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Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation
Published on: February 26, 2013
Low-Dose Direct Oral Anticoagulation vs Dual Antiplatelet Therapy After Left Atrial Appendage Occlusion: The ADALA
Xavier Freixa1, Ignacio Cruz-González2, Pedro Cepas-Guillén1
1Department of Cardiology, Institut Cardiovascular, IDIBAPS, Hospital Clinic of Barcelona, Barcelona, Spain.
Insights
Low-dose direct oral anticoagulation (DOAC) demonstrated a better safety and efficacy profile than dual antiplatelet therapy (DAPT) for patients undergoing left atrial appendage occlusion (LAAO). This finding suggests a potential new standard of care, pending larger trial confirmation.
Area of Science:
- Cardiology
- Interventional Cardiology
- Clinical Trials
Background:
- Optimal antithrombotic therapy post-left atrial appendage occlusion (LAAO) remains undefined due to a lack of randomized trials.
- Percutaneous LAAO is an alternative to anticoagulation for stroke prevention in atrial fibrillation.
Purpose of the Study:
- To compare the efficacy and safety of low-dose direct oral anticoagulation (DOAC) versus dual antiplatelet therapy (DAPT) for three months following LAAO.
- To evaluate the composite endpoint of major bleeding and thromboembolic events after LAAO.
Main Methods:
- The ADALA study was a prematurely terminated, investigator-initiated, multicenter, prospective, open-label, randomized trial.
- 90 patients were randomized to receive either low-dose DOAC (apixaban 2.5 mg BID) or DAPT (aspirin plus clopidogrel) for 3 months post-LAAO.
- The primary endpoint was a composite of safety (major bleeding) and efficacy (thromboembolic events, including device-related thrombosis).
Main Results:
- Low-dose DOAC was associated with a significant reduction in the primary endpoint compared to DAPT (4.5% vs 21.7%, HR 0.19, P=.02).
- The low-dose DOAC group showed a lower rate of device-related thrombosis (0% vs 8.7%, P=.04) and a trend towards fewer major bleeding events.
- No significant differences were observed in stroke or systemic embolism rates between the groups.
Conclusions:
- Low-dose DOAC appears to offer a superior balance of efficacy and safety compared to DAPT in the short term after LAAO.
- Results should be interpreted cautiously due to the study's small sample size and premature termination.
- Larger randomized trials are necessary to confirm these findings and establish definitive antithrombotic guidelines post-LAAO.
Importance:
Optimal antithrombotic therapy after percutaneous left atrial appendage occlusion (LAAO) is not well established as no randomized evaluation has been performed to date.
Objective:
To compare the efficacy and safety of low-dose direct oral anticoagulation (low-dose DOAC) vs dual antiplatelet therapy (DAPT) for 3 months after LAAO.
Design, Setting, And Participants:
The ADALA (Low-Dose Direct Oral Anticoagulation vs Dual Antiplatelet Therapy After Left Atrial Appendage Occlusion) study was an investigator-initiated, multicenter, prospective, open-label, randomized clinical trial enrolling participants from June 12, 2019, to August 28, 2022 from 3 European sites. Patients who underwent successful LAAO were randomly assigned 1:1 to low-dose DOAC vs DAPT for 3 months after LAAO. The study was prematurely terminated when only 60% of the estimated sample size had been included due to lower recruitment rate than anticipated due to the COVID-19 pandemic.
Interventions:
The low-dose DOAC group received apixaban, 2.5 mg every 12 hours, and the DAPT group received aspirin, 100 mg per day, plus clopidogrel, 75 mg per day, for the first 3 months after LAAO.
Main Outcomes And Measures:
The primary end point was a composite of safety (major bleeding) and efficacy (thromboembolic events including stroke, systemic embolism, and device-related thrombosis [DRT]) within the first 3 months after successful LAAO. Secondary end points included individual components of the primary outcome and all-bleeding events.
Results:
A total of 90 patients (mean [SD] age, 76.6 [8.1] years; 60 male [66.7%]; mean [SD] CHADS-VASc score, 4.0 [1.5]) were included in the analysis (44 and 46 patients in the low-dose DOAC and DAPT groups, respectively). A total of 53 patients (58.8%) presented with previous major bleeding events (60 gastrointestinal [66.7%] and 16 intracranial [17.8%]). At 3 months, low-dose DOAC was associated with a reduction of the primary end point compared with DAPT (2 [4.5%] vs 10 [21.7%]; hazard ratio, 0.19; 95% CI, 0.04-0.88; P = .02). Patients in the low-dose DOAC group exhibited a lower rate of DRT (0% vs 6 [8.7%]; P = .04) and tended to have a lower incidence of major bleeding events (2 [4.6%] vs 6 [13.0%]; P = .17), with no differences in thromboembolic events such as stroke and systemic embolism between groups (none in the overall population).
Conclusions And Relevance:
This was a small, randomized clinical trial comparing different antithrombotic strategies after LAAO. Results show that use of low-dose DOAC for 3 months after LAAO was associated with a better balance between efficacy and safety compared with DAPT. However, the results of the study should be interpreted with caution due to the limited sample size and will need to be confirmed in future larger randomized trials.
Trial Registration:
ClinicalTrials.gov Identifier: NCT05632445.
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