Biatrial versus Left Atrial lesion sets for Surgical Ablation of Atrial Fibrillation: Results from 600 patients

S. Yousef¹, J. A.. Brown², D. Ahmad³, Y. Wang¹, F. Thoma¹, D. Serna-Gallegos¹, J. Bonatti⁴, P. Yoon⁵, D. West⁶, D. Kaczorowski⁷, D. Chu⁸, I. Sultan^1
1University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania ²UPMC, Pittsburgh, Pennsylvania ³University of Pittsburgh, Pittsburgh, Pennsylvania ⁴UPMC Heart and Vascular Institute, Pittsburgh, Pennsylvania ⁵University of Pittsburgh, Wexford, Pennsylvania ⁶University of Pittsburgh, Latrobe, Pennsylvania ⁷University of Pittsburgh, Venetia, Pennsylvania ⁸University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania

Purpose: The objective of this study was to compare outcomes of left atrial versus biatrial lesion sets for ablation of atrial fibrillation (AF).

Methods: This was a retrospective study using an institutional database of adult cardiac surgical procedures performed from 2014 to 2023. All patients undergoing either left atrial or biatrial lesion sets along with concomitant operations were included in the study. Cumulative incidence of readmissions for AF were compared, as were cumulative incidence of postoperative ablations/cardioversions. A multivariable Fine and Gray model was fitted to estimate the hazard of reinterventions for AF (ablations and/or cardioversions), where death was treated as a competing risk.

Results: Of the 648 patients who underwent surgical ablation for AF, 345 had left atrial lesion sets and 303 had biatrial lesion sets. Those undergoing biatrial ablation were more likely to have NYHA class III/IV heart failure. Most patients in the left atrial group had paroxysmal AF (50.7%), while most in the biatrial group had persistent AF (75.6%). Patients in the biatrial group were more likely to undergo concomitant mitral valve surgery but less likely to undergo left atrial appendage procedures when compared to the left atrial group. Patients who underwent biatrial ablation had longer bypass and cross-clamp times. Operative mortality and prolonged ventilation rates were higher in the biatrial group. Permanent pacemaker rates were also higher in the biatrial group (11.5% vs 2.9%, p< 0.001). Ischemic stroke rates were comparable. Median follow-up was 3.4 [1.1-5.0] years in the left atrial group and 5.7 [1.5-7.5] years in the biatrial group. Cumulative incidence of readmissions due to AF were comparable between groups. Cumulative incidence of subsequent ablations and/or cardioversions were higher in the left atrial group (p < 0.001). On multivariable regression, biatral ablation was significantly associated with a decreased hazard of ablation/cardioversion when compared to left atrial ablation (HR 0.54, 95% CI 0.35-0.84, p=0.006).

Conclusion: When compared with left atrial lesion sets, biatrial lesion sets were associated with higher pacemaker rates but decreased need for subsequent ablations and/or cardioversions for AF.

Identify the source of the funding for this research project: None