WHY THIS STUDY?

Optimal antithrombotic therapy after percutaneous left atrial appendage closure (LAAO) is not well established as no randomized evaluation has been performed to date.   Different antithrombotic regimens with either oral anticoagulation (OAC) or antiplatelet agents are currently used. Among all, dual antiplatelet therapy (DAPT) with aspirin and clopidogrel for 3 months is the most accepted regimen. The purpose of the present study was to compare a strategy of anticoagulation with low dose direct OAC (ld-DOAC with apixaban 2.5 mg/12h) versus the current standard of care (DAPT with aspirin and clopidogrel) after LAAO.   

HOW WAS IT EXECUTED?

This was a phase IV multicenter randomized, open-label, controlled trial comparing the efficacy and safety of ld-DOAC vs. DAPT after LAAO, both for 3 months. Patients were randomized after undergoing successful LAAO without procedural complications. After the initial 3-month period, patients were switched to long term aspirin in both groups. The primary endpoint was a combined of efficacy (thromboembolic events and device related thrombosis) and safety (major bleeding) at 3 months. Device related thrombosis (DRT) was assessed either by CT or transesophageal echocardiography (TEE) at 3 months.  

WHAT WERE THE ESSENTIAL RESULTS?

A total of 91 patients were included in the study (46 to ld-DOAC and 45 to DAPT).  No differences in baseline characteristics were observed.  Most of patients (54%) presented previous major bleedings (gastrointestinal in 69% and intracranial in 20%). Mean CHA2DS2VASc and HASBLED were 4.0±1.5 and 3.5±1.2 respectively. At 3 months, ld-DOAC was associated with a reduction of the primary endpoint compared to DAPT (n=2/5% with ld-DOAC vs. n=10/22% with DAPT) (figure 1). DOAC presented a significant reduction in thromboembolic events by reducing the rate of DRT (0% with ld-DOAC vs. n=5/11% with DAPT). Although there was no significant difference in the incidence of major bleedings, the rate of any bleeding (major and minor) was also reduced with the use of ld-DOAC (n=2/4.7% with DOAC vs. n=14/30.4% with DAPT).  

WHY IT IS IMPORTANT?

This is the first randomized study comparing two antithrombotic strategies post-LAAO. According to our results, the use of ld-DOAC for 3 months after LAAO conferred a better balance among efficacy (thromboembolic protection) and safety (major bleeding prevention) as compared to DAPT.  

PLEASE LIST THE DEVICE(S)/TECHNOLOGY(IES) INVOLVED IN THIS TRIAL

None of the LAAO companies has sponsored the trial. The following devices have been implanted: Amplatzer Amulet (Abbot Medical) Watchman FLX (Boston Scientific) Lambre (Lifetech Scientific)