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

Background: Intracardiac echocardiography (ICE) is increasingly used to guide left atrial appendage closure (LAAC). Objectives: The aim of this study was to investigate the efficacy and safety of ICE-guided LAAC with the Watchman FLX device. Methods: 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 CHA2DS2-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 peri-device leaks (>5 mm) at 45-day TEE. Results: A total of 100 patients were enrolled. The mean age was 76 ± 8 years, the mean CHA2DS2-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. Conclusions: 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.