Outcomes of Left Atrial Appendage Occlusion Treatment With Amulet After Unsuccessful Watchman FLX Device: A Multicenter Observational Study.

Abstract

Introduction: Watchman FLX (W-FLX) is the most widely used left atrial appendage occlusion (LAAO) device to prevent atrial fibrillation (AF) related strokes in the United States. However, successful LAAO with W-FLX can be challenging in patients with complex left atrial appendage (LAA) anatomies. This analysis aimed to assess the procedural success rates of LAA occlusion (immediate and short-term outcomes) using the Amulet device, in patients with prior failed LAAO with W-FLX device.

Methods and results: This was a multicentric retrospective analysis of 62 consecutive patients with unsuccessful LAAO with W-FLX, who subsequently underwent an attempted Amulet occluder placement. The primary endpoint was successful Amulet implantation. Secondary endpoints included peri-device leak (PDL) and device-related thrombus assessed by transesophageal echocardiography (TEE) at 45 days, safety end point through 7 days or hospital discharge (whichever was later) and major adverse events (MAEs) through 45 days. The Amulet occluder was successfully implanted in 98.38% of patients (n = 61/62). No clinically relevant PDL or device-related thrombus was noted at 45 days. There was one pericardial effusion noted a week after Amulet implant that underwent successful percutaneous pericardiocentesis. The reasons for W-FLX failure were all anatomical in nature. We identified five distinct anatomical patterns that posed challenges for W-FLX deployment but were amenable to successful Amulet implantation.

Conclusion: The disc-lobe design of Amulet allows a high degree of successful LAAO in challenging anatomical variants (whale-tail, bilobed LAA, shallow vertical chicken-wing or seahorse, oval wide with posterior sloping trabeculations, and extensively trabeculated broccoli morphologies) with prior failed W-FLX implants. These findings may help guide device selection on pre-LAAO imaging, thereby enhancing resource utilization and contributing to more efficient and safer LAAO procedures.