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.