Conformal Left Atrial Appendage Seal Device for Left Atrial Appendage Closure: First Clinical Use

Objectives: The authors report the first clinical experience with the Conformal Left Atrial Appendage Seal (CLAAS) device.

Background: The CLAAS device was designed to address the limitations of first-generation left atrial appendage closure (LAAC) devices by providing an implant that is minimally traumatic, can be deployed in a noncoaxial fashion, and does not require postprocedural oral anticoagulation.

Methods: Patients with atrial fibrillation at high stroke risk (CHA₂DS₂-VASc score ≥2) were recruited using standard selection criteria. The LAAC procedure was guided by transesophageal echocardiography with patients under general anesthesia. The CLAAS device is composed of a foam cup, with a Nitinol endoskeleton with an expanded polytetrafluoroethylene cover, delivered with a standard delivery system using a tether for full recapture. All patients received dual-antiplatelet therapy for 6 months, followed by aspirin alone. Transesophageal echocardiographic follow-up was scheduled for 45 days and 1 year.

Results: Twenty-two patients (63.7% with CHA₂DS₂-VASc scores ≥3, 76.2% with HAS-BLED scores ≥3) were enrolled. The device was successfully implanted in 18 patients and unsuccessfully in 4 patients. There were no serious procedural complications. On transesophageal echocardiography performed at 45 days, 1 significant leak (≥5 mm) was seen, which was due to a large posterior lobe not appreciated at the time of implantation, and 1 device-related thrombus was noted, which resolved on oral anticoagulation. There were no periprocedural strokes, major pericardial effusions, or systemic or device embolization.

Conclusions: This first-in-human study demonstrates the clinical feasibility of the CLAAS device for LAAC.