DAPT vs. Oral Anticoagulation Following LAAO With WATCHMAN FLX

Quick Takes

  • Following implantation of the WATCHMAN FLX LAAO device, clinicians can choose from OAC plus aspirin or DAPT initial therapy.
  • In this large registry-based analysis, OAC plus aspirin and DAPT were associated with similar rates of composite thrombotic/hemorrhagic outcomes.
  • Initial DAPT therapy was associated with less bleeding than DOAC plus aspirin in this real-world analysis of WATCHMAN FLX LAAO implantation.

Study Questions:

Is dual antiplatelet therapy (DAPT) a safe alternative to oral anticoagulation (OAC) with aspirin after left atrial appendage occlusion (LAAO)?


The authors analyzed the National Cardiovascular Data Registry (NCDR) LAAO Registry for patients undergoing WATCHMAN FLX LAAO implantation between August 2020–September 2021. Patients were propensity matched based on receipt of DAPT, direct oral anticoagulant (DOAC) plus aspirin, or warfarin plus aspirin. The primary endpoint was a composite of death, stroke, major bleeding, and systemic embolism assessed at 45 days. Components of the primary endpoint along with device-related thrombosis were assessed during the same period.


The authors identified 49,968 patients undergoing WATCHMAN FLX during the study period. These patients had a mean age of 77 years and 40% were women. OAC plus aspirin was used in 28,410 patients (56.9%), the majority of whom received DOAC plus aspirin (86.2%). The median CHA2DS2-VASc score was 5.0 ± 1.4. In the propensity-matched analysis, the rate of the 45-day composite endpoint was similar in all groups (DAPT 3.44% vs. DOAC 4.06%, p = 0.13; DAPT 3.23% vs. warfarin 3.08%, p = 0.75). The individual components of death, stroke, and device-related thrombosis were also similar between groups. Major bleeding was slightly higher in the DOAC group as compared to DAPT (3.48% vs. 3.25%, p = 0.04).


The authors conclude that DAPT has a similar safety profile as OAC plus aspirin following LAAO with WATCHMAN FLX.


LAAO is an increasingly common procedure to reduce stroke and systemic embolism risk for patients with nonvalvular atrial fibrillation, particularly those at high risk for anticoagulant-related bleeding. While the initial studies required warfarin therapy for 45 days after LAAO, the Food and Drug Administration has since approved the use of either warfarin plus aspirin or DAPT therapy for 45 days post-implantation in the WATCHMAN FLX device. While limited by a retrospective design, this large and well-conducted study provides reassurance to clinicians that both an OAC plus aspirin and DAPT approach post WATCHMAN FLX LAAO provide similar clinical outcomes across a composite of thrombotic and hemorrhagic complications.

Perhaps even more helpful is that the DAPT strategy was associated with fewer bleeding events than the DOAC plus aspirin strategy, suggesting that this may be particularly useful for patients with a history of OAC-related bleeding. Of note, this analysis did not look at the use of DOAC monotherapy (either full-dose or half-dose), which has been shown to have low rates of both bleeding and device-related thrombosis in the prior version of the WATCHMAN device. Nonetheless, clinicians can feel comfortable using a variety of different antithrombotic strategies for patients undergoing WATCHMAN FLX LAAO and to tailor these strategies to individual patient risks.

Clinical Topics: Anticoagulation Management, Anticoagulation Management and Atrial Fibrillation

Keywords: Anticoagulants, LAAO Registry, Platelet Aggregation Inhibitors

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