Hemodynamic effects of left atrial appendage occlusion

Abstract

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.

Keywords: Atrial strain; Electrophysiology; Interventional echocardiography; Left atrial appendage occlusion; Right ventricular global longitudinal strain; Ventricular filling pressure.