Short‐term effects of dapagliflozin on maximal functional capacity in heart failure with reduced ejection fraction ( DAPA‐VO ₂ ): a randomized clinical trial

Aims This study aimed to evaluate the effect of dapagliflozin on 1 and 3‐month maximal functional capacity in patients with stable heart failure with reduced ejection fraction (HFrEF). Methods and results In this multicentre, randomized, double‐blind clinical trial, 90 stable patients with HFrEF were randomly assigned to receive either dapagliflozin ( n = 45) or placebo ( n = 45). The primary outcome was a change in peak oxygen consumption (peakVO 2 ) at 1 and 3 months. Secondary endpoints were changes at 1 and 3 months in 6‐min walk test (6MWT) distance, quality of life (Minnesota Living with Heart Failure Questionnaire [MLHFQ]), and echocardiographic parameters (diastolic function, left chamber volumes, and left ventricular ejection fraction). We used linear mixed regression analysis to compare endpoint changes. Estimates were adjusted for multiple comparisons. The mean age was 67.1 ± 10.7 years, 69 (76.7%) were men, 29 (32.2%) had type 2 diabetes, and 80 (88.9%) were in New York Heart Association class II. Baseline means of peakVO 2 , 6MWT and MLHFQ were 13.2 ± 3.5 ml/kg/min, 363 ± 110 m, and 23.1 ± 16.2, respectively. The median (25th–75th percentile) of N ‐ terminal pro‐brain natriuretic peptide was 1221 pg/ml (889–2100). Most patients were on treatment with sacubitril/valsartan (88.9%), beta‐blockers (91.1%), and mineralocorticoid receptor antagonists (74.4%). PeakVO 2 significantly increased in patients on treatment with dapagliflozin (1 month: +Δ 1.09 ml/kg/min, 95% confidence interval [CI] 0.14–2.04; p = 0.021, and 3 months: +Δ 1.06 ml/kg/min, 95% CI 0.07–2.04; p = 0.032). Similar positive findings were found when evaluating changes from baseline. No significant differences were observed in secondary endpoints. Conclusions Among patients with stable HFrEF, dapagliflozin resulted in a significant improvement in peakVO 2 at 1 and 3 months. Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT04197635.