Predisposing factors for development of DAT are multifactorial and include patient characteristics, echocardiographic findings, procedural results, and device-related factors. Therefore, antithrombotic treatment after LAA occlusion is currently recommended. Moreover, in cases of DAT, intensification of antithrombotic therapy was required to resolve the thrombus, which may increase the risk of a bleeding complication. 2 Although most patients diagnosed with DAT are asymptomatic at the time of diagnosis, DAT can be associated with thromboembolic events (mostly neurologic). In a recent review, the rate of device-associated thrombosis (DAT) after LAA occlusion with Watchman was 3.4%. Based on the postimplantation treatment protocols from the PROTECT AF and PREVAIL trials, the vast majority of Watchman implantations described in the literature were accompanied by warfarin anticoagulation for 45 days, followed by dual antiplatelet therapy (DAPT) for 6 months postprocedure and aspirin thereafter. Ideally, antithrombotic therapy should be pursued until complete occluder endothelialization occurs. The implantation of thrombogenic devices in patients with nonvalvular AF who are at high risk of thrombosis in the left atrium requires antithrombotic therapy to prevent on-device thrombus formation ( Figure 1). 2015 16:1198–1206, by permission of Oxford University Press.Īfter LAA closure with the Watchman device, thrombosis may appear on the surface of the device. Cardiac CT angiography for device surveillance after endovascular left atrial appendage closure. Reprinted from Saw J, Fahmy P, DeJong P, et al. Contrast-enhanced CT images revealing an atrialside device thrombus on a Watchman device at the fabric insert (white arrow) and adjacent to the device (black arrow). The Watchman device allows patients to cut down on their risk of strokes without suffering long-term effects of blood thinner use.Figure 1. Patients on blood thinners may have recurrent hospitalizations for significant bleeding or may develop significant anemia due to slow chronic blood loss. Because of the risk for major bleeding, there are many patients who are unable to tolerate standard recommended blood thinners. Although these medications can be very effective in reducing risk of stroke, all these medications carry risks for major bleeding. By thinning a patient’s blood, these medications can significantly reduce a patient’s risk of stroke typically by 65-75%. There are many blood thinning medications currently available, the most common brand being Warfarin. For decades, the main way to reduce risk of stroke in patients with atrial fibrillation was with blood thinning medications. This device ultimately reduces the risk of stroke in patients and can avoid the bleeding risks associated with many blood thinning medications. The Watchman device is an alternative to Warfarin and other blood thinner medications. This is where the main risk of stroke comes from in patients with atrial fibrillation a blood clot typically forms in the left atrial appendage and then can travel in a patient’s bloodstream to the brain and give the patient a stroke. The left atrial appendage is a small pouch in a person’s left atrium, or left upper chamber of the heart. Over 90% of blood clots formed due to atrial fibrillation occur in the left atrial appendage. This can then lead to stagnant blow blood flow, which could then result in a blood clot. In atrial fibrillation, the upper chambers of the heart, also called the atria, are beating so fast that they are quivering, and as a result the blood is not flowing properly. Why is someone with atrial fibrillation more likely to have a stroke? A patient with atrial fibrillation is five times more likely to have a stroke then someone without atrial fibrillation, including an ischemic stroke. Atrial fibrillation is the most common irregular heart rhythm, which can significantly increase a patient’s risk of stroke. There are millions of patients throughout the United States living with non-valvular atrial fibrillation.