Transition from WATCHMAN V.2.5 to WATCHMAN FLX for closure of the left atrial appendage: echocardiographic and clinical findings

INTRODUCTION: Interventional closure of the left atrial appendage (LAAC) has been established as an alternative treatment for patients with atrial fibrillation (AF) and an elevated risk of stroke. The WATCHMAN FLX (WM FLX) as the newest WATCHMAN LAAC device differs in several technical characteristics from its precursor, the WATCHMAN V.2.5 (WM V.2.5). METHODS: The data presented here are derived from a retrospective single-centre study. All patients in which an LAAC was performed between February 2017 and March 2021 with either a WM V.2.5 or WM FLX device were included. RESULTS: 169 patients were included in this study, of whom 95 had been treated with WM V.2.5 and 74 with WM FLX, respectively. Directly after implantation, only minor differences regarding membrane thickness and connector protrusion were noted, whereas no relevant differences were found regarding device sizing, device compression or peridevice leakage, respectively. However, at 3-month follow-up, device compression was significantly reduced in WM FLX indicating a continued device expansion which was paralleled by a reduced number of peridevice leakage in comparison to WM V.2.5. Additionally, the combined clinical endpoint of death, stroke/transistoric ischaemic attack, tamponade, device embolisation, device-related thrombosis or peridevice leakage was reduced in WM FLX. CONCLUSION: LAAC using the WM FLX device results in a continued device expansion over the first 3 months based on differences in radial force in comparison to WM V.2.5. This is accompanied by a reduction in adverse clinical endpoints.