Assessment of concomitant paroxysmal atrial fibrillation ablation in mitral valve surgery patients based on continuous monitoring: does a different lesion set matter?†

The efficacy of concomitant ablation techniques in patients with paroxysmal atrial fibrillation (AF) undergoing mitral valve surgery remains under debate. The aim of this prospective, randomized, single-centre study was to compare pulmonary vein isolation (PVI) only versus a left atrial maze (LAM) procedure in patients with paroxysmal AF during mitral valve surgery. Between February 2009 and June 2011, 52 patients with a mean age of 54.2 (standard deviation 7.2 years) underwent mitral valve surgery and concomitant bipolar radiofrequency ablation for paroxysmal AF. Patients were randomized into the PVI group (n = 27) and the LAM group (n = 25). After surgery, an implantable loop recorder for continuous electrocardiography (ECG) monitoring was implanted. Patients with an AF burden (AF%) of < 0.5% were considered AF free (responders). The mean follow-up was 18.6 months (standard deviation 2.1 months), and the patient' data were evaluated every 3 months. All patients were alive at discharge. No procedure-related complications occurred for either the ablation or the loop recorder implantation. Mean aortic clamping and ablation times were significantly longer in the LAM group than in the PVI group. The incidence of early AF paroxysm recurrence was significantly higher in the PVI group than in the LAM group (62.9 vs 24.0%, P < 0.001). At 20 months after surgery, 15 (55.6%) of the 27 patients in the PVI group and 22 (88.0%) of the 25 patients in the LAM group had no documented atrial arrhythmias and were considered responders (AF burden < 0.5%). The mean AF burden during all follow-up periods was significantly lower in the LAM group (23.6 +/- 8.7%) than in the PVI group (6.8 +/- 2.2%) (P < 0.001). According to continuous ECG monitoring data, freedom from AF was significantly higher after the concomitant LAM procedure than after PVI in patients with paroxysmal AF who underwent mitral valve surgery.