Outcomes at 1 Year After Transcatheter LAA Occlusion

Quick Takes

  • Among a cohort of 36,000 patients with atrial fibrillation who underwent Watchman left atrial appendage occlusion (LAAO), 1-year stroke rate was low (1.53%).
  • The rate of stroke or systemic embolism (2.19%) was markedly lower than the rate of major bleeding (6.93%).
  • The majority of major bleeding events occurred in the 45 days following implantation and likely were influenced by oral anticoagulant ± antiplatelet use.

Study Questions:

What are the clinical outcomes at 1 year following transcatheter left atrial appendage occlusion (LAAO) in the United States?

Methods:

The authors examined the National Cardiovascular Data Registry LAAO Registry for patients with atrial fibrillation who underwent Watchman transcatheter LAAO between 2016–2018. The primary endpoint was ischemic stroke and secondary endpoints included ischemic stroke or systemic embolism, mortality, and major bleeding at 1 year.

Results:

The study included 36,681 patients who underwent Watchman LAAO with a mean age of 76.0 ± 8.1 years and a mean CHA2DS2-VASc score of 4.8 ± 1.5. Prior stroke was present in 25.5% of patients, while clinically relevant bleeding had occurred in 69.5% of patients (11.9% with intracranial hemorrhage). Median follow-up was 374 days (interquartile range, 212-425 days). The estimated 1-year rate of ischemic stroke was 1.53% (95% confidence interval [CI], 1.39-1.69%) and the estimated 1-year rate of ischemic stroke or systemic embolism was 2.19% (95% CI, 2.01-2.38%). The estimated 1-year rate of mortality was 8.52% (95% CI, 8.19-8.87%) and major bleeding was 6.93% (6.65%-7.21%). Most episodes of major bleeding occurred in the first 45 days following hospital discharge after LAAO implantation.

Conclusions:

The authors concluded that in a national cohort of patients undergoing Watchman LAAO, the rate of thromboembolic events is rare in the first-year post-procedure, while mortality rates were notably higher.

Perspective:

While several randomized trials have demonstrated efficacy of LAAO using the Watchman device as compared to anticoagulation alone in patients with atrial fibrillation, this is the first large “real-world” study of US patients. Notably, despite the high stroke risk of the population (mean CHA2DS2-VASc score of 4.8), the rate of stroke or systemic embolism was low (2.19%). While the rate of major bleeding was notably higher (6.93%), the majority of these bleeds occurred in the first 45 days after hospital discharge following LAAO implantation, when the majority of patients were taking oral anticoagulation and/or antiplatelet therapy. Future studies are needed to assess the risk of thromboembolism and bleeding in the absence of anticoagulation or multiple antithrombotic agents. Furthermore, the newer-generation Watchman FLX device was not included in this study population, but may impact thromboembolic risk. Nonetheless, this “real-world” analysis of the Watchman LAAO provides reassuring evidence of efficacy and safety, re-affirming LAAO as a viable therapy for stroke prevention in atrial fibrillation for patients who are not good candidates for anticoagulation therapy.

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

Keywords: Anticoagulants, Arrhythmias, Cardiac, Atrial Appendage, Atrial Fibrillation, Brain Ischemia, Coronary Occlusion, Embolism, Fibrinolytic Agents, Geriatrics, Hemorrhage, Intracranial Hemorrhages, Ischemic Stroke, Patient Discharge, Platelet Aggregation Inhibitors, Secondary Prevention, Stroke, Thromboembolism, Vascular Diseases


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