Coffee might benefit patients treated for atrial fibrillation

Adults treated for atrial fibrillation (AFib/AF) who consume a daily cup of coffee are 39% less likely to have an irregular heart rhythm episode compared to those who consume no caffeine.

These findings were presented on Nov. 9, 2025 at the American Heart Association’s Scientific Sessions, and they were published simultaneously in JAMA/Journal of the American Medical Association.

“Our study results suggest that caffeinated coffee may not be responsible for raising the risk of AFib and may even reduce it,” said senior study author Gregory M. Marcus, M.D., M.A.S., a professor of medicine at the University of California, San Francisco.”

He added, “It is reasonable for health care professionals to let their AFib patients consider experimenting with naturally caffeinated substances that they may enjoy, such as caffeinated tea and coffee. However, some people may still find that caffeine or caffeinated coffee triggers or worsens their AFib.”

The authors noted that it is widely assumed that caffeinated coffee is proarrhythmic. No prior randomized trial has evaluated the effects of caffeinated coffee consumption in subjects with atrial fibrillation.

Investigators for the Does Eliminating Coffee Avoid Fibrillation (DECAF) trial enrolled 200 adult subjects who had been diagnosed with persistent atrial fibrillation. All subjects were preparing for cardioversion therapy, with medication or by electrical shock.

The subjects reported that they consumed about one cup of caffeinated coffee per day, and they agreed to follow guidance on caffeine consumption for 6 months after cardioversion therapy.

Half of the subjects were randomized to one cup of coffee daily, and the other half were told to avoid all caffeine.

The researchers reported that, during the 6-month study period, 47% of the subjects in the coffee-consuming group had recurrent atrial fibrillation or atrial flutter (rapid but regular heartbeat) lasting more than 30 seconds. This was compared with 64% of the no-caffeine group, indicating a 39% lower risk among the coffee consumers.

The results were similar when atrial flutter episodes were excluded.

The authors concluded, “In this randomized clinical trial of patients with persistent AF undergoing cardioversion, consumption of caffeinated coffee compared with abstinence from coffee and caffeine was associated with a significantly lower recurrence of AF or atrial flutter. The current results contrast with the traditional assumption that coffee promotes atrial arrhythmogenesis, but fit with some observational data on the subject. These findings could be considered in patients with AF and a personal preference for consumption of coffee and other caffeinated products.”