Letter by Shroff and Orlandi Regarding Article, “Randomized Trial of Atorvastatin for Reduction of Postoperative Atrial Fibrillation in Patients Undergoing Cardiac Surgery: Results of the ARMYDA-3 (Atorvastatin for Reduction of Myocardial Dysrhythmia After Cardiac Surgery) Study”
To the Editor:
We read with great interest the study by Patti and colleagues1 that suggests a beneficial effect of atorvastatin in preventing postoperative atrial fibrillation in cardiac surgery patients.
The placebo arm in this study had fewer patients on β-blockers (60% versus 72%, P=0.08), more patients with left atrial enlargement (46% versus 36%, P=0.16), more patients with mitral valve disease (7% versus 2%, P=0.10) and more patients undergoing valve surgery (25% versus 16%). All these variables are known to have a strong association with atrial fibrillation.2 Although these individual differences were not statistically significant, the combination of these variables likely contributed to the magnitude of the treatment effect.
It would be helpful for clinicians to know the incremental benefit of atorvastatin in patients already receiving β-blocker therapy. We also invite the authors to comment on the difference in the clinical outcome after adjusting for the magnitude of left atrial enlargement. Recent data demonstrate that left atrial volume is a strong predictor of atrial fibrillation after cardiac surgery.3 Therefore, it would be relevant to know how left atrial enlargement was measured in the study.
Lastly, 75% patients in the placebo arm of this study and 83% patients in the atorvastatin arm underwent elective coronary bypass surgery. In modern cardiology practice, it would be unusual for patients with established coronary disease to undergo elective bypass surgery without any prior statin therapy. This study, however, highlights the potential benefit of even a short course of statin therapy prior to surgery in preventing atrial fibrillation.
Patti G, Chello M, Candura D, Pasceri V, D’Ambrosio A, Covino E, Di Sciascio G. Randomized trial of atorvastatin for reduction of postoperative atrial fibrillation in patients undergoing cardiac surgery: results of the ARMYDA-3 (Atorvastatin for Reduction of MYocardial Dysrhythmia After cardiac surgery) study. Circulation. 2006; 114: 1455–1461.
Hogue CW Jr., Creswell LL, Gutterman DD, Fleisher LA; American College of Chest Physicians. Epidemiology, mechanisms, and risks: American College of Chest Physicians guidelines for the prevention and management of postoperative atrial fibrillation after cardiac surgery. Chest. 2005; 128 (2 Suppl): 9S–16S.