Digoxin and prognosis of heart failure in older patients with preserved ejection fraction: Importance of heart rate. Results from an observational and multicenter study

Background: The value of digoxin in heart failure (HF) remains controversial, particularly in patients with preserved ejection fraction (HFpEF). This study evaluated the 1-year risk of events after digoxin treatment for acute heart failure (AHF) in patients > 70 years old with HFpEF. Methods: 1833 patients were included in this analysis (mean age, 82 years). The main endpoints were all-cause death and the composite of death and/or HF re-admission within 1 year. Cox regression analysis was used to evaluate the association between digoxin treatment and prognosis. Results: 401 patients received digoxin treatment; of these, 86% had atrial fibrillation. The mean baseline heart rate was 86 +/- 22 bpm. At the 1-year follow-up, 375 patients (20.5%) died and 684 (37.3%) presented composite endpoints. Patients treated with digoxin showed higher rates of death (3.21 vs. 2.44 per 10 person-years, p = .019) and composite endpoint (6.72 vs. 5.18 per 10 person-years, p = .003). After multivariate adjustment, digoxin treatment remained associated with increased risks of death (HR = 1.46, 95% CI: 1.16-1.85, p = .001) and the composite endpoint (HR = 1.35, 95% CI: 1.13-1.61, p = .001). A distinctive prognostic effect of digoxin was found across the heart rate continuum; the risks for both endpoints were higher at lower heart rates and neutral at higher heart rates (p of the interactions = 0.007 and 0.03, respectively). Conclusions: In older patients with HFpEF discharged after AHF, digoxin treatment was associated with increased mortality and/or re-admission, particularly in patients with lower heart rates.