Can Coffee Actually Reduce Atrial Fibrillation Recurrence?

A New Randomized Trial Says Yes.

For decades, patients with atrial fibrillation (AF) have been told that caffeine is a trigger for arrhythmias. Many clinicians have reinforced this idea, urging patients to reduce or eliminate caffeinated coffee because it was assumed to stimulate the heart and increase the risk of AF episodes. This belief has been deeply ingrained in both medical culture and patient experience. But a new randomized clinical trial published in JAMA now challenges that long-held assumption in a powerful and surprising way. The DECAF trial (Does Eliminating Coffee Avoid Fibrillation?) demonstrates that caffeinated coffee not only fails to increase AF recurrence but may actually lower it.

The DECAF trial enrolled 200 adults with persistent AF, or atrial flutter with a history of AF, who were scheduled for electrical cardioversion. All participants were current or past coffee drinkers, which ensured the study reflected real-world behavior. After successful cardioversion, participants were randomized into two groups for six months: one group was instructed to consume at least one cup of caffeinated coffee each day, and the other told to abstain completely from all coffee (including decaf) and all caffeine-containing products. The study was conducted across five hospitals in the US, Canada, and Australia between 2021 and 2024, with follow-up completed in 2025. Although open-label, all arrhythmia events were confirmed through physician-reviewed ECGs, wearable monitors, or implanted cardiac devices, giving the outcome measures strong clinical validity. The primary endpoint, recurrence of AF or atrial flutter lasting at least 30 seconds, was straightforward and clinically meaningful.

The results were striking and run counter to decades of conventional wisdom. At six months, 47% of patients in the coffee consumption group experienced recurrence, compared with 64% in the abstinence group. That represents a 39% lower hazard of recurrence in the coffee group. A separate analysis of AF alone, not counting atrial flutter, showed a nearly identical benefit. Importantly, no increase in adverse events was observed in the coffee group, meaning the overall safety profile of daily caffeinated coffee remained neutral while recurrence risk decreased.

Why would coffee reduce AF recurrence? Coffee contains polyphenols with anti-inflammatory properties, and inflammation is a well-established driver of AF. Some cases of AF are vagally mediated, and caffeine’s sympathetic-stimulating effects may counteract such mechanisms. Coffee’s mild diuretic effect may help reduce blood pressure and fluid retention, further impacting AF risk. There is also the lifestyle component: prior research, including the CRAVE trial, shows that random assignment to coffee consumption leads to a measurable increase in daily physical activity, and physical activity is strongly protective against AF recurrence. These mechanisms, acting together or independently, make the biological plausibility of the trial’s findings reasonable and potentially meaningful for patient care.

One noteworthy aspect of the DECAF study is that very few screened individuals were willing to participate. Many refused because they believed that coffee worsened their AF, even though this belief appears to be rooted more in long-standing assumptions than in data. The DECAF trial adds important randomized evidence to clarify this misconception and provides valuable reassurance to AF patients who enjoy coffee.

The practical takeaway from this trial is clear: for most individuals with AF, moderate caffeinated coffee intake is not harmful and may even be protective. And importantly, the study examined typical daily coffee consumption, not energy drinks or high-dose caffeine supplements, so the findings should not be extrapolated to extreme caffeine exposure. But for patients accustomed to drinking one or more cups of caffeinated coffee daily, there is now strong evidence that continued consumption is not only safe but may reduce AF recurrence after cardioversion. As always, individual triggers vary, and patients should discuss these findings with their cardiologists. Still, the DECAF trial marks a major step in rewriting a long-held narrative and offers a reassuring message: your morning cup of coffee may be part of the solution, not the problem.