National outcomes of surgical ablation for atrial fibrillation at the time of mitral surgery.

Objectives: Current guidelines recommend concomitant surgical ablation at the time of mitral surgery for patients with atrial fibrillation; however, there is a paucity of data on long-term outcomes in this population. We sought to assess long-term clinical outcomes in patients undergoing concomitant surgical ablation at the time of mitral surgery.

Methods: The United States Centers for Medicare and Medicaid data were used to identify patients undergoing mitral repair or replacement from 2015 to 2019. After excluding prior cardiac surgery, endocarditis and emergencies, we identified 11 410 patients undergoing isolated mitral repairs or replacement with pre-operative atrial fibrillation. Of these, 3268 (29%) received surgical ablation and 8142 (71%) did not. Propensity score matching was performed on 27 baseline characteristics. The primary outcome was freedom from death or stroke at 4 years. The secondary outcome was all-cause mortality at 4 years. Both were assessed using Cox-proportional hazard models.

Results: Propensity matching yielded 3268 well-matched patient pairs (mean age: 74, 53% female, median CHA2DS2-Vasc score 4). There was no difference in all-cause mortality at 30 days (2.7% with concomitant ablation vs 2.8% without, P = 0.762). Patients undergoing concomitant ablation at the time of surgery had significantly higher freedom from death or stroke at 4 years (81% vs 77%, HR: 0.84, 95% CI 0.74-0.96). However, overall freedom from death between groups was not statistically significant (84% with concomitant ablation vs 82% without, HR: 1.14, 95% CI 0.76-1.01).

Conclusions: Surgical ablation at the time of isolated mitral surgery is underutilized but associated with improved long-term outcomes.