BACKGROUND: Cerebral vasospasm and related delayed ischaemic deficits (DIDs) 
occur in about 17% to 40% of patients with aneurysmal subarachnoid haemorrhage 
(SAH) and lead to a poor outcome. Cholesterol-reducing agents might improve 
unfavourable outcomes.
OBJECTIVES: To assess the effects of cholesterol-reducing agents for improving 
outcomes in patients with aneurysmal SAH.
SEARCH METHODS: We searched the Cochrane Stroke Group Trials Register (May 
2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The 
Cochrane Library 2012, Issue 5), MEDLINE (1948 to May 2012) and EMBASE (1980 to 
May 2012). We also searched three Chinese databases: SinoMed, CNKI and VIP (May 
2012). In an effort to identify further published, ongoing and unpublished 
trials we searched relevant clinical trials and research registers (May 2012), 
contacted pharmaceutical companies and investigators known to be involved in 
previous trials and screened the reference lists of all relevant articles 
identified.
SELECTION CRITERIA: We included randomised controlled trials (RCTs) that 
compared cholesterol-reducing agents with control or placebo treatment in 
participants with aneurysmal SAH.
DATA COLLECTION AND ANALYSIS: Two review authors independently applied the 
inclusion criteria, reviewed the relevant trials and extracted data. We did not 
perform meta-analysis as we only included one RCT in the review.
MAIN RESULTS: We included one study in which 39 patients received either 
simvastatin (80 mg daily; n = 19) or placebo (n = 20) for 14 days. The incidence 
of DIDs (secondary outcome) was 26% (5/19) in the simvastatin group versus 60% 
(12/20) in the placebo group (risk ratio (RR) 0.44, 95% confidence interval (CI) 
0.19 to 1.01, P = 0.05). This means that, in this study, simvastatin had no 
effect on DIDs. Two patients in the simvastatin group and one patient in the 
placebo group had elevated levels of aspartate transaminase or alanine 
transaminase. One patient in the simvastatin group had a raised creatine 
phosphokinase. There were no results from this trial for the primary outcome of 
death or dependency at six months.
AUTHORS' CONCLUSIONS: We cannot draw any conclusions about the effectiveness and 
safety of lowering cholesterol in aneurysmal SAH because of insufficient 
reliable evidence from only one small trial. More RCTs are needed.