Study Overview
Objective. To evaluate the effects of dapagliflozin in patients with heart failure with reduced ejection fraction in the presence or absence of type 2 diabetes.
Design. Multicenter, international, double-blind, prospective, randomized, controlled trial.
Setting and participants. Adult patients with symptomatic heart failure with an ejection fraction of 40% or less and elevated heart failure biomarkers who were already on appropriate guideline-directed therapies were eligible for the study.
Intervention. A total of 4744 patients were randomly assigned to receive dapagliflozin (10 mg once daily) or placebo, in addition to recommended therapy. Randomization was stratified by the presence or absence of type 2 diabetes.
Main outcome measures. The primary outcome was the composite of a first episode of worsening heart failure (hospitalization or urgent intravenous therapy) or cardiovascular death.
Main results. Median follow-up was 18.2 months; during this time, the primary outcome occurred in 16.3% (386 of 2373) of patients in the dapagliflozin group and in 21.2% (502 of 2371) of patients in the placebo group (hazard ratio [HR], 0.74; 95% confidence interval [CI], 0.65-0.85; P < 0.001). In the dapagliflozin group, 237 patients (10.0%) experienced a first worsening heart failure event, as compared with 326 patients (13.7%) in the placebo group (HR, 0.70; 95% CI, 0.59-0.83). The dapagliflozin group hadlower rates of death from cardiovascular causes (9.6% vs 11.5%; HR, 0.82; 95% CI, 0.69-0.98) and from any causes (11.6% vs 13.9%; HR, 0.83; 95% CI, 0.71-0.97), compared to the placebo group. Findings in patients with diabetes were similar to those in patients without diabetes.
Conclusion. Among patients with heart failure and a reduced ejection fraction, the risk of worsening heart failure or death from cardiovascular causes was lower among those who received dapagliflozin than among those who received placebo, regardless of the presence or absence of diabetes.