The Efficacy of Enavogliflozin in Heart Failure With Preserved Ejection Fraction

1\. Inclusion Criteria: 1\) Age ≥19 2) New York Heart Association (NYHA) II-III dyspnea 3) Diagnosis of HFpEF (Exams conducted within 6 months from screening) \[must satisfy all (1), (2), and (3)\] 1. Left ventricular ejection fraction (LVEF) ≥50% 2. NT-proBNP ≥220 pg/mL or BNP ≥80 pg/mL, if in sinus rhythm NT-proBNP ≥660 pg/mL or BNP ≥240 pg/mL, if in atrial fibrillation 3. Satisfying either noninvasive or invasive criteria I. Noninvasive: Echocardiography with at least one of the following criteria * LAVI ≥34 ml/m2 * Lateral E/e' ≥9 * LVMI ≥115 g/m2 if male or ≥95 g/m2 if female * LV wall thickness ≥12mm II. Invasive: LVEDP ≥16mmHg or pulmonary capillary wedge pressure(PCWP) ≥15mmHg 4) Stable/chronic ambulatory patients without hospitalization within the last 30 days due to heart failure decompensation episode 5) Patients taking heart failure medication without change for at least 3 weeks before screening 2\. Exclusion Criteria: 1. Unwillingness or inability to comply with the procedures described in this protocol 2. The ability to walk is, in the investigator's opinion, clearly limited by joint disease or other locomotor problems or lung diseases rather than by cardiorespiratory fitness 3. NYHA IV dyspnea 4. Type 1 diabetes mellitus 5. Estimated glomerular filtration rate (eGFR) \<60 ml/min/1.73m2 (Chronic Kidney Disease Epidemiology Collaboration \[CKD-EPI\] formula) 6. Anemia (Hb \<7g/dL) 7. Severe hepatic impairment (Child-Pugh class C) 8. Acute myocardial infarction or unstable angina within 30 days before inclusion or planned coronary revascularization at the time of inclusion 9. Significant left-sided valvular heart disease (moderate to severe stenosis and severe regurgitation) 10. Heart failure due to any of the following: infiltrative cardiomyopathy (amyloidosis, sarcoidosis), active myocarditis, constrictive pericarditis, hypertrophic cardiomyopathy 11. Symptomatic hypotension (systolic blood pressure \<90mmHg) 12. Severe chronic obstructive pulmonary disease (postbronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity(FVC) \<70% and FEV1 \<50%) 13. Treated with sodium-glucose cotransporter-2 inhibitors (SGLT2i) within 30 days before inclusion 14. History of diabetic ketoacidosis while in treatment with SGLT2i 15. Recurrent genitourinary tract infections 16. History of Hypersensitivity reaction to SGLT2i 17. Non-cardiac co-morbid conditions are present with life expectancy \<2 year or that may result in protocol non-compliance (per site investigator's medical judgment) 18. Female patients who are currently or planning to become pregnant 19. Female patients who are lactating 20. Patients participating in other clinical trials