Intracardiac Echocardiography to Guide Watchman FLX Implantation: The ICE LAA Study

Intracardiac echocardiography (ICE) is increasingly used to guide left atrial appendage closure (LAAC). The aim of this study was to investigate the efficacy and safety of ICE-guided LAAC with the Watchman FLX device. The ICE LAA (I Can See Left Atrial Appendage) study was a prospective, multicenter study with independent adjudication of echocardiographic data by a core laboratory and clinical events by a clinical events committee. Patients with atrial fibrillation with CHA DS -VASc scores ≥2 and clinical indications for LAAC were eligible. Preplanning with either cardiac computed tomography or transesophageal echocardiography (TEE) within 7 days prior to LAAC was mandatory. Intraprocedural ICE was carried out from the left atrium. The primary outcome was the rate of significant peridevice leaks (>5 mm) at 45-day TEE. A total of 100 patients were enrolled. The mean age was 76 ± 8 years, the mean CHA DS -VASc score was 4.0 ± 1.5, and the mean HAS-BLED score was 2.5 ± 0.9. The incidence of the primary outcome of significant peridevice leak (>5 mm) was 0%; all patients evaluated by TEE at 45 days had effective LAAC. All patients received Watchman FLX devices, and technical success was 100%. The number of devices per case was 1.0 ± 0.1. ICE successfully guided the assessment of device release criteria, including device compression (19.2% ± 7.1%; recommended range: 10%-30%). No subject required conversion to TEE. Procedural complications were 4 access-site bleeds. There was no stroke, transient ischemic attack, systemic embolization, pericardial effusion, device embolization, or device-related thrombus during the procedure or 45-day follow-up. ICE can be used to successfully guide LAAC with the Watchman FLX, with excellent procedural success, a high rate of effective LAAC, and minimal periprocedural complications. (I Can See Left Atrial Appendage [ICELAA] Clinical Study; NCT04196335).