Biatrial or Left Atrial Lesion Set for Ablation During Mitral Surgery: Risks and Benefits

Controversy exists when performing surgical atrial fibrillation ablation whether there is an increase in postoperative complications using biatrial (BA) lesions compared with only left atrial (LA) lesions, and some studies indicate similar efficacy. This study compares the clinical outcomes of BA and LA ablation lesions in mitral valve surgery patients.

From 2004 through 2014, 2,137 patients had mitral valve surgery with or without other surgeries in a single center. Of those, 836 (39%) had preoperative atrial fibrillation, and of those, 724 (86%) underwent atrial fibrillation ablation surgery; 257 patients had BA lesion sets and 359 had LA lesion sets. Propensity score matching of BA and LA patients was performed.

Baseline differences included more postoperative complications in the BA group, specifically, permanent pacemaker placement (13% versus 7%; p = 0.006). Freedom from atrial fibrillation off antiarrhythmic drugs (72% BA versus 75% LA; p = 0.50), postoperative ablation (7% BA versus 5% LA; p = 0.20), stroke (0.11 versus 0.11 per 10 person-years; p = 0.91), and survival were similar between the groups. After matching, patients in the LA group had a higher freedom from postoperative ablation (p = 0.015), but no difference in freedom from atrial fibrillation off antiarrhythmic drugs (79% BA versus 69% LA; p = 0.09), and no difference in permanent pacemaker placement (10% versus 12%; p = 0.57).

Patients undergoing mitral surgery with LA or BA ablation had similar outcomes, survival, and complications. Limiting lesions to the LA is an effective alternative to BA ablation for patients undergoing ablation with concomitant mitral valve surgery.