Could Caffeine Induce Arrhythmias in Patients with Heart Failure?

Caffeine consumption, even in high doses, did not induce arrhythmias in patients with systolic heart failure who were at high risk for ventricular arrhythmias, according to the results of a recent study.

The potential proarrhythmic effects of caffeine are controversial, with few studies having addressed the effect of caffeine at high doses in patients with heart failure.
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In order to further examine this relationship, researchers conducted a double-blind, randomized, crossover trial involving 51 patients with chronic heart failure and moderate-to-severe systolic dysfunction.

The participants were given either 100 mg of caffeine or lactose capsules, along with 5 doses of 100 mL decaffeinated coffee at 1-hour intervals for a total of 500 mg of caffeine or placebo over a 5-hour time frame. This was followed by a 1-week washout period, then another instance of 500 mg of caffeine.

Overall, no significant differences were observed between the caffeine and placebo groups, either in the number of ventricular and supraventricular premature beats, bigeminal cycle, or nonsustained tachycardia during continuous electrocardiographic monitoring. No increase in ventricular premature beats were observed in patients with higher levels of plasma caffeine compared with lower plasma levels.

“After 500 mg of caffeine administered over a 5-hour period, we found no statistically significant effect of caffeine ingestion on the frequency of ventricular or supraventricular ectopies, even during the physical stress of a treadmill test,” the researchers concluded.

“These results challenge the intuitive perception that caffeine intake should be limited in patients with heart disease and at risk for arrhythmia.

—Michael Potts

Reference:

Zuchinali P, Souza GC, Pimentel M, et al. Short-term effects of high-dose caffeine on cardiac arrhythmias in patients with heart failure 9published online October 17, 2016]. JAMA Intern Med. doi:10.1001/jamainternmed.2016.6374.