Clinical Electrophysiology -> Atrial Fibrillation & Atrial Flutter: -> Pharmacology (Antiarrhythmic drugs and anticoagulants) D-AB28 - Left Atrial Appendage Closure- Trials and Tribulations (ID 32) Abstract Plus


Background: Choosing an appropriate antithrombotic regimen for patients undergoing Watchman implantation might be challenging. Dual antiplatelet therapy (DAPT) is prescribed to prevent device-related thrombosis (DRT); however, the benefit/risk profile of DAPT in this population with high bleeding risk is still debated. A strategy including half-dose of novel oral anticoagulant (NOAC) may have the potential of preventing DRT.
Objective: We sought to report the effectiveness and complications of two different antithrombotic regimens post left atrial appendage occlusion.
Methods: If no significant leak was detected at 45-day transesophageal echocardiography (TEE), DAPT (Group1) or half dose of NOAC (Group 2) were prescribed up until 6 months post-procedure. After 6 months, Group1 patients were switched to ASA alone, whereas Group2 ones were kept on half dose of NOAC alone. A second and third TEE was performed at 6 and 12 months to confirm complete appendage sealing and exclude the presence of a subclinical DRT. The rates of thromboembolic (TE) events, DRTs and bleeding events in the timeframe between the two follow-up TEEs are reported separately and as a composite endpoint.
Results: Overall, 415 patients (mean age: 75±8 yrs, 50.6% males) were included. On the basis of the antithrombotic strategy prescribed at the time of their first follow-up TEE, patients were categorized into two groups (Group1: 273pts vs Group2: 142pts). Baseline clinical characteristics were similar between groups (CHA2DS2-VASc: 4.6±1.5 vs 4.5±1.5; p=0.63/HAS-BLED: 3.2±1.2 vs 3.1±0.9; p=65). No differences in the incidence of TE events were observed [0.73% (n=2) vs 0.0% (n=0); p=0.55]. At one year of follow-up, 7 DRTs (2.6%) were documented in Group1 vs none in Group2 (p=0.1). Group2 had an incidence of bleeding events that was significantly lower of that of Group1 [0.7% (1 minor bleeding) vs 4.8% (2 major and 11 minor bleedings); p=0.041]. Half-dose of NOAC resulted in a significant reduction of the composite endpoint of TE/bleeding events and DRT (p=0.002).
Conclusion: An antithrombotic regimen that included long-term prescription of half dose of NOAC after Watchman implantation resulted in less bleeding events and effectively prevented the occurrence of TE events and DRT.