Effects of Metformin Treatment on Myocardial Efficiency in Patients With Heart Failure

Background: Heart failure (HF) is a common disease and diabetes/insulin resistance are present in approximately 50 % of HF patients. Metformin is the most commonly prescribed oral anti-diabetic drug, and registry and experimental studies show beneficial effects of metformin in HF, but randomized trials are needed. Objectives: To investigate if treatment with metformin in patients with HF has beneficial effects on myocardial efficiency, Design: A randomized, double-blind, placebo-controlled, single-center design. 36 patients with systolic heart failure will be randomized to either metformin (N = 18) or placebo (N= 18) for 3 months. Methods: Patients will undergo echocardiography at rest and during exercise along with \[11C\]-acetate PET. Primary outcome parameter is changes in myocardial external efficiency from visit 1 to 3 months of therapy.