Coffee may help protect against A-fib, the most common irregular heartbeat, study finds

Drinking caffeinated coffee is safe for people with atrial fibrillation and may help protect against recurrence of the disease, according to a new study.

More than 10 million Americans live with atrial fibrillation, or A-fib, a common heart disorder that causes heart palpitations and can lead to heart failure, blood clots and stroke. Doctors have long tried to understand whether caffeine — which can increase heart rate and blood pressure — seems to trigger episodes that feel like a thumping or thumping in the chest and cause dizziness or shortness of breath.

“There is no standard advice regarding atrial fibrillation and caffeine,” said Dr. Gregory Marcus, a cardiologist and professor of medicine at the University of California, San Francisco, who led the DECAF (Does Eliminating Coffee Prevent Fibrillation?) study. “It is very common for me to encounter patients who have stopped drinking caffeinated coffee only because their doctor told them to because of their atrial fibrillation. »

Results of the DECAF study, a four-year clinical trial examining the effects of coffee consumption in people with a history of resolved or treated cardiac arrhythmia, were presented Sunday at the American Heart Association’s annual conference in New Orleans and published in JAMA. Marcus is an associate editor of JAMA.

Researchers recruited 200 older people in Australia, Canada and the United States who regularly drank coffee at some point in the past five years. The average age was 70 and a third were women.

For six months, participants were randomized into two groups: those who quit caffeine and those who drank at least one cup every day. Everyone self-reported their coffee and caffeinated beverage intake during telehealth or video recordings that took place one, three, and six months after the trial began.

Using data from electrocardiograms, or EKGs, taken in a doctor’s office, wearable heart monitors, and implantable heart devices, Marcus and his team determined if and when people in each group had their first recurrent episode of A-fib. They included episodes of atrial flutter, a related condition that also causes abnormal contractions in the upper chambers of the heart.

Both groups had roughly the same drinking habits. Not everyone was a coffee drinker at the start of the study, but the number of daily coffee drinkers in each group was similar.

Before the study began, 60% of people in the coffee-drinking group and 65% of the no-coffee group said coffee had never triggered an episode of A-fib.

During the six-month study, 111 people, or 56 percent, had a recurrent episode of atrial flutter. People in the coffee-drinking group were less likely to have a recurrence – 47% compared to 64% of people in the no-coffee group – and took longer to have their first episode.

(About a third of people in the no-coffee group admitted to drinking at least one cup during the study, while the rest did not.)

One cup a day “perfectly safe”

This is the latest study showing that coffee may reduce the risk of heart problems and other metabolic diseases.

Previous observational research suggested that people who drank coffee were at lower risk of fibrosis A, but the new trial shows a cause-and-effect relationship, Marcus said.

“I was somewhat surprised at the magnitude of protection that caffeinated coffee appears to have in preventing atrial fibrillation,” Marcus said.

Dr. Johanna Contreras, a cardiologist at Mount Sinai Fuster Heart Hospital in New York, said the most important takeaway from the study was that drinking one cup of coffee a day appears to be perfectly safe for people with fibrosis A, rather than that coffee is protective.

“There’s no hard and fast rule. Not everyone has the same reaction to caffeine,” said Contreras, who was not involved in the trial.

The study has notable limitations, including the effects of caffeinated beverages other than coffee. The trial did not track differences in exercise habits or diet. People who drink coffee might also get more exercise, Marcus suggested.

The study found that drinking just one cup of coffee per day appeared to have a protective effect, and although some people in the study drank more, it is unclear whether more than one cup of coffee per day could have an effect on the recurrence of A fibroids.

Moderation is key, Contreras said.

“If people drink six or seven cups of coffee and then Red Bulls and Celsius, that’s different,” she said.

It’s unclear why coffee consumption was associated with a lower risk of recurrence of irregular heartbeat. It’s possible that an anti-inflammatory compound found in coffee, not specifically caffeine, reduced recurrence in the coffee-drinking group, Marcus said.

If caffeine is involved, it’s possible that boosting the body’s adrenaline response with caffeine could help stave off A-fib. People often report episodes when they are relaxed, such as during sleep or after a large meal, when adrenaline is low, Marcus said, when the “rest and digest” part of the nervous system is activated.

Additionally, the trial only included people who were not currently experiencing episodes of A-fib. The results may not apply to people with this unmanaged disorder.

“If someone was in the midst of A-fibrillation, caffeine could certainly increase the pulse rate during that episode and therefore make the symptoms worse,” he said.

For people who already drink coffee regularly, “this shows that you can have a cup of coffee in the morning and be OK if you have A-fib,” Contreras said.