Atrial fibrillation is characterized by irregularly irregular heart rhythm with an increased morbidity and mortality. It is associated with an increased risk of thromboembolism due to formation of ...blood clot in the left atrium. Most of these blood clots are formed in the left atrial appendage. The risk of blood clot formation is reduced with the use of anticoagulants. The patients who cannot take anticoagulants due to an increased bleeding risk can undergo percutaneous left atrial appendage (LAA) closure. A Watchman device is used for this purpose. LAA closure with the Watchman device is associated with some adverse effects, and one of them is device-related thrombus. Currently, there are no specific guidelines for the management of device-related thrombus. We present a case of Watchman device-related thrombus which developed 16 hours after the device placement. We will also discuss various options for the management of acute thrombosis.
BACKGROUND:In patients with atrial fibrillation, left atrial appendage closure with the Watchman device prevents thromboembolism from the left atrial appendage; however, thrombus may form on the left ...atrial face of the device, and then potentially embolize. Herein, we studied the incidence, predictors, and clinical outcome of device-related thrombus (DRT) using a large series of clinical trial cohorts of patients undergoing Watchman implantation.
METHODS:We studied the device arms of 4 prospective Food and Drug Administration trialsPROTECT-AF (Watchman Left Atrial Appendage System for Embolic Protection in Patients With Atrial Fibrillation) (n=463); PREVAIL (Evaluation of the Watchman LAA Closure Device in Patients With Atrial Fibrillation Versus Long Term Warfarin Therapy) (n=269); CAP (Continued Access to PROTECT AF registry) (n=566); and CAP2 (Continued Access to PREVAIL registry) (n=578). Surveillance transesophageal echocardiographs were performed at 45 days and 12 months in all patients, and also at 6 months in the randomized control trials. We assessed both the incidence of DRT during these transesophageal echocardiographs (and other unscheduled transesophageal echocardiographs), and clinical outcomes of postprocedure stroke or systemic embolism (SSE) and adjusted for CHA2DS2-VASC and HAS-BLED scores.
RESULTS:Of 1739 patients who received an implant (7159 patient-years follow-up; CHA2DS2-VASc=4.0), DRT was seen in 65 patients (3.74%). The rates of SSE with and without DRT were 7.46 and 1.78 per 100 patient-years (adjusted rate ratio, 3.55; 95% confidence interval CI, 2.18–5.79; P<0.001), and ischemic SSE rates were 6.28 and 1.65 per 100 patient-years (adjusted rate ratio, 3.22; 95% CI, 1.90–5.45, P<0.001). On multivariable modeling analysis, the predictors of DRT were as followshistory of transient ischemic attack or stroke (odds ratio OR, 2.31; 95% CI, 1.26–4.25; P=0.007), permanent atrial fibrillation (OR, 2.24; 95% CI, 1.19–4.20; P=0.012); vascular disease (OR, 2.06; 95% CI, 1.08–3.91; P=0.028); left atrial appendage diameter (OR, 1.06 per mm increase; 95% CI, 1.01–1.12; P=0.019); left ventricular ejection fraction (OR, 0.96 per 1% increase; 95% CI, 0.94–0.99; P=0.009). DRT and SSE both occurred in 17 of 65 patients (26.2%). Of the 19 SSE events in these patients with DRT, 9 of 19 (47.4%) and 12 of 19 (63.2%) occurred within 1 and 6 months of DRT detection. Conversely, after left atrial appendage closure, most SSEs (123/142, 86.62%) occurred in patients without DRT.
CONCLUSIONS:After left atrial appendage closure with Watchman, DRT (≈3.7%) is not frequent but, when present, is associated with a higher rate of stroke and systemic embolism.
The Amulet (Abbott) left atrial appendage occluder investigational device exemption trial is the largest randomized trial evaluating the safety and effectiveness of the Amulet left atrial appendage ...occluder compared with the Watchman 2.5 device (Boston Scientific) through 5 years.
This analysis evaluated the device effect on 3-year outcomes in the Amulet investigational device exemption trial.
The medication regimen and key clinical outcomes were reported through 3 years including: 1) the composite of ischemic stroke or systemic embolism (SE); 2) the composite of all strokes, SE, or cardiovascular (CV) death; 3) major bleeding; and 4) all-cause death and CV death.
A total of 1,878 patients at 108 sites were randomized. A significantly higher percentage of patients were free of oral anticoagulation usage at 3 years with Amulet (96.2%) vs Watchman (92.5%) (P < 0.01). Clinical outcomes were comparable for the composite of ischemic stroke or SE (5.0% vs 4.6%; P = 0.69); the composite of all strokes, SE, or CV death (11.1% vs 12.7%; P = 0.31); major bleeding (16.1% vs 14.7%; P = 0.46); all-cause death (14.6% vs 17.9%; P = 0.08); and CV death (6.6% vs 8.5%; P = 0.14) for Amulet and Watchman, respectively. Through 3 years, device factors (device-related thrombus or peridevice leak ≥3 mm) preceded ischemic stroke events and CV deaths more frequently in Watchman compared with Amulet patients.
The Amulet occluder demonstrated continued safety and effectiveness with over 96% free of oral anticoagulation usage through 3 years in a high-risk population compared to the Watchman device. (AMPLATZER Amulet LAA Occluder Trial Amulet IDE; NCT02879448).
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