ACE2 and heart failure: At 3 months after OT, there were no statistically significant differences in the serum Ang-(1-7) and ACE2 concentrations between heart failure patients and the healthy individuals (3.03 ± 2.07 vs. 3.10 ± 1.10 ng/ml, P=0.854 and 6.10 ± 2.04 vs. 4.84 ± 2.25 ng/ml, P=0.061, respectively; Figures 2 and 3).