BackgroundIn heart failure with reduced ejection fraction (HFrEF), sodium–glucose co-transporter inhibitors (SGLT-2i) have persistently shown cardiovascular benefits through different trials. However, their impact on ventricular remodeling and cardiac hemodynamics has not been sufficiently studied. This study aimed to study how SGLT-2i initiation affects invasive hemodynamics and cardiac magnetic resonance imaging (CMR)-derived ventricular volumes, function, and fraction of the extracellular volume (ECV) in HFrEF patients with non-ischemic dilated cardiomyopathy (NIDCM).ResultsIn this study, 23 patients with HFrEF and a mean age of 42, including 82.6% males, all have NIDCM and underwent right heart catheterization and CMR at the initiation of dapagliflozin and at 6-month follow-up. The addition of dapagliflozin resulted in significant reductions in the following invasive hemodynamic parameters compared to baseline: left ventricular end-diastolic pressure (23.4 vs 19.7 mmHg, p = 0.003), mean pulmonary artery pressure (31.3 vs 27.7 mmHg, p = 0.03), and systemic vascular resistance (18 vs 15 Wood units, p = 0.047). Among the studied CMR-derived measurements, only the percentage of extracellular volume fraction was significantly less at follow-up (33.7 vs 32.16%, p = 0.001). Additionally, functional class showed significant improvement with a notable reduction of the NT-proBNP level and a considerable decrease in diuretic dose (median: 40 vs 80 mg, p = 0.01).ConclusionAdding dapagliflozin to patients with HFrEF due to NIDCM improved invasively measured hemodynamics and significantly reduced left ventricular extracellular volume fraction measured by CMR, with no significant change in ventricular volumes or ejection fraction.