This study aimed at determining ACE2 protein expression in left ventricular myocardial cells at various stages of HF resulting from ischemic heart disease, including stage A (at-risk for HF), stage B (pre-HF), and stages C/D (symptomatic and advanced HF) [26], by quantitative and semi-quantitative immunohistochemical evaluation. Here, ACE2 is linked to coronary artery disorder.