Predictors of digoxin use and risk of mortality in ED patients with atrial fibrillation

Abstract

ObjectivesThe aim of this study was to evaluate factors of digoxin use and its relation to mortality in ED patients with atrial fibrillation (AF). MethodsThe Chinese AF registry enrolled 2016 AF patients from 20 representative EDs, and the period of study was one year. Predictors of digoxin use and its relation to mortality were assessed by logistic and Cox regression analyses. ResultsDigoxin was assigned in 609 patients (30.6%), and younger age, lower body mass index values, and existence of permanent AF, heart failure (HF), chronic obstructive pulmonary disease, and valvular heart disease were identified to be factors associated with digoxin use. During the follow-up, compared to patients without digoxin therapy, digoxin-treated patients had significantly higher risk of all-cause death (17.2% vs. 13.0%, P=0.012) and cardiovascular death (15.1% vs. 6.7%, P<0.001), but similar risk of sudden cardiac death (1.1% vs. 0.7%, P=0.341). However, after adjustment for related covariates, digoxin use was no longer notably associated with increased all-cause mortality (hazards ratio [HR] 0.973, 95% confidence interval [CI] 0.718–1.318) and cardiovascular death (HR 1.313, 95% CI 0.905–1.906). Besides, neutral associations of digoxin treatment to mortality were obtained in relevant subgroups, with no interactions observed between digoxin and gender, HF, valvular heart disease, or concomitant warfarin treatment in mortality risk. ConclusionsIn ED patients with AF, digoxin was more frequently assigned to vulnerable patients with concomitant HF or valvular heart disease, and digoxin use was not related to a significantly increased risk of mortality.