Following adjustment for age, gender, BMI, hypertension, prior MI, current smoking status, hyperlipidemia, diabetes mellitus, Gensini score, aortic clamp time, number of grafts and pre-CABG medications, the risk of developing postoperative MI following CABG was significantly higher in the lowest serum ACE2 level quartile group, compared with the highest quartile group (hazard ratio, 2.94; 95% CI, 1.85–4.16; P=0.009). This evidence concerns the gene ACE2 and diabetes mellitus.