The ADALA trial showed a more favorable efficacy-safety profile with low-dose direct oral anticoagulation (LD-DOAC) vs dual antiplatelet therapy (DAPT) at 3 months after left atrial appendage occlusion (LAAO). However, outcomes after switching both regimens to single antiplatelet therapy (SAPT) remain uncertain. This study reports the 1-year results, focusing on outcomes after the switch to SAPT.

The ADALA trial was a multicenter, randomized clinical trial that enrolled 91 patients with atrial fibrillation and contraindications to oral anticoagulation. After successful LAAO, participants were randomized to receive LD-DOAC or DAPT for 3 months, after which all patients transitioned to SAPT. The primary endpoint was a composite of thromboembolic events, device-related thrombus (DRT), or major bleeding at 1-year.

At 12 months, the primary endpoint was significantly lower in the LD-DOAC group compared with the DAPT group (9.1% vs 32.6%; HR, 0.25; 95%CI, 0.08-0.74; P=.013), mainly driven by a reduction in DRT (0% vs 11.6%; P=.023). Major bleeding was numerically lower with LD-DOAC (9.1% vs 19.6%; P=.167), and total bleeding events were significantly reduced (13.6% vs 37.0%; P=.013). Landmark analysis showed significant differences during the initial 3 months (P <.001) but not from 3 to 12 months (P=.195). All DRT cases treated with LD-DOAC (n=4) resolved completely without bleeding.

LD-DOAC reduced thromboembolic and bleeding events compared with DAPT during the first year after LAAO, driven by a marked reduction in early DRT. No DRT events occurred after LD-DOAC withdrawal, supporting a strategy of LD-DOAC for 3 months followed by SAPT in this high-risk population.