乌鸦传媒

Just in time for the holidays: Even a small amount of alcohol intake was associated with atrial fibrillation (Afib), according to a systematic review.

And after a diagnosis of Afib, "those who continue to consume alcohol have higher rates of progression from paroxysmal to persistent Afib, more Afib recurrences following pulmonary vein isolation, and potentially higher rates of adverse outcomes, such as thromboembolism," , of Baker IDI Heart and Diabetes Institute in Australia, and colleagues wrote in the Dec. 13 issue of the .

"Habitual drinking at moderate levels, as well as binge drinking, predisposes to Afib, with an increase in Afib recurrence in those who continue to drink. Although a small amount of alcohol is considered cardioprotective, these benefits do not extend to Afib," the authors wrote in what they dubbed a "sobering" review.

Patients commonly present to emergency departments nationwide with "holiday heart syndrome," or Afib precipitated by alcohol, they noted. One study found that while "many patents develop Afib at the time of intoxication, others may present 12 to 36 hours later," they added -- with a quarter of patients showing recurrences at 1 year with subsequent binges.

Although heavy habitual alcohol consumption and binge drinking are closely associated with Afib, three large meta-analyses have also shown a link between light-to-moderate alcohol consumption and the condition, according to the authors.

Yet , of Beth Israel Deaconess Medical Center, commented to 乌鸦传媒 that his group's Copenhagen City Heart Study "might still be the largest prospective study of alcohol and Afib ever done and it showed an association only at very high doses."

"I think the data are quite consistent that heavy drinking – even in occasional binges – leads to Afib. Whether moderate drinking (and especially moderate drinking without occasional binges – since those are common in otherwise moderate drinkers) is related to Afib is, to me, still uncertain," Mukamal wrote in an email.

As to why the trend was only observed in pooled analyses, Kistler's group wrote: "Many of the individual studies were underpowered to demonstrate a relationship between alcohol and Afib, particularly in the primary prevention population, where the incidence of Afib was relatively low."

The authors of the review pointed out several limitations to interpretation of these observational studies, including self-reported alcohol intake -- in lieu of objective urine or blood sampling -- and the lack of dedicated electrophysiological monitoring leading to the possibility of underreported Afib episodes.

Even so, , of University of California San Francisco Medical Center, told 乌鸦传媒 that he believed this to be a "very reasonable, comprehensive, and fair review" that "helps to summarize decades of research regarding alcohol and Afib."

Importantly, Kistler and colleagues pointed out several lingering uncertainties regarding the link between alcohol and Afib, namely the mechanism by which alcohol leads to Afib, either acutely or chronically. They proposed several mechanisms, including electrical atrial remodeling, autonomic modulation, and effects on atrial excitation-contraction remodeling leading to tissue fibrosis.

"It is very likely that certain individuals are more or less prone to alcohol-induced Afib, and we have yet to determine how to identify these patients," said Marcus, who was not involved in the review. "Alcohol is clearly a risk factor for some people with Afib," he emphasized.

"It is likely important to distinguish the acute effects by which alcohol can trigger a discrete episode of Afib and the chronic effects of cumulative alcohol exposure as a risk factor for the development of the disease. More research, particular in humans, is needed to identify the mechanism by which alcohol might cause Afib," according to Marcus.

"Finally, given possible beneficial effects of moderate alcohol consumption regarding coronary disease and MI," he added, "we need to figure out how to optimally counsel our patients regarding the appropriate use of alcohol for their overall cardiovascular health."

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