Potential of a Novel Large Left Atrial Appendage Closure Device: Short‐Term Outcomes of the WATCHMAN FLX Pro 40‐mm Versus 35‐mm

Key Points The novel WATCHMAN FLX Pro 40‐mm device enables closure of larger left atrial appendages with procedural safety comparable to that of the 35‐mm device. During the transition from the WATCHMAN FLX to the WATCHMAN FLX Pro, the overall use of large devices (≥ 35‐mm) remained similar between groups (WATCHMAN FLX: 35‐mm, 35%; WATCHMAN FLX Pro: 35‐mm, 25%; 40‐mm, 10%). The 40‐mm device was more frequently implanted in male patients and in those with non‐paroxysmal atrial fibrillation. However, the largest 40‐mm device was associated with a higher incidence of significant peri‐device leakage both at the time of the procedure and at the 3‐month follow‐up, suggesting careful patient selection and procedural planning are warranted.