Inclusion Criteria:

• Signed informed consent prior to any study specific procedures.
• Male or female subject.
• Age ≥ 18.
• Symptoms of dyspnea (NYHA II-III) with no non-cardiac or ischemia explanation.
• EF ≥ 50%.
• Elevated pulmonary capillary wedge pressure (PCWP) during exercise (≥ 25 mmHg) ascertained at Visit 1. Patients that have consented to study procedures but do not meet this invasive criterion will be considered as screen failures and will not be randomized.

Exclusion Criteria:

• Type I diabetes.
• Type II diabetes with poor control (HgbA1c ≥ 10%).
• Recent hospitalization (< 30 days) or revascularization (< 90 days).
• Primary cardiomyopathy (such as amyloid).
• Constrictive pericarditis.
• Dyspnea due to primary lung disease or myocardial ischemia in the opinion of the investigator.
• Severe anemia (hemoglobin < 9 gm/dl).
• Significant left-sided valvular heart disease (> moderate stenosis, > moderate regurgitation).
• Severe kidney disease (estimated GFR < 30) or liver disease.
• Women of child bearing potential not willing to use a medically accepted method of contraception OR who are currently pregnant (confirmed with positive pregnancy test) or breast feeding.
• History of serious hypersensitivity reaction to dapagliflozin.
• Subjects on dialysis.
• Subjects with severe hepatic impairment (Child-Pugh class C).
• Currently taking Empagliflozin or Canagliflozin.

Eligibility last updated 8/25/21. Questions regarding updates should be directed to the study team contact.