Project description:AimsCardiac computed tomography (CT) is increasingly utilized during follow-up after left atrial appendage closure (LAAC). Hypoattenuated thickening (HAT) is a common finding and might represent either benign device healing or device-related thrombosis (DRT). The appearance and characteristics of HAT associated with the Watchman FLX have not been previously described. Therefore, we sought to investigate cardiac CT findings during follow-up after Watchman FLX implantation with a focus on HAT and DRT.Methods and resultsRetrospective single-centre, observational study including all patients with successful Watchman FLX implantation and follow-up cardiac CT between March 2019 and September 2021 (n = 244). Blinded analysis of CT images was performed describing the localization, extent, and morphology of HAT and correlated to imaging and histology findings in a canine model. Relevant clinical and preclinical ethical approvals were obtained.Overall, HAT was present in 156 cases (64%) and could be classified as either subfabric hypoattenuation (n = 59), flat sessile HAT (n = 78), protruding sessile HAT (n = 16), or pedunculated HAT (n = 3). All cases of pedunculated HAT and five cases of protruding sessile HAT were considered as high-grade HAT (n = 7). Subfabric hypoattenuation and flat sessile HAT correlated with device healing and endothelialization in histological analysis of explanted devices.ConclusionSubfabric hypoattenuation and flat sessile HAT are frequent CT findings for Watchman FLX, likely representing benign device healing and endothelialization. Pedunculated HAT and protruding HAT are infrequent CT findings that might represent DRT.
Project description:RationaleAmong atrial fibrillation patients with high risk of bleeding, left atrial appendage occlusion has emerged as an alternative to long-term oral anticoagulation therapy for stroke prevention. Device-related thrombus remains a major concern because it may result in recurrent embolic events. To date, there is no consensus on the optimal method of treating device-related-thrombus.Patient concernsA 78-year-old man with atrial fibrillation had an episode of intracranial hemorrhage while taking warfarin. He subsequently underwent percutaneous placement of a 30-mm Watchman device to the left atrial appendage. He was prescribed dual anti-platelet therapy with aspirin and clopidogrel.DiagnosisReassessment echocardiography 3 months later found device-related thrombus.InterventionsThe antithrombotic regimen was switched from dual antiplatelet therapy to apixaban.OutcomesReassessment echocardiography 3 months later revealed complete resolution of the device-related thrombus. Apixaban was stopped. He had dual antiplatelet therapy for 6 more months followed by life-long aspirin. There was no bleeding complication since implantation of Watchman device.LessonsWe demonstrated successful treatment of device-related thrombus with a short course of apixaban with complete resolution of thrombus. Further randomized controlled trials are required to determine the choice and duration of drug therapy for device-related thrombus.
Project description:BackgroundLeft atrial appendage occlusion devices are commonly used to prevent stroke in patients with persistent atrial fibrillation who are unable to tolerate anticoagulation. However, certain patient- and device-related characteristics increase the risk for the development of a device-related thrombus (DRT). The presence of a DRT increases the risk of stroke and should be treated. Management of DRT lacks consensus but is mostly focused on anticoagulation. In patients with large thrombi that need to be managed urgently, percutaneous extraction may be a viable option.Case summaryIn this report, we describe the successful management of a DRT via percutaneous thrombus extraction technology in an 81-year-old woman with a large thrombus attached to a WATCHMAN™ device. The patient initially presented with shortness of breath, and on imaging a pedunculated thrombus was detected. The thrombus was extracted using a Penumbra Lightning 12™ (Penumbra Inc., Alameda, CA, USA) catheter with a Sentinel™ (Boston Scientific, Marlborough, MA, USA) cerebral embolic protection device. The patient had no neurologic sequelae and was started on anticoagulation.DiscussionPercutaneous thrombectomy can be safely performed to extract large left atrial occlusion DRT that require urgent management, without any neurologic sequelae. We believe this can be used in patients with a large DRT who would not be adequately managed with anticoagulation and in whom surgery is not feasible.
Project description:BackgroundLong-term outcomes following left atrial appendage occlusion outside clinical trials and small registries are largely unknown. Collecting these data was a condition of US market authorization of the WATCHMAN device. The aim of this analysis was to evaluate the rates of stroke, bleeding, and death among Medicare beneficiaries following left atrial appendage occlusion implantation during initial commercial availability of the WATCHMAN left atrial appendage occlusion device overall and in important subgroups.MethodsAll Medicare fee-for-service beneficiaries ≥65 years of age who underwent left atrial appendage occlusion from April 1, 2016, to August 31, 2020, were included based on the International Classification of Diseases, Tenth Revision, and Current Procedural Terminology codes. Over a 5-year follow-up period, the cumulative incidence over time of mortality, ischemic stroke, and major bleeding were calculated using the International Classification of Diseases, Tenth Revision, diagnosis codes for the full study cohort and within important prespecified subgroups.ResultsWATCHMAN recipients (n=48 763) were a median of 77 (interquartile range, 72-82) years of age, 42% female, and mostly White (93%). The median CHA2DS2VASc score was 4 (interquartile range, 3-5) with prior major bleeding in 42% and prior stroke in 12%. At 5 years, death occurred in 44%, bleeding in 15% (with higher risk early following implantation), and ischemic stroke in 7%. Each of these end points was more common with greater baseline age. Male patients had greater 5-year mortality than female patients (46.9% versus 40.6%), but there was no difference between sexes in the rates of ischemic stroke (6.6% versus 7.5%) or major bleeding (14.9% for both). WATCHMAN recipients with prior ischemic stroke or a major bleeding event were older and frailer; these groups had higher rates of ischemic stroke, major bleeding, and death.ConclusionsCompared with patients enrolled in the pivotal clinical trials, Medicare beneficiaries undergoing WATCHMAN implantation were older, more female, and had more comorbid conditions. Substantial long-term mortality and major bleeding following WATCHMAN reflect the high-risk nature of the patient population, while the ischemic stroke rate was relatively low (<1.5% per year).
Project description:An 82-year-old man who had undergone Watchman FLX (Boston Scientific) device implantation presented with dyspnea. Multimodality evaluation demonstrated a small fistula from the proximal circumflex artery to the left atrial appendage. Anatomically, the left circumflex artery is close to the atrial appendage; therefore, it is plausible that fistula formation could be a late complication of implantation of the device.
Project description:We report an unusual case of incomplete endothelialization of the Watchman device >3 years after its implantation. Animal data suggest that device endothelialization occurs ∼45 days post-implantation; however, data on humans are lacking. Guidelines on anticoagulation are based on expectation from animal studies. (Level of Difficulty: Advanced.).
Project description:BackgroundCardiac computed tomography imaging with contrast is being used increasingly to image left atrial appendage occlusion (LAAO) devices. Contrast flow across a device, also known as a transfabric leak (TFL), may indicate a lack of complete LAAO-device endothelialization. The data on the rate, predictors, and clinical events associated with TFL are limited.MethodsAll patients who underwent an LAAO-device implantation with a WATCHMAN FLX device and received a postimplantation computed tomography scan were included in this single-centre retrospective cohort study. Patients were classified as either having or not having a TFL, according to 3 currently proposed definitions of TFL. Clinical and procedural differences between the 2 groups were determined. An exploratory univariate logistic regression model to evaluate predictors of TFL was constructed.ResultsA total of 56 individuals were included in the cohort. The rate of TFL varied from 27% to 52%, depending on the radiographic definition employed. No clinically important patient or procedural characteristics were noted between the groups with vs without TFL. No predictors of TFL were identified. Six deaths and one stroke occurred during a median follow-up period of 673 days.ConclusionsTFLs occur commonly post-LAAO procedures, suggesting that complete endothelialization of LAAO devices in humans may not be similar to that reported in animal models. Additional study into the best imaging approach to identify TFLs, and clinical events associated with TFLs, is necessary to clarify the significance of TFLs.
Project description:BackgroundIn the recent ESC/EACTS guidelines, left atrial appendage (LAA) occlusion or exclusion in patients undergoing (thoracoscopic) atrial fibrillation (AF) ablation surgery is recommended. The Watchman device (WD, Boston Scientific, Minnesota) has proved to reduce the risk of thromboembolic events by closing of the LAA, yet no data exist on WD implantation during surgical AF ablation. The objective is to determine if WD implantation is safe and feasible in a hybrid AF ablation setting (i.e., combination of thoracoscopic epicardial surgical and endocardial catheter ablation) and could become subject of further testing to serve as a bail-out in cases in which surgical LAA occlusion methods cannot be applied, due to, for example, severe adhesions.MethodsIn this prospective, single center, pilot study, 10 consecutive patients undergoing a hybrid ablation qualifying for LAA exclusion (CHA2DS2-VASc ≥ 1) were included. At the end of the hybrid ablation, the LAA was occluded endocardially using the WD. The feasibility endpoint was successful implantation. The safety endpoint concerned major complications.ResultsOne patient was excluded and replaced because the LAA was insufficiently visible on transesophageal echocardiography. In 10/11 patients, device delivery was successful (mean time: 35 minutes). No major complications occurred. Transesophageal echocardiography after 6 weeks and 6 months showed successful occlusion of the LAA without significant peridevice flow.ConclusionImplantation of the WD seems to be feasible and safe in the setting of hybrid AF ablation and could be an alternative to epicardial occlusion in surgical AF ablation procedures. Larger studies are required to confirm these findings. This trial is registered with NCT02471131.