Effect of Sodium−Glucose Co‐Transporter‐2 Inhibitor on Estimated Plasma Volume in a Patient With Heart Failure With Reduced Ejection Fraction and a Patient With Heart Failure With Preserved Ejection Fraction

Background The increased diuresis after sodium−glucose cotransporter 2 inhibitor (SGLT2i) was associated with a reduction of the estimated plasma volume (ePV) in type 2 diabetic patients. Hypothesis We hypothesized that the early effect of SGLT2i on ePV may be monitored by the change of biomarkers of hemoconcentration. Patients and Methods We analyzed the early‐ and long‐term effect of SGLT2i empagliflozin on the ePV as assessed by biomarkers of hemoconcentration in a nondiabetic patient with heart failure and reduced ejection fraction (HFrEF) and a nondiabetic patient with heart failure and preserved ejection fraction (HFpEF). The ePV was calculated from hemoglobin and hematocrit levels by Duarte formula and ePV change was calculated by Strauss formula. Results The ePV change was −22.56% between baseline and 1 month, and −37.60% between baseline and 12 months follow‐up in a patient with HFrEF, and −6.18% and −16.40% in a patient with HFpEF, respectively. Conclusion The early effect of SGLT2i on ePV in patients with heart failure may be monitored by biomarkers of hemoconcentration.