Statins Reduce Short- and Long-Term Mortality Associated With Postoperative Atrial Fibrillation After Coronary Artery Bypass Grafting: Impact of Postoperative Atrial Fibrillation and Statin Therapy on Survival

Background: Postoperative atrial fibrillation (POAF) is a frequent complication of coronary artery bypass grafting (CABG) surgery. The objective of this study was to determine the impact of POAF on both short- and long-term mortality following isolated CABG. Hypothesis: POAF is associated with a poorer short and long-term mortality following CABG. Methods: We retrospectively analyzed the preoperative and operative data of 6728 consecutive patients undergoing a first isolated CABG. Results: The incidence of POAF was 27.8%. Operative mortality was higher in patients with POAF compared to those without POAF (2.3% vs 0.9%, P < 0.001). On multivariate analysis, POAF remained an independent predictor of operative mortality (odds ratio [OR]: 1.78, P = 0.01). Patients with POAF also had reduced long-term survival (6-year survival: 85.3% vs 89.2%, P < 0.001). After adjusting for other predictors of mortality, POAF was significantly associated with increased long-term mortality (hazard ratio [HR]: 1.35, P = 0.04). Of note, after adjustment for potential confounders, statin treatment had a highly protective effect in POAF patients for both operative mortality (OR: 0.38, P = 0.003) and long-term mortality (HR: 0.62, P = 0.03), whereas it had no significant effect in patients without POAF. Conclusions: POAF is an independent predictor of both short- and long-term mortality following CABG. Moreover, statin therapy was independently associated with better survival in patients with POAF. Dr. Pibarot holds the Canada Research Chair in Valvular Heart Diseases, Canadian Institutes of Health Research. Dr. Mathieu is a research scholar from the Fonds de Recherches en Sante du Quebec, Montreal, Canada. Dr. Despres has served as a speaker for Abbott Laboratories, AstraZeneca, Solvay Pharma, GlaxoSmithKline, and Pfizer Canada Inc.; has received research funding from Eli Lilly Canada; and has served on the advisory boards of Novartis, Theratechnologies, Torrent Pharmaceuticals Ltd., and Sanofi-Aventis. The authors have no other funding, financial relationships, or conflicts of interest to disclose.