MACE: major adverse cardiovascular events, MI: myocardial infarction, HHF: hospitalization for heart failure, HR: hazard ratio, DPP-4i: dipeptidyl peptidase-4 inhibitor, CVOT: cardiovascular outcome trials, HF: heart failure, CV: cardiovascular, ACS: acute coronary syndrome, SU: sulphonylureas, RCT: randomized control trials, OADs: oral anti-diabetic drugs. Here, DPP4 is linked to acute coronary syndrome.