ACE2 and aortic valve stenosis: We did not find a statistically significant difference in serum ACE2 activities in patients with AS treated without RAASi (No RAASi, 83 ± 93 mU/L, n = 16, Fig. 2), treated with ACE inhibitors (ACEi, 90 ± 61 mU/L, n = 68, Fig. 2), with angiotensin receptor blockers (ARB, 78 ± 62 mU/L, n = 15, Fig. 2), or with aldosterone antagonists (AA, 96 ± 46 mU/L, n = 11, Fig. 2).