The Outcome of the Cox Maze Procedure in Patients With Previous Percutaneous Catheter Ablation to Treat Atrial Fibrillation

Abstract

Surgical ablation may be performed on symptomatic patients who failed catheter ablation. We investigated the outcomes of patients who presented for Cox Maze III/IV procedure (CM III/IV) after failing at least one left-sided ablation. Forty patients were identified as having had at least one left-sided ablation (mean 2.3 ablations per patient). Rhythm was verified using electrocardiograms and 24-hour Holter monitoring. Health-related Quality of life (HRQL) (SF-12) and the Symptom Frequency and Severity Checklist were collected before surgery and postoperatively. The majority of patients (N=38) presented with long standing persistent atrial fibrillation (mean, 50.16 months). There was 1 operative death, 1 noncardiac death in late follow-up (mean, 25.5 months), and no embolic strokes. The return to sinus rhythm off class I/III antiarrhythmic drugs at 6, 12, and 24 months was 76% (29/38), 89% (23/26), 93% (13/14), respectively: 7 patients required cardioversion; 4 patients required another ablation. For every additional ablation before surgery, there was almost 4 times greater odds of receiving a follow-up intervention (OR=3.58, p=0.02, CI: 1.21-10.56). Exit block was tested on 96 previously ablated pulmonary veins and 91 (95%) were found to conduct. HRQL and symptom/severity scores improved significantly postoperatively (p=0.02)/(p=0.03), respectively. Surgical ablation following failed catheter ablation is safe and effective. Over 90% of the tested pulmonary veins were not isolated at time of surgery questioning the validity of documented acute conduction block during catheter ablation. Increase in the number of ablations before the surgical ablation may be related to inferior outcomes.