Patient Characteristics, Clinical Outcomes, and Effect of Dapagliflozin in Relation to Duration of Heart Failure: Is It Ever Too Late to Start a New Therapy?

Background: The impact of heart failure (HF) duration on outcomes and treatment effect is largely unknown. We aim to compare baseline patient characteristics, outcomes and the efficacy and safety of dapagliflozin, in relation to time from diagnosis of HF in DAPA-HF. Methods: HF duration was categorized as ≥2 to ≤12 months, >1-2 years, >2-5 years and >5 years. Outcomes were adjusted for prognostic variables and analyzed using Cox regression. The primary endpoint was the composite of worsening HF or cardiovascular death. Treatment effect was examined within each duration category and by duration threshold. Results: The number of patients in each category was: 1098 (≥2 to ≤12 months), 686 (>1-2 years), 1105 (>2-5 years) and 1855 (>5 years). Longer-duration HF patients were older and more comorbid with worse symptoms. The rate of the primary outcome (per 100 person-years) increased with HF duration: 10.2 (95% CI 8.7-12.0) for ≥2 to ≤12 months, 10.6 (8.7-12.9) >1-2 years, 15.5 (13.6-17.7) >2-5 years and 15.9 (14.5-17.6) for >5 years. Similar trends were seen for all other outcomes. The benefit of dapagliflozin was consistent across HF duration and on threshold analysis. The hazard ratio for the primary outcome ≥2 to ≤12 months was 0.86 (0.63-1.18), >1-2 years 0.95 (0.64-1.42), >2-5 years 0.74 (0.57-0.96) and >5 years 0.64 (0.53-0.78), P-interaction=0.26. The absolute benefit was greatest in longest duration HF, with a number needed-to-treat of 18 for HF >5 years, compared with 28 for ≥2 to ≤12 months. Conclusions: Longer-duration HF patients were older, had more comorbidity and symptoms, and higher rates of worsening HF and death. The benefits of dapagliflozin were consistent across HF duration. Registration: ClinicalTrials.gov; Unique identifier: NCT03036124.