Trial results for the WATCHMAN FLX™ Pro Left Atrial Appendage Closure (LAAC) Device in patients with Atrial Fibrillation were posted on 2025-10-15, showing 0 participants experienced a device leak greater than 5 mm at 45-day post-implant TEE.
Background
Atrial fibrillation (AFib) is a common heart rhythm disorder that significantly increases the risk of stroke. For many patients, long-term oral anticoagulation is prescribed to prevent blood clots. However, some patients are unsuitable for or cannot tolerate these medications due to a high risk of bleeding. In such cases, left atrial appendage closure (LAAC) devices offer an alternative strategy to reduce stroke risk. The left atrial appendage is a small pouch in the heart where most stroke-causing blood clots form in patients with non-valvular AFib. By closing off this appendage, LAAC devices aim to prevent these clots from forming and entering the bloodstream. Collecting real-world data on these devices, such as the WATCHMAN FLX™ Pro, is crucial for understanding their performance and safety in diverse patient populations outside of controlled clinical trial settings.
Trial design
The HEAL-LAA Clinical Trial (NCT05809596) was a completed study designed to collect real-world data on the WATCHMAN FLX™ Pro Left Atrial Appendage Closure (LAAC) Device in patients with non-valvular atrial fibrillation. The study enrolled 949 participants and focused on conditions including Atrial Fibrillation, Bleeding, and Stroke. The trial did not specify a phase (NA) as its primary objective was real-world data collection. The primary efficacy endpoint was defined as the rate of device leak greater than 5 mm at 45-day post-implant transesophageal echocardiogram (TEE) for the primary analysis subjects. The primary safety endpoint was a composite rate of all-cause mortality, all stroke, systemic embolism, and major bleeding for the primary analysis subjects. The study was a single-arm design, focusing on the performance of the WATCHMAN FLX™ Pro device without a comparator arm.
Key results
The trial results provided key measurements for both efficacy and safety endpoints:
- For the primary efficacy endpoint, which assessed the rate of device leak greater than 5 mm at 45-day post-implant TEE for the primary analysis subjects, 0 participants were reported with such a leak.
- Regarding the primary safety endpoint, a composite rate of all-cause mortality, all stroke, systemic embolism, and major bleeding for the primary analysis subjects was observed in 54 participants.
What this means
The reported results from the HEAL-LAA Clinical Trial provide important real-world insights into the performance of the WATCHMAN FLX™ Pro LAAC Device in patients with atrial fibrillation. The finding of 0 participants experiencing a device leak greater than 5 mm at 45-day post-implant TEE suggests high efficacy in achieving adequate sealing of the left atrial appendage, which is critical for preventing clot formation and subsequent stroke. This low rate of significant device leak is a positive indicator for the device's design and implantation success in a real-world setting. The safety data, indicating 54 participants experienced a composite of serious adverse events, provides valuable information for clinicians assessing the overall risk-benefit profile of the device. These data points contribute to the growing body of evidence supporting the WATCHMAN FLX™ Pro device as a viable option for stroke risk reduction in patients with non-valvular atrial fibrillation, particularly those for whom long-term oral anticoagulation is not suitable.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the study NCT05809596, titled "HEAL-LAA Clinical Trial", were posted on 2025-10-15 on clinicaltrials.gov.