Coffee may not trigger atrial fibrillation episodes: study

Results from a randomized clinical trial suggests that drinking caffeinated coffee will not increase the risk of triggering certain arrythmias. Coffee drinking was also associated with getting more exercise, at the expense of less sleep. The results come from the CRAVE (coffee and real-time atrial and ventricular ectopy) trial, which were announced on November 14 at the American Heart Association’s annual scientific sessions. The sessions were held virtually and in person in Boston. The trial investigated the acute effects of caffeinated coffee consumption in healthy people. “These data add to the growing evidence that those who have supraventricular arrythmias or atrial fibrillation, or are at risk for those, should not necessarily avoid coffee,” said Dr. Gregory Marcus, electrophysiologist and lead investigator of the study. Dr. Marcus is a professor of medicine at the University of California in San Francisco. Analysis of the data did suggest that people prone to premature ventricular contractions or ventricular arrythmias should avoid drinking coffee. The trial randomized 100 healthy adults who were willing to go without coffee for a maximum of two consecutive days. The mean age was 38 years old. All participants were provided with a FitBit watch, which monitored step counts and sleep duration. They were outfitted with a patch for continuous ECG monitoring, continuous glucose monitoring and the researchers genotyped all participants for caffeine metabolism-related SNPs. The participants were texted every evening with the instruction to either consume coffee or not the following day. They were asked to press a button on the ECG monitoring patch at the actual time when they had the coffee. On average, participants wore the ECG monitoring patch for 12.8 days. Coffee consumption was associated with significantly fewer episodes of supraventricular tachycardia (SVT) compared to abstaining from coffee. “We could find no evidence that coffee increased the risk for those arrythmias, and in fact some suggestion that coffee could reduce the risk of those arrythmias,” Dr. Marcus said. In contrast, having coffee brought more than a doubling of risk of experiencing a premature ventricular contraction compared to not having coffee. There was no effect of having coffee on glucose levels. Read: All about anticoagulation with AF Coffee did get participants moving more. Having coffee meant participants took an average of 1,058 more daily steps than not having coffee. Every additional drink of coffee meant 587 more steps a day. The downside was less sleep: coffee consumption brought an average of 36 fewer minutes of sleep compared to no coffee consumption. Participants’ genetic make-up affected their response to coffee. Those who had a genetic variant that makes them metabolize caffeinated coffee more slowly got even less sleep after a coffee than those without the genetic variant. People who had a variant associated with fast metabolism of coffee experienced more SVTs when they had coffee than those without the genetic variant. While most studies of coffee consumptions rely on self-reporting, Dr. Marcus and colleagues took steps to ensure that the changes in ECG were connected to a cup of coffee. All coffee (even if participants drank it on days when they were meant to abstain) was reimbursed if the participants provided a time and date-stamped receipt. Participants downloaded an app which tracked their location to map visits to coffee shops. They were also asked to press a button on their ECG patch whenever they had coffee. Dr. Marcus reported that compliance to the study protocol was good. Read: Key clinical guidelines and statements: July through September 2021 Dr. Sana Al-Khatib, an electrophysiologist and professor of medicine at Duke University Medical Centre, provided commentary on the CRAVE study at the scientific sessions. She noted that the question of risk of coffee consumption triggering arrthymias was an important one. “This is a question we’ve asked frequently in clinical practice,” she said. She pointed out that CRAVE’s patient population was young, had a low BMI and could operate a smartphone. “These are not representative of the average patient we see in clinical practice,” she said. Whether the increased physical activity with coffee translates into clinical outcomes deserves another study, Dr. Al-Khatib said. Dr. Marcus was also an investigator in another trial, called I-STOP AF. In the study, patients exposed to caffeinated coffee reported no increase in atrial fibrillation episodes. “This fits quite well with other observational data, growing evidence that caffeine may really not be important in terms of increasing atrial fibrillation risk,” Dr. Marcus said. While coffee may be a risk factor for atrial fibrillation episodes, alcohol remains a trigger. When patients were exposed to alcohol, in the I-STOP AF study, there were more atrial fibrillation episodes. “Alcohol, also consistent with the literature has, more and more, demonstrated very consistent evidence of a near-term harmful effect regarding increase atrial fibrillation episode risk,” Dr. Marcus said. Read: AB study exploring benefits of pharmacist screening for atrial fibrillation

Coffee may not trigger atrial fibrillation episodes: study

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