Medium-to-long-term success rate of left atrial appendage closure using endocardial sutures and postoperative anticoagulant strategies.

Introduction: Surgical endocardial closure of the left atrial appendage (LAA) may reduce thromboembolic risk in patients with atrial fibrillation (AF); however, evidence regarding its medium-to-long-term durability remains limited. This study evaluated the efficacy and safety of endocardial suture closure of the LAA during concomitant cardiac surgery. Methods: This retrospective study included 50 patients with valvular heart disease and AF who underwent valve surgery, the Cox-Maze IV procedure, and LAA closure using an endocardial suture technique between 2013 and 2018. Intraoperative transesophageal echocardiography (TEE) was used to assess immediate closure. Transthoracic echocardiography and TEE were performed during follow-up. Closure failure was defined as a residual LAA stump >1 cm or residual to-and-fro flow between the left atrium and LAA. Results: The mean follow-up duration was 7.16 ± 1.73 years. Intraoperative TEE showed no residual LAA stump or to-and-fro flow in any patient. At follow-up, no patient had a residual stump >1 cm, whereas residual to-and-fro flow was detected in 5 patients (10.0%), corresponding to a medium-to-long-term closure success rate of 90.0%. Four of these five patients (80.0%) developed thrombus within the residual LAA stump, and one experienced an ischemic stroke. No stroke occurred among patients with imaging-confirmed successful LAA closure. Discussion: Endocardial suture closure provided a high medium-to-long-term imaging success rate in this single-center cohort. Residual to-and-fro flow, even in the absence of a stump >1 cm, may be clinically relevant because it was frequently accompanied by thrombus formation. These findings should be interpreted as hypothesis-generating because of the limited sample size and low event rate. Postoperative anticoagulation decisions should remain individualized and guideline-informed.