Comparing RFR and FFR methods for heart artery treatment

Prospective Evaluation of Long-term Clinical Outcomes After Resting Full-cycle Ratio (RFR)-Guided Percutaneous Coronary Revascularization; A Multi-center, International, Single Arm Interventional, Comparing Registry (COMFORT Study)

Observational Sejong General Hospital · NCT06075160

This study is testing if using a new method called resting full-cycle ratio (RFR) instead of the traditional fractional flow reserve (FFR) can help patients with narrowed heart arteries get better treatment without unnecessary procedures.

Quick facts

Study typeObservational
Enrollment1167 (estimated)
Ages20 Years to 90 Years
SexAll
SponsorSejong General Hospital Academic / other
Locations1 site (Bucheon-si, Gyeonggi-do)
Trial IDNCT06075160 on ClinicalTrials.gov

What this trial studies

This observational study aims to evaluate the clinical outcomes of coronary interventions guided by resting full-cycle ratio (RFR) compared to fractional flow reserve (FFR) in patients with intermediate coronary artery stenosis over a two-year follow-up period. The study focuses on the functional assessment of coronary stenoses to determine the necessity of revascularization, potentially avoiding unnecessary procedures. By utilizing RFR, which does not require hyperemic agents like adenosine, the study seeks to improve patient comfort and streamline the intervention process.

Who should consider this trial

Good fit: Ideal candidates include patients with intermediate coronary artery stenosis who are considering RFR-guided coronary intervention.

Not a fit: Patients with severe left ventricular dysfunction, acute coronary syndrome, or other significant comorbidities may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a less invasive and more comfortable method for assessing coronary artery disease, leading to better patient outcomes.

How similar studies have performed: Previous studies have shown success with similar approaches, particularly with the use of iFR, indicating potential for RFR to also be effective.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Patients with intermediate coronary artery stenosis (visually 50-90% diameter stenosis) who decided to undergoing a RFR-guided coronary intervention according to clinical necessity
* Patients who voluntarily decided to participate in this study and signed informed consent

Exclusion Criteria:

* Severe left ventricular systolic dysfunction (LVEF \<30%)
* Cardiogenic shock
* Culprit vessel in acute coronary syndrome
* Donor vessel to supply chronic total occlusion lesion of non-target vessel
* Symptomatic valvular heart disease or cardiomyopathy
* Hemodynamic instability at the time of intervention (heart rate \<50 beats per minute, systolic blood pressure \<90mmHg)
* Previous CABG with patent grafts to the interrogated vessel
* Pregnancy or breastfeeding
* Non-cardiac co-morbid conditions are present with life expectancy \<1 year or that may result in protocol non-compliance

Where this trial is running

Bucheon-si, Gyeonggi-do

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Coronary Artery Diseasephysiologic assessmentintermediate stenosis
Last reviewed 2026-06-13 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.