NCT06075160

Resting Full-cycle Ratio (RFR)-Guided Revascularization

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)

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 1,167 (estimated)
• Sponsor: Sejong General Hospital · Academic / Other
• Sex: All
• Age: 20 Years – 90 Years
• Healthy volunteers: Not accepted

Summary

The purpose of this study is to compare the clinical outcomes of a 2-year follow-up to determine whether RFR-guided coronary intervention is non-inferior to FFR-guided coronary intervention in patients with intermediate coronary stenosis.

Detailed description

Myocardial ischemia is a key determinant of clinical prognosis in patients with coronary artery disease. In this regard, functional assessment of intermediate coronary stenoses with transtenotic pressure ratios provides a more accurate measure of stenosis-derived myocardial ischemia in comparison to conventional coronary angiography (3-5). One of the major clinical benefit of fractional flow reserve (FFR) is that, by acting as a gatekeeper, non-ischemia-causing lesions suitable for optimal medical treatment can be accurately identified, avoiding unnecessary coronary stenting. However, despite being support with the highest level of recommendation by the current guidelines for guiding clinical-decision making, adoption of FFR in the real world practice is still very low, mainly due to the need of hyperemic agents like adenosine that frequently cause patient discomfort, and time consumption. To overcome such limitations of pressure-wire derived index from the need of adenosine, other alternatives have been looking for over the last years. Instantaneous wave-free ratio (iFR), a resting trans-stenotic pressure index obtained as the ratio of distal coronary pressure to aortic pressure during the diastolic wave-free period, demonstrated a good diagnostic accuracy to define functional significance of coronary lesions without need of adenosine, using FFR as reference. Recently, two large, randomized trials demonstrated that iFR-guided coronary revascularization is clinically non-inferior to FFR-guided revascularization with respect to one-year risk of major adverse cardiac events. Accordingly, like FFR, iFR is now receiving the highest level of recommendations to guide clinical decision making in patients with stable intermediate coronary stenosis. A new adenosine-free index, the resting full-cycle ratio (RFR), has recently emerged. RFR is defined as the lowest ratio of intracoronary distal pressure to aortic pressure under resting condition, irrespective of systole or diastole, and has demonstrated equivalent diagnostic performance to iFR. RFR has an advantage over iFR, because it is not limited by sensitive land marking of components of the pressure waveform unlike iFR. This novel physiologic index without the need of adenosine has the potential to increase the worldwide adoption of coronary physiology in guiding coronary revascularization in daily clinical practice. However, there is a paucity of important data regarding clinical outcomes of RFR-guided revascularization strategy. We hypothesize long-term clinical outcome of RFR-guided revascularization is non-inferior to that of FFR-guided revascularization, and it reduce the rate of PCI than FFR-guided revascularization. Therefore, we sought to investigate the long-term effectiveness and safety of RFR-based decision making in patients with one or more intermediate coronary stenosis, and to assess whether it is non-inferior to FFR-guided revascularization.

Conditions

• Coronary Artery Disease

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Resting full-cycle ratio (RFR)-guided revascularization	The decision of coronary intervention is based on an RFR cut-value of 0.89. If RFR ≤ 0.89, target lesion will be revascularized, and if RFR \> 0.89, PCI will be deferred. However, even if RFR ≤ 0.89, PCI can be deferred if the RFR gradient of the lesion ≤ 0.02, or if the diffused type of stenosis, because physiological gain is expected to be very low.
DIAGNOSTIC_TEST	Fractional flow ratio (FFR)-guided revascularization	Study participants of FFR-guided PCI arm will be selected from a large-scaled, ongoing FFR registry. The decision of coronary intervention is based on an FFR cut-value of 0.80. If FFR ≤ 0.80, target lesion will be revascularized, and if RFR \> 0.80, PCI will be deferred.

Timeline

• Start date: 2022-07-27
• Primary completion: 2026-12-31
• Completion: 2026-12-31
• First posted: 2023-10-10
• Last updated: 2023-10-10

Locations

1 site across 1 country: South Korea