Procedural and Short-Term Results With the New Watchman FLX Left Atrial Appendage Occlusion Device

Objectives: This study sought to report early experience with the new-generation Watchman FLX device (Boston Scientific, Marlborough, Massachusetts).

Background: The new-generation Watchman FLX features a reduced height, improved anchoring and fabric coverage, and a closed distal end. These design modifications aim to simplify implantation, allow full recapture and repositioning, and reduce peridevice leak and device-related thrombosis.

Methods: A total of 165 patients undergoing left atrial appendage (LAA) occlusion (LAAO) with Watchman FLX were enrolled in a prospective, multicenter registry at 12 centers participating in the European limited market release program.

Results: Mean age was 75.4 ± 8.9 years, and CHA₂DS₂-VASc score 4.4 ± 1.4. A total of 128 patients (77.6%) had a history of major bleeding, including previous intracranial hemorrhage in 55 cases (33.3%). LAA landing zone minimal and maximal mean diameters were 19.1 ± 3.6 mm and 22.3 ± 3.7 mm, and 24.2% of LAA were considered complex by dimensions. Technical success was achieved in all patients. Successful implantation at first attempt was achieved in 129 cases (78.2%), and a second device was required in 6 cases (3.6%). Procedure-related complications occurred in 3 patients (1.8%): 2 access-related (1.2%) and 1 pericardial effusion (0.6%). No peri-procedural strokes, deaths, or device embolizations occurred. Forty-nine patients (29.7%) were discharged with single antiplatelet therapy, 105 (63.6%) on dual antiplatelet, and 11 (6.7%) on anticoagulation. Imaging follow-up displayed just 1 peridevice leak ≥5 mm and 7 cases of device-related thrombosis (4.7%). During a median follow-up of 55 days (interquartile range: 45 to 148 days), there were 6 hemorrhagic complications (4.8%), 1 patient (0.8%) had an ischemic stroke, and 1 (0.8%) died. No late device embolizations occurred.

Conclusions: LAAO with the Watchman FLX is safe and effective in a wide range of LAA morphologies, with a low procedural complication rate, high degree of LAA sealing, and favorable short-term efficacy.