Improvement in Left Atrial Strain among Patients Undergoing Percutaneous Left Atrial Appendage Closure

Nonthrombogenic Roles of the Left Atrial Appendage: JACC Review Topic of the Week

The atrial appendage (LAA) is a well-established source of cardioembolism in patients with atrial fibrillation. Therefore, research involving the LAA has largely focused on its thrombogenic attribute and the utility of its exclusion in stroke prevention. However, recent studies have highlighted several novel functions of the LAA that may have important therapeutic implications. In this paper, we provide a concise overview of the LAA anatomy and summarize the emerging data on its nonthrombogenic roles.

Left atrial function after standalone totally thoracoscopic left atrial appendage exclusion in atrial fibrillation patients with absolute contraindication to oral anticoagulation therapy

Background

Left atrial appendage (LAA) is a common source of thrombi in patients with atrial fibrillation (AF). The effect on left atrial (LA) function of the Totally Thoracoscopic (TT)-LAA exclusion with epicardial clip is currently unknown. This study aims at evaluating the effect of TT-LAA exclusion on LA function.

Methods

Standalone TT-LAA exclusion with the clip device was performed in 26 patients with AF and contraindication to oral anticoagulation (OAC). A 3D CT scan, trans-esophageal echocardiography, spirometry and cerebrovascular doppler ultrasound were performed preoperatively. Clip positioning and LAA exclusion were guided and confirmed by intraoperative trans-esophageal echo. To evaluate LA function, standard transthoracic echocardiography and 2D strain of LA were performed before surgery, at discharge and at 3-month follow-up.

Results

The mean CHA2DS2-VASc and HASBLED scores were 4.6 and 2.4 respectively. There were no major complications during the procedure. At median follow-up of 10.3 months, 1 (3.8%) non-cardiovascular death, 1 (3.8%) stroke and 4 (15.4%) cardiovascular hospitalizations occurred. At 2D strain of LA, the reservoir function decreased significantly at discharge, compared to baseline and recovered at 3-months follow-up. Furthermore, NT-proBNP increased significantly after the procedure with a return to baseline after 3 months. Changes in E/A were persistent at 3 months.

Conclusion

Our data in a small cohort suggest that TT-LAA exclusion with epicardial clip can be a safe procedure with regards to the atrial function. The LAA amputation impairs the reservoir LA function on the short term, that recovers over time.

A systematic review and meta-analysis of the impact of the left atrial appendage closure on left atrial function

Background

Left atrial (LA) appendage closure (LAAC) is effective in patients with atrial fibrillation who are not candidates for long‐term anticoagulation. However, the impact of LAAC on LA function is unknown. The aim of this study is to evaluate the impact of LAAC on atrial function.

Methods

This meta‐analysis was conducted according to Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines. A search strategy was designed to utilize PubMed/Medline, EMBASE, and Google scholar for studies showing the effect of LAAC on the LA function from inception to November 20, 2021. The standardized mean difference (SMD) was calculated from the means and standard deviations.

Results

Of 247 studies initially identified, 8 studies comprising 260 patients were included in the final analysis. There was a significant increase in LA emptying fraction following LAAC compared with preoperative function (SMD: 0.53; 95% confidence interval [CI]: 0.04–1.01; p = .03; I² = 75%). In contrast, there were no significant differences in LA volume (SMD: −0.07; 95% CI: −0.82–0.69; p = .86; I² = 92%) peak atrial longitudinal strain (SMD: 0.50; 95% CI: −0.08–1.08; p = .09; I² = 89%), peak atrial contraction strain (SMD: 0.38; 95% CI: −0.22–0.99; p = .21; I² = 81%), strain during atrial contraction (SMD: −0.24; 95% CI: −0.61–0.13; p = .20; I² = 0%), strain during ventricular systole (SMD: 0.47; 95% CI: −0.32–1.27; p = .24; I² = 89%), strain during ventricular diastole (SMD: 0.09; 95% CI: −0.32–0.51; p = .66; I² = 65%).

Conclusion

LAAC is associated with improvement in the left atrial emptying fraction, but did not significantly influence other parameters.

A Novel Echocardiographic-Based Classification for the Prediction of Peri-Device Leakage Following Left Atrial Appendage Occluder Implantation

(1) Background: The assessment of residual peri-device leakages (PDL) after left atrial appendage occlusion (LAAO) remains crucial for post-procedural management. Our study aimed to verify a novel echocardiographic classification for the prediction of PDL. (2) Methods: Echocardiographic data of 72 patients who underwent percutaneous LAAO were evaluated. All echo images were analyzed by two independent investigators using standard analysis software (Image-Arena IA-4.6.4.44 by TomTec^®, Munich, Germany). A total number of 127 studies was evaluated. Forty-four patients had baseline studies, at 45 days and at 6 months post-implantation. We propose a morphological classification of LAA devices based on the amount of echodensity inside the devices into three types: type A showing complete homogenous thrombosis, type B incompletely thrombosed device with inhomogeneous echo-free space <50% of device, and type C with partially thrombosed device in which the echo free space was >50% of device in various planes, which we called the “ice-cream cone” sign. Each type was matched to the degree of PDL and clinical outcome parameters. (3) Results: Patients with type C had the highest percentage of PDL at 45 days follow-up (type A: 24%, type B: 31%, type C 100% PDL, p < 0.001) and at 6 months follow-up (type A: 7%, type B: 33%, type C 100% PDL, p < 0.001). Notably, device size in patients with PDL was larger than that in patients without PDL at 6 months follow-up (25.6 ± 3.5 mm vs. 28.7 ± 3.4 mm, p = 0.004). Device size in patients with type C appearance was the largest of the three types (type A: 25.9 ± 3.6 mm, type B: 25.8 ± 3.4 mm, type C 29.8 ± 3.0 mm, type A vs. C; p = 0.019; type B vs. C, p = 0.007). (4) Conclusions: In conclusion, PDL are common post-LAAO, and their frequency is underestimated and under-recognized. PDL are much more common in patients with larger LAA ostial sizes and likely lower longitudinal compression. Type C appearance of the LAAO devices (“ice-cream cone sign”) has a high positive predictive value for PDL. Further studies are needed for better delineation of the clinical importance of this proposed classification.

Hemodynamic effects of left atrial appendage occlusion

BACKGROUND

Percutaneous left atrial appendage occlusion (LAAO) devices have emerged as alternatives to anticoagulation for embolic stroke prevention in patients with non-valvular atrial fibrillation (NVAF). The left atrial appendage is known to produce vasoactive neuroendocrine hormones involved in cardiovascular homeostasis. The hemodynamic impact of LAA occlusion on cardiac function remains poorly characterized.

METHODS

This is a single-center, retrospective study of sixty-seven consecutive patients who received LAAO utilizing the WATCHMAN device from May 2017 to June 2019. All patients received a comprehensive 2D transthoracic echocardiogram (TTE) prior to the procedure and a post-procedural TTE. 2D echocardiographic pre-/post-procedural measurements including left ventricular ejection fraction, tricuspid regurgitation, estimated pulmonary artery pressure, diastolic parameters, and left atrial and right ventricular strain were statistically analyzed using the paired t-test.

RESULTS

Seventy percent of study patients were male with an overall mean age of 73.0 ± 9.0 years. Analysis of post-procedural LAAO revealed statistically significant improvement in left ventricular ejection fraction (52.4 ± 12.6 vs. 56.7 ± 12.7, p < 0.001), an increase in mitral E/e' (14.1 ± 6.5 vs. 18.3 ± 10.8, p < 0.001), and a decrease right ventricular global longitudinal strain (RVGLS) (- 17.5 ± 4.6 vs. - 19.6 ± 5.7, p = 0.027) as compared to pre-procedural TTE. Peak left atrial longitudinal strain (PALS) improved post-LAAO (20.6 ± 12.2 to 22.9 ± 12.9, p = 0.040) with adjustment for cardiac arrhythmias. Post-LAAO, heart failure hospitalizations occurred in 23.9% of patients.

CONCLUSIONS

Percutaneous LAAO results in real-time atrial and ventricular hemodynamic changes as assessed by echocardiographic evaluation of LV filling pressures (E/e'), PALS, RVGLS, and LVEF.