[Use of metformin in patients with type 2 diabetes and acute myocardial infarction: safety and impact on glycemic control].

Background: Myocardial infarction (MI) in patients with diabetes type 2 (T2DM) occurs 1.5-3.0 times higher than in general population. Metformin is contraindicated for patients with T2DM and acute coronary syndrome due to the risk of developing lactic acidosis. Using metformin more than 48 hours of MI is a topical question, which will help to improve patient's safety.

Aim: To evaluate the safety and quality of glycemic control using metformin in patients with T2DM during inpatient treatment for MIMATERIALS AND METHODS: The study included 161 patients with T2DM, who were hospitalized consecutively with acute MI with ST-elevation and underwent percutaneous coronary intervention (PCI). Average time of metformin initiation was 5th day from admission. Creatinine was assessed at admission and 48 hours after PCI. The acid-base balance and lactate were assessed at admission and on the 3rd day after the start of using metformin. Criteria for the effectiveness of glycemic control was the proportion of glycemic measurements in target range of 6.1-10.0 mmol/l during hospitalization ("hospital time in range", hTIR). hTIR >55% was considered to be a critical level. The long-term outcome was estimated at 365 days after hospitalization.

Results: Metformin was prescribed to 99 patients (61%) ("M+"group) during the hospitalization, 62 patients were in "M-"group. Use of metformin was accompanied with better glycemic control in the «M+» group compared to the «M-»: mean glycemia 9.3 ± 1.6 vs 10.3 ± 2.3 mmol/l (p=0,002), SD 2.87 ± 1.1 vs 3.26 ± 1.8 (p=0,049), hTIR 60 ± 18% vs 48 ± 23% (p<0,001). There were clinically insignificant changes in acid-base balance on the 3rd day from the start of metformin use in the "M+" group, the lactate level did not increase. Use of metformin before to hospitalization with MI was not associated with an increased risk of developing acute kidney injury (AKI): RR 0.85 (0.37-1.96), p=0,691.

Conclusion: Use of metformin in patients with T2DM and acute MI is associated with better glycemic control. Carrying out angiography in patients, treated with metformin before the hospitalization, is not accompanied by an increased risk of developing AKI. Appointment of metformin in 3-7 days after angiography does not lead to an increase level of lactate and significant deviations in acid-base balance.