Heart Failure Progression Delayed with Metformin Treatment

SAN FRANCISCO, CA—Metformin may delay progression to advanced ACC Stage C heart failure from early ACC Stage A and Stage B heart failure, a retrospective observational study conducted in patients with left ventricular hypertrophy (LVH) presented at ACC.13, the American College of Cardiology's 62nd Annual Scientific Session, has found.

Heart failure may lead to insulin resistance. However the role of metformin, an oral anti-diabetic insulin sensitizer has not been effectively studied in heart failure. Investigators hypothesized that metformin may delay the progression of heart failure in high-risk American College of Cardiology (ACC) Stage A and Stage B groups.

The study included 300 consecutive patients with echocardiogram-confirmed LVH identified during the 2005 calendar year, authors Manova David, MD and Christopher Droogan, PhD, of Lankenau Medical Center in Wynnewood, PA, reported. A total of 212 patients met the exclusion criteria, which include patients with established heart failure, end stage renal disease, on palliative care, and without follow-up data.

Patients were divided into three arms: patients without diabetes not on metformin but with LVH and other risk factors (n=50); patients with diabetes and LVH who were not on metformin (n=25); and patients with diabetes and LVH who were on metformin (n=13). The authors reviewed the case records from January 1, 2005–April 30, 2011. “Primary endpoint was development of heart failure (ACC Stage C) during the study period,” they noted.

A significant difference in development of heart failure was observed in patients with diabetes who were taking metformin (0%) compared to patients without diabetes not on metformin (28%), and those with diabetes but not taking metformin (52%).

Within the group with diabetes, there was a significant reduction in incidence of heart failure between the metformin vs. the non-metformin group (risk reduction 54%; P=0.001). In patients with LVH, ejection fraction or change in ejection fraction did not predict for development of heart failure. No symptoms of heart failure developed in the group that received metformin.

“Metformin may play a part in preventing the development of heart failure at early stages, and chronic kidney disease may be a confounding factor but this needs to be studied in a larger sample size,” Drs. David and Droogan concluded. They added that further evidence and a randomized control trial may be needed to validate this finding.