Serum ACE2 activity as a novel biomarker of assessment of severe aortic stenosis

Abstract Background Aortic stenosis (AS) is the most prevalent valve disease in developed countries, with its incidence rising in the aging population. The current criteria for aortic valve replacement (AVR) are based on subjective symptoms and left ventricular ejection fraction (LVEF), which may not adequately reflect left ventricular (LV) dysfunction. This highlights the necessity for objective biomarkers to evaluate subclinical LV dysfunction. Serum angiotensin-converting enzyme 2 (sACE2) has emerged as a promising novel biomarker for cardiovascular diseases. Aims To investigate the association between sACE2 activity and different flow-grade categories of severe AS, compare it with the traditional biomarker N-terminal pro-brain natriuretic peptide (NT-proBNP), and assess the utility of sACE2 as a biomarker for AS. Methods sACE2 and NT-proBNP were measured in 175 patients (97 male, 78 female, mean age 75±8 years) diagnosed with severe AS (aortic valve area, AVA≤1 cm²). Patients were classified into 5 groups depending on LV flow state and pressure gradient levels: normal flow-low gradient (NF-LG), normal flow-high gradient (NF-HG), low flow-high gradient (LF-HG), low flow-low gradient (LF-LG), and paradoxical low flow-low gradient (PLF-LG) AS. Results Both biomarkers showed a general increase with advanced stages of severe AS (NF-LG: 65.0±4.2 U/ml; LF-LG: 148.1±16.8 U/ml; P