Objective: This meta-analysis of randomized, controlled trials evaluated effects of statins on postoperative atrial fibrillation risk after cardiac surgery.

Methods: Randomized, controlled trials evaluating statins in cardiac surgery were selected from MEDLINE (1996-August 2009), Cochrane CENTRAL Register, and manual review of references without any language restrictions. End points examined included postoperative atrial fibrillation, intensive care unit stay, and total hospital stay. Meta-regression analyses were conducted to determine whether statins' effects were duration or dose dependent. A random-effects model was used in all instances.

Results: Eight trials (n = 774) were identified and subjected to meta-analysis. Statins reduced postoperative atrial fibrillation risk (relative risk 0.57, 95% confidence interval 0.45-0.72, P < .0001, risk difference -0.14, 95% confidence interval -0.20 to -0.08, P < .0001, number needed to treat 8) and total hospital stay (weighted mean difference -0.66 days, 95% confidence interval -1.01 to -0.30 days, P = .0004) relative to placebo. Intensive care unit stay was also reduced (weighted mean difference -0.17 days, 95% confidence interval -0.37 to 0.03 days, P = .09) but did not meet prespecified criteria for statistical significance. Metaregression analysis revealed association between duration of preoperative statin prophylaxis and postoperative atrial fibrillation risk reduction (3% reduction per day, P = .008). No association was found between statin dose used and risk reduction (P = .47).

Conclusions: Evidence suggests that statins are associated with reduced risk of postoperative atrial fibrillation and shorter hospital stay after cardiac surgery and that earlier therapy results in more profound benefit.