The long-term safety and efficacy of concomitant Cox maze procedures for atrial fibrillation in patients without mitral valve disease

Objective: Newly published guidelines made the highest level recommendation for surgical treatment for atrial fibrillation. However, the number of patients without a mitral valve procedure with atrial fibrillation who are treated with concomitant surgical ablation is still low (15%-25%), because surgeons are reluctant to perform procedures in patients who would not otherwise require left atriotomy. The purpose of this study was to compare the outcomes of concomitant Cox maze with and without mitral valve procedures. Methods: Patients who underwent concomitant Cox maze procedures were prospectively followed since September 2005. Of the 711 patients, 238 did not receive mitral valve surgery. Propensity score matching was conducted to balance preoperative characteristics between patients with and without mitral valve procedures (164/group after matching). Results: Before matching, patients in the mitral valve group were younger (65 vs 67 years, P =.047) and had higher euroSCORE II (European System for Cardiac Operative Risk Evaluation; 3.2% vs 2.6%, P =.002), larger mean left atrial size (5.3 vs 4.8 cm, P <.001), and shorter median atrial fibrillation duration (19 vs 25 months, P =.064). Early outcomes were similar for the matched groups. Cumulative 5-year freedom from stroke did not differ between matched mitral valve and non–mitral valve groups (96.1% vs 96.6%, P =.667). At each time point, the proportion in sinus rhythm off antiarrhythmic medications was similar for the matched groups, including 5 years after surgery (68% vs 63%, P =.492). Conclusions: The Cox maze procedure is safe and effective with comparable outcomes when performed concomitant to mitral valve or non–mitral valve surgery. Surgeons should base the decision to perform surgical ablation procedures on atrial fibrillation pathophysiology and the benefit to patients, not on the type of concomitant procedure.