Abstract Body (Do not enter title and authors here): Hypothesis and Purpose: While conventional wisdom holds that caffeinated coffee is proarrhythmic, observational data (prone to confounding) suggests that coffee drinkers may experience a lower risk of atrial fibrillation (AF). A randomized trial assessing the effects of coffee on AF has not previously been performed.
Study Design and Methods: The Does Eliminating Coffee Avoid Fibrillation (DECAF) trial was an international, multicenter, prospective, open-label randomized clinical trial.
Population: Coffee-drinking patients with a history of AF undergoing planned electrical cardioversion for AF or atrial flutter.
Intervention: After successful cardioversion, patients were randomized 1:1 with stratification by site to caffeinated coffee consumption or coffee abstinence for 6 months. Patients in the coffee consumption arm were encouraged to drink at least one cup of caffeinated coffee daily, or one espresso shot, as per their usual lifestyle. Patients in the coffee abstinence arm were encouraged to abstain from both caffeinated/decaffeinated coffee and other caffeinated products.
Power Calculations: 200 patients were required to provide 80% power to detect the lower hazard of recurrence expected based on prior observational evidence using a two-tailed alpha of 0.05.
Primary End Point: The primary endpoint was clinical or device-detected recurrence of AF or atrial flutter lasting longer than 30 seconds.
Outcomes: Between 2021 and 2024, 200 patients (69±11 years, 71% male) were randomized to coffee consumption (n=100) or coffee abstinence (n=100) at 5 sites in the United States, Australia, and Canada. Baseline characteristics between the groups were balanced. Median coffee intake at baseline and follow-up in the abstinence group was 7 (IQR 7-18) and 0 (IQR 0-2) cups/week respectively, and in the coffee consumption group was 7 (IQR 7-18) and 7 (IQR 6-11) cups/week. In the primary intention-to-treat analysis, AF or atrial flutter recurrence was less in the coffee consumption (47%) than the coffee abstinence group (64%), resulting in a 39% lower hazard of recurrence (HR 0.61, 95% CI 0.42-0.89, p=0.010; Figure). A similar benefit of coffee consumption was observed with AF recurrence only as an endpoint. As-treated analyses incorporating any cross-over yielded similar results. There was no significant difference in adverse events between the groups.
Conclusions: Consumption of caffeinated coffee reduced AF recurrence compared to abstinence from coffee and caffeine.