INS and diabetes mellitus: Univariable analysis in the training cohort showed a significant association of postoperative morality with several predictors including age, critical state, diabetes on insulin, stroke, recent myocardial infarction (MI) within 90 days, CCS angina class IV, lower limb arterial stenosis, left ventricular ejection fraction (LVEF) ≤35%, LV (left ventricular) dilatation, ischemic mitral regurgitation, increased serum creatinine, and mitral valve replacement (MVR).