Impact of Empagliflozin on Functional Capacity in Heart Failure with Preserved Ejection Fraction

This is a single-arm, open label, pilot study of 8 subjects with HFpEF. The subjects will undergo screening tests (exercise stress echo and blood work) to evaluate for potential exclusion criteria and provide familiarization to the exercise protocol. Those included will undergo an echocardiogram and invasive cardiopulmonary exercise test. This involves placement of a right heart catheter in the pulmonary artery and undergoing seated, upright exercise. During the exercise test, the subject's oxygen uptake (VO2), intra-cardiac pressures (right atrial pressure, pulmonary capillary wedge pressure) and cardiac output (Qc) will be measured. The subject will take a dose of empagliflozin in the lab and wait for at least 60 minutes. They will repeat a shortened version of the exercise test in the afternoon. After baseline testing, each subject will take 10mg empagliflozin daily for 12 weeks. They will have repeat blood work (specific electrolytes and renal function) 30 days after starting medication to screen for renal injury. After 12 weeks, they will return for another invasive cardiopulmonary exercise test and echocardiogram.