Efficacy and safety of the new generation Watchman FLX device compared to the Watchman 2.5: a systematic review and meta-analysis.

Introduction: The first-generation Watchman 2.5 (W 2.5)^TM presented several limitations, such as challenges in implantation within complex left atrial appendage (LAA) anatomies, higher incidence of peri-device leak, device recapture, and device-related thrombus (DRT). The newer generation Watchman FLX (W-FLX)^TM was introduced with a modified design aiming to overcome these limitations. The purpose of this meta-analysis is to conduct a comparative assessment of the safety and efficacy of the W-FLX and 2.5 devices in clinical practice.

Method: The meta-analysis was conducted according to the preferred reporting items for systematic review and meta-analysis protocols (PRISMA). Studies were located through a search strategy utilizing PubMed, Cochrane, Google scholar and MEDLINE from inception to March 2023, with a primary objective to compare the safety and efficacy of the W-FLX and W 2.5 devices. After applying the selection criteria, five studies were included in this analysis.

Results: The analysis included five studies comprising 54,727 patients. The W-FLX is associated with an increase in procedural success (OR 7.49 [95% CI 1.98-28.26, P = 0.02; I² = 0%]), and a significant reduction in mortality (OR 0.52 [95% CI 0.51-0.54, P<0.01; I² = 0%], major bleeding 0.57 [95% CI 0.51-0.64, P<0.01; I² = 0%]), device embolism (OR 0.35 [95% CI 0.18-0.70, P = 0.02; I² = 0%]), and pericardial effusion (OR 0.33 [95% CI 0.26-0.41, P<0.01; I² = 0%]). The rates of DRT and stroke were similar between the two groups.

Conclusion: Compared to the W 2.5, the W-FLX was associated with a higher procedural success rate and significantly reduced adverse outcomes including mortality, major bleeding, device embolization, and pericardial effusion.