Gender differences in left atrial appendage closure for Japanese patients - From the Terminator registry

Abstract Background Transcatheter left atrial appendage closure (LAAC) with the WATCHMAN device has emerged as an alternative treatment option to oral anticoagulants. The WATCHMAN device was introduced in Japan in 2019, followed by the newer WATCHMAN FLX device in 2021. However, few studies have investigated sex differences in the outcomes of the LAAC procedure. Objective This study aimed to evaluate sex differences in LAAC procedures in Japan. To adjust for confounding factors, we employed two innovative matching methods: propensity score (PS) and inverse probability of treatment weighting (IPTW). Methods The TERMINATOR (Transcatheter Modification of Left Atrial Appendage by Obliteration with Device) registry is a multicenter, real-world registry involving 23 institutions in Japan. This study enrolled 1,817 patients with atrial fibrillation who underwent LAAC at these institutions between September 2019 and September 2023. The primary efficacy endpoint was a composite of ischemic stroke, transient ischemic attack, or systemic embolism at 12 months. The primary safety endpoint was a composite of hemorrhagic stroke or anemia requiring transfusion at 12 months. The secondary endpoint was all-cause mortality through 12 months. A retrospective analysis was performed to compare clinical outcomes following LAAC, using propensity score matching (PSM) at a 1:1 ratio and IPTW to minimize potential bias. Results Of the 1,171 patients analyzed, 332 (28.4%) were women. Compared with men, women were older (78.1 ± 7.7 years vs. 74.86 ± 8.1 years; P 0.001) and more likely to have paroxysmal atrial fibrillation (45.2% vs. 36.6%; P = 0.007). The CHA2DS2-VA and HAS-BLED scores were comparable between the sexes (4.4 ± 1.3 vs. 4.5 ± 1.4; P = 0.751 and 3.3 ± 0.8 vs. 3.3 ± 0.9; P = 1.000, respectively). After PSM, 330 men and 330 women were selected for the final analysis. As shown in the Kaplan–Meier analysis (Figure), no statistical differences were observed between the sexes in the primary efficacy and safety endpoints or the secondary endpoint. The IPTW method produced similar results. Conclusion In patients with atrial fibrillation undergoing LAAC, women demonstrated similar safety and efficacy outcomes compared with men.