Coffee and AFib: What the DECAF and CRAVE Trials Found
Coffee and AFib: What the DECAF and CRAVE Trials Found
In the DECAF trial, 200 coffee drinkers with persistent atrial fibrillation were randomized after cardioversion: AFib or flutter came back in 47% of those told to drink coffee (about one cup a day) and 64% of those told to abstain, a 39% lower hazard (JAMA, 2026). The trial tested brewed coffee in existing drinkers, not other caffeine products or high doses. Whether coffee and AFib is a concern for you is a question for your cardiologist.
Key Takeaways
- DECAF found moderate coffee drinking was associated with less AFib recurrence after cardioversion, not more, in existing coffee drinkers. It did not find that coffee treats or prevents AFib.
- CRAVE, in healthy adults without AFib, found that coffee days produced more premature ventricular contractions (extra heartbeats felt as palpitations) but not more premature atrial contractions.
- Large observational studies and genetic analyses have not found that coffee or caffeine increases arrhythmia risk in general populations.
- Talk to your cardiologist before changing your coffee habit or treatment plan. If you experience chest pain, fainting, severe shortness of breath, or a racing heartbeat that will not settle, call 911.
What Is AFib, and Why Was Coffee Blamed?
Atrial fibrillation is an irregular rhythm in the upper chambers of the heart. Instead of contracting in a coordinated pattern, the atria quiver, which can pool blood and raise stroke risk. Symptoms range from chest fluttering to fatigue and dizziness.
For decades, cardiologists told patients with AFib to avoid coffee on the logic that a stimulant would trigger episodes. That advice was based on clinical intuition, not trial data.
Coffee and AFib: What the DECAF Trial Found
DECAF (Drinking caffEinated Coffee and Atrial Fibrillation) was the first randomized trial to directly test coffee consumption against abstinence in people with AFib (Wong et al., JAMA, 2026; PMID 41206802).
The trial enrolled 200 adults at five hospitals in the US, Canada, and Australia. All were current or recent coffee drinkers with persistent AFib (or flutter with AF history) scheduled for electrical cardioversion. Mean age: 69. Seventy-one percent male. Open-label: participants and doctors knew group assignments.
The coffee arm drank at least one cup of caffeinated coffee daily. The abstinence arm avoided caffeinated and decaffeinated coffee and other caffeine. By follow-up: 7 cups per week versus 0.
Over six months, AFib or flutter recurred in 47% of the coffee group and 64% of the abstinence group. Hazard ratio: 0.61 (95% CI 0.42 to 0.89, P = .01), a 39% lower hazard in the coffee group. A comparable result was observed for AFib recurrence alone, with no difference in adverse events.
What DECAF cannot tell you
- Open-label bias. Participants knew their assignment, which can influence behavior and symptom reporting.
- Narrow population. Persistent AFib, existing coffee drinkers, post-cardioversion. The result does not automatically apply to paroxysmal AFib or people who never drank coffee.
- Modest dose. About one cup of coffee a day. The trial says nothing about higher intake, energy drinks, caffeine pills, or caffeine pouches.
- Six months. Longer-term effects remain unknown.
- Abstainers also gave up decaf. The comparison is coffee versus no coffee and no decaf, not coffee versus decaf.
The authors described the finding as coffee being "associated with less recurrence." The trial does not show that coffee treats AFib.
Does Caffeine Cause Heart Palpitations? What CRAVE Measured
If your heart skips or thumps after coffee, you are not imagining it. CRAVE measured exactly that, in a different population.
CRAVE (Marcus et al., NEJM, 2023; PMID 36947466) enrolled 100 healthy adults (mean age 39, 51% women), randomized day by day for 14 days: drink caffeinated coffee or avoid all caffeine. Each participant wore a continuous ECG patch and an accelerometer.
The rhythm findings
- Premature atrial contractions (PACs): 58 vs. 53 per day. Rate ratio 1.09. Not statistically significant (P = .10). This was the primary outcome.
- Premature ventricular contractions (PVCs): 154 vs. 102 per day. Rate ratio 1.51 (P < .05).
PACs and PVCs are extra beats, not atrial fibrillation. Most people have them daily without knowing. Some feel PVCs as a thump, flutter, or skipped beat, which is what "palpitations after coffee" usually means.
Coffee days also produced 1,058 more steps and 36 fewer minutes of sleep. CRAVE studied healthy adults, not people with AFib. If you feel palpitations, a cardiologist can determine whether they are benign PVCs or something else.
What the Big Cohort Studies Show
Several large observational studies have looked at coffee and arrhythmia risk. None are randomized trials, so they show associations, not causes.
Kim et al. (2021): 386,258 UK Biobank participants, 4.5-year follow-up. Each additional daily cup associated with 3% lower risk of arrhythmia (HR 0.97) and AF/flutter specifically. Mendelian randomization using caffeine-metabolism genes found no association (JAMA Intern Med; PMID 34279564).
Cheng et al. (2014): Meta-analysis of six cohorts (228,465 participants). AFib incidence 6% lower per 300 mg/day caffeine (RR 0.94), though the overall pooled result was not statistically significant (Can J Cardiol; PMID 24680173).
Chieng et al. (2022): 449,563 UK Biobank participants, 12.5 years. Ground coffee (HR 0.83 at 4 to 5 cups/day) and instant (HR 0.88 at 2 to 3 cups/day) were each associated with less arrhythmia. Decaf was not (Eur J Prev Cardiol; PMID 36162818).
Larsson et al. (2023): Mendelian randomization found genetically higher plasma caffeine was not strongly associated with AF (BMJ Medicine; PMID 36936261).
The pattern: habitual coffee drinking is not associated with higher arrhythmia risk. Observational data cannot prove coffee itself is the reason.
The Evidence at a Glance
| Study | Year | Design | n | Exposure | Rhythm Finding | Key Limitation |
|---|---|---|---|---|---|---|
| DECAF | 2026, JAMA | Open-label RCT | 200 | ~1 cup/day coffee vs. abstinence | 47% vs. 64% AFib recurrence; HR 0.61 | Persistent AFib only; open-label |
| CRAVE | 2023, NEJM | Randomized crossover | 100 | Coffee vs. no caffeine, day by day | PACs similar; PVCs 51% higher | Healthy adults, not AFib patients |
| Kim et al. | 2021, JAMA Intern Med | Cohort + MR | 386,258 | Each additional daily cup | HR 0.97 per cup for AF/flutter | Observational; MR showed no caffeine signal |
| Cheng et al. | 2014, Can J Cardiol | Meta-analysis | 228,465 | Per 300 mg/day caffeine | 6% lower AF incidence | Overall pooled RR not significant |
| Chieng et al. | 2022, Eur J Prev Cardiol | Cohort | 449,563 | Ground, instant, decaf | Ground/instant: less arrhythmia; decaf: no link | Cannot identify active compounds |
| Larsson et al. | 2023, BMJ Medicine | Mendelian randomization | Multiple GWAS | Genetically predicted caffeine | No strong association with AF | Does not test non-caffeine compounds |
Is It the Coffee or the Caffeine?
The data raises this question but does not answer it.
DECAF tested brewed caffeinated coffee. Chieng found decaf did not share the arrhythmia association. Larsson's Mendelian randomization, isolating caffeine genetically, found no clear signal for caffeine itself. Which coffee benefits come from caffeine and which from other bean compounds (chlorogenic acids, diterpenes, trigonelline) remains open.
Coffee is not a caffeine delivery device and nothing else. The DECAF result does not transfer to energy drinks, caffeine pills, pre-workouts, or other caffeine products. Those were not tested and lack the non-caffeine compounds that may matter.
Dose matters too. A 2011 meta-analysis (Mesas et al.) found 200 to 300 mg of caffeine raised systolic blood pressure by 8.1 mmHg and diastolic by 5.7 mmHg within an hour in people with hypertension, lasting at least three hours. Hypertension is a common companion to AFib.
What to Ask Your Cardiologist
The studies on this page describe populations, not your heart. The right move is a conversation with your cardiologist. These questions can start it:
- Does the DECAF result apply to my type of AFib?
- I feel palpitations after coffee. Should I track them, and how?
- Does my blood pressure change the picture?
- Do energy drinks or caffeine supplements count differently from coffee?
- Do any of my medications interact with caffeine?
- What symptoms mean I should call you or go to the ER?
If you experience chest pain, fainting, severe shortness of breath, or a racing heartbeat that will not settle, call 911.
The Old Advice Was Not Tested. Now Part of It Has Been.
For years, the standard recommendation was to avoid caffeine if you had AFib. That advice was never based on a randomized trial. Now one trial has tested moderate coffee consumption in a specific group of AFib patients after cardioversion, and coffee was associated with less recurrence, not more. CRAVE confirmed that caffeine does produce more extra ventricular beats in healthy people, which may explain the palpitations many coffee drinkers feel.
Neither trial says coffee is safe for everyone with a heart rhythm condition. The honest summary is narrower than most headlines: one cup of brewed coffee a day, in people who already drank coffee, after cardioversion for persistent AFib, over six months, was not harmful and may have helped. Everything outside that frame remains open.
Roon is a caffeine pouch, not coffee, and was not tested in any study on this page.
Frequently Asked Questions
Can you drink coffee if you have AFib?
The DECAF trial found that about one cup of caffeinated coffee a day was associated with less AFib recurrence in existing coffee drinkers after cardioversion. But it was open-label, enrolled only persistent-AFib patients, and lasted six months. It does not prove coffee is safe for all AFib patients. Your cardiologist can weigh DECAF against your rhythm history, medications, and blood pressure.
Does caffeine trigger AFib?
No randomized trial has shown that moderate caffeine from coffee triggers AFib episodes. CRAVE found more premature ventricular contractions on coffee days in healthy adults, but not more premature atrial contractions, and CRAVE participants did not have AFib. Individual responses vary; your cardiologist is the right person to assess your situation.
What did the DECAF trial find?
Two hundred persistent-AFib patients after cardioversion: half drank about one cup of coffee a day, half abstained from coffee and other caffeine. Over six months, AFib or flutter recurred in 47% of the coffee group versus 64% of the abstinence group (HR 0.61, P = .01). The trial was open-label and relatively small.
Is decaf better for AFib?
Possibly not. In the Chieng et al. (2022) UK Biobank study, ground and instant caffeinated coffee were associated with less arrhythmia, but decaffeinated coffee was not. In DECAF, the abstinence group gave up decaf too, so the comparison was caffeinated coffee versus no coffee at all. No trial evidence supports switching to decaf for rhythm benefits.
Why does coffee give me heart palpitations?
The CRAVE trial measured this: on coffee days, healthy adults had about 51% more premature ventricular contractions (PVCs) than on caffeine-free days. PVCs are extra heartbeats that many people feel as a thump, skip, or flutter. They are common and usually benign, but if yours are frequent or come with dizziness, fainting, or anxiety-like symptoms, ask your doctor to evaluate them.
Are energy drinks the same as coffee for AFib?
No study on this page tested energy drinks, caffeine pills, pre-workouts, or any caffeine product other than brewed coffee. Energy drinks often contain higher caffeine doses plus other stimulants. Extending the DECAF result to them is not supported by the data. The FDA notes that people with medical conditions should consult a provider about caffeine.
Related Reading
- Which Coffee Benefits Come from Caffeine?
- How Much Caffeine Is in a Cup of Coffee?
- Nicotine and Your Heart
- Slow Caffeine Metabolizer: What Your CYP1A2 Gene Means
Written by Roon Team
