Purpose: More than 120,000 patients now have taken part in randomized trials evaluating statin therapy for stroke prevention. We aimed to conduct a comprehensive review of all randomized trials and determine the therapeutic potential of statins for all strokes.

Methods: We searched 10 electronic databases (from inception to December 2006). We additionally contacted study authors and authors of previous reviews. We extracted data on study characteristics and outcomes related to all-cause mortality, all-stroke incidence, specific type of strokes, and cholesterol changes. We pooled data using a random-effects model and conducted meta-regression.

Results: We included 42 trials assessing statin therapy for all-stroke prevention (n=121,285), resulting in a pooled relative risk (RR) of 0.84 (95% confidence interval [CI], 0.79-0.91). The pooled RR of statin therapy for all-cause mortality (n=116,080) was 0.88 (95% CI, 0.83-0.93). Each unit increase in low-density lipoprotein (LDL) resulted in a 0.3% increased RR of death (P=.02). Seventeen trials evaluated statins on cardiovascular death (n=57,599, RR 0.81, 95% CI, 0.74-0.90), and 11 evaluated nonhemorrhagic cerebrovascular events (n=58,604, RR 0.81, 95% CI, 0.69-0.94). Eleven trials reported hemorrhagic stroke incidence (total n=54,334, RR 0.94, 95% CI, 0.68-1.30) and 21 trials reported on fatal strokes (total n=82,278, RR 0.99, 95% CI, 0.80-1.21). Only one trial reported on statin therapy for secondary prevention.

Conclusions: Statin therapy provides high levels of protection for all-cause mortality and nonhemorrhagic strokes. This overview reinforces the need to consider prolonged statin treatment in patients at high risk of major vascular events, but caution remains for patients at risk of bleeds.