Dr John Mandrola practices cardiac electrophysiology in Louisville, KY. He finished training at Indiana University in 1996. His practice encompasses catheter ablation, including an eight-year experience with AF ablation, device implantation, and consultative EP. Outside of the EP lab, Dr Mandrola's two hobbies include competitive cycling and writing. He has maintained a medical, fitness, and cycling blog, Dr John M, for the past two years.
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ESC 2012: Does alcohol intake increase the risk of AF?Aug 29, 2012 09:11 EDT
If you counsel patients with atrial fibrillation, one topic that comes up a lot is alcohol.
Is it safe to drink? How much? I heard that alcohol helps prevent heart disease? Is one drink a day okay?
These are questions that AF caregivers hear often. I know I do.
I realize that Trials and Fibrillations is supposed to be a high-tech EP blog, but as a doctor on the front lines of perhaps the least healthy state in the US, I don't dismiss lifestyle factors. There's a reason this disease is running amok.
That's why I went to the session entitled, A drinker, rather than a smoker, is at high risk for atrial fibrillation in the general male population.
Japanese researchers set out to clarify the risk of developing AF in smokers and drinkers in a male population. They studied a community 60 miles outside of Tokyo, analyzing 75 361 men (average age 62) who participated in an annual health exam between the years 2000 and 2007. AF was assessed with 403 000 12-lead ECGs, recorded annually over the study period. Drinking and smoking behaviors were assessed with self-reported questionnaires.
They looked at AF prevalence at study onset then seven years later. The results were interesting.
- 49% of the subjects were drinkers (one or more drinks daily), and 40% were regular smokers.
- At study onset, the AF prevalence overall was 1.55%, with drinkers having a higher likelihood of AF than nondrinkers—1.7% vs 1.4%.
- Over the seven-year period, drinkers were 48% more likely to develop AF, while those who smoked did not see an increased risk.
- The striking finding was that drinking alcohol increased the risk more than hypertension (odds ratio=1.38) and body-mass index (BMI) (OR=1.36) and only slightly less than age (OR=1.8).
These data allowed for provocative conclusions (quoted directly from final slide):
- Drinkers are at a high risk for AF.
- However, smoking is not a risk factor for AF.
- With regard to lifestyle modifications for AF prevention, the risks of drinking should be emphasized more than those of smoking.
These kind of data pose a problem, don't they?
Just yesterday at ESC, there was a session entitled, "Eat, drink, and be merry." The topic of red wine was addressed. The consensus on alcohol's role in the prevention of atherosclerosis is complicated, but at least it seems a threshold of intake might exist—a J-shaped dose-response curve. Specifically, one to two drinks per day might not be harmful. Whether alcohol itself prevents atherosclerosis is debatable.
It's a different story for alcohol and AF. Although today's presentation involved a retrospective database analysis, which has significant limitations, including its evaluation of men only, the data warrant serious consideration.
Three things push me into believing what this study purports:
Consistency with previous trials : Here is a 2011 meta-analysis of 14 studies that concluded not consuming alcohol is most favorable in terms of AF risk reduction. Although statistically heavy, this study indicates that AF risk may increase incrementally with just one drink per day. And yes, there is actually a study (Journal of the American College of Cardiology) proposing that whiskey intake enhances vulnerability to AF in patients without heart failure or cardiomyopathy.
Biologic plausibility : Alcohol is not inert. It may act to increase adrenergic tone, decrease vagal tone, impair inotropy, and alter refractory periods and conduction velocity. Two obvious clinical variables associated with (excess) alcohol intake include sleep disturbance and hypertension.
Anecdotal experience of an AF doctor : Chalk this one up as the weakest of the three. Before there were checklists, quality measures, and tiered levels of evidence, doctors had only their experience and gut feeling to go on. Surely this counts for something? Although it would be foolish to say AF follows rules, it's not a stretch to say there may be trends. Here are a few typical AF vignettes to ponder: the frazzled middle-aged executive who slows his (or her) brain each night with a couple of cocktails; the business traveler who adds nightly drinks to the inflammation of travel; and then there is the retiree who starts with gin and tonics at four o'clock. I could go on. You get the picture. Trends indeed.
How to conclude?
I have been going to EP conferences for almost a decade, and rarely have I ever sat through a lecture on the importance of counseling AF patients on basic lifestyle issues. You may hear lifestyle mentioned in passing, but it's not emphasized. Audiences at EP symposia hear the newest on ablation, anticoagulants, and devices. Electrophysiologists don't often focus on "upstream" things like obesity, sleep disorders, and sadly, yes, alcohol.
Maybe that should change?
Perhaps Europe will not be leading in this charge. Here's an interesting image. Beer and wine sold at the ESC—starting in the morning!