overall mortality.