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

Early and late hospital readmissions after percutaneous left atrial appendage closure

INTRODUCTION AND OBJECTIVES

Percutaneous left atrial appendage closure (LAAC) has emerged as a nonpharmacological alternative for the prevention of thromboembolic events in patients with nonvalvular atrial fibrillation. However, there are few data on readmissions after LACC. The aim of this study was to determine the rate of early (≤ 30 days) and late (31-365 days) readmission after LAAC, and to assess the predictors and clinical impact of rehospitalization.

METHODS

This multicenter study included 1419 consecutive patients who underwent LAAC. The median follow-up was 33 [17-55] months, and follow-up was complete in all but 54 (3.8%) patients. The primary endpoint was readmissions for any cause. Logistic regression and Cox regression analysis were performed to determine the predictors of readmission and its clinical impact.

RESULTS

A total of 257 (18.1%) patients were readmitted within the first year after LAAC (3.2% early, 14.9% late). The most common causes of readmission were bleeding (24.5%) and heart failure (20.6%). A previous gastrointestinal bleeding event was associated with a higher risk of early readmission (OR, 2.65; 95%CI, 1.23-5.71). The factors associated with a higher risk of late readmission were a lower body mass index (HR, 0.96-95%CI, 0.93-0.99), diabetes (HR, 1.38-95%CI, 1.02-1.86), chronic kidney disease (HR, 1.60; 95%CI, 1.21-2.13), and previous heart failure (HR, 1.69; 95%CI, 1.26-2.27). Both early (HR, 2.12-95%CI, 1.22-3.70) and late (HR, 1.75; 95%CI, 1.41-2.17) readmissions were associated with a higher risk of 2-year mortality.

CONCLUSIONS

Readmissions within the first year after LAAC were common, mainly related to bleeding and heart failure events, and associated with patients' comorbidity burden. Readmission after LAAC confered a higher risk of mortality during the first 2 years after the procedure.

Clinical effectiveness and safety comparison between direct oral anticoagulants and warfarin for nonvalvular atrial fibrillation patients following percutaneous left atrial appendage closure operation intervention: a prospective observational study

The main objective of this study was to investigate the optimal post-left atrial appendage closure (LAAC) anticoagulation strategy, focusing on minimizing device-related thrombosis (DRT) and thromboembolism (TE) events without increasing bleeding risk. After successful LAAC, consecutive participants were treated with 45-day anticoagulants (rivaroxaban 15 mg daily, dabigatran 110 mg twice a day, and warfarin). The efficacy endpoints included DRT, TE, and hospital readmissions due to cardiac caused, while safety endpoints encompassed bleeding events, monitored over a 12-month follow-up period. The incidence of DRT was relatively lower in the rivaroxaban group compared to both the dabigatran and warfarin groups (rivaroxaban vs. dabigatran: HR = 0.504, 95% CI 0.208-1.223, log-rank P = 0.101; rivaroxaban vs. warfarin: HR = 0.468, 95% CI 0.167-1.316, log-rank P = 0.093). The median [interquartile range] length and width of DRT in the rivaroxaban group were 1.92 [1.68-2.15] mm and 1.49 [1.28-1.76] mm, both significantly lower than those in the dabigatran (length = 2.15 [1.99-2.25] mm, P = 0.036; width = 1.60 [1.54-1.85] mm, P = 0.035) and warfarin groups (length = 2.26 [2.11-2.44] mm, P = 0.006; width = 1.74 [1.54-1.85] mm, P = 0.006). Kaplan-Meier survival analysis indicated that procedural bleeding was more common in the warfarin group. The 12-month incidence of TE was significantly lower in the rivaroxaban group compared to the dabigatran (HR = 0.466, 95% CI 0.221-0.984, log-rank P = 0.029) and warfarin groups (HR = 0.456, 95% CI 0.188-0.966, log-rank P = 0.042). Long-term antithrombotic therapy with reduced dose of rivaroxaban significantly reduced the risk of DRT and composite endpoints without increasing bleeding events, compared to warfarin and dabigatran, for patients following LAAC.

Efficacy and Safety of New Oral Anticoagulants versus Warfarin in the Resolution of Atrial Fibrillation with Left Atrial/Left Atrial Appendage Thrombus: A Systematic Review and Meta-Analysis

Background

To compare the efficacy and safety of novel oral anticoagulants (NOACs) and vitamin K antagonists (VKAs) in nonvalvular atrial fibrillation (NVAF) patients with left atrial/left atrial thrombosis through a systematic review and meta-analysis.

Methods

The CBM (China Biology Medicine disc), CNKI (China National Knowledge Infrastructure), VIP (Chinese Technology Periodical Database), Wanfang, PubMed, Embase, Cochrane Library, and Web of Science databases were searched for relevant studies from their inception to June 30, 2022.

Results

Twelve articles (eight cohort studies and four randomized controlled trials) involving 982 patients were included. Meta-analysis showed that NOACs had a significantly higher thrombolysis rate than VKAs (78.0% vs. 63.5%, odds ratio (OR) = 2.32, 95% confidence interval (CI) 1.71 to 3.15, p < 0.0001). Subgroup analysis revealed rivaroxaban to be more effective than VKAs, whereas there was no significant difference between dabigatran and apixaban. There were no significant differences in embolic events, bleeding, or all-cause mortality. Thrombus resolution analysis showed higher left ventricular end-diastolic diameter and smaller left atrial diameter in the effective group than in the ineffective group.

Conclusions

NOACs are more effective in thrombolysis than VKAs in NVAF patients with left atrial thrombosis, and there is no increased risk of adverse events compared with VKAs.

Right juxtaposition of left atrial appendage combined with multiple cardiac malformations: A case report and review of literature

BACKGROUND

Juxtaposition of the atrial appendages is an extremely rare congenital cardiac malformation. It is usually discovered incidentally during autopsy or surgery. This report aims to increase awareness of right juxtaposition of the left atrial appendage.

CASE PRESENTATION

We report a Chinese Han female aged 2 years and 10 months with recurrent lung infections after birth, who was diagnosed with congenital heart disease, corrected transposition of the great arteries, ventricular septal defect, and arterial ductus arteriosus at the local hospital and improved after the pulmonary artery banding procedure. The patient presented to our hospital with intermittent cough. During preoperative evaluation, a review of imaging data revealed a right juxtaposition of the left atrial appendage on enhanced computed tomography.

CONCLUSION

Right juxtaposition of the left atrial appendage is a rare congenital heart anomaly that often occurs in conjunction with complex cardiac malformations. Diagnosis requires a combination of imaging modalities to improve detection rates. Careful identification of cardiac structures during surgery is crucial, as alterations in cardiac anatomy may increase surgical risks. For instance, the opening of juxtaposed atrial appendages could be mistaken for an atrial septal defect.

Left Atrial Appendage Closure with Watchman vs Amulet Devices: Similarities and Differences

PURPOSE OF REVIEW

Left atrial appendage closure (LAAC) has shown to be non-inferior to oral anticoagulation (OAC) for non-valvular atrial fibrillation (AF). LAAC is now becoming a leading method for stroke prophylaxis in patients who have atrial fibrillation and are unable to tolerate OAC. There are currently two FDA-approved endocardial closure devices, namely, the Watchman FLX and Amplatzer Amulet.

RECENT FINDINGS

Current data highlights that both devices offer similar efficacy and safety for LAAC. While the two devices differ in terms of intraprocedural complication rates, they offer similar short- to long-term outcomes in regard to peri-device leaks, device-related thrombosis, and mortality. With similar risk and safety profiles, both devices are indicated for patients who are unable to tolerate OAC. Newer clinical studies are directed to establish the efficacy of both devices as the primary method for stroke prevention in AF as an alternate to OAC.

Long-Term Imaging and Clinical Outcomes of Surgical Left Atrial Appendage Occlusion With AtriClip

Surgical left atrial appendage (LAA) occlusion with an AtriClip (AtriCure, West Chester, Ohio) is frequently performed for stroke prophylaxis in patients with atrial fibrillation (AF). We conducted a retrospective analysis of all patients with long-standing persistent AF who underwent hybrid convergent ablation and LAA clipping. Contrast-enhanced cardiac computed tomography was performed at 3 to 6 months after LAA clipping to assess the degree of complete closure and the residual LAA stump. A total of 78 patients (64 ± 10 years, 72% male) underwent LAA clipping as part of hybrid convergent AF ablation, from 2019 to 2020. Median size of AtriClip used was 45 mm. Mean LA size was 4.6 ± 1 cm. At 3-to-6 months follow-up computed tomography, 46.2% of patients (n = 36) had a residual stump proximal to the deployed LAA clip. Mean depth of residual stump was 3.95 ± 5.5 mm, with 19% of patients (n = 15) having a stump depth of ≥10 mm and 1 patient requiring more endocardial LAA closure owing to large stump depth. During 1-year follow-up, 3 patients developed stroke; device leak of 6 mm was noted in 1 patient; and none of the patients had a thrombus proximal to the clip. In conclusion, high incidence of residual LAA stump was observed with AtriClip. Larger studies with long-term follow-up are needed to better assess the thromboembolic implications of a residual stump after AtriClip placement.

The Comparative Effectiveness and Safety of Different Anticoagulation Strategies for Treatment of Left Atrial Appendage Thrombus in the Setting of Chronic Anticoagulation for Atrial Fibrillation or Flutter

PURPOSE

To compare effectiveness of different treatments for atrial fibrillation (AF) patients who were scheduled for cardioversion (CV) or ablation (CA) presenting with left atrium appendage (LAA) thrombus despite chronic oral anticoagulation therapy (OAC).

METHODS

This was a retrospective cohort study. We analyzed 2014-2019 medical records of patients scheduled for CV or CA of AF who were diagnosed with LAA thrombus despite optimal OAC and had a follow-up transesophageal echocardiogram (TOE). Changes in treatment were divided into the following groups: switch to a drug with different mechanism of action, switch to a drug with similar mechanism of action, initiation of combination therapy, or deliberate no change in treatment. Patients with contraindications to non-vitamin K antagonists were excluded from the analysis.

RESULTS

We analyzed data of 129 patients comprising 181 cycles of treatment. The overall effectiveness of LAA thrombus dissolution was 51.9% regardless of the number of cycles and 42.6% for the first cycle of treatment. Any change of treatment was more effective than deliberate no change-OR 2.97 [95% CI: 1.07-8.25], P = 0.031, but no particular strategy seemed to be more effective than the other. Left atrium area (OR 0.908 [95% CI: 0.842-0.979]) and number of treatment cycles (OR 0.457 [95% CI: 0.239-0.872]) were both adversely related to thrombus resolution. There was one ischemic and three bleeding adverse events during the treatment.

CONCLUSION

LAA thrombus resolution in patients already on OAC may require a change of previous OAC treatment but the overall effectiveness of dissolution seems to be about 50%.

Left Atrial Appendage Depth and Tachycardia Bradycardia Syndrome as Important Predictors of Left Atrial Appendage Thrombus in Patients with Nonvalvular Atrial Fibrillation

Background

Atrial fibrillation (AF) is the most common heart rhythm disorder that has been shown to be associated with a significant increase in stroke and systemic embolism risk. The left atrial appendage (LAA) is a finger-like extension originating from the left atrium; the formation of thrombus in LAA is the main reason of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (NVAF). This study is aimed at finding out the risk of left atrial appendage thrombus (LAAT) in patients with nonvalvular atrial fibrillation (NVAF).

Method

We retrospectively examined the clinic and left atrial computer tomography angiography (CTA) features of patients assessed in Zhengzhou No. 7 People's Hospital between January 2020 and January 2021 derivation. Student's t-test, chi-square test, receiver operating characteristics (ROC) curves, and logistic regression analysis were used to identify predictors of LAAT.

Result

Of 480 patients included in the analysis, LAAT was found in approximately 9.2% of all patients. Univariate demographic predictors of LAAT included left atrium top and bottom diameter (LTD), left atrial appendage depth (LAAD), CHA2DS2-VASc, tachycardia bradycardia syndrome (TBS), and nonparoxysmal atrial fibrillation (PAF). In a multiple logistic regression analysis, the independent predictors of thrombus were LAAD > 23.45 mm (odds ratio: 4.216, 95% CI: 1.869-9.510, P = 0.001), TBS (odds ratio: 4.076, 95% CI: 1.655-10.038, P = 0.002), and non-PAF (odds ratio: 2.896, 95% CI: 1.183-7.094, P = 0.02).

Conclusion

In NVAF patients with LAAT, evidence suggested that larger LAAD, non-PAF, and TBS present a high risk of LAAT. This is the first report demonstrating that the LAAD and TBS are associated with LAAT in patients with NVAF.

Catheter Ablation of Life-Threatening Ventricular Arrhythmias in Athletes

A recent surveillance analysis indicates that cardiac arrest/death occurs in ≈1:50,000 professional or semi-professional athletes, and the most common cause is attributable to life-threatening ventricular arrhythmias (VAs). It is critically important to diagnose any inherited/acquired cardiac disease, including coronary artery disease, since it frequently represents the arrhythmogenic substrate in a substantial part of the athletes presenting with major VAs. New insights indicate that athletes develop a specific electro-anatomical remodeling, with peculiar anatomic distribution and VAs patterns. However, because of the scarcity of clinical data concerning the natural history of VAs in sports performers, there are no dedicated recommendations for VA ablation. The treatment remains at the mercy of several individual factors, including the type of VA, the athlete's age, and the operator's expertise. With the present review, we aimed to illustrate the prevalence, electrocardiographic (ECG) features, and imaging correlations of the most common VAs in athletes, focusing on etiology, outcomes, and sports eligibility after catheter ablation.

Depolarization of the Rat Atria in Experimental Simulation of the Holiday Heart Syndrome

In the study of the sequence of depolarization of the atrial subepicardium of rats in the short-term alcohol consumption model (the "Holiday heart" syndrome), the localization of the sources of atrial arrhythmias was determined for the first time. The difference in the excitation of the right and left atria was discovered: the right atrium is activated anterogradely from the sinoatrial node, whereas the left atrium is activated retrogradely from the ectopic focus located in the left auricular appendage.

Risks and Benefits of Removal of the Left Atrial Appendage

PURPOSE OF REVIEW

In patients with atrial fibrillation who are unable to take novel oral anticoagulants for stroke prophylaxis due to bleeding risk or other contraindications, left atrial appendage (LAA) occlusion and exclusion devices have shown benefit. In this review, we highlight the risks and benefits associated with LAA removal.

RECENT FINDINGS

LAA, once considered a vestigial organ, has been shown to have physiological, anatomical, and arrhythmogenic properties. Device-related complications such as pericardial effusion, device embolization, device-related thrombus, while uncommon, are still present. With increased operator experience related to appendage occlusion, overall procedural complications have declined. Further refinements in device technology will help decrease complications. While benefits of appendage removal are plenty, procedural complications need to be weighed into the equation when making decisions regarding LAA occlusion.