Objectives Postoperative atrial fibrillation (POAF) is the most common complication following cardiac surgery. A variety of POAF risk factors has been reported, but study results have been inconsistent or contradictory, particularly in patients with preexisting atrial fibrillation. The incidence of POAF was evaluated in a group of 10,390 cardiac surgery patients among a comprehensive range of risk factors to identify reliable predictors of POAF. Methods This 20-year retrospective study examined the relationship between POAF and demographic factors, preoperative health conditions and medications, operative procedures, and postoperative complications. Multivariate logistic regression models were used to evaluate potential predictors of POAF. Results Increasing age, mitral valve surgery (OR=1.91), left ventricular aneurysm repair (OR=1.57), aortic valve surgery (OR=1.52), race (Caucasian) (OR=1.51), use of cardioplegia (OR=1.36), use of an intra-aortic balloon pump (OR=1.28), previous congestive heart failure (OR=1.28), and hypertension (OR=1.15) were significantly associated with POAF. The nonlinear relationship between age and POAF revealed the acceleration of POAF risk in patients 55 or older. In patients undergoing coronary artery bypass grafting, increasing age and previous congestive heart failure were the only factors associated with a higher risk of POAF. There was no trend in incidence of POAF over time. No protective factors against POAF were detected, including commonly prescribed categories of medications. Conclusions The persistence of the problem of POAF, and the modest predictability using common risk factors, suggest that limited progress has been made in understanding its etiology and treatment.

The use of bipolar radiofrequency ablation has simplified the Cox-maze procedure, making it applicable to virtually all patients with atrial fibrillation undergoing concomitant cardiac surgery. The Cox-maze IV procedure produces similar surgical outcomes to the Cox-maze III procedure at 1 year of follow-up.

Isolating the entire posterior left atrium by creating a box lesion instead of a single connecting lesion between the pulmonary veins showed a significantly lower incidence of early atrial tachyarrhythmias, higher freedom from atrial fibrillation recurrence at 1 and 3 months, and lower use of antiarrhythmic drugs at 3 and 6 months. A complete box lesion should be included in all patients undergoing the Cox maze procedure.