Disclosures: Marcus reports receiving grants from Baylis, Eight Sleep and Jawbone and personal fees from InCarda and Johnson & Johnson outside the submitted work. Please see the study for all other authors’ relevant financial disclosures.
September 09, 2021
4 min read

As little as one alcoholic drink may double odds of atrial fibrillation event

Disclosures: Marcus reports receiving grants from Baylis, Eight Sleep and Jawbone and personal fees from InCarda and Johnson & Johnson outside the submitted work. Please see the study for all other authors’ relevant financial disclosures.
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In patients with paroxysmal atrial fibrillation, one alcoholic drink doubled the odds of having an atrial fibrillation episode within 4 hours of its consumption, a small, prospective, case-crossover analysis showed.

CVD is the leading cause of death among American adults, according to the CDC.

The quote is: These data provide more evidence that minimizing or even entirely avoiding alcohol is likely to be of benefit. The source of the quote is: Gregory Marcus, MD, MAS.

Gregory Marcus, MD, MAS, a professor of medicine at the University of California at San Francisco, and colleagues recruited 100 adults (mean age, 64 years; 79% men; 85% white) with paroxysmal atrial fibrillation who said they drank an average of one alcoholic drink per month. Each participant continuously wore an ECG monitor and a transdermal ethanol sensor around their ankle for 4 weeks. The participants were asked to press a button on the ECG monitor every time they consumed the equivalent of a glass of wine poured at a restaurant, a 12-ounce container of beer or a shot of spirits. Fingerstick blood tests verified participants’ alcohol consumption.

“Such a study examining real-time effects is vulnerable to confounding related to exposures that are reliably contemporaneous with alcohol consumption, such as those that might occur during socializing occasions,” Marcus and colleagues wrote. “Because no other behavior has been objectively shown to enhance the risk for a discrete atrial fibrillation event, such possible confounders are based on speculation.”

The researchers wrote in Annals of Internal Medicine that 56 of the adults had at least one episode of atrial fibrillation during the study period. An atrial fibrillation episode was linked to a twofold increased odds of having one alcoholic drink (OR = 2.02; 95% CI, 1.38-3.17) and greater than threefold higher odds of at least two drinks (OR = 3.58; 95% CI, 1.63-7.89) in the previous 4 hours.

In addition, instances of atrial fibrillation were also linked to higher odds of peak blood alcohol concentration (OR = 1.38; 95% CI, 1.04-1.83 for each 0.1% increase in blood alcohol concentration) and the total area under the curve of alcohol exposure (OR = 1.14; 95% CI, 1.06-1.22 for each 4.7% increase in alcohol exposure) as provided by the transdermal ethanol sensor in the previous 12 hours.

Marcus and colleagues cautioned their findings may not necessarily be applicable to the general population. Even so, their results “suggest that curbing alcohol consumption may have immediately beneficial effects in the prevention of atrial fibrillation.”

Previously published studies suggest that not all primary care providers may know their patients’ drinking routines to even begin discussing ways to prevent, diagnose and treat diseases stemming from its use, including atrial fibrillation.

For instance, for about a decade, the U.S. Preventive Services Task Force has recommended that all adults be screened in primary care settings for “unhealthy” or “risky” alcohol use — four drinks (or 56 grams) daily or 14 drinks (or 196 grams) weekly for healthy men aged 64 years and younger as well as three drinks (or 42 grams) daily or seven drinks (or 98 grams) weekly for nonpregnant women and men older than 65 years. The USPSTF also recommends that primary care providers offer brief counseling sessions to patients who report drinking in excess.

However, a recent analysis indicated that 23.5% of survey respondents were not asked by a primary care health professional if they drank alcohol in the past year. In a follow-up survey of respondents who said they drank alcohol, just 11.8% were asked if they had a drinking problem. The analysis also revealed that only 7.3% of regular and chronic drinkers were referred to treatment. Another survey analysis showed that among an estimated 14.1 million U.S. adults with alcohol use disorder in the past year, only 1.6% reported receiving one of four FDA-approved medications for treating the disorder.

We asked Marcus to explain how his study fits in the broader spectrum of the relationship between alcohol use and cardiovascular events, how its findings may impact clinical practice and more.

Healio Primary Care: Why did you choose to look into this topic?

Marcus: Alcohol is the most commonly used drug in the world, yet we know amazingly little about its true health effects, particularly cardiovascular effects that occur immediately upon consumption. Patients with atrial fibrillation have long reported that alcohol can acutely trigger an arrhythmia episode, but this has never been objectively assessed. Examining these sorts of real-time effects has been difficult in ambulatory populations, but more modern technology now enables us to continuously assess individuals in natural environments.

Healio Primary Care: The relationship between alcohol and cardiovascular events has been studied extensively. What did your study look at that has not been reported on before?

Marcus: The great majority of research examining relationships between alcohol and heart disease has focused on chronic effects, such as whether long-term, self-reported drinking patterns are associated with the eventual development of the diagnosis of disease. This is the first study to assess real-time relationships between alcohol consumption and the chance a discrete atrial episode will occur in a matter of hours.

This study also did not rely on self-reports, which is a common limitation of most alcohol-related studies. The other overarching question independent of alcohol is whether the occurrence of any given atrial fibrillation episode is simply due to bad luck or whether there are environmental influences or even modifiable behaviors, such as alcohol consumption, that influence the likelihood an arrhythmia event will occur.

Healio Primary Care: Were the findings surprising? Why or why not?

Marcus: The finding that a single drink was associated with a substantially heightened risk of an [atrial fibrillation] event in the next few hours was surprising. Conventional wisdom, which has relied on anecdotes and small case series, holds that excessive alcohol consumption is required to trigger an atrial fibrillation episode. It was also interesting to observe consistent timing between alcohol consumed in the increased chance that atrial fibrillation would occur, generally requiring a few hours, which may help us understand mechanistic relationships between alcohol and near-term cardiovascular effects.

Healio Primary Care: Should these findings change clinical practice?

Marcus: These findings bolster the growing evidence that alcohol consumption increases the risk for atrial fibrillation — now we have evidence this is not simply a long-term phenomenon, but rather that, in an immediate sense, any given drink increases the chance an atrial fibrillation episode will occur.

We still do not fully understand the net clinical benefits vs. risks of regular, light alcohol consumption in the general population, and there is a lot more research to do before we can confidently inform the public about optimizing their overall health when it comes to alcohol. However, for those with a diagnosis of atrial fibrillation who hope to do everything they can to reduce their risk for an arrhythmia episode, these data provide more evidence that minimizing or even entirely avoiding alcohol is likely to be of benefit.


Boersma P, et al. National Center for Health Statistics. Heavy drinking among U.S. adults. https://www.cdc.gov/nchs/products/databriefs/db374.htm. Accessed Aug. 31, 2021.

Han B, et al. JAMA Psych. 2021;doi:10. 1001/jamapsychiatry.2021.1271.

Sahker E, Arndt S. Int J Drug Policy. 2017;doi:10.1016/j.drugpo.2016.11013.

USPSTF. Unhealthy alcohol use in adolescents and adults: screening and behavioral counseling interventions. https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/unhealthy-alcohol-use-in-adolescents-and-adults-screening-and-behavioral-counseling-interventions. Accessed Aug. 31, 2021.