Patients with diabetes mellitus (DM) are classified as "vulnerable patients" suffering from acute coronary syndrome (ACS) 2-3 times more often and have a pessimistic prognosis compared with normoglycemic patients. Hyperglycemia at admission to the intensive care worsens the long-term prognosis of ACS not only in patients with diabetes mellitus but also in patients without a history of diabetes. However, medical care for these patients is not normally focused on hyperglycemia. The particular problem lies in defining the target levels of glycemia and the period required for achieving those, as well as the selection of the appropriate glucose-lowering drugs. Several randomized clinical trials (RCTs) were used as a basis for evaluating aggressive insulin therapy and non-insulin hypoglycemic drugs in terms of cardiac safety and potential cardioprotective effects. The problem is closely related to the mechanisms of their impact on glycemic parameters: fasting and postprandial glycemia, variability, as well as the risk of hypoglycemia. Incretins, due to their glucose-dependent effects on insulin and glucagon secretion which regulate glycemic variability, are of special interest. According to finalized RCT which assessed the use of incretins after ACS, the cardiovascular end-points demonstrated cardiac safety of alogliptin and lixisenatide. However, alogliptin therapy was shown to improve the prognosis in women (OR = 0.60), patients with GFR > 60 ml/min (OR = 0.67) and patients suffering from diabetes type 2 for less than 5 years (OR = 0.61) . The relevance of the findings is discussed.