August 31, 2021
Consuming alcohol increases the risk for an atrial fibrillation (AF) episode hours later, according to a study published online August 30 in Annals of Internal Medicine. Modifying the drinking behavior of patients with a history of AF events could make a difference.
Past research has associated long-term alcohol consumption with the development of AF, and abstinence from alcohol has been associated with a lower overall AF burden. However, lead study author Greg Marcus, MD, a cardioelectrophysiolgist at the University of California, San Francisco, said many patients say that alcohol is a trigger for discrete AF episodes.
To test whether that was possible, the researchers enrolled 100 patients who had a history of AF events and who drank at least one drink per month. Participants wore a transdermal alcohol sensor and an ambulatory, single-lead electrocardiogram device for 4 weeks. They were instructed to press a button on the electrocardiogram device each time they consumed a standard alcoholic beverage. In addition, blood samples were tested for phosphatidylethanol (PEth) at the participants' 2-week and 4-week visits. PEth is a phospholipid formed in the blood after alcohol intake. It remains in the blood for up to 4 weeks after alcohol consumption.
The study findings confirmed what the patients had reported. The odds of an AF episode were 38% greater with every 0.1% increase in peak blood alcohol concentration over the previous 12 hours (odds ratio [OR], 1.38; 95% CI, 1.04 – 1.83; P = .024). Moreover, an episode of AF was associated with twofold greater odds (OR, 2.02; 95% CI, 1.38 – 3.17) of having consumed one alcoholic drink in the past 4 hours. It was associated with more than threefold greater odds of having consumed two or more drinks (OR, 3.58; 95% CI, 1.63 – 7.89).
"The major takeaway is, among atrial fibrillation patients, consuming alcohol substantially heightened their risk for any given atrial fibrillation event in the subsequent few hours," Marcus said. "The more alcohol consumed, the higher that risk."
The acute effect of alcohol on these arrhythmias also means that modifying alcohol consumption could immediately benefit some patients. "These data combined with other evidence suggest that recommending minimizing or completely eliminating alcohol will likely be helpful to them," Marcus said.
The study's reliance on wearables and sensors was impressive, said Mariann R. Piano, PhD, director of the Center for Research Development and Scholarship, Vanderbilt University School of Nursing, Nashville, Tennessee. Often, these types of studies are "self-reported and confounded by recall bias," she said. But this study passively documented arrhythmia events and blood alcohol level without any patient input. The additional measures of alcohol consumption were used to validate the blood alcohol sensor.
The study's focus on patients with a history of AF highlighted a high-risk patient group, according to Piano, who co-authored an editorial about the study. However, the findings may not be applicable to the general population.
Marcus said alcohol's role in causing these types of arrhythmias is probably a matter of degree. AF patients are more prone to events than the general population and are therefore more sensitive to alcohol, he said. But excessive alcohol consumption could increase the chance of AF in the general population.
The study is not without its limitations, however. For instance, "it would have been really ideal if we knew what that blood alcohol was" before an episode, Piano said. The number of drinks is a good start, but two drinks can affect persons differently, depending on their weight and height. Also, baseline PEth values suggest that patients had been drinking before the study, she said. Ideally, patients could have been asked to abstain from alcohol for a period before the study to determine a negative baseline PEth value and minimize the effects of previous drinking on AF episodes.
Moving forward, this research should inform how clinicians care for their AF patients, both experts agree. "We need to talk to patients about how much they drink," Piano said. In addition, patients should be advised to closely monitor what they're drinking.
"This definitely sharpens the focus of the importance of a thorough alcohol history when we see an atrial fibrillation patient and to counsel them to reduce or eliminate alcohol, even among those that don't have alcohol use disorders," Marcus said.
Preliminary results of the study were presented as a late-breaking clinical trials presentation at the American College of Cardiology meeting in May.
Marcus has received grants from Baylis, Jawbone, and Eight Sleep and has received personal fees from InCarda and Johnson & Johnson. Co-authors have received personal fees from VivaLNK, Huba Pharmaceuticals, Johnson & Johnson, and Merck and grants from Samsung and Amgen, Inc. The editorialists have reported no relevant financial relationships.