The impact of surgical ablation in patients with low ejection fraction, heart failure, and atrial fibrillation

Abstract

Surgical ablation procedures that use the Cox-Maze procedure lesion set were shown to be very effective. However, many surgeons are reluctant to perform the procedure, especially in high-risk patients such as those with reduced left ventricular (LV) function. This study explored the potential impact of the Cox-Maze III/IV procedure on patients with low ejection fraction (EF<40%) and symptoms of heart failure experiencing atrial fibrillation (AF) who present for cardiac surgery. A prospective study whereby patients with persistent or long-standing persistent AF who had surgical ablation were followed. Echocardiograms (echo) were obtained; patients with preoperative EF <40% were included. Health-related quality of life (HRQL-SF-12) and AF symptom severity were obtained at baseline and follow-up. Rhythm was captured by electrocardiogram (EKG) and 24-h Holter. In the past 5 years, 482 patients had surgical ablation (424 full Cox-Maze) of whom 44 patients met the inclusion criteria; however, two patients did not have an available follow-up echo, leaving 42 patients for analysis. Mean age was 61.1 ± 12.9 years, and additive European System for Cardiac Operative Risk Evaluation (EuroSCORE) of 7.5 ± 3.1. There was one operative death, there were no strokes or transient ischemic attacks (TIAs) at follow-up, and EF improved from 30 ± 5.0% to 45 ± 13.0% at a mean of 1.5 ± 11.3 months, postoperatively. The return to NSR at time of follow-up echo was 86% (35/40). The physical functioning HRQL scores improved (37.0 ± 12.3 to 46.8 ± 9.1, p = 0.02) at 12 months (population norm = 38.1 ± 9.9) with a significant improvement in symptom severity. Kaplan-Meier event-free survival at 24 months was 87% (confidence interval (CI): 80.4-91.6) (events considered were redo valve replacement, ventricular assist device or death). This is a unique study assessing a high-risk group of patients. Surgical ablation in patients with low EF can be performed in a safe and effective way without added operative risk. Given the potential long-term clinical advantages of a successful surgical ablation in patients with low EF and heart failure, we believe that surgical ablation should be considered in such patients when they present to surgery.