Senior author Dr. Tamara Horwich, an assistant professor of medicine in the division of cardiology at the David Geffen School of Medicine at the University of California, Los Angeles, said the study involved 401 patients with an average age of 56, with type 2 diabetes and advanced systolic heart failure.
The study participants were tracked for 14 years in a comprehensive heart failure management program.
The study, published in the Journal of Cardiac Failure, suggests in patients with both advanced heart failure and diabetes, use of metformin is safe, and may be associated with better heart failure survival.
"The diabetes drug metformin previously carried a ‘black box warning’ from the U.S. Food and Drug Administration against its use in treating diabetes in heart failure patients," Horwich said in a statement.
"In fact, many medications commonly used to lower serum glucose levels have theoretic or demonstrated adverse effects on heart failure. As a result, many physicians have been reluctant to use metformin and other similar medications to treat this patient group."
However, the analysis shows using metformin to treat diabetes in patients with advanced, systolic heart failure is not only safe, but may also play a role in improving outcomes compared to conventional diabetes care, Horwich said.