Despite endorsement of Digoxin in clinical practice guidelines, there exist limited data on its safety in atrial fibrillation / atrial flutter.
The goal of a study was to evaluate the association of Digoxin with mortality in atrial fibrillation / flutter.
Using complete data of the TREAT-AF ( The Retrospective Evaluation and Assessment of Therapies in AF ) study from the U.S. Department of Veterans Affairs ( VA ) healthcare system, researchers identified patients with newly diagnosed, nonvalvular atrial fibrillation seen within 90 days in an outpatient setting between VA fiscal years 2004 and 2008.
Researchers used multivariate and propensity-matched Cox proportional hazards to evaluate the association of Digoxin use with death.
Residual confounding was assessed by sensitivity analysis.
Of 122,465 patients with 353,168 person-years of follow-up ( age 72.1 ± 10.3 years, 98.4% male ), 28,679 ( 23.4% ) patients received Digoxin.
Cumulative mortality rates were higher for Digoxin-treated patients than for untreated patients ( 95 vs 67 per 1,000 person-years; p less than 0.001 ).
Digoxin use was independently associated with mortality after multivariate adjustment ( hazard ratio, HR=1.26, 95% confidence interval [CI]: 1.23 to 1.29, p less than 0.001 ) and propensity matching ( HR=1.21, 95% CI: 1.17 to 1.25, p less than 0.001 ), even after adjustment for drug adherence.
The risk of death was not modified by age, sex, heart failure, kidney function, or concomitant use of beta-blockers, Amiodarone ( Cordarone ), or Warfarin ( Coumadin ).
In conclusion, Digoxin was associated with increased risk of death in patients with newly diagnosed atrial fibrillation / flutter, independent of drug adherence, kidney function, cardiovascular comorbidities, and concomitant therapies.
These findings challenge current cardiovascular society recommendations on use of Digoxin in atrial fibrillation / flutter. ( Xagena )
Mintu P et al, J Am Coll Cardiol 2014;64:660-668