Do we increase the operative risk by adding the Cox Maze III procedure to aortic valve replacement and coronary artery bypass surgery?

Abstract

Objective: Recent reports from Europe and the United States have suggested that patients presenting for open surgery with a significant history of atrial fibrillation (AF) have inferior early and late outcomes if AF is left untreated. On the other hand, there is reluctance among surgeons to treat AF surgically, especially when atriotomies may be required otherwise, which is the case with aortic valve replacement (AVR) or coronary artery bypass grafting (CABG). The objective of this study was to explore the potential impact of the addition of the Cox Maze III procedure on short- and long-term outcomes of patients when combined with AVR or CABG.

Methods: Since 2005, 485 patients have undergone the Cox Maze III procedure at Inova Heart and Vascular Institute, 95 of whom had a full Cox Maze III with an AVR or CABG (Cox Maze III/AVR = 30; Cox Maze III/CABG = 47; Cox Maze III/AVR/CABG = 18). In addition, 4255 patients with no history of AF underwent AVR or CABG without surgical ablation (AVR = 422; CABG = 3518; AVR/CABG = 315). Data from our CABG, valve, and AF registries were used for analyses. Patients with and without the Cox Maze III were propensity score matched using a 0.10 caliper to improve balance on clinical and demographic variables. Differences in perioperative and postoperative outcomes by group were evaluated using the Fisher exact test, and a Kaplan-Meier survival analysis was completed. Health-related quality of life (Short Form 12) was obtained at baseline and 6 months post-surgery (n = 72).

Results: All 95 patients who underwent the Cox Maze III were propensity score matched with patients who did not undergo the Cox Maze III. Mean age (t = 0.3, P = .79) and European System for Cardiac Operative Risk Evaluation score (t = -1.8, P = .07) were similar between the groups. There were no significant differences in major postoperative morbidities between the groups despite the Cox Maze III group being on bypass longer (164.4 vs 108.8 minutes; t = -9.8, P < .001). Pacemaker implantation was significantly higher in the Cox Maze III group (P = .03). Survival during follow-up (mean = 35 months) was not different between patients who did and did not undergo the Cox Maze III procedure (log rank = 0.49, P = .48). Improvement in physical health-related quality of life was similar for both groups (F = 0.01, P = .94). At 1 year, 94% of the patients (60/64) who underwent the Cox Maze III procedure were in sinus rhythm (81% off class I and III antiarrhythmic drugs).

Conclusions: The addition of the Cox Maze III procedure to AVR or CABG did not convey an increase in major morbidity and perioperative risk. Patients who underwent the Cox Maze III procedure demonstrated similar survival over time with improvement in health-related quality of life. The Cox Maze III should not be denied to patients in whom the cardiac surgical procedure does not include atriotomies because of the perceived increased operative risk. The Cox Maze III may significantly improve their outcome.