Outcomes of Different Device Sizing Strategies Using the Newer‐Generation WATCHMAN Devices for Closure of Borderline‐Sized Left Atrial Appendage
Motoki Fukutomi, Naoki Saito, Shinya Wada, Mizuho Hoshina, Shunsuke Sasaki, Sunao NakamuraABSTRACT
Background
In left atrial appendage closure (LAAC) using newer‐generation WATCHMAN FLX/FLX Pro devices, managing borderline‐sized LAA within overlapping zones is common, but optimal device sizing strategies remain unknown.
Aims
To compare clinical outcomes and device‐related complications between smaller and larger device sizing strategies for borderline‐sized LAA.
Methods
This single‐center retrospective study evaluated 91 patients undergoing newer‐generation WATCHMAN implantation for borderline‐sized LAA between September 2021 and June 2024. Follow‐up imaging (transesophageal echocardiography and/or cardiac computed tomography angiography) was performed 45‐120 days post‐LAAC, and one‐year clinical outcomes were assessed.
Results
Patients were divided into smaller ( n = 36) and larger ( n = 55) device groups. The composite primary endpoint (cardiovascular mortality and ischemic stroke) was similar between groups (8.3% vs. 3.6%; hazard ratio [HR], 0.372; 95% CI: 0.074–2.650, p = 0.334). However, the secondary efficacy endpoint‐peridevice leak (PDL) 〉3 mm and/or device‐related thrombus (DRT)‐was significantly higher in the smaller device group at initial follow‐up, even after covariate adjustment (13.9% vs. 1.8%; HR, 0.091; 95% CI: 0.009–0.887, p = 0.039). Similar findings were observed at one year.
Conclusion
For borderline‐sized LAA treated with newer‐generation WATCHMAN devices, smaller and larger sizing strategies yielded similar one‐year clinical outcomes. However, the larger device strategy showed a lower incidence of PDL >3 mm and/or DRT.