Safety and Efficacy of Single Versus Dual Antiplatelet Therapy After Left Atrial Appendage Occlusion

The optimal antiplatelet strategy after left atrial appendage (LAA) occlusion able to protect from device-related thrombosis, paying the lowest price in terms of bleeding increase, is unclear. In a real-world, observational study we performed a head-to-head comparison of single versus dual antiplatelet therapy (SAPT vs DAPT) in patients who underwent LAA occlusion. We included 610 consecutive patients, stratified according to the type of post-procedural antiplatelet therapy (280 on SAPT and 330 on DAPT). Primary outcome measure was the incidence of the net composite end point including Bleeding Academic Research Consortium classification 3-5 bleeding, major adverse cardiovascular events or device-related thrombosis at 1-year follow-up. The use of SAPT compared with DAPT was associated with similar incidence of the primary net composite end point (9.3% vs 12.7% p = 0.22), with an adjusted hazard ratio (HR) of 0.69, 95% confidence interval 0.41 to 1.15; p = 0.15) at multivariate analysis. However, SAPT significantly reduced Bleeding Academic Research Consortium classification 3-5 bleeding (2.9% vs 6.7%, p = 0.038; adjusted HR 0.37, 0.16 to 0.88; p = 0.024). The occurrence of ischemic events (major adverse cardiovascular events or device-related thrombosis) was not significantly different between the 2treatment strategies (7.8% vs 7.4%; adjusted HR 1.34, 0.70 to 2.55; p = 0.38). In patients who underwent LAA occlusion, post-procedural use of SAPT instead of DAPT was associated with reduction of bleeding complications, with no significant increase in the risk of thrombotic events. These hypothesis-generating findings should be confirmed in a specific, randomized study.