US Pharm. 2019;44(2):HS-6-HS-8.

Researchers at the University of Arizona have discovered that metformin, a drug commonly used to treat type 2 diabetes, might also be used to treat heart failure with preserved ejection fraction (HFpEF), a condition that is predicted to affect over 8% of people aged 65 years or older by the 2020.

The study, which was published December 19 in the Journal of General Physiology, shows that metformin relaxes a key heart muscle protein called titin, allowing the heart to properly fill with blood before pumping it around the body.

Nearly half of all heart failure patients are considered to have HFpEF, in which the heart can properly contract but, because the wall of the left ventricle is stiffer than normal, it fails to fully relax between beats, reducing its capacity to fill with blood. This reduces blood supply to the rest of the body, leading to shortness of breath with exertion and difficulty exercising.

Henk L. Granzier, Nancy Sweitzer, and colleagues at the Sarver Heart Center at the University of Arizona investigated whether metformin could be an effective treatment for HFpEF because the drug has been shown to increase left ventricular dilation and lower the rate of heart failure in patients with diabetes. The researchers gave metformin to mice with HFpEF-like symptoms and found that the drug reduced left ventricular stiffness, thereby improving the animals’ capacity for exercise.

“We therefore conclude that metformin is a potential therapy for patients with HFpEF,” Granzier says. “Because the drug is already approved and well tolerated in humans, using it to target titin stiffness presents a unique opportunity for immediate translation to the clinic.”