Device-Related Thrombus on LAA Occluders

Study Questions:

What are the incidence, predictors, and prognosis of thrombus formation on left atrial appendage (LAA) occlusion devices in patients with atrial fibrillation?


The study authors reported the outcome of 469 patients treated with two LAA closure devices in eight centers in France from February 2012 to January 2017. The Watchman device was deployed in 272 patients and the Amplatzer device was used in 197 patients. Mean follow-up was 13 ± 13 months.


There were 98 major adverse events in 89 patients. These included 26 thrombi on devices, 19 ischemic strokes, 2 transient ischemic attacks, 18 major hemorrhages, and 33 deaths. The incidence of device-related thrombus in patients with LAA imaging was 7.2% per year. Predictors of device thrombosis were age (hazard ratio [HR], 1.07 per 1-year increase; 95% confidence interval [CI], 1.01-1.14; p = 0.02) and history of stroke (HR, 3.68; 95% CI, 1.17-11.62; p = 0.03). Dual antiplatelet therapy (HR, 0.10; 95% CI, 0.01-0.76; p = 0.03) and oral anticoagulation at discharge (HR, 0.26; 95% CI, 0.09-0.77; p = 0.02) were protective with respect to the risk of device thrombosis. Independent predictors of stroke ad TIA on follow-up were thrombus on the device (HR, 4.39; 95% CI, 1.05-18.43; p = 0.04) and history of vascular disease (HR, 5.03; 95% CI, 1.39-18.23; p = 0.01).


Thrombus formation on LAA occlusion devices was relatively frequent and was strongly associated with a higher risk of ischemic stroke on follow-up.


LAA occlusion has emerged as a promising therapy in patients with atrial fibrillation who are unable to tolerate long-term anticoagulation therapy. This study raises concerns that a significant number of these devices act as a nidus for thrombus formation. While both antiplatelet and anticoagulation therapy appeared to be protective, the ideal antithrombotic regimen for these patients remains unknown. This study invokes the need for active surveillance imaging of patients treated with these devices while we await further research to define the ideal follow-up and adjunct therapy for these patients.

Clinical Topics: Anticoagulation Management, Arrhythmias and Clinical EP, Noninvasive Imaging, Prevention, Anticoagulation Management and Atrial Fibrillation, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Echocardiography/Ultrasound

Keywords: Anticoagulants, Arrhythmias, Cardiac, Atrial Fibrillation, Atrial Appendage, Brain Ischemia, Echocardiography, Transesophageal, Embolism, Hemorrhage, Ischemic Attack, Transient, Risk, Secondary Prevention, Stroke, Thrombolytic Therapy, Thrombosis, Vascular Diseases

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