Left Atrial Appendage Closure after Ablation for Atrial Fibrillation

Background: Oral anticoagulation is recommended after ablation for atrial fibrillation among patients at high risk for stroke. Left atrial appendage closure is a mechanical alternative to anticoagulation, but data regarding its use after atrial fibrillation ablation are lacking.

Methods: We conducted an international randomized trial involving 1600 patients with atrial fibrillation who had an elevated score (≥2 in men and ≥3 in women) on the CHA₂DS₂-VASc scale (range, 0 to 9, with higher scores indicating a greater risk of stroke) and who underwent catheter ablation. Patients were randomly assigned in a 1:1 ratio to undergo left atrial appendage closure or receive oral anticoagulation. The primary safety end point, tested for superiority, was non-procedure-related major bleeding or clinically relevant nonmajor bleeding. The primary efficacy end point, tested for noninferiority, was a composite of death from any cause, stroke, or systemic embolism at 36 months. The secondary end point, tested for noninferiority, was major bleeding, including procedure-related bleeding, through 36 months.

Results: A total of 803 patients were assigned to undergo left atrial appendage closure, and 797 to receive anticoagulant therapy. The mean (±SD) age of the patients was 69.6±7.7 years, 34.1% of the patients were women, and the mean CHA₂DS₂-VASc score was 3.5±1.3. At 36 months, a primary safety end-point event had occurred in 65 patients (8.5%) in the left atrial appendage closure group (device group) and in 137 patients (18.1%) in the anticoagulation group (P<0.001 for superiority); a primary efficacy end-point event had occurred in 41 patients (5.3%) and 44 patients (5.8%), respectively (P<0.001 for noninferiority); and a secondary end-point event had occurred in 3.9% and 5.0% (P<0.001 for noninferiority). Complications related to the appendage closure device or procedure occurred in 23 patients.

Conclusions: Among patients who underwent catheter-based atrial fibrillation ablation, left atrial appendage closure was associated with a lower risk of non-procedure-related major or clinically relevant nonmajor bleeding than oral anticoagulation and was noninferior to oral anticoagulation with respect to a composite of death from any cause, stroke, or systemic embolism at 36 months. (Funded by Boston Scientific; OPTION ClinicalTrials.gov number, NCT03795298.).