Background and purpose: The recently published Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) study showed that statins exert a marginally beneficial effect on stroke prevention in patients with a history of cerebrovascular disease. Interestingly, the magnitude of the beneficial effect shown in this study is smaller than in similar studies, which included patients without a history of cerebrovascular disease. In SPARCL, an increased occurrence of hemorrhagic strokes in patients on statin treatment was observed, an effect that was also earlier described in the Heart Protection Study in a subgroup of patients with a history of cerebrovascular disease. The purpose of this systematic review was therefore to investigate the effect of statin treatment on the occurrence of ischemic and hemorrhagic strokes in patients with a history of cerebrovascular disease.
Methods: We systematically searched the PUBMED database for the combination of the variables "statin" AND "stroke." Furthermore, we searched for relevant studies in the Cochrane Library and Cochrane Central Register of Controlled Trials and handsearched citations. Pooled effect sizes were expressed in relative risk estimates with corresponding 95% CIs.
Results: Four studies were included investigating the effect of statins in 8832 patients with a history of cerebrovascular disease. The pooled relative risk for statin users of overall stroke during follow-up was 0.88 (95% CI: 0.78 to 0.99). The pooled relative risk of ischemic stroke was 0.80 (95% CI: 0.70 to 0.92) and of hemorrhagic stroke 1.73 (95% CI: 1.19 to 2.50).
Conclusions: In patients with a history of cerebrovascular disease, statins clearly decrease the risk of ischemic stroke. However, this beneficial effect is partly lost by an increased risk of hemorrhagic stroke.