Left Atrial Appendage Closure: Two Steps Forward, One Step Back

Validation study of new left atrial appendage closure device measurement by two-dimensional and three-dimensional transesophageal echocardiography

BACKGROUND

In left atrial appendage closure using WATCHMAN FLX, accurate device measurement by transesophageal echocardiography (TEE) is important. We aimed to experimentally validate appropriate methods of device measurement with two-dimensional (2D) and three-dimensional (3D) TEE compared with actual size.

METHODS

We prepared a full range of device sizes (20, 24, 27, 31, 35 mm), each with five different compression rates. Each device was measured by 2D and 3D TEE at depths of 2, 4, and 6 cm in vitro using inner, outer, and middle line methods. We compared the difference between the actual size by caliper and measurements at each compression rate and depth by the three methods in 2D and 3D TEE.

RESULTS

A total of 450 patterns of measurements were analyzed. The differences using the middle line method were much less than those using the inner and outer line methods in 2D and 3D TEE (2D TEE: 0.45 ± 0.36 vs. 2.55 ± 0.99 vs. 2.59 ± 0.72 mm, p < 0.01; 3D TEE: 0.34 ± 0.27 vs. 2.38 ± 0.69 vs. 1.86 ± 0.77 mm, p < 0.01). Moreover, the differences in measurements by 3D TEE were more accurate than those of 2D TEE in the inner (2.47 ± 1.86 vs. 1.86 ± 0.77 mm, p < 0.01) and middle (0.58 ± 0.37 vs. 0.34 ± 0.27 mm, p < 0.01) line methods.

CONCLUSIONS

Middle line method by 3D TEE is the most reliable approach for device measurement at left atrial appendage closure using WATCHMAN FLX device.

Single antiplatelet therapy after left atrial appendage closure in patients with AF: safety and effectiveness

INTRODUCTION AND OBJECTIVES

The optimal antithrombotic strategy following left atrial appendage closure (LAAC) is poorly defined in patients with nonvalvular atrial fibrillation. We assessed the safety and effectiveness of a single antiplatelet treatment (SAPT) strategy after LAAC in a population at high risk of ischemic and bleeding events.

METHODS

This single-center, observational, prospective study included a consecutive cohort of patients who underwent LAAC using the LAmbre device (Lifetech Scientific, China) and who were discharged with SAPT. The primary outcome was a composite of stroke, systemic embolism, and device-related thrombosis during follow-up. Secondary endpoints were cardiovascular mortality and major bleeding events (BARC ≥3a). Clinical follow-up was performed at 1, 6, and 12 months and subsequently on an annual basis. Transesophageal echocardiography was performed at 1 and 12 months of follow-up.

RESULTS

The study comprised 74 patients. The median age was 77 [72-83] years and 43% were women. The cohort exhibited a high prevalence of comorbidities and cardiovascular risk factors. The median CHA2DS2-VASc and HAS-BLED scores were 4 [3-6] and 4 [4-5], respectively. The median length of follow-up was 2.5 years (188 patients-year). During follow-up, device-related thrombosis occurred in 3 patients (4%). Ischemic stroke occurred in 1 patient (1.3%, rate 0.5%/y), representing a 90.9% relative risk reduction compared with the risk predicted by CHA2DS2-VASc. Major bleeding events occurred in 12 patients (16%, 6.4%/y), with a relative risk reduction of 26.4% of that predicted by HAS-BLED. Cardiovascular-related mortality was observed in 2 patients (2.7%).

CONCLUSIONS

SAPT appears to be a safe and effective treatment following LAAC in patients at high ischemic and hemorrhagic risk. Further studies are needed to confirm our findings.

Atrial fibrillation: Primary prevention, secondary prevention, and prevention of thromboembolic complications: Part 2

Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, once thought to be benign as long as the ventricular rate was controlled, is associated with significant cardiac morbidity and mortality. Increasing life expectancy driven by improved health care and decreased fertility rates has, in most of the world, resulted in the population aged ≥65 years growing more rapidly than the overall population. As the population ages, projections suggest that the burden of AF may increase more than 60% by 2050. Although considerable progress has been made in the treatment and management of AF, primary prevention, secondary prevention, and prevention of thromboembolic complications remain a work in progress. This narrative review was facilitated by a search of MEDLINE to identify peer-reviewed clinical trials, randomized controlled trials, meta-analyses, and other clinically relevant studies. The search was limited to English-language reports published between 1950 and 2021. Atrial fibrillation was searched using the terms primary prevention, hyperthyroidism, Wolff-Parkinson-White syndrome, catheter ablation, surgical ablation, hybrid ablation, stroke prevention, anticoagulation, left atrial occlusion and atrial excision. Google and Google scholar as well as bibliographies of identified articles were reviewed for additional references. In these two manuscripts, we discuss the current strategies available to prevent AF, then compare non-invasive and invasive treatment strategies to diminish AF recurrence. In addition, we examine the pharmacological, percutaneous device and surgical approaches to prevent stroke as well as other types of thromboembolic events.

Impact and predictors of device-related thrombus after percutaneous left atrial appendage closure

Device-related thrombus (DRT) is a known complication occurring in up to 7% of patients undergoing percutaneous left atrial appendage closure (LAAC). Since the target population of LAAC is generally ineligible for oral anticoagulant therapies, DRT raises important concerns. The aim of this review will be to summarize available evidence on DRT after LAAC focusing on its possible impact on outcomes. Recent findings showed a tighter association between DRT and neurological ischemic events. Antithrombotic regimen adopted after LAAC may have a protective effect against DRT. Many patient-related and procedural factors have been identified as possible predictors of DRT. A tailored approach, which takes into account DRT, is needed in the patient selection for LAAC and in the postprocedural follow-up.

Massive Device-Related Thrombus After LAA Occlusion: Intraoperative Insights Into Mechanism

In patients with a contraindication to oral anticoagulation, the left atrial appendage occlusion devices are an approved alternative. Device-related thrombus is a recognized complication, but underlying mechanisms are incompletely understood. In this case series, the authors describe potentially the same mechanism of thrombosis with intraoperative images of incomplete endothelialization. (Level of Difficulty: Intermediate.).

Embolic Cerebrovascular Accident Secondary to Device-Related Thrombus Post WATCHMAN Device Implantation

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias encountered. Aggressive and appropriate management, along with identification and modification of risk factors, remains at the forefront of evidence-based practice. Thrombus formation (primarily in the left atrial appendage) and consequent thromboembolism are risks associated with AF. Anticoagulation is utilized to prevent and reduce AF-induced complications such as stroke, heart failure, and death. However, in instances when the risk of bleeding from anticoagulation outweighs the benefits of stroke prevention, other modalities such as left atrial appendage closure (LAAC) devices like the WATCHMAN device (Boston Scientific, MA) are utilized. LAAC devices, such as the WATCHMAN device, are also not without significant risks, one of them being device-related thrombus (DRT) formation. We present a case of device-related thrombus formation post WATCHMAN implantation and a subsequent embolic cerebrovascular accident (CVA).

Lessons learned from experimental models of cerebrovascular aneurysms to improve endocardial device occlusion of the left atrial appendage

In patients with atrial fibrillation, left atrial appendage (LAA) occlusion devices represent an alternative to anticoagulation but are associated with residual peridevice leaks (PDLs) and device-related thrombi (DRT). Similarly, cerebrovascular aneurysms can be treated with coil embolization, but pericoil leaks represent a significant limitation. In experimental models of cerebrovascular aneurysms, endothelial denudation achieved independently with (1) embolization with radioactive coils, (2) mechanical removal of the endothelium, or (3) radiofrequency ablation was dramatically effective in preventing or eliminating pericoil leaks.

Anatomical, physiological, and blood flow similarities exist between the LAA and saccular aneurysms. Concepts developed in treating aneurysm leaks can be used to treat similar problems in the LAA. Learning from aneurysms, we conceived of a novel technique to denude local endothelium and thus eliminate residual leaks around LAA-occlusion devices. We recently successfully tested this hypothesis in patients with a PDL in a prospective manner in a multicenter study. In this article, we expand on the rationale of the technique developed to close PDLs and potentially also prevent DRTs.

MAUDE Database Analysis of Post-Approval Outcomes following Left Atrial Appendage Closure with the Watchman Device

Left atrial appendage closure (LAAC) is an important strategy to reduce stroke risk in patients with non-valvular atrial fibrillation (AF) who are at high risk of bleeding on long-term anticoagulation. Real-world assessments of the safety of the Watchman LAAC device remain limited. The objective of this study was to determine the frequency and timing of adverse events associated with Watchman LAAC device implants performed after FDA approval. Adverse events associated with Watchman LAAC implants performed between March 2015 and March 2019 were identified through a search of the FDA Manufacturer and User Facility Device Experience (MAUDE) database. During the study period, 3,652 unique adverse events were identified. An estimated 43,802 Watchman implants were performed in the United States during the study period. The overall adverse event rate was 7.3% and the mortality rate was 0.4%. Of the 159 unique types of adverse events identified, pericardial effusion was most common (1.4%). Most adverse events (73%) occurred intraoperatively (59%) or within 1 day of the procedure (15%). However, 19% of deaths, 24% of strokes and 27% of device embolizations occurred >1 month after implantation. The rates of most Watchman-related adverse events reported in the MAUDE database were comparable to those observed in clinical trials. A majority of adverse events occurred within 1 day of implant. In conclusion, while the absolute event rates were low, a significant proportion of device embolizations, strokes, and deaths occurred >1 month after Watchman implant.

[Second look: practical diagnostic and therapeutic checks in neurorehabilitation]

Post-acute inpatient neurorehabilitation facilities are increasingly treating patients who are not only severely ill and multimorbid but who are also referred from non-neurological departments. These patients are still often medically unstable so that the previous diagnostics and treatment must be reevaluated and when necessary adapted or supplemented. Certain interdisciplinary diagnostic and therapeutic problems, such as antithrombotic therapy, regularly reoccur. This article presents these problems in a checklist fashion, which should provide indications in individual cases when previously carried out measures need to be questioned and adapted.

The Year in Electrophysiology: Selected Highlights From 2018

This article is the first in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan, the associate editor-in-chief, Dr. Augoustides, and the editorial board for the opportunity to start this series, namely the research highlights of the year that pertain to electrophysiology in relation to cardiothoracic and vascular anesthesia. This first article focuses on esophageal thermal injury during radiofrequency ablation, perioperative management of patients presenting for ablation procedures, left atrial appendage occlusion devices, and, finally, heart failure diagnostic devices.