Regular Coffee, Tea Intake Not Linked to PVCs in Cohort Study

Pam Harrison

February 10, 2016

SAN FRANCISCO, CA — Whether or not they have the jitters, most regular coffee drinkers can at least be assured the caffeine probably isn't giving them extra heartbeats, at least according to an analysis based on a cohort from the prospective Cardiovascular Health Study (CHS)[1].

There were no significant associations between intake of coffee, tea, or chocolate daily or periodically and hourly rate of premature atrial contractions (PACs) or premature ventricular contractions (PVCs). Nor were they associated with daily prevalence of supraventricular tachycardia (SVT).

Coffee intake up to four times weekly was marginally associated with an increase in runs of ventricular tachycardia in the study, published January 26, 2016 in the Journal of the American Heart Association.

The results don't address acute consumption of caffeine-containing products; still, "our findings suggest that clinical recommendations advising against the regular consumption of caffeinated products to prevent cardiac ectopy and arrhythmia should be reconsidered," write the authors, led by Dr Shalini Dixit (University of California, San Francisco).

"Anecdotally in my practice, there do appear to be some patients where caffeine is an important trigger for arrhythmias, especially high doses of caffeine," observed Dr Gregory Marcus (University of California, San Francisco) for heartwire from Medscape. "So there still may be a relationship between caffeine and arrhythmias. But I suspect it's somewhat idiosyncratic to the individual."

He added, "What do I tell my own patients—and my own practice is all arrhythmias—when they ask me, can I drink coffee or should I avoid caffeine?" said Marcus, who is senior author on the study. "What I tell them is, you can experiment. And if you try and it's not a problem for you, then it should be okay."

As reported, 1416 individuals were randomly selected from the study's overall cohort to undergo 24-hour Holter monitoring during their initial assessment. Patients also completed a baseline food frequency questionnaire. Their mean age was 72 years.

In adjusted analyses of 1388 evaluable patients, investigators observed no statistically significant association between coffee, tea, or chocolate consumption and PACs, PVCs, or number of SVT/VT runs.

Ectopy and Arrhythmias (Median Rate and Interquartile Range) by Coffee Intake Levels

Coffee frequency N PACs/h, n PVCs/h, n SVT runs in 24 h, n VT runs in 24 h, n
Never 448 2 (1–11) 1 (0–7.5) 0 (0–2) 0 (0–106)
1–3 times/mo 103 3 (1–24) 1 (0–7) 0 (0–2) 0 (0–13)
1–4 times/wk 133 3 (1–14) 1 (0–8) 1 (0–2) 0 (0–76)
"Almost every day" 620 3 (1–11) 1 (0–7) 0 (0–2) 0 (0–11)

Investigators also observed an estimated statistically nonsignificant 0.48% decrease in PACs/hour as well as an estimated statistically nonsignificant 2.8% decrease in PVCs/hour for every one-serving/week increase in regular consumption of caffeine-containing products.

"There is a plethora of literature in the modern era that . . . supports their findings in more broadly based patient populations," note Drs Peter Wilson and Heather Bloom (Emory University, Atlanta, GA), referring to the authors of the current analysis, in an accompanying editorial[2]. "Data examining risk of ventricular arrhythmias are similarly robust and indicate no increase in arrhythmia risk when caffeine is consumed."

Other contemporary vehicles for dietary caffeine may represent a more pressing concern, according to Wilson and Bloom. "There are multiple case reports in the literature regarding arrhythmias and/or death following excessive energy-drink consumption prior to exercise," they write.

Moreover, "many specialized caffeinated beverages have a large number of calories and that may be a health hazard for the development of hyperglycemia and diabetes mellitus. A restaurant double espresso (2 oz, 150-mg caffeine, 0 calories) habit may not be problematic, but how healthy is a Venti Peppermint Mocha (20 oz, 415-mg caffeine, 440 calories) or a Monster Energy (16 oz, 160-mg caffeine, 300 calories)?"

They conclude, "There is little risk for atrial or ventricular arrhythmias at most of the levels of caffeine consumption in our society. Future research in this area is especially of interest concerning newer caffeinated beverages with greater amounts of caffeine per serving and with a large number of calories."

Marcus discloses research support from the National Institutes of Health, Patient Centered Outcomes Research Institute, SentreHeart, Medtronic, and Pfizer and is a consultant for and holds equity in InCarda; the coauthors had no relevant financial relationships. Both Wilson and Bloom report that they have no relevant financial relationships.

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