Background: Recent studies of patients with heart failure and of patients under intensive care indicate that digoxin may increase mortality if the patient has atrial fibrillation (AF).
Aim: To study which patients receive digoxin treatment for AF and what the prognosis is for patients given this treatment.
Method: 2824 patients with AF was studied prospectively for a mean of 4.6 years. Information about medication was obtained from the local hospital registry. Information about diagnoses, hospitalisations and deaths was obtained from national registries. Propensity score matching and Cox regression was used to account for confounding.
Results: Factors associated with digoxin use were permanent AF (Hazard Ratio (HR) 3.2, confidence interval (CI) 2.7-3.9), absence of pacemaker (HR 2.2, CI 1.6-3.0), history of heart failure (HR 2.0, CI 1.7-2.5), treatment at an Internal Medicine ward rather than a Cardiology ward (HR 1.6, CI 1.3-2.0), female sex (HR 1.6, CI 1.3-1.9) and age ¡Ý80 years (HR 1.4, 1.1-1.7).
More patients with than without digoxin died (51% vs. 31%, p<0.0001). After adjustment for covariates, however, no disadvantages related to digoxin use could be found regarding all-cause mortality, myocardial infarction , ischemic stroke, time to readmission to hospital or days at hospital/year at risk. The only endpoint significantly associated with digoxin use was pacemaker implantations which were more common in digoxin treated patients (HR 2.0, CI 1.2-3.4).
Conclusion: Digoxin is mainly given to an elderly and frailer subset of AF-patients and is thus associated with an increased mortality. When differences in patient characteristics are accounted for digoxin use appears to be neutral regarding mortality and major cardiovascular events in AF patients.