The CORE - μFR Clinical Trial

μFR -Guided Complete Revascularization in Patients With Acute Coronary Syndromes

Acute coronary syndromes (ACS) are frequently associated with multivessel coronary artery disease (CAD), and current guidelines recommend complete revascularization beyond the culprit lesion. Angiography-guided PCI is the standard approach, but anatomical assessment does not always reflect the functional significance of intermediate lesions, while FFR-guided strategies are limited by the need for pressure wires and hyperemia. Murray-law-based quantitative flow ratio (μFR) is a wire-free angiography-derived physiological index that may improve decision-making for revascularization in ACS patients.

The Core-μFR is an investigator-driven, multicenter, randomized, open-label and prospective trial designed to evaluate whether μFR can act as a gatekeeper for complete revascularization in patients with ACS and multivessel disease by identifying non-culprit lesions that truly require PCI.

Patients with ACS (either STEMI or NSTE-ACS) undergoing primary PCI will be considered eligible if they present multivessel CAD on visual assessment with the intention to treat the non-culprit vessel in a staged procedure within the same hospitalization. After the pPCI, eligible patients will be randomized to either group A or group B and μFR will be performed in a blinded fashion with the operator unaware of the functional result. Patients in group A will undergo a staged PCI of all NCVs guided by coronary angiography, as per standard of care. In group B, μFR will be used as a gatekeeper for staged revascularization. Operators will only be informed whether at least one non-culprit vessel is μFR-positive, without disclosure of the specific vessel involved or the μFR values. If at least one non-culprit vessel has μFR ≤0.80, patients will undergo angiography-guided PCI of all non-culprit vessels previously deemed suitable for treatment by visual assessment. If μFR is >0.80 in all non-culprit vessels, staged PCI will be deferred and the patient will be discharged without further revascularization. Finally, to test the functional reproducibility, a blinded post-hoc μFR assessment will be performed on the baseline angiograms of the staged procedures in all the patients undergoing complete revascularization. Clinical follow-up will be performed at 30 days and 1 year from randomization.

Study Overview

• Status: Not yet recruiting
• Conditions: Multivessel Coronary Artery Disease; STEMI - ST Elevation Myocardial Infarction; Acute Coronary Syndromes (ACS); NSTEMI - Non-ST-Segment Elevation Myocardial Infarction
• Intervention / Treatment: Procedure: Angiography-guided PCI; Procedure: μFR based-PCI

• Study Type: Interventional
• Enrollment (Estimated): 350
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Emanuele Barbato, MD, PhD; Phone Number: +39 06 3377 6115; Email: emanuele.barbato@uniroma1.it
• Study Contact Backup: Name: Emanuele Gallinoro, MD, PhD; Phone Number: +39 06 3377 5005; Email: egallinoro@gmail.com

Study Locations

• Italy
  • RM
    • Roma, RM, Italy, 00189
      • Azienda ospedaliero - universitaria Sant'Andrea
      • Contact: Emanuele Barbato, MD, PhD; Phone Number: +39 06 3377 6115; Email: emanuele.barbato@uniroma1.it
      • Contact: Emanuele Gallinoro, MD, PhD; Phone Number: +39 06 3377 5005; Email: egallinoro@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Patients presenting with ACS within 72 hours of successful culprit PCI

2. Residual coronary artery disease, defined as at least one additional stenosis in any non-culprit vessel (NCV) with the following characteristics:

   1. at least 50% diameter stenosis by visual assessment
   2. a vessel diameter of at least 2.5 mm
   3. amenable to successful PCI

Exclusion Criteria:

1. Cardiogenic shock or severe heart failure (NYHA class ≥III)
2. Severely impaired renal function: creatinine >2 mg/dl or estimated glomerular filtration rate (eGFR) <30 ml/min/1,73 m²
3. Allergy to iodine-containing contrast agents which cannot be adequately pre-medicated
4. Pregnancy or intention to become pregnant during the trial
5. Life expectancy less than one year
6. Ambiguity in the identification of the culprit vessel/lesion
7. Clinical presentation as myocardial infarction and non-obstructive coronary artery disease (MINOCA) and/or Tako-Tsubo Syndrome
8. Any ambiguity in the diagnosis of ACS
9. Inability to provide informed consent
10. Patients with only one coronary artery lesion with diameter stenosis >90% and/or TIMI flow <3
11. Patients in whom the NCV is treated at the time of the index procedure
12. An interrogated lesion is at the site of a myocardial bridge
13. An interrogated lesion is a culprit lesion responsible for the acute myocardial infarction
14. An interrogated lesion is in a bypass graft
15. Poor angiographic image quality precluding vessel contour detection or with suboptimal contrast opacification
16. Severe vessel overlap in the stenosed segment or severe tortuosity of any interrogated vessel deemed not amenable to μFR measurement

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Group A - Angiography-guided PCI (standard strategy); Patients will undergo a staged PCI of all non-culprit vessels identified before randomization according to angiography and operator judgment, as per standard of care. μFR will be analyzed off-line by the core lab and will not be available to the operator.	Procedure: Angiography-guided PCI; staged PCI of all NCVs will be performed as per standard of care
Experimental: Group B - μFR based-PCI; μFR will be analyzed off-line by the core lab. Coronary revascularization will be deferred if the μFR > 0.80 in all the non-culprit vessels identified before randomization. If μFR ≤ 0.80 in at least one non-culprit vessels identified before randomization, patients will undergo a staged PCI. Operators remain blinded to μFR values, and treatment of vessels is based on angiography only.	Procedure: μFR based-PCI; staged PCI will be deferred if the μFR > 0.80 in all the NCVs or performed if the μFR is ≤ 0.80 in at least one NCVs

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Primary efficacy endpoint	Number of stents implanted and number of procedures	Periprocedural
Primary safety endpoint	MACE (major adverse cardiovascular event) defined as the composite of all-cause mortality, non-culprit vessel unplanned revascularization, non-fatal myocardial infarction (defined according to the Fourth Universal Definition of Myocardial Infarction, including procedural MI and spontaneous MI)	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Inappropriate revascularization	Inappropriate revascularization according to μFR value	Periprocedural
Change in clinical decision making	Change in clinical decision making about revascularization strategy from intended PCI to medical therapy	Periprocedural
μFR reproducibility	Test-re-test repeatability of μFR	Periprocedural
Length of stay	Duration of hospitalization	Periprocedural

Collaborators and Investigators

• Sponsor: University of Roma La Sapienza

Study record dates

Study Major Dates

• Study Start (Estimated): May 18, 2026
• Primary Completion (Estimated): June 25, 2027
• Study Completion (Estimated): June 30, 2028

Study Registration Dates

• First Submitted: May 4, 2026
• First Submitted That Met QC Criteria: May 13, 2026
• First Posted (Actual): May 20, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 19, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Revascularization; Murray-law based Quantitative Flow Ratio (μFR); Non culprit vessel
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Infarction; Necrosis; Myocardial Ischemia; Myocardial Infarction; Ischemia; Pathological Conditions, Signs and Symptoms; ST Elevation Myocardial Infarction; Acute Coronary Syndrome
• Other Study ID Numbers: Rif. 8306, Prot. 0284/2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No