Changes in Left Atrial Appendage Dimensions Following Volume Loading During Percutaneous Left Atrial Appendage Closure

ObjectivesThis study sought to determine whether volume loading alters the left atrial appendage (LAA) dimensions in patients undergoing percutaneous LAA closure.BackgroundPercutaneous LAA closure is increasingly performed in patients with atrial fibrillation and contraindications to anticoagulation, to lower their stroke and systemic embolism risk. The safety and efficacy of LAA closure relies on accurate device sizing, which necessitates accurate measurement of LAA dimensions. LAA size may change with volume status, and because patients are fasting for these procedures, intraprocedural measurements may not be representative of true LAA size.MethodsThirty-one consecutive patients undergoing percutaneous LAA closure who received volume loading during the procedure were included in this study. After an overnight fast and induction of general anesthesia, patients had their LAA dimensions (orifice and depth) measured by transesophageal echocardiography before and after 500 to 1,000 ml of intravenous normal saline, aiming for a left atrial pressure >12 mm Hg.ResultsSuccessful implantation of LAA closure device was achieved in all patients. The average orifice size of the LAA at baseline was 20.5 mm at 90°, and 22.5 mm at 135°. Following volume loading, the average orifice size of the LAA increased to 22.5 mm at 90°, and 23.5 mm at 135°. The average increase in orifice was 1.9 mm (p < 0.0001). The depth of the LAA also increased by an average of 2.5 mm after volume loading (p < 0.0001).ConclusionsIntraprocedural volume loading with saline increased the LAA orifice and depth dimensions during LAA closure. Operators should consider optimizing the left atrial pressure with volume loading before final device sizing.     

Conformal Left Atrial Appendage Seal Device for Left Atrial Appendage Closure: First Clinical Use

ObjectivesThe authors report the first clinical experience with the Conformal Left Atrial Appendage Seal (CLAAS) device.BackgroundThe CLAAS device was designed to address the limitations of first-generation left atrial appendage closure (LAAC) devices by providing an implant that is minimally traumatic, can be deployed in a noncoaxial fashion, and does not require postprocedural oral anticoagulation.MethodsPatients with atrial fibrillation at high stroke risk (CHA₂DS₂-VASc score ≥2) were recruited using standard selection criteria. The LAAC procedure was guided by transesophageal echocardiography with patients under general anesthesia. The CLAAS device is composed of a foam cup, with a Nitinol endoskeleton with an expanded polytetrafluoroethylene cover, delivered with a standard delivery system using a tether for full recapture. All patients received dual-antiplatelet therapy for 6 months, followed by aspirin alone. Transesophageal echocardiographic follow-up was scheduled for 45 days and 1 year.ResultsTwenty-two patients (63.7% with CHA₂DS₂-VASc scores ≥3, 76.2% with HAS-BLED scores ≥3) were enrolled. The device was successfully implanted in 18 patients and unsuccessfully in 4 patients. There were no serious procedural complications. On transesophageal echocardiography performed at 45 days, 1 significant leak (≥5 mm) was seen, which was due to a large posterior lobe not appreciated at the time of implantation, and 1 device-related thrombus was noted, which resolved on oral anticoagulation. There were no periprocedural strokes, major pericardial effusions, or systemic or device embolization.ConclusionsThis first-in-human study demonstrates the clinical feasibility of the CLAAS device for LAAC.     

The NCDR Left Atrial Appendage Occlusion Registry

BackgroundLeft atrial appendage occlusion (LAAO) to prevent stroke in patients with atrial fibrillation has been evaluated in 2 randomized trials; post-approval clinical data are limited.ObjectivesThe purpose of this study was to describe the National Cardiovascular Data Registry (NCDR) LAAO Registry and present patient, hospital, and physician characteristics and in-hospital adverse event rates for Watchman procedures in the United States during its first 3 years.MethodsThe authors describe the LAAO Registry structure and governance, the outcome adjudication processes, and the data quality and collection processes. They characterize the patient population, performing hospitals, and in-hospital adverse event rates.ResultsA total of 38,158 procedures from 495 hospitals performed by 1,318 physicians in the United States were included between January 2016 and December 2018. The mean patient age was 76.1 ± 8.1 years, the mean CHA₂DS₂-VASc (congestive heart failure, hypertension, 65 years of age and older, diabetes mellitus, previous stroke or transient ischemic attack, vascular disease, 65 to 74 years of age, female) score was 4.6 ± 1.5, and the mean HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly) score was 3.0 ± 1.1. The median annual number of LAAO procedures performed for hospitals was 30 (interquartile range: 18 to 44) and for physicians was 12 (interquartile range: 8 to 20). Procedures were canceled or aborted in 7% of cases; among cases in which a device was deployed, 98.1% were implanted with <5-mm leak. Major in-hospital adverse events occurred in 2.16% of patients; the most common complications were pericardial effusion requiring intervention (1.39%) and major bleeding (1.25%), whereas stroke (0.17%) and death (0.19%) were rare.ConclusionsThe LAAO Registry has enrolled >38,000 patients implanted with the device. Patients were generally older with more comorbidities than those enrolled in the pivotal trials; however, major in-hospital adverse event rates were lower than reported in those trials.     

Left Atrial Appendage Closure

Stroke prevention is the primary goal in atrial fibrillation (AF) given its clinical and socioeconomic impact. With AF, the prevalence of thromboembolic stroke continues to rise and there is an urgent need to develop better strategies of stroke prevention. Warfarin, although effective when used appropriately, is burdened by underutilization, narrow therapeutic windows, and life-threatening bleeding complications. Novel pharmacologic agents have been plagued by off-target toxicity and only modest improvement in bleeding complications over warfarin. Because most thromboemboli arise from the left atrial appendage (LAA), surgical exclusion of the LAA is often used in AF patients undergoing cardiac surgery. Percutaneous device LAA closure has now been developed as an adjunct and as an alternative to pharmacotherapy in patients with AF. Promising randomized data are available with the WATCHMAN device, while several other devices are in various stages of clinical and preclinical development.     

Left Atrial Appendage Stenosis

We describe an unusual case with an anatomic narrowing at the opening of the left atrial appendage demonstrated by two-dimensional color Doppler and continuous-wave Doppler transesophageal echocardiography.     

Multiple Thromboembolic Events from a Left Atrial Appendage Occlusion Device

Left atrial appendage occlusion devices are an alternative to oral anticoagulation in patients with nonvalvular atrial fibrillation who are at risk of ischemic stroke. Thromboprophylaxis after implantation is recommended, but the optimal regimen is unknown. We report a clinicopathologic case in which thrombus adherent to an incompletely endothelialized WATCHMAN device (Boston Scientific, Marlborough, MA) resulted in multiple thromboembolic events, contributing to a fatal outcome. This case illustrates uncertainties regarding the device's endothelialization process.     

Left Atrial Appendage Closure Versus Direct Oral Anticoagulants in High-Risk Patients With Atrial Fibrillation

BackgroundPercutaneous left atrial appendage closure (LAAC) is noninferior to vitamin K antagonists (VKAs) for preventing atrial fibrillation (AF)–related stroke. However, direct oral anticoagulants (DOACs) have an improved safety profile over VKAs, and their effect on cardiovascular and neurological outcomes relative to LAAC is unknown.ObjectivesThis study sought to compare DOACs with LAAC in high-risk patients with AF.MethodsLeft Atrial Appendage Closure vs. Novel Anticoagulation Agents in Atrial Fibrillation (PRAGUE-17) was a multicenter, randomized, noninferiority trial comparing LAAC with DOACs. Patients were eligible to be enrolled if they had nonvalvular AF; were indicated for oral anticoagulation (OAC); and had a history of bleeding requiring intervention or hospitalization, a history of a cardioembolic event while taking an OAC, and/or a CHA₂DS₂-VASc of ≥3 and HAS-BLED of >2. Patients were randomized to receive LAAC or DOAC. The primary composite outcome was stroke, transient ischemic attack, systemic embolism, cardiovascular death, major or nonmajor clinically relevant bleeding, or procedure-/device-related complications. The primary analysis was by modified intention to treat.ResultsA high-risk patient cohort (CHA₂DS₂-VASc: 4.7 ± 1.5) was randomized to receive LAAC (n = 201) or DOAC (n = 201). LAAC was successful in 181 of 201 (90.0%) patients. In the DOAC group, apixaban was most frequently used (192 of 201; 95.5%). At a median 19.9 months of follow-up, the annual rates of the primary outcome were 10.99% with LAAC and 13.42% with DOAC (subdistribution hazard ratio [sHR]: 0.84; 95% confidence interval [CI]: 0.53 to 1.31; p = 0.44; p = 0.004 for noninferiority). There were no differences between groups for the components of the composite endpoint: all-stroke/TIA (sHR: 1.00; 95% CI: 0.40 to 2.51), clinically significant bleeding (sHR: 0.81; 95% CI: 0.44 to 1.52), and cardiovascular death (sHR: 0.75; 95% CI: 0.34 to 1.62). Major LAAC-related complications occurred in 9 (4.5%) patients.ConclusionsAmong patients at high risk for stroke and increased risk of bleeding, LAAC was noninferior to DOAC in preventing major AF-related cardiovascular, neurological, and bleeding events. (Left Atrial Appendage Closure vs. Novel Anticoagulation Agents in Atrial Fibrillation [PRAGUE-17]; NCT02426944)     

The Left Atrial Appendage: Anatomy,Function, and Noninvasive Evaluation

The left atrial appendage (LAA) is a finger-like extension originating from the main body of the left atrium. Atrial fibrillation (AF) is the most common clinically important cardiac arrhythmia, occurring in approximately 0.4% to 1% of the general population and increasing with age to >8% in those >80 years of age. In the presence of AF thrombus, formation often occurs within the LAA because of reduced contractility and stasis; thus, attention should be given to the LAA when evaluating and assessing patients with AF to determine the risk for cardioembolic complications. It is clinically important to understand LAA anatomy and function. It is also critical to choose the optimal imaging techniques to identify or exclude LAA thrombi in the setting of AF, before cardioversion, and with current and emerging transcatheter therapies, which include mitral balloon valvuloplasty, pulmonary vein isolation, MitraClip (Abbott Laboratories, Abbott Park, Illinois) valve repair, and the implantation of LAA occlusion and exclusion devices. In this review, we present the current data regarding LAA anatomy, LAA function, and LAA imaging using the currently available noninvasive imaging modalities.     

Inverted Left Atrial Appendage Bonded to Atrial Septum

Inverted left atrial appendage (LAA) is a rare surgical complication. Our patient, a boy aged 2 years, was diagnosed with a partial atrioventricular defect with mild regurgitation of the left atrioventricular valve and a large primum atrial septal defect. Direct postoperative transesophageal echocardiography revealed a new left atrial mass attached to the atrial septum, without left ventricle inflow obstruction. Out of concern about the nature of this mass, we chose surgical direct examination. Intraoperatively, we diagnosed it as an inverted LAA accidentally attached to the atrial septum suture line. Awareness of this condition can avoid unnecessary diagnostic and therapeutic procedures.