Primary prevention of cardiovascular mortality and events with statin treatments: a network meta-analysis involving more than 65,000 patients.

OBJECTIVES This study aimed to evaluate the effectiveness of 3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors (statins) in primary prevention of cardiovascular events. BACKGROUND The role of statins is well established for secondary prevention of cardiovascular disease (CVD) clinical events and mortality. Little is known of their role in primary cardiovascular event prevention. METHODS We conducted comprehensive searches of 10 electronic databases from inception to May 2008. We contacted study investigators and maintained a comprehensive bibliography of statin studies. We included randomized trials of at least 12-month duration in predominantly primary prevention populations. Two reviewers independently extracted data in duplicate. We performed random-effects meta-analysis and meta-regression, calculated optimal information size, and conducted a mixed-treatment comparison analysis. RESULTS We included 20 randomized clinical trials. We pooled 19 trials (n = 63,899) for all-cause mortality and found a relative risk (RR) of 0.93 (95% confidence interval [CI]: 0.87 to 0.99, p = 0.03 [I(2) = 5%, 95% CI: 0% to 51%]). Eighteen trials (n = 59,469) assessed cardiovascular deaths (RR: 0.89, 95% CI: 0.81 to 0.98, p = 0.01 [I(2) = 0%, 95% CI: 0% to 41%]). Seventeen trials (n = 53,371) found an RR of 0.85 (95% CI: 0.77 to 0.95, p = 0.004 [I(2) = 61%, 95% CI: 38% to 77%]) for major cardiovascular events, and 17 trials (n = 52,976) assessed myocardial infarctions (RR: 0.77, 95% CI: 0.63 to 0.95, p = 0.01 [I(2) = 59%, 95% CI: 24% to 74%]). Incidence of cancer was not elevated in 10 trials (n = 45,469) (RR: 1.02, 95% CI: 0.94 to 1.11, p = 0.59 [I(2) = 0%, 95% CI: 0% to 46%]), nor was rhabdomyolysis (RR: 0.97, 95% CI: 0.25 to 3.83, p = 0.96 [I(2) = 0%, 95% CI: 0% to 40%]). Our analysis included a sufficient sample to reliably answer our primary outcome of CVD mortality. CONCLUSIONS Statins have a clear role in primary prevention of CVD mortality and major events.