This study investigated the potential efficacy of SGLT2 inhibitors empagliflozin and oral ketone supplementation as treatments for heart failure with preserved ejection fraction (HFpEF), which is often associated with obesity and type 2 diabetes mellitus.

20-week-old obese ZSF-1 rats were given different treatments for 12 weeks, including vehicle, empagliflozin, ketone ester (KE), or a combination of empagliflozin and KE. Cardiac magnetic resonance imaging (CMR) and hyperpolarized carbon-13 (13C) labeled pyruvate magnetic resonance spectroscopy imaging were used to evaluate cardiac function and metabolism, while histological and molecular markers of cardiac remodeling were assessed in the left ventricle.

The untreated HFpEF rats exhibited obesity, diabetes, cardiac hypertrophy, atrial enlargement, lung congestion, and increased cardiomyocyte size and cardiac expression of atrial natriuretic peptide (ANP) and fibrosis marker col1a1 and TIMP1. The treatment groups exhibited decreased body weight, increased circulating ketone levels, and reduced blood glucose levels. All treatment regimens significantly attenuated ventricular hypertrophy, atrial enlargement, and lung congestion. Furthermore, all treatments significantly reduced cardiomyocyte size and the expression of ANP and fibrosis marker. The combination of empagliflozin and KE showed the greatest improvement in diastolic function and cardiac ATP levels. Interestingly, hyperpolarized [1-13C] pyruvate detected a decrease in lactate/pyruvate ratio in the hearts treated with empagliflozin.

Obese ZSF1 rats exhibit features of clinical HFpEF with predominant background of obesity and diabetes. A combination of empagliflozin and KE has greater benefits in treating HFpEF. Targeting cardiometabolic dysregulation may be a promising approach for HFpEF treatment.