Recurring Bleeding Events Requiring Red Blood Cell Transfusion After Left Atrial Appendage Closure Are Associated...

Background: Left atrial appendage closure (LAAC) is an established alternative to oral anticoagulation for stroke prevention in patients with nonvalvular atrial fibrillation who are at high risk of thromboembolic events or bleeding complications. Methods: In this single-center retrospective study, we analyzed 70 consecutive patients who underwent successful LAAC with the Watchman™ device between 2012 and 2024. Acute procedural outcomes, long-term thromboembolic and bleeding events, transfusion requirements and mortality were evaluated. Mean follow-up duration was 1210 days. Results: Procedural success was achieved in 98.6% of cases with a low periprocedural complication rate. Ischemic stroke/transient ischemic attack occurred in 2.8% of patients; no hemorrhagic strokes or stroke-related deaths were observed. LAAC resulted in a significant reduction in both the number (144 vs. 56 events; 2.36 vs. 1.55 events per patient, p < 0.05) and severity of bleeding events. Nonetheless, 42.9% of patients required bleeding-related hospitalization after implantation, predominantly within the first 6 months during dual antiplatelet therapy. Overall mortality was 40% with a 12% yearly mortality rate; heart failure and infections were leading causes of death. Pre- and postprocedural transfusion requirements were independently associated with a six-fold increase in mortality risk (HR = 5.97). Conventional risk scores (CHA₂DS₂-VASc, HAS-BLED) failed to predict transfusion needs; atrial enlargement, right ventricular dysfunction, smoking and alcohol consumption were associated with higher risk. Conclusions: LAAC is a safe and effective alternative to long-term anticoagulation, significantly reducing bleeding burden without increasing thromboembolic mortality. Persistent postprocedural bleeding remains a major determinant of long-term prognosis, underscoring the need for individualized, multidisciplinary post-implant management.