Dose-related effect of statins in patients with endovascular coiling or microsurgical clipping for aneurysmal subarachnoid hemorrhage: updated study-level meta-analysis.

Abstract

We aimed to quantitatively assess the effects of short-term statin use on delayed ischemic neurologic deficits (DINDs) and clinical outcomes in patients with aneurysmal subarachnoid hemorrhage (SAH) through a meta-analysis of the available evidence. We searched the electronic databases up to April 8, 2016 to retrieve relevant studies comparing the outcomes between immediate statin-treated in statin-naïve patients and untreated patients following aneurysmal SAH. Meta-analysis was performed using Review Manager 5.3. Eight randomized controlled clinical trials (RCTs) and 5 observational studies involving 2148 patients met the eligibility criteria. In the RCTs, statins were found to significantly reduce the occurrence of DINDs (relative risk (RR), 0.76; 95% confidence interval (CI), 0.61-0.94; P=0.01), but did not significantly reduce poor functional outcomes (RR, 1.01; 95% CI, 0.87-1.16; P=0.93) or mortality (RR, 0.80; 95% CI, 0.58-1.11; P=0.18). In observational studies, statin use was not associated with any reduction in DINDs, poor outcome, or mortality. Meta-analysis of RCTs indicated a significant reduction in DINDs and mortality in patients with high-dose statin use (RR, 0.63; 95% CI, 0.42-0.95; P=0.03; I 2=0%; and RR, 0.36; 95% CI, 0.15-0.86; P=0.02; I 2=0%, respectively). The present meta-analysis suggests that statin use may prevent DINDs in patients with aneurysmal SAH. Based on our findings, the role of statins in improving neurological outcome was limited. However, the risk of DINDs and mortality decreased with higher statin doses in a dose-dependent manner. Hence, further well-designed RCTs with modified protocols in specific patients are required.