Digoxin and mortality in atrial fibrillation: a prospective cohort study.
OBJECTIVE
The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) study showed that rhythm-control treatment of patients with atrial fibrillation (AF) offered no survival advantage over a rate-control strategy. In a subgroup analysis of that study, it was found that digoxin increased the death rate [relative risk (RR) = 1.42), but it was suggested that this may have been attributable to prescription of digoxin for patients at greater risk of death, such as those with congestive heart failure (CHF). No study has investigated a priori the effect of digoxin on mortality in patients with AF. This study aimed to address this question.


METHODS
Using data from the Registry of Information and Knowledge about Swedish Heart Intensive care Admissions (RIKS-HIA), we studied the 1-year mortality among patients admitted to coronary care units with AF, CHF, or AF+CHF with or without digoxin (n = 60,764) during 1995-2003. Adjustment for differences in background characteristics and other medications and treatments was made by propensity scoring.


RESULTS
Twenty percent of patients with AF without CHF in this cohort were discharged with digoxin. This group had a higher mortality rate than the corresponding group not given digoxin [adjusted RR 1.42 (95% CI 1.29-1.56)], whereas no such difference was seen among patients with CHF with or without AF, although these patients had a nearly three-times higher mortality.


CONCLUSIONS
The results suggest that long-term therapy with digoxin is an independent risk factor for death in patients with AF without CHF.
Hallberg
Pär
P
Department of Medical Sciences, Clinical Pharmacology, Uppsala University Hospital, Uppsala University, 751 85, Uppsala, Sweden. par.hallberg@medsci.uu.se
Lindbäck
Johan
J
Lindahl
Bertil
B
Stenestrand
Ulf
U
Melhus
Håkan
H
D000368:Aged; D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects*; D001281:Atrial Fibrillation / Q000097:blood / Q000188:drug therapy* / Q000401:mortality* / Q000503:physiopathology; D003404:Creatinine / Q000097:blood; D004077:Digoxin / Q000009:adverse effects*; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000188:drug therapy* / Q000401:mortality* / Q000503:physiopathology; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy / Q000401:mortality; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012042:Registries; D012107:Research Design; D018570:Risk Assessment; D012307:Risk Factors; D013318:Stroke Volume; D013548:Sweden; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left
D000889:Anti-Arrhythmia Agents; D004077:Digoxin; D003404:Creatinine