A small alcoholic beverage a day is associated with an increased risk of atrial fibrillation

A study of nearly 108,000 people found that people who regularly consume a modest amount of alcohol have an increased risk of atrial fibrillation, a condition in which the heart beats at an abnormal rate.

The study, published today (Wednesday) in European Heart Journal [1], found that compared to no alcohol at all, only one alcoholic beverage per day was associated with a 16% increased risk of atrial fibrillation over an average (mean) follow-up time of almost 14 years. This means that while four out of 100 teetotal sufferers may develop atrial fibrillation during the study period, five out of 100 may develop the condition if they drink less than one alcoholic drink per week and more than 75% of them. they drank up to one drink a day [2]. The researchers classified an alcoholic beverage as containing 12 g of ethanol, which is the equivalent of a small glass of wine (120 ml), a small beer (330 ml) or 40 ml of spirits.

It is well known that people who drink a lot of alcohol regularly have an increased risk of developing heart failure, and heart failure can increase the incidence of atrial fibrillation. Several studies have shown a slightly higher risk of heart problems in people who never drink alcohol; they often show that this risk is reduced for people who consume a modest amount, and then suddenly increases as more alcohol is consumed, creating a “J” shape on the graphs. So far, it has not been clear whether this was also the case with atrial fibrillation.

However, in the current study led by Professor Renate Schnabel, a cardiologist at the University of Heart and Vascular Center, Hamburg-Eppendorf (Germany), researchers found that although low doses of alcohol were associated with a reduced risk of heart failure, compared to teetotalizers, a similar reduction in the “J” shape of the risk was not observed for atrial fibrillation. This suggests that the increased risk of atrial fibrillation among people who consume small amounts of alcohol was not triggered by heart failure.

Prof. Schnabel said: “To our knowledge, this is the largest study on alcohol consumption and the long-term incidence of atrial fibrillation in the community. Previous studies have not had enough power to examine this question, although they have been able to show a relationship between alcohol consumption and other heart and blood vessel problems, such as heart attack and heart failure. In our study, we can now show that even very little regular alcohol consumption can increase the risk of atrial fibrillation.

“These findings are important because regular alcohol consumption, ‘a glass of wine a day’ to protect the heart, as is often recommended, for example, in the secular press, probably should not be suggested without balancing the risks and possible benefits all diseases of the heart and blood vessels, including atrial fibrillation. “

The researchers analyzed information on 107,845 people who took part in five community studies in Sweden, Norway, Finland, Denmark and Italy. Participants underwent medical examinations when they joined the studies between 1982 and 2010 and provided information about their medical history, lifestyle (including alcohol and tobacco use), employment levels and education. A total of 100,092 participants did not have atrial fibrillation when they registered and their average age was almost 48 years (range 24-97 years).

During the average follow-up period of almost 14 years, 5,854 people developed atrial fibrillation. The associations between alcohol consumption and the risk of atrial fibrillation were similar for all types of alcoholic beverages and for men and women.

In addition to the 16% increased risk of atrial fibrillation compared to medications seen in people who drink only one alcoholic drink a day, the researchers found that the risk increased with increasing alcohol consumption; up to two drinks a day was associated with an increased risk of 28% and this increased to 47% for those who consumed more than four.

The exact mechanisms by which modest amounts of alcohol can trigger atrial fibrillation are unknown. Studies have shown that heavy drinking for a short period of time can trigger “holiday heart syndrome” in some people, and in some patients with atrial fibrillation, small amounts of alcohol can trigger arrhythmia episodes.

Limitations of the study include the fact that study participants reported the type and amount of alcohol they drank and this could lead to under-reporting; the available information did not allow the researchers to analyze the effects of excessive alcohol consumption; some episodes of atrial fibrillation may be asymptomatic and therefore may not have been reported; only adults across Europe were included in the analyzes and therefore it may not be possible for the results to be generalized to other populations; since the study was observational, it can only show an association between alcohol consumption and atrial fibrillation and not that alcohol causes atrial fibrillation.

In an accompanying editorial [3], Jorge A. Wong and David Conen of the Institute for Population Health Research at McMaster University, Hamilton, Canada, write that the research “makes an important contribution to understanding the relationship between alcohol consumption and incidental AF, especially in the lower spectrum of a significant relationship between alcohol and AF was identified and even small amounts of alcohol were associated with an increased, albeit low, risk of incident.

“Together with a recent randomized study showing that a reduction in alcohol consumption has led to a reduction in recurrence of AF, these data suggest that decreasing alcohol consumption may be important for both prevention and management of AF. Importantly, any reduction from low to moderate alcohol consumption to prevent the potential for AF must be balanced against the potentially beneficial association that small amounts of alcohol may have compared to other cardiovascular outcomes. The net clinical benefit of consuming small amounts of alcohol. Alcohol requires further study, ideally in randomized studies with adequate potency. Until then, each individual must make their own best-educated decision about whether consuming up to one alcoholic beverage a day is useful and safe. “

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[1] “Alcohol consumption, cardiac biomarkers and the risk of atrial fibrillation and adverse outcomes”, by Dora Csengeri et al. European Heart Journal. doi: 10.1093 / eurheartj / ehaa953

[2] Absolute risk data are not provided in the research paper. Absolute risk was calculated using additional information from researchers and the RealRisk web tool for risk and evidence communication from Cambridge Winton University: https: //url.wintoncentre.UK/p6lcb

[3] “Alcohol Consumption, Atrial Fibrillation, and Cardiovascular Disease: Finding the Right Balance,” by Jorge A. Wong and David Conen. European Heart Journal. doi: 10.1093 / eurheartj / ehaa955