Antithrombotic Therapy After Left Atrial Appendage Occlusion

Quick Takes

  • Most patients undergoing Watchman LAAO did not follow pivotal trial protocols post-procedure.
  • Use of warfarin or DOAC only therapy post-implantation was associated with fewer adverse events at 45 days than warfarin plus aspirin.
  • Use of warfarin only post-procedure was associated with fewer adverse events at 6 months than warfarin plus aspirin therapy.

Study Questions:

What are the patterns of post-procedure antithrombotic care after left atrial appendage occlusion (LAAO) with the Watchman device, and how do they associate with adverse events?


Using the LAAO Registry of the National Cardiovascular Data Registry, patients who underwent LAAO with the Watchman device between 2016 and 2018 were included. The authors assessed adherence to the post-procedure trial protocol, including follow-up, imaging, and antithrombotic therapy use. They compared the most commonly used antithrombotic strategies with adverse events at 45 days and 6 months using multivariable Cox frailty regression.


Among 31,994 patients who underwent successful LAAO, only 12.2% received the full post-procedure treatment protocol from the pivotal trials. The most common deviation from the trial protocol involved discharge medications. The most common discharge medication strategies were warfarin plus aspirin (36.9%), direct oral anticoagulant (DOAC) plus aspirin (20.8%), warfarin only (13.5%), DOAC only (12.3%), and dual antiplatelet therapy (5.0%). In multivariable analyses, the adjusted risk of adverse events through 45 days was lower for patients discharged on warfarin alone (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.57-0.84) and DOAC alone (HR, 0.73; 95% CI, 0.57-0.93) as compared to warfarin plus aspirin. Similar reductions in adverse events at 6 months were seen in the warfarin alone cohort.


The authors concluded that practitioners rarely used the full Food and Drug Administration approved post-procedure treatment protocol for patients undergoing Watchman LAAO device implantation. They also concluded that use of warfarin or DOAC only therapy without aspirin was associated with a lower risk of adverse events.


The Watchman LAAO device offers significant stroke prevention for patients who are at risk of bleeding complications associated with anticoagulant use. However, in the pivotal trials, patients were discharged on warfarin plus aspirin for 45 days, after which they typically continued on DAPT until 6 months. This study highlights that most patients receiving Watchman LAAO between 2016 and 2018 received an alternative course of antithrombotic therapy. This may be related to increasing familiarity with DOAC medications and/or perceived risk of bleeding with combination oral anticoagulation and antiplatelet therapy. Reassuringly, the outcomes for patients who receive warfarin or DOAC only therapy were as good or better than for those who received the “standard” warfarin plus aspirin therapy immediately post-procedure. How these results translate to the newer-generation Watchman FLX device remains to be explored.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Cardiovascular Care Team, Geriatric Cardiology, Prevention, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: Anticoagulants, Arrhythmias, Cardiac, Aspirin, Atrial Appendage, Atrial Fibrillation, Coronary Occlusion, Fibrinolytic Agents, Frailty, Geriatrics, LAAO Registry, Patient Discharge, Platelet Aggregation Inhibitors, Secondary Prevention, Stroke, Vascular Diseases, Warfarin

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