The Kaiser Permanente study, published online in the journal Circulation: Arrhythmia and Electrophysiology, found adults with irregular heartbeats (called atrial fibrillation) but no evidence of heart failure had a 71 percent higher risk of death and a 63 percent higher risk of hospitalization if they were taking the drug.
 

Digoxin is a drug derived from digitalis, which has been used for more than a century for heart-rate control in patients with atrial fibrillation, and it remains commonly used for this purpose worldwide. Current clinical practice guidelines for the management of atrial fibrillation recommend the use of digoxin alone for resting heart-rate control in sedentary individuals.
 

"Our findings suggest that the use of digoxin should be re-evaluated for the treatment of atrial fibrillation in contemporary clinical practice," said study co-author Anthony Steimle, M.D., chief of cardiology at Kaiser Permanente Santa Clara Medical Center. "Given the other options available for heart-rate control, digoxin should be used with caution in the management of atrial fibrillation, especially in the absence of symptomatic systolic heart failure."
 

The findings echo those of a 2013 study that linked digoxin with a 72 percent higher rate of death among adults with newly diagnosed systolic heart failure.
 

The findings are based on a review of the medical charts of almost 15,000 adults within Kaiser Permanente's Northern and Southern California regions who had recently diagnosed atrial fibrillation and no prior heart failure or digoxin use. Researchers examined the independent association between newly initiated digoxin use and the risks of death and hospitalization.
 

"Digoxin remains commonly used for rate control in atrial fibrillation, but very limited data exist to support this practice — mostly small, older clinical studies with very limited follow-up that did not assess the long-term effects of digoxin on mortality or hospitalization," said Alan S. Go, M.D., a research scientist at the Kaiser Permanente Division of Research in Oakland, Calif.
 

"In contrast, this study included the largest and most diverse sample of adults with incident atrial fibrillation not complicated by heart failure treated in clinical practice reported to date, with results that were consistent across age and gender. We believe these findings, which build on earlier work, have significant value in guiding clinical cardiology decision-making in regard to digoxin use in the modern era."