Background: Left atrial appendage (LAA) obliteration is a proven stroke-preventive measure for patients with nonvalvular atrial fibrillation (AF). However, the efficacy of LAA obliteration for patients with AF after bioprosthetic mitral valve replacement (MVR) remains unclear.
Aim: This study aimed to estimate the efficacy of LAA obliteration in preventing embolism and to investigate the predictors of thromboembolism after bioprosthetic MVR.
Methods: We retrospectively studied 173 AF subjects with bioprosthetic MVR; among them, 81 subjects underwent LAA obliteration using an endocardial running suture method. The main outcome measure was the occurrence of thrombosis events (TEs). The mean follow-up time was 40 ± 17 months.
Results: AF rhythm was observed in 136 patients postoperatively. The incidence rate of TEs was 13.97 % for postoperative AF subjects; a dilated left atrium (LA; > 49.5 mm) was identified as an independent risk factor of TEs (OR = 10.619, 95 % CI = 2.754-40.94, p = 0.001). For postoperative AF patients with or without LAA, the incidence rate of TEs was 15.8 % (9/57) and 12.7 % (10/79; p = 0.603), respectively. The incidence rate of TEs was 2.7 % (1/36) and 4.2 % (2/48) for the subgroup patients with a left atrial diameter of < 49.5 mm, and 38.1 % (8/21) and 25.8 % (8/31) for those with a left atrial diameter of > 49.5 mm (p = 0.346).
Conclusion: Surgical LAA obliteration in patients with valvular AF undergoing bioprosthetic MVR did not reduce TEs, even when the CHA2DS2-VASc score (a score for estimating the risk of stroke in AF) was ≥ 2 points.
Keywords: Atrial fibrillation; Bioprosthetic mitral valve replacement; Left atrial appendage; Left atrial dimension; Thrombosis events.