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Caffeine Ingestion in Patients with Heart Failure

Zuchinali et al report a randomized double blind placebo controlled trial of short term high dose (500 mg caffeine over 5 hours) in patients with moderate to severe left ventricular systolic dysfunction. The primary end-point was frequency of ventricular premature beats on continuous electrocardiographic monitoring. Caffeine was not associated with an increase in the primary end-point or other measured outcomes.

Abstract

IMPORTANCE

The presumed proarrhythmic action of caffeine is controversial. Few studies have assessed the effect of high doses of caffeine in patients with heart failure due to left ventricular systolic dysfunction at high risk for ventricular arrhythmias.

OBJECTIVE

To compare the effect of high-dose caffeine or placebo on the frequency of supraventricular and ventricular arrhythmias, both at rest and during a symptom-limited exercise test.

DESIGN, SETTING, AND PARTICIPANTS

Double-blinded randomized clinical trial with a crossover design conducted at the heart failure and cardiac transplant clinic of a tertiary-care university hospital. The trial included patients with chronic heart failure with
moderate-to-severe systolic dysfunction (left ventricular ejection fraction <45%) and New York Heart Association functional class I to III between March 5, 2013, and October 2, 2015.

INTERVENTIONS

Caffeine (100mg) or lactose capsules, in addition to 5 doses of 100 mL decaffeinated coffee at 1-hour intervals, for a total of 500mg of caffeine or placebo during a 5-hour protocol. After a 1-week washout period, the protocol was repeated.
MAIN OUTCOMES AND MEASURES Number and percentage of ventricular and supraventricularpremature beats assessed by continuous electrocardiographic monitoring.

RESULTS

We enrolled 51 patients (37 [74%] male; mean [SD] age, 60.6 [10.9] years) with predominantly moderate-to-severe left ventricular systolic dysfunction (mean [SD] left ventricular ejection fraction, 29% [7%]); 31 [61%] had an implantable cardioverterdefibrillator device. No significant differences between the caffeine and placebo groups were
observed in the number of ventricular (185 vs 239 beats, respectively; P = .47) and supraventricular premature beats (6 vs 6 beats, respectively; P = .44), as well as in couplets, bigeminal cycles, or nonsustained tachycardia during continuous electrocardiographic monitoring. Exercise test–derived variables, such as ventricular and supraventricular
premature beats, duration of exercise, estimated peak oxygen consumption, and heart rate, were not influenced by caffeine ingestion.We observed no increases in ventricular premature beats (91 vs 223 vs 207 beats, respectively) in patients with higher levels of plasma caffeine concentration compared with lower plasma levels (P = .91) or with the placebo group (P = .74).

CONCLUSIONS

AND RELEVANCE Acute ingestion of high doses of caffeine did not induce arrhythmias in patients with systolic heart failure and at high risk for ventricular arrhythmias.

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