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Recruiting Phase 2, Phase 3 NCT07738523

NCT07738523 Caffeine Consumption and Rate Control in Permanent Atrial FIBrillation: The CAFIB Trial

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Clinical Trial Summary
NCT ID NCT07738523
Status Recruiting
Phase Phase 2, Phase 3
Sponsor Hospital Universitario Getafe
Condition Atrial Fibrillation (AF)
Study Type INTERVENTIONAL
Enrollment 50 participants
Start Date 2026-07-27
Primary Completion 2027-12-31

Eligibility & Interventions

Sex All sexes
Min Age 18 Years
Max Age 80 Years
Study Type INTERVENTIONAL
Interventions
Dietary Caffeine Intake

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

In Phase 2, researchers evaluate early signs of effectiveness. You may be randomized to receive the active treatment or a comparator. Monitoring continues closely.

This trial targets 50 participants in total. It began in 2026-07-27 with a primary completion date of 2027-12-31.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

The CAFIB trial is a multicenter, randomized, open-label, crossover clinical trial designed to determine whether habitual caffeine consumption in coffe adversely affects rate control in patients with permanent atrial fibrillation (AF). The rationale stems from the discrepancy between traditional clinical recommendations, which often advise patients with arrhythmias to avoid caffeine, and the growing body of evidence suggesting that moderate coffee consumption is not associated with an increased risk of AF and may even confer cardiovascular benefits. However, no randomized study has specifically investigated this issue in patients with permanent AF, a population in whom rate control remains the cornerstone of management. The primary hypothesis is that continued moderate caffeine consumption is non-inferior to caffeine abstinence regarding 24-hour mean heart rate control. Participants will be randomly assigned in a 1:1 ratio to one of two treatment sequences stratified according to baseline coffee intake (1 cup/day vs. \>1 cup/day). Owing to the nature of the intervention, the study is open-label; nevertheless, Holter recordings will be analyzed by blinded investigators, and the statistical analysis will also be performed blinded to treatment allocation to minimize bias. Eligible participants are adults with permanent AF diagnosed for more than three months, stable ventricular rate control (\<110 bpm at rest), unchanged rate-control medication for at least two months, and habitual coffee consumption of at least one caffeinated cup per day. Patients with advanced heart failure, recent major cardiovascular events, cognitive impairment, implanted cardiac pacing devices, or other conditions likely to interfere with study outcomes are excluded. The intervention compares two dietary strategies: continuation of regular caffeinated coffee consumption (at least one cup daily) versus complete caffeine abstinence, while allowing decaffeinated coffee. Energy drinks are prohibited in both groups, and participants assigned to abstinence are advised to avoid compensatory caffeine intake from other sources. No washout period is planned between crossover phases because caffeine has a biological half-life of less than 24 hours. Adherence will be assessed using caffeine consumption diaries and structured interviews at each study visit. The primary endpoint s the 24-hour mean heart rate measured by ambulatory Holter electrocardiography. Secondary endpoints include changes in mean HR from baseline, percentage of time with HR \>110 bpm or \<50 bpm, ventricular ectopic burden, symptom severity assessed using the modified EHRA classification, quality of life evaluated with the AFEQT questionnaire, circulating biomarkers of heart failure, adverse events, and changes in concomitant medical therapy. Patients will undergo three scheduled visits (baseline, 30 days, and 60 days), each including clinical assessment, ECG, 24-hour Holter monitoring, blood sampling, and quality-of-life questionnaires. Sample size calculation was based on detecting a clinically relevant difference of 5 bpm, assuming a standard deviation of 7 bpm, 80% statistical power, and a two-sided α of 0.05. After accounting for an anticipated 25% dropout rate and potential protocol deviations, a total of 50 patients (25 per treatment sequence) will be recruited. The primary analysis will follow the intention-to-treat principle, complemented by a per-protocol analysis. Statistical models will adjust for clinically relevant covariates, including age, sex, baseline heart rate, and concomitant rate-control therapy, while multivariable regression analyses will explore predictors of optimal heart rate control. The protocol acknowledges several limitations, including its open-label design, reliance on self-reported caffeine intake to assess adherence, interindividual variability in caffeine metabolism, and limited external validity to stable, habitual coffee consumers with permanent AF. Despite these limitations, CAFIB represents the first randomized trial specifically evaluating the impact of caffeine consumption on ventricular rate control in permanent AF.

Eligibility Criteria

Inclusion Criteria: * Age ≥18 years. * Permanent atrial fibrillation diagnosed for more than 3 months. * Stable rate-control status, defined as a resting heart rate \<110 bpm without changes in rate-control medication during the previous 2 months. * Habitual caffeine consumption (≥1 cup/day of caffeinated coffee). * Willingness to participate in the study, including acceptance of complete caffeine abstinence for up to two months if assigned to the abstinence arm. Exclusion Criteria: * Age \<18 years or \>80 years. * Previous diagnosis of cognitive impairment or dementia. * Legal incapacity or inability to provide informed consent. * Inability to understand or complete quality-of-life questionnaires. * Presence of a cardiac implantable electronic device with pacing capability (pacemaker, implantable cardioverter-defibrillator, or cardiac resynchronization therapy device). * Previous successful atrioventricular node ablation. * Decompensated heart failure (New York Heart Association class III-IV) or hospitalization for heart failure within the previous 3 months. * Acute coronary syndrome within the previous 3 months. * Stroke within the previous 3 months. * Cardiac surgery within the previous 3 months. * Severe unrepaired valvular heart disease.

Contact & Investigator

Central Contact

Martín Negreira-Caamaño, MD, PhD

✉ martin.negcam@gmail.com

📞 +34 916839360

Frequently Asked Questions

Who can join the NCT07738523 clinical trial?

This trial is open to participants of all sexes, aged 18 Years or older, up to 80 Years, studying Atrial Fibrillation (AF). Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT07738523 trial and what does that mean for participants?

Phase 2 trials evaluate whether the treatment shows signs of effectiveness while continuing to monitor safety. More participants are enrolled than in Phase 1 to help refine the treatment protocol.

Is NCT07738523 currently recruiting?

Yes, NCT07738523 is actively recruiting participants. Contact the research team at martin.negcam@gmail.com for enrollment information.

Where is the NCT07738523 trial being conducted?

This trial is being conducted at Getafe, Spain.

Who is sponsoring the NCT07738523 clinical trial?

NCT07738523 is sponsored by Hospital Universitario Getafe. The trial plans to enroll 50 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: September 2026  ·  Data Methodology