Effect of Dapagliflozin on 6-Minute Walk Distance in Heart Failure With Preserved Ejection Fraction: PRESERVED-HF

BACKGROUND: Heart failure with preserved ejection fraction is associated with significant functional limitations, yet treatments for improving exercise performance have been elusive. We sought to explore the association between prespecified patient characteristics and changes in 6-minute walk distance that constitute a clinically significant response to dapagliflozin. METHODS: We performed a responder analysis to understand patient characteristics associated with clinically meaningful improvement in 6-minute walk test (6MWT) distance ≥15 m among patients randomized to 12 weeks of dapagliflozin versus placebo in the double-blind PRESERVED-HF trial (Effects of Dapagliflozin on Biomarkers, Symptoms and Functional Status in Patients With Preserved Ejection Fraction Heart Failure). RESULTS: A total of 289 randomized patients had 6MWT distance completed at baseline and 12 weeks. Patients randomized to dapagliflozin improved walking distance by ≥15 m more frequently than those on placebo (n=64, 44% versus n=48, 34%). After adjusting for baseline covariates, patients randomized to dapagliflozin were more likely to experience a clinically meaningful improvement in 6MWT distance compared with those that received placebo (adjusted odds ratio, 1.66 [95% CI, 1.00–2.75]; P=0.05). Dapagliflozin-treated patients were also less likely to have a ≥15 m reduction in 6MWT distance compared with placebo-treated patients (adjusted odds ratio, 0.56 [95% CI, 0.33–0.94]; P=0.03). These results were consistent across all prespecified subgroups (all P values for interaction were not significant). CONCLUSIONS: Compared with those on placebo, patients with heart failure with preserved ejection fraction randomized to dapagliflozin were more likely to experience a clinically meaningful improvement and less likely to experience a deterioration in physical function over 12 weeks as measured by 6MWT distance. Beneficial response to dapagliflozin was consistent across prespecified subgroups. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03030235.