Left Atrial Appendage Remodeling After Lariat Left Atrial Appendage Ligation

Risk factors, clinical implications, and management of peridevice leak following left atrial appendage closure: A systematic review

BACKGROUND

Left atrial appendage closure (LAAC) is a treatment modality for stroke prevention in patients with atrial fibrillation (AF). One of the potential complications of LAAC is a peri-device leak (PDL), which could potentially increase the risk of thromboembolism formation.

METHODS

This systematic review was done according to PRISMA guidelines. Using four databases, all primary studies through April 2022 that met selection criteria were included. Outcomes of interest were studies reporting on PDL characteristics, risk factors and management.

RESULTS

A total of 116 studies met selection criteria (97 original studies and 19 case reports/series). In the original studies (n = 30,133 patients), the weighted mean age was 72.0 ± 7.4 years (57% females) with a HAS-BLED and CHA2DS2-VASc weighted means of 2.8 ± 1.1 and 3.8 ± 1.3, respectively. The most common definition of PDL was based on size; 5 mm: major, 3-5 mm: moderate, < 1 mm minor, or trivial. Follow up time for PDL detection was 7.15 ± 9.0 months. 33% had PDL, irrespective of PDL severity/size, and only 0.9% had PDL of greater than 5 mm. The main risk factors for PDL development included lower degree of over-sizing, lower left ventricular ejection fraction, device/LAA shape mismatch, previous radiofrequency ablation, and male sex. The most common methods to screen for PDL included transesophageal echocardiogram and cardiac CT. PDL Management approaches include Amplatzer Patent Foramen Ovale occluder, Hookless ACP, Amplatzer vascular plug II, embolic coils, and detachable vascular coils; removal or replacement of the device; and left atriotomy.

CONCLUSION

Following LAAC, the emergence of a PDL is a significant complication to be aware of. Current evidence suggests possible risk factors that are worth assessing in-depth. Additional research is required to assess suitable candidates, timing, and strategies to managing patients with PDL.

Computed Tomography Scan Evidence for Left Atrial Appendage Short-Term Remodeling Following Percutaneous Occlusion: Impact of Device Oversizing

Background The interrelationships between left atrial appendage (LAA) dimensions and device following implantation are unknown. We aimed to analyze the impact of Watchman device implantation on LAA dimensions following its percutaneous closure and potential predictors of remodeling. Methods and Results All consecutive LAA closure procedures performed at 2 centers between November 2017 and December 2020 were included in the WATCH-DUAL (Watchman 2.5 Versus Watchman FLX in a Dual-Center Left Atrial Appendage Closure Cohort) registry. This study included patients who had pre- and postintervention computed tomography scan analysis. The LAA and device dimensions were measured in a centralized core lab by 3-dimensional computed tomography scan reconstruction methods, focusing on the device landing zone. This analysis included 104 patients (age, 76.0 [range, 72.0-83.0] years; 72% men; 53% Watchman FLX; 47% Watchman 2.5). The baseline characteristics were comparable between Watchman 2.5 and Watchman FLX groups, except for the higher use of oversizing in the latter group. The median delay for computed tomography control was 49 (range, 43-64) days. The landing zone area (median, 446 [range, 363-523] versus 290 [222-366] mm2; P<0.001) and minimal diameter (median, 23.0 [range, 20.7-24.8] versus 16.7 [14.7-19.4] mm; P<0.001) significantly increased after implantation. The absolute (median, 157 [range, 98-220] versus 85 [18-148] mm2, P<0.001) and relative (median, 50% [range, 32%-79%] versus 26% [4%-50%]; P<0.001) increases in landing zone area were more pronounced in patients with oversized device. Baseline LAA dimensions were smaller, landing zone eccentricity larger, and oversized device more frequent in patients with significant overexpansion compared with the others. Conclusions LAA dimensions increased at the site of the Watchman prosthesis after implantation, suggesting a local positive remodeling after the procedure. This phenomenon was more pronounced in the case of oversized devices.

Percutaneous Treatment Approaches in Atrial Fibrillation: Current Landscape and Future Perspectives

Atrial fibrillation (AF), the most common sustained arrhythmia in clinical practice, represents a major cause of morbidity and mortality, with an increasing prevalence. Pharmacologic treatment remains the cornerstone of its management through rhythm and rate control, as well as the prevention of thromboembolism with the use of oral anticoagulants. Recent progress in percutaneous interventional approaches have provided additional options in the therapeutic arsenal, however. The use of the different catheter ablation techniques can now lead to long arrhythmia-free intervals and significantly lower AF burden, thus reducing the rate of its complications. Particularly encouraging evidence is now available for patients with persistent AF or concomitant heart failure, situations in which catheter ablation could even be a first-line option. In the field of stroke prevention, targeting the left atrial appendage with percutaneous device implantation may reduce the risk of thromboembolism to lower rates than that predicted with conventional ischemic risk scores. Left atrial appendage occlusion through the approved Watchman or Amplatzer devices is a well-established, efficacious, and safe method, especially in high-ischemic and bleeding risk patients with contraindications for oral anticoagulation.

Role of the Left Atrial Appendage in Systemic Homeostasis, Arrhythmogenesis, and Beyond

The left atrial appendage (LAA) affects body homeostasis via atrial natriuretic peptide and the renin-angiotensin-aldosterone system and plays an important role in atrial compliance. Approximately 90% of clots in nonvalvular atrial fibrillation (AF) are formed in the LAA. AF is the most common sustained cardiac arrhythmia and is frequently associated with stroke. Because anticoagulation for stroke prophylaxis carries a higher bleeding risk, LAA closure via epicardial and endocardial approaches has gained popularity and is being increasingly pursued for arrhythmogenic, homeostatic, and stroke-reduction benefits. This review discusses the homeostatic role of the LAA and its involvement in arrhythmogenesis and thrombus formation.

Why Follow-up Examinations After Left Atrial Appendage Closure Are Important: Detection of Complications During Follow-up and How to Deal with Them

PURPOSE OF REVIEW

Device-related thrombus (DRT) formation and incomplete left atrial appendage closure (LAAC) are the two major complications that can occur after LAAC and can potentially limit the success of such a procedure. This review discusses the incidence, clinical and/or prognostic significance, detection methods, treatment options, and potential strategies to prevent these complications.

RECENT FINDINGS

It has recently been proven that the presence of a DRT represents an independent predictor for ischemic stroke after LAAC. Continued need for anticoagulation due to incomplete LAAC is clinically relevant to the patient. The appearances of a DRT or an incompletely closed LAA after a LAAC procedure are not rare complications. Due to the clinical and/or prognostic significance of these complications, it is important to detect them in a timely manner during follow-up by using the appropriate diagnostic imaging techniques. Since a DRT is associated with an increased risk of stroke, the therapy should be aggressive. In the case of incomplete LAA closure, an additional closure device may be used to complete occlusion and avoid lifelong anticoagulation therapy.

Epicardial versus Endocardial Closure: Is One Better than the Other?

Left atrial appendage occlusion is an evolving technology with demonstrable benefits of stroke prophylaxis in patients with atrial fibrillation unsuitable for anticoagulation. This has resulted in the development of a plethora of transcatheter devices to achieve epicardial exclusion and endocardial occlusion. In this review, the authors summarize the differences in technique, target patient population, outcomes, and complication profiles of endocardial and epicardial techniques.

Correlation between LAA Morphological Features and Computational Fluid Dynamics Analysis for Non-Valvular Atrial Fibrillation Patients

The left atrial appendage (LAA) is a complex cardiovascular structure which can yield to thrombi formation in patients with non-valvular atrial fibrillation (AF). The study of LAA fluid dynamics together with morphological features should be investigated in order to evaluate the possible connection of geometrical and hemodynamics indices with the stroke risk. To reach this goal, we conducted a morphological analysis of four different LAA shapes considering their variation during the cardiac cycle and computational fluid dynamics (CFD) simulations in AF conditions were carried out. The analysis of main geometrical LAA parameters showed a huger ostium and a reduced motility for the cauliflower and cactus shapes, as well as a lower velocity values from the CFD analysis. Such findings are in line with literature and highlight the importance of coupling dynamics imaging data with CFD calculations for providing information not available at clinical level.

Anatomy and Physiologic Roles of the Left Atrial Appendage: Implications for Endocardial and Epicardial Device Closure

The left atrial appendage has been implicated as a major nidus for thrombus formation, particularly in atrial fibrillation. This discovery has prompted substantial interest in the development of left atrial appendage exclusion devices aimed at decreasing systemic thromboembolism risk. Its deceptively simple appearance belies the remarkable complexity that characterizes its anatomy and physiology. We highlight the key anatomic features and variations of the left atrial appendage as well as its relationships with surrounding structures. We also summarize crucial anatomic factors that should be taken into account by the interventional cardiologist when planning for or performing left atrial appendage exclusion procedures.

Incomplete Closure of the Left Atrial Appendage: Implication and Management

Incomplete left atrial appendage closure (LAAC) occurs in ∼30-40 % of cases following both surgical and percutaneous closure methods. Incomplete surgical LAAC may further be classified as incompletely surgically ligated LAA (ISLL) or LAA stump. ISLL is associated with a significantly increased risk of thrombus formation/thromboembolism. Moreover, this risk is highest in the absence of oral anticoagulation (OAC) and inversely correlates with the size of the ISLL neck. Not only routine screening for ISLL seems critical, but also long-term OAC should strongly be considered in this high-risk cohort. Alternatively, complete endocardial occlusion using a surrogate method may represent a reasonable option, particularly in those intolerant to long-term OAC therapy. Although thrombus formation/thromboembolic events have also been described in patients with incomplete LAAC following percutaneous occlusion, an association between the two remains less clear. However, given the rise and growing interest in percutaneous LAAC methods, additional research in this area is clearly warranted.