Digoxin, for its wide use and history, may not be as safe for use in atrial fibrillation patients as it is assumed to be. Or is it? A study published Aug. 19 in the Journal of the American College of Cardiology attempted to answer this question.

Lead by Mintu P. Turakhia, MD, MAS, of the Veterans Affairs Palo Alto Health Care System in California, the research team utilized the data amassed by the TREAT-AF (the Retrospective Evaluation and Assessment of Therapies in Atrial Fibrillation) study. The TREAT-AF cohort was developed using patients treated in the Veterans Administration health system. Of the 122,465 new atrial fibrillation patients enrolled in the cohort, 23.4 percent were treated with digoxin.

While the research team acknowledged the efficacy of digoxin in heart failure, despite debates around that topic of late, they were looking to see whether atrial fibrillation patients benefited from use of digoxin or not.

What they found was that patients treated with digoxin had an increased risk for mortality, whether adjusted for other variables (hazard ratio 1.26), or matched (hazard ratio 1.21). These increased rates remained regardless of age, other drugs or comorbid conditions.

It was important to note, however, a general lack of female patients due to the nature of the patient pool. Turakhia et al acknowledged this problem with a recommendation that further studies should follow up on how sex affects atrial fibrillation mortality.

"The take-home point is to question whether people should really be on this drug," said Turakhia in a press release. "These data challenge the current guidelines."

Matthew R. Reynolds, MD, MSc, of Lahey Hospital & Medical Center in Burlington, Mass., agreed. In an editorial, Reynolds wrote that the role of digoxin in treating atrial fibrillation, in light of the findings of this study, should be carefully considered when other, better heart rate control methods are available.

“Going forward, the role of digoxin in AF treatment may continue to diminish,” Reynolds wrote. “For now, there are still clinical circumstances (HF [heart failure], difficult rate control, low blood pressure) where this old herbal remedy remains useful.”

“We are not asserting this drug should never be used,” Turakhia said. “However in light of many other drugs that can be used to slow down the heart rate in atrial fibrillation, patients and providers need to ask whether digoxin should be the treatment choice when there are other, safer drugs.”

For more on digoxin and questions about current use, read “Duel Over Digoxin: Is It Safe for HF?”