USA: A recent study involving older U.S. adults hospitalized for heart failure (HF) with comorbid diabetes found metformin initiation to be independently associated with substantial improvements in 12-month clinical outcomes. This was driven by findings among patients with an ejection fraction (EF) >40%. Conversely, regardless of EF, sulfonylurea initiation was related to excess risk of death and HF hospitalization.
According to the study, starting metformin treatment in patients with type 2 diabetes shortly after they were hospitalized for heart failure was linked with a reduced rate of repeat hospitalization for heart failure (HHF) during the subsequent year when their left ventricular ejection fraction (LVEF) was greater than 40%.
The study was published in the journal JACC: Heart Failure on December 08, 2021.
Metformin and sulfonylureas are prescribed frequently to diabetes patients for blood sugar control. The impact of these therapies on clinical outcomes in patients with comorbid HF and diabetes is not clear. To clarify the same, Muhammad Shahzeb Khan, Division of Cardiology, Duke University School of Medicine, Durham, North Carolina, USA, and colleagues sought to characterize associations between initiation of metformin and sulfonylurea therapy and clinical outcomes among patients with comorbid HF and diabetes (overall and by EF phenotype).
For this purpose, the researchers evaluated Medicare beneficiaries hospitalized for HF in the Get With The Guidelines–Heart Failure Registry between 2006 and 2014 with diabetes and not prescribed metformin or sulfonylurea before admission. Patients with newly prescribed therapy within 90 days of discharge were compared with patients not prescribed therapy in parallel separate analyses for metformin and sulfonylurea.
Multivariable models landmarked at 90 days evaluated the associations between prescription of therapy, and mortality and hospitalization for HF (HHF) at 12 months. Negative control (falsification) endpoints included hospitalization for urinary tract infection, hospitalization for gastrointestinal bleed, and influenza vaccination. Prespecified subgroup analyses were stratified by EF ≤40% versus >40%.
Of 5,852 patients, 454 (7.8%) were newly prescribed metformin and 504 (8.6%) were newly prescribed sulfonylurea.
Based on the study, the researchers found the following:
After adjustment, metformin prescription was independently associated with reduced risk of composite mortality/HHF (HR: 0.81), but individual components were not statistically significant.
Findings among patients with EF >40% accounted for associations with mortality/HHF (HR: 0.68) and HHF (HR: 0.58) endpoints.
After adjustment, sulfonylurea initiation was associated with increased risk of mortality (HR: 1.24) and HHF (HR: 1.22) with nominal statistical significance.
Associations between sulfonylurea initiation and endpoints were consistent regardless of EF. Neither metformin initiation nor sulfonylurea initiation were associated with negative control endpoints.
"In this population of older U.S. adults hospitalized for HF with comorbid diabetes, metformin initiation was independently associated with substantial improvements in 12-month clinical outcomes, driven by findings among patients with EF >40%," wrote the authors. "By contrast, sulfonylurea initiation was associated with excess risk of death and HF hospitalization, regardless of EF."
Reference:
The study titled, "Clinical Outcomes With Metformin and Sulfonylurea Therapies Among Patients With Heart Failure and Diabetes," was published in the journal JACC: Heart Failure.
DOI: https://www.jacc.org/doi/10.1016/j.jchf.2021.11.001