Clinical trial Recruiting at 1 site Interventional Ages 18 to 85

Comparing AF ablation and AV node ablation for heart failure patients

Official title: Rate or Rhythm Control in CRT: the RHYTHMIC Study

Run by Guy's and St Thomas' NHS Foundation Trust · NCT04664686 · Data updated 2026-11-12

This study tests whether a heart procedure to control rhythm or a procedure to control rate works better for heart failure patients with atrial fibrillation who are already getting special heart therapy.

Quick facts

Study typeInterventional
Ages18 Years to 85 Years
SexAll
Enrollment70 (estimated)
SponsorGuy's and St Thomas' NHS Foundation Trust
Academic / other
Locations1 site (London)
StatusRecruiting
StartedOctober 19, 2021
Main results expectedSeptember 30, 2027
Study endsSeptember 30, 2027
Registry record updatedJanuary 26, 2026
Trial IDNCT04664686 on ClinicalTrials.gov

Is this trial a fit for you?

Likely a good fit

Ideal candidates are patients with heart failure, atrial fibrillation, and CRT who have less than 95% biventricular pacing and meet specific clinical criteria.

Probably not a fit

Patients with a life expectancy of less than one year, permanent atrial fibrillation, or those with certain contraindications will not benefit from this study.

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

This clinical trial involves 70 patients with heart failure and atrial fibrillation who are receiving cardiac resynchronization therapy (CRT) but have less than 95% biventricular pacing. Participants will be randomized to receive either AF catheter ablation for rhythm control or AV-node ablation for rate control. The study will evaluate the outcomes at six months through echocardiography and clinical assessments, including various tests to measure heart function and quality of life. The goal is to determine which approach is more effective in managing their condition.

Why it matters

Potential benefit: If successful, this study could provide insights into the most effective treatment for heart failure patients with atrial fibrillation, potentially improving their quality of life and heart function.

How similar studies have gone: Other studies have shown promising results with catheter ablation techniques in similar patient populations, suggesting that this approach may be effective.

Who can join: the full rules

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Ability to provide informed consent to participate and willing to comply with the clinical investigation plan and follow-up schedule.
* QRS duration \>120ms on surface ECG, severe left ventricular systolic impairment (EF≤35%) and clinical symptoms of heart failure despite optimum medical therapy (NYHA class II-IV) at time of CRT implant or upgrade
* Successful CRT implant or upgrade including atrial lead
* Biventricular pacing percentage \<95% secondary to atrial fibrillation at least 3 months post implant or upgrade
* Clinically indicated for AV node ablation

Exclusion Criteria:

* Life expectancy \<1 year
* Presence of atrial or ventricular thrombus
* Permanent atrial fibrillation
* Mechanical aortic valve replacement
* Severe peripheral vascular disease
* Female participants who are pregnant, lactating or planning pregnancy during the course of the study.
* Participation in other studies with active treatment / investigational arm

Where it's running

  • Guys and St Thomas' NHS Foundation Trust
    London, United Kingdom
    Recruiting

Study contacts

  • Principal investigator: Christopher A Rinaldi — Guy's and St Thomas' NHS Foundation Trust
  • Study coordinator: Christopher A Rinaldi
  • Email: aldo.rinaldi@kcl.ac.uk
  • Phone: 02071889257

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

How to take part

  1. Review the eligibility criteria above with your treating physician.
  2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
  3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.
Last reviewed 2026-11-14 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.