Effects of 6-month administration of tofogliflozin on cardiac function in elderly patients with heart failure with preserved ejection fraction: A retrospective study of a patient cohort

Patients with type 2 diabetes mellitus are frequently hospitalized for heart failure. The ratio of early diastolic mitral inflow velocity to early diastolic mitral annulus velocity (E/e'), measured by echocardiography, is a simple and convenient indicator of diastolic dysfunction. Various large clinical trials have reported that sodium glucose transporter-2 inhibitor therapy reduced cardiovascular events and hospitalizations in heart failure patients. We examined the effect of tofogliflozin on various physiological and cardiac function. A retrospective analysis was performed on elderly patients aged 65 years or older with type 2 diabetes mellitus attending Himi Municipal Hospital who were taking oral tofogliflozin 20 mg/day. Measurement of physiological and hormonal variables, blood sampling, and echocardiographic evaluations at 0, 1, 3, and 6 months were performed on those with ejection fraction (EF) of 40% or greater at the time of treatment. Statistical analysis was performed using t-tests and mixed-effects models, with brain natriuretic peptide less than or not less than 100 pg/mL, estimated glomerular filtration rate (eGFR) less than or not less than 50 mL/min/1.73 m2, and diuretics administered or not. Hypoglycemic effects were observed at 0, 1, 3, and 6 months. At each time point, EF was retained and E/e' was significantly reduced. On the other hand, most physiological parameters and laboratory results showed no clinical abnormalities. Mixed-effects models showed time-dependent reduction of E/e' in high/low brain natriuretic peptide, high/low eGFR, with or without diuretics between baseline and at 6 months. The interaction with time was significant in high/low eGFR. Tofogliflozin was shown to improve E/e', a measure of diastolic function, while maintaining EF, with hypoglycemic effects and no clinical side effects.