A new observational study published in the Journal of the American College of Cardiology, questions the safety of using digoxin, one of the oldest drugs used in heart failure and atrial fibrillation (AF). The few trials supporting its use were performed in heart failure (HF) patients before newer treatments arrived and there have been no good trials in AF.

Researchers examined data on more than 122,000 patients in the Veterans Affairs system who had newly diagnosed AF. During 350,000 patient-years of follow-up, roughly one-quarter of the patients died. Nearly 29,000 patients who received digoxin were matched with an equal number of controls who did not. The risk for death was higher among digoxin recipients than controls — a finding that remained significant after multivariable adjustment (hazard ratio, 1.21).

Digoxin was associated with increased risk of death in patients with newly diagnosed AF, independent of drug adherence, kidney function, cardiovascular comorbidities, and concomitant therapies. These findings challenge current cardiovascular society recommendations on use of digoxin in AF.

Asked whether doctors should stop using the drug, lead author of the study Turakhia said: “Absolutely not. I don’t want readers to conclude that all patients should stop the drug and that all clinicians should cease using it. There may be perfectly valid reasons to use digoxin, and some studies over the years have shown benefit in heart failure, at least for the outcome of hospitalization. However, in light of the many safer drugs that can be used for rate control, clinicians need to ask whether digoxin should be the treatment of choice. We examined digoxin as early or initial therapy for new AF — not treatment failures or other nuanced scenarios — and we still found a mortality signal.”