Effects of Angiotensin Receptor-Neprilysin Inhibitor in Arrhythmogenicity Following Left Atrial Appendage Closure in an Animal Model

Purpose Left atrial appendage (LAA) closure decreases atrial natriuretic peptide (ANP) levels, which indirectly increases the risk of arrhythmogenicity. We aimed to determine the effect of a combined angiotensin receptor-neprilysin inhibitor (ARNi) on arrhythmogenicity following LAA closure in an animal model. Methods Twenty-four rabbits were randomized into four groups: (1) control, (2) LAA closure (LAAC), (3) heart failure (HF)-LAAC, and (4) HF-LAAC with sacubitril/valsartan (+ARNi). HF models were developed in the HF-LAAC and HF-LAAC+ARNi groups. Epicardial LAA exclusion was performed in the LAAC, HF-LAAC, and HF-LAAC+ARNi groups. ANP levels were measured. An electrophysiological study was performed. The myocardium was harvested for histopathological analysis. Results The ANP level decreased in the LAAC group (785 ± 103 pg/mL, p = 0.03), failed to increase in the HF-LAAC group (917 ± 172 pg/mL, p = 0.3), and increased in the HF-LAAC+ARNi group (1524 ± 126 pg/mL, p