Design and Rationale of the Swiss-Apero Randomized Clinical Trial: Comparison of Amplatzer Amulet vs Watchman Device in Patients Undergoing Left Atrial Appendage Closure.

Residual or newly acquired leaks are routinely appraised after left atrial appendage closure (LAAC). The Watchman and the Amulet are the two most frequently used devices for LAAC but no randomized study has so far assessed their comparative leak rates after intervention. The "Comparison of Amplatzer Amulet vs Watchman devices in patients undergoing left atrial appendage closure" (Swiss-Apero, clinicaltrial.gov NCT03399851) is an academic-sponsored multicenter, randomized clinical trial comparing Amulet versus Watchman/FLX devices among patients undergoing a clinically indicated LAAC. The study is designed to assess the superiority of Amulet vs. Watchman/FLX in terms of leaks detected by cardiac computed tomography angiography (CCTA) at 45 days (primary endpoint) and 13 months (secondary endpoint) after intervention by an imaging Core Laboratory. The Swiss-Apero study is the first randomized clinical trial comparing Amulet and Watchman/FLX with respect to the prevalence of post-procedural leak as assessed with CCTA.