The long-term influence of lesion set in the surgical ablation of atrial fibrillation during mitral valve surgery: Multicenter propensity-score weighted study

Objective: This study aimed to assess the effect of the lesion sets for surgical ablation of atrial fibrillation on long-term outcomes and identify the optimal lesion set.

Methods: Between 2005 and 2017, 1825 patients underwent surgical ablation concomitant to mitral valve surgery in the participating institutions. Of these, 529 underwent left atrial ablation, whereas the remainder had biatrial ablation. The clinical and rhythm outcomes were compared, considering death as a competing event. Inverse probability treatment weighting was used to mitigate the selection bias.

Results: The patients undergoing left atrial ablation were younger and less frequently had long-standing atrial fibrillation with a shorter duration or required concomitant tricuspid valve surgery. Adjusted analysis showed that left atrial ablation was associated with a lower risk of early pacemaker implantation (odds ratio, 0.16; 95% CI, 0.07-0.38; P < .001) than biatrial ablation. Over a median follow-up of 70.4 months (interquartile range, 44.1-111.2 months), the left atrial ablation group presented a higher risk of atrial fibrillation recurrence (subdistribution hazard ratio, 1.26; 95% CI, 1.12-1.41; P < .001), with a 5-year cumulative incidence of 34.2% compared with 28.6% in the biatrial group. The risk of late mortality (subdistribution hazard ratio, 1.17; 95% CI, 0.74-1.86; P = .507) and stroke (subdistribution hazard ratio, 1.21; 95% CI, 0.82-1.79; P = .345) did not differ between the groups.

Conclusions: In patients undergoing surgical ablation concomitant to mitral valve surgery, both lesion sets provided comparable incidence of mortality and stroke. However, biatrial ablation was associated with a superior rhythm outcome at the expense of a higher risk of early pacemaker implantation.