One glass of wine, beer or other alcoholic beverage may significantly increase the risk of an atrial fibrillation (AFib) episode within the next four hours, according to results of the HOLIDAY Monitors study presented May 17 during ACC.21.

The study, led by Gregory M. Marcus, MD, FACC, looked at alcohol consumption and AFib episodes in 100 patients with paroxysmal or intermittent AFib who consumed at least one alcoholic beverage per month. All participants wore an electrocardiogram (ECG) monitor to continuously track heart rhythm, as well as a transdermal alcohol sensor on their ankle to detect if patients consumed two to three drinks. Patients were instructed to press a button on the heart monitor each time they had an alcoholic drink. In addition, phosphatidylethanol testing was used to measure alcohol consumption at the middle and end of the study period to corroborate self-reported drinking events.

Participants were an average age of 64 years and the majority were white (85%) and male (80%). The patients wore the ECG monitor a median of 27 days (interquartile range [IQR], 15.28) and consumed a median of 19 drinks (IQR, 10-38) on a median of 12 days (IQR, 7-21).

Overall, more than half of the patients (56) experienced an AFib episode during the four-week study period. AFib occurred a median of five days (IQR, 2.5-12.5). The study showed that one glass of wine, beer or other alcoholic beverage was associated with twofold greater odds of an AFib episode within the next four hours (95% confidence interval [CI], 1.28-3.17; p=0.002). Among patients who consumed two or more drinks in one sitting, there was a more than threefold increased risk of an AFib episode (95% CI, 1.63-7.89; p=0.002).

According to the ankle sensor that monitored alcohol intake, every 0.1% increase in inferred blood alcohol concentration over the previous 12 hours was associated with 38% greater odds of an AFib episode (odds ratio [OR], 1.38; 95% CI, 1.04-1.83; p=0.024). In addition, evidence from the sensors demonstrated that total alcohol consumption over time also predicted the chance AFib would occur.

Marcus noted that other factors – such as race/ethnicity, sex, genetics or other environmental exposures – that influence alcohol's effect on the heart in various ways and need to be studied. The findings also contradict previous research suggesting that moderate alcohol use has a potentially protective effect on the heart. According to Marcus, precision medicine could help identify which patients are at high risk for alcohol-related AFib.

"There is conventional wisdom that alcohol is 'good' or 'healthy' for the heart, based on observational studies, but that relates to coronary heart disease and heart attack. These new data present an interesting conundrum regarding the overall risks versus benefits of alcohol in moderation," Marcus said. "But the data is very clear that more is not better when it comes to alcohol; those who drink more have a higher risk of heart attack and death."

Going forward, Marcus plans to look at how these findings may apply to the general population and identify other factors, including genetics, that may influence the relationship between alcohol and AFib.

Clinical Topics: Arrhythmias and Clinical EP, Diabetes and Cardiometabolic Disease, Dyslipidemia, Implantable Devices, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias

Keywords: ACC Annual Scientific Session, ACC21, Dyslipidemias, Arrhythmias, Cardiac, Atrial Fibrillation, Alcohol Drinking

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