The Influence of Metformin on Chronic Heart Failure Clinical Course in Patients With Prediabetes

This is a single centre trial designed to investigate the benefit, if any, of 12-month metformin 2000 mg/day treatment on clinical course of chronic heart failure in 78 patients with coronary artery disease and impaired glucose tolerance. Participants will be seen in three occasions: screening, baseline randomization, 6 month, final 12 month, during which clinical and laboratory indicators will be assessed. There will also be three telephone visits at: month 1, month 3, month 9. At a screening visit an initial history will be performed during following informed consent. Participants will undergo a laboratory, clinical and instrumental screening in Chronic Heart Failure department of National Centre of cardiology and Internal Medicine named after academician M.Mirrakhimov. Among with anthropologic and clinical data, prior to metformin administration, blood samples were evaluated. Participants who meet all inclusion criteria will return for the randomization during hospitalization to either Metformin or Lifestyle modification alone. After 6 months of observation safety indicators will be evaluated, as well as fasting and postprandial glucose, creatinine, ECG. In the active arm, therapy will be metformin in an initial dose of 1000 mg/day (metformin 500 mg х2/day). Participants will continue on Metformin 500 mg x2/day for 2 weeks, following safety blood checks this dose will be increased to 2000 mg/day. If the higher dose cannot be tolerated it will be reduced to 1000 mg/day (or stopped if not tolerated). The target dose of Metformin at 2000 mg/day was chosen based on previous study of metformin in nondiabetic heart failure patients with IR