Caffeinated Coffee Consumption or Abstinence to Reduce Atrial Fibrillation: The DECAF Randomized Clinical Trial
Key Takeaway
Daily caffeinated coffee lowered six‑month post‑cardioversion AF recurrence. Prospective, multicenter, open-label randomized clinical trial; Level 1b (2011 OCEBM).
Background
Conventional advice discourages caffeine in atrial fibrillation (AF). Prior observational data suggested neutral/beneficial associations, but randomized evidence in AF patients was lacking.
Patients
200 adults (mean age 69; 71% male) with persistent AF or atrial flutter (with AF history) undergoing successful electrical cardioversion at 5 hospitals (US/Canada/Australia). All were current or recent coffee drinkers.
Intervention
Caffeinated coffee encouraged (≥1 cup/day) and usual caffeine use; achieved median 7 cups/week.
Control
Abstinence from coffee (including decaf) and all caffeine; achieved median 0 cups/week.
Outcome
Primary: Clinically detected AF or atrial flutter recurrence ≥30 seconds over 6 months. Secondary: AF-only recurrence; adverse events (ED visits, hospitalizations, MI, stroke/TIA, HF exacerbation, death).
Follow up period
6 months.
Results
| Outcome | Coffee (n=100) | Abstinence (n=100) | Effect size (95% CI) | Absolute risk reduction | NNT |
|---|---|---|---|---|---|
| Primary: AF/flutter recurrence | 47% | 64% | HR 0.61 (0.42–0.89) | 17% | 6 |
| Secondary: AF recurrence only | — | — | HR 0.62 (0.43–0.91) | — | — |
| AF/flutter–related hospitalization | 10% | 15% | — | 5% | 20 |
| Any hospitalization | 23% | 21% | — | −2% | — |
Limitations
- Open-label; no blinding of participants or clinicians.
- Modest sample; event monitoring not protocol-mandated.
- Imperfect adherence in abstinence group; self-reported intake.
- Some baseline imbalances; subgroup findings exploratory.
- Not powered for uncommon adverse events.
- Enrolled persistent AF; generalizability to paroxysmal AF uncertain.
Funding
Public research grants (Australia/US); investigators disclosed industry ties.
Citation
Wong CX, Cheung CC, Montenegro G, et al. Caffeinated Coffee Consumption or Abstinence to Reduce Atrial Fibrillation: The DECAF Randomized Clinical Trial. JAMA. Published online November 9, 2025. doi:10.1001/jama.2025.21056. Trial registration: NCT05121519.