Metformin boosts outcomes for patients with HF and diabetes—sulfonylurea initiation makes things worse
Metformin initiation is independently associated with improved clinical outcomes among patients with both heart failure (HF) and diabetes, according to a new study published in JACC: Heart Failure.
Metformin and sulfonylureas are both commonly prescribed for glycemic control. The study's authors aimed to learn how each treatment option might impact patients who also present with HF.
The group analyzed data from 5,852 Medicare patients with diabetes who were hospitalized for HF between 2006 and 2014. Patients had not been prescribed metformin or sulfonylureas prior to admission.
The group’s mean age was 75 years old, and 51.6% were women. The median ejection fraction (EF) among the patient cohort was 45%, and 41.9% of patients had an EF less than 40%.
Among the 5,852 patients, 7.8% were prescribed metformin and 8.6% were prescribed sulfonylurea. An additional 2.3% were prescribed both metformin and sulfonylurea.
Patients given metformin were more likely to be younger or taking an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker. They were also less likely to present with ischemic heart disease or have an implantable cardioverter-defibrillator or cardiac resynchronization therapy device.
Patients given sulfonylureas were more likely to have longer index hospital lengths of stay or present with a lower body mass index. Atrial fibrillation was less common among these patients.
In the analysis, metformin was independently associated with a lower composite risk of mortality or hospitalization for HF after 12 months. This association was "exclusively driven" by risk reductions seen in patients with EF greater than 40%.
Sulfonylurea initiation, on the other hand, was independently associated with a greater composite risk of mortality and hospitalization for HF.
"These findings support the potential use of metformin among patients with heart failure with preserved ejection fraction and diabetes mellitus (DM), and the need for confirmatory randomized clinical trials," wrote lead author Muhammad Shahzeb Khan, MD, with the division of cardiology at Duke University School of Medicine, and colleagues. "In addition, in the context of multiple alternative antidiabetic medications being available with favorable or neutral effects on cardiovascular outcomes, these findings suggest that sulfonylureas may best be avoided among patients with HF and DM."
Read the full study here.