Metformin, an inexpensive way to reduce heart failure hospitalization, finds JAHA Study

Taiwan: The use of metformin -- first‐line oral antidiabetic drug recommended for the treatment of type 2 diabetes -- lowers the risk of hospitalization for heart failure (HF), a recent study in the Journal of the American Heart Association has found.

According to Mayo Clinic, heart failure, sometimes known as congestive heart failure, occurs when your heart muscle doesn't pump blood as well as it should. Certain conditions, such as narrowed arteries in your heart (coronary artery disease) or high blood pressure, gradually leave your heart too weak or stiff to fill and pump efficiently.

The study led by Chin‐Hsiao Tseng, National Taiwan University Hospital, Taipei, Taiwan, aimed to evaluate whether metformin has a beneficial effect on heart failure patients.

For the purpose, the researchers used data from Taiwan's National Health Insurance database. They analyzed patients with new-onset type 2 diabetes who were followed up from January 1, 2006, to December 31, 2011. Specifically, an unmatched cohort including 172,542 metformin ever-users and 43,744 never-users, as well as a propensity score matched-pair cohort (matched cohort I: 41,714 ever-users and 41,714 never-users) were assessed for the main analyses.

Key findings of the study include:

• Respective incidence rates of heart failure hospitalization in ever users and never users were 304.25 and 864.31 per 100 000 person‐years in the unmatched cohort (hazard ratio, 0.350; 95% CI, 0.329–0.373) and were 469.66 and 817.01 per 100 000 person‐years in the matched cohort I (hazard ratio, 0.571; 95% CI, 0.526–0.620).


• A dose‐response pattern was consistently observed while estimating hazard ratios for the tertiles of cumulative duration of metformin therapy.


• Findings were supported by another propensity score-matched cohort created after excluding 10 potential instrumental variables in the estimation of propensity score (matched cohort II).


• An approximately 40% lower risk was consistently observed among ever users in different models derived from the matched cohorts I and II, but models from the matched cohort II were less subject to model misspecification.

"This population‐based retrospective cohort study supports a reduced risk of HHF associated with metformin use in patients with type 2 diabetes mellitus," wrote the authors. "Because metformin is inexpensive and safe and would not cause hypoglycemia when used as monotherapy, its protection against HF is worthy of more extensive investigation in both patients with diabetes mellitus and people without diabetes mellitus."

More Information: "Metformin Use Is Associated With a Lower Risk of Hospitalization for Heart Failure in Patients With Type 2 Diabetes Mellitus: a Retrospective Cohort Analysis" published in the Journal of the American Heart Association.

DOI: https://doi.org/10.1161/JAHA.118.011640

Journal Information: Journal of the American Heart Association