Clinical outcomes in patients with atrial fibrillation treated with digoxin, according to the presence of heart failure: Insights from the MISOAC-AF trial

Abstract

Background: Digoxin is widely used in atrial fibrillation (AF) and heart failure (HF). However, current evidence regarding its association with clinical outcomes is conflicting.

Aim: To investigate the relationship between digoxin therapy and adverse outcomes in patients with AF, with or without HF, in a contemporary AF cohort.

Methods: We performed a retrospective analysis of data from 698 patients, who were followed over a median of 2.5 years. The primary outcome was all-cause mortality and the secondary outcome was all-cause hospitalization, in a time-to-event analysis. Propensity scores were used to derive matched populations, balanced on key baseline covariates. To limit potential confounding, inverse probability of treatment weighting (IPTW) analysis was performed.

Results: Among patients with HF, 39 (10.5%) were administered digoxin at baseline, whereas 331 (89.5%) were not. Digoxin administration was not associated with an increased risk of death (hazard ratio (HR) in the digoxin group, 1.21; 95% Confidence Interval (CI), 0.69 to 2.13, p = 0.50) or hospitalization of any cause (HR 1.15; 95% CI, 0.67 to 1.96; p = 0.60). Among patients without HF, 11 (3.5%) were administered digoxin, with neutral effects on all-cause mortality (HR: 3.25; 95% CI, 0.98 to 10.70), p = 0.06) and all-cause hospitalization (HR, 1.15; 95% CI, 0.67 to 1.96, p = 0.60). Qualitatively, consistent results were observed using IPTW.

Conclusions: Among patients with AF, digoxin administration was not associated with an increased risk of death and hospitalization for any cause, irrespective of HF status.

Keywords: Atrial fibrillation; Death; Digitalis; Heart failure; Hospitalization; Mortality.