Coffee consumption not associated with atrial arrhythmias in healthy individuals

Introduction and methods

Background

Coffee is one of the most commonly consumed beverages worldwide, but the acute health effects of coffee consumption remain largely uncertain [1]. Coffee consumption is often discouraged due to assumed proarrhythmic effects [2], but data supporting this warning is conflicting [3-6].

Aim of the study

The authors investigated the acute effects of caffeinated coffee consumption on cardiac ectopy, physical activity, sleep, and glucose levels in healthy individuals.

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Methods

The CRAVE (Coffee and Real-time Atrial and Ventricular Ectopy) trial was an prospective, randomized, single-center, case-crossover trial, conducted during a 14-day period. 100 healthy adults (mean age 39 years, 51% female) were randomly assigned to alternate between consuming and avoiding caffeinated coffee during 2-day periods. The participants were informed about the assignment via daily text messages. Participants were fitted with a continuously recording electrocardiogram (ECG), wrist-worn accelerometer to register step counts and sleep duration, and a continuously recording glucose monitoring device. Participants used a smartphone app to continuously monitor their geolocation data to track visits to coffeeshops. Individuals were excluded if they had a history of AF or HF; had an implanted pacemaker or cardioverter-defibrillator; had been prescribed beta-blockers, nondihydropyridine calcium-channel blockers or Vaughn–Williams class 1 or 3 antiarrhythmic medications; or had a medical reason to avoid coffee.

Outcomes

The primary outcome was the number of premature atrial contractions per 24h period.

Main results

• The mean number of premature atrial contractions per day was similar when participants consumed coffee compared to caffeine-avoidance days (58 vs. 53, respectively; rate ratio: 1.09; 95%CI: 0.98-1.20; P=0.10).
• The mean number of premature ventricular contractions per day was higher when participants consumed coffee compared to caffeine-avoidance days (154 vs. 102, respectively; rate ratio: 1.51; 95%CI: 1.18-1.94).
• The mean number of daily episodes of nonsustained supraventricular tachycardia and nonsustained ventricular tachycardia was similar when participants consumed coffee compared to caffeine-avoidance days (0.17 vs. 0.20, respectively; rate ratio: 0.83; 95%CI: 0.68-1.02; for nonsustained supraventricular tachycardia; and 0.01 vs. 0.01, respectively; rate ratio: 1.14; 95%CI: 0.43-2.99; for nonsustained ventricular tachycardia).
• Daily step count was higher on days when participants consumed coffee compared to caffeine-avoidance days (mean difference: 1058; 95%CI: 441-1675).
• Sleep duration per night was lower on days when participants consumed coffee compared to caffeine-avoidance days (mean difference: 36 minutes; 95%CI: 25-47).
• Daily average glucose levels were similar on days when participants consumed coffee compared to caffeine-avoidance days (mean difference: -0.41; 95%CI: -5.42-4.60).
• Participants drank more coffee compared to their usual amounts of coffee on days when they were assigned to consume coffee.

Conclusion

References

Find this article online at N Engl J Med.