Prospective randomized comparison of left atrial and biatrial radiofrequency ablation in the treatment of atrial fibrillation.

OBJECTIVE The aim of this study was to compare, in patients with permanent atrial fibrillation (AF), the efficacy and safety of left atrial ablation with that of a biatrial procedure and to assess the risk factors for late failure of sinus rhythm restoration. METHODS Between January 2004 and January 2007, 299 consecutive patients underwent the radiofrequency ablation procedure for AF associated with concomitant cardiac surgery. According to a prospective, open, and randomized trial, 149 patients underwent left atrial plus cavotricuspid isthmus ablation (left atrial group), while 150 patients underwent biatrial ablation (biatrial group). The postoperative and mid-term follow-up results were compared between the two groups. Both univariate and multivariate analyses were used to assess the risk factors for late recurrence of AF. RESULTS There were seven in-hospital deaths (2.3%), including two in the left atrial group (1.3%) and five in the biatrial group (3.3%), and there were no differences in the incidence of the mortality and complications during the postoperative and follow-up periods between the groups. At discharge, sinus rhythm was maintained in 77.1% of the patients, including 78.2% of those in the left atrial group and 75.9% in the biatrial group (p=0.68). Follow-up was completed in 97% of the patients, with a mean time of 28+/-5 months. At the latest follow-up, two deaths occurred in the biatrial group. Sinus rhythm was documented in 237 (85.0%) out of all the patients, including 85.2% (121/142) in the left atrial group and 84.1% (116/138) in the biatrial group patients (p=0.87). Using a multivariate analysis, a left atrial diameter of >/=80 mm (p=0.02) was an independent predictor for a late recurrence of AF. CONCLUSIONS Both the left atrial combined with cavotricuspid isthmus ablation and biatrial maze procedure is safe and effective in treating patients with AF, with an acceptable sinus conversion rate, mortality and morbidity. A left atrial dimension of >/=80 mm was a significant predictor for a late recurrence of AF.