Brief Summary The Purpose of the Study : The purpose of this study is to find a safe and reliable "one-stop" solution for treating heart attack patients who have multiple blocked arteries. Currently, doctors face a dilemma: Testing these other blockages during the heart attack procedure is often unreliable.
The most accurate method requires asking the patient to return 30 days later for a second invasive procedure, which is a significant burden.
The Study's Hypothesis : We are testing a new tool called UFR, which uses ultrasound images to measure blockages. Our hypothesis (or "educated guess") is that this new UFR tool is not affected by the body's stress during a heart attack and can provide a true, reliable measurement right away.
The Question the Study is Trying to Answer ： The main question this study is trying to answer is: Can the new "one-stop" UFR tool, used during the initial heart attack procedure, accurately predict which blockages are truly serious... thereby eliminating the need for patients to return for a second procedure 30 days later? Researchers will also follow 200 patients for one year, using advanced scans (like UFR, standard tests, and MRI), to better understand how the heart and arteries heal and change over time.
Age >18 years, any sex.
The participant is able to understand the study procedures and provides voluntary written informed consent.
STEMI Cohort: Symptom onset < 12 hours with ECG findings of ST-segment elevation myocardial infarction.
High-Risk NSTEMI Cohort: Meets at least one of the following: GRACE score > 140, dynamic ECG changes (ST-T), or significant Troponin elevation.
Presence of cardiogenic shock on presentation, or persistent hemodynamic instability despite successful PCI of the culprit vessel.
Known severe allergy to iodinated contrast media or gadolinium-based contrast agents (used for CMR).
Female participants who are pregnant, breastfeeding, or planning pregnancy within the 1-year study period.Unprotected left main coronary artery disease (stenosis <50%) requiring intervention.
Prior history of Coronary Artery Bypass Grafting (CABG) surgery.The target NCV has received prior PCI (e.g., existing stent) or surgical revascularization.
The study population will be sourced from patients presenting with Acute Coronary Syndrome (STEMI or High-Risk NSTEMI) to the Emergency Department and/or cardiology services of participating multi-center hospitals. Eligible participants will be identified and screened for enrollment in the Cardiac Catheterization Laboratory (Cath Lab) immediately following their successful index PCI procedure (T0).
Cohort
Prospective
IVUS-based Fractional Flow Reserve (UFR)
Diagnostic testUFR is a "virtual" fractional flow reserve calculated from Intravascular Ultrasound (IVUS) images using computational fluid dynamics. In this study, it is calculated from IVUS runs of the Non-Culprit Vessel (NCV) performed at the T0 (Acute) procedure. This T0 UFR value is the primary diagnostic test being evaluated against the T1 (30-day) pFFR gold standard. UFR will also be assessed at the T2 (1-year) follow-up.
Invasive Coronary Physiology Measurement (FFR/RFR/IMR)
Diagnostic testInvasive physiological measurements are performed using a standard pressure-sensing guidewire.T0 (Acute): FFR, RFR, and IMR are measured in the Non-Culprit Vessel (NCV) and the post-PCI Culprit Vessel (CV).T1 (30-Day): FFR and RFR are measured in the NCV. This T1 pFFR (threshold\< 0.80) serves as the gold standard comparator for the primary endpoint.T2 (1-Year): FFR is reassessed in the CV and any untreated NCV.
Cardiac Magnetic Resonance (CMR)
Diagnostic testThe scan is performed prior to discharge to quantify myocardial injury, including infarct size, Left Ventricular Ejection Fraction (LVEF), and the extent of Microvascular Obstruction (MVO). CMR data serves as the "tissue" component for the secondary 'structure-function-tissue' coupling analysis.
Diagnostic Performance of Acute UFR (T0) Compared to Staged pFFR (T1) in Non-Culprit Vessels
To assess the diagnostic performance of UFR measured at T0 (Acute) against the gold-standard pFFR (threshold ≤ 0.80) measured at T1 (30 Days). Performance will be assessed by 1) Diagnostic accuracy (Sensitivity, Specificity, PPV, NPV), 2) Correlation (Pearson coefficient and Bland-Altman analysis), and 3) Comparison of Area Under the Curve (AUC).
Functional Re-classification Rate ("Functional Drift") from T0 to T1 (STEMI vs. NSTEMI)
To quantify and compare the rate of functional re-classification of pFFR and RFR in the NCV between T0 (Acute) and T1 (Stable). This will be compared head-to-head between the STEMI and High-Risk NSTEMI cohorts.
Correlation between Acute Culprit Vessel IMR and Sub-Acute MVO (Coupling 1)
To determine the quantitative correlation between the Index of Microcirculatory Resistance (IMR) measured in the Culprit Vessel at T0 and the extent of Microvascular Obstruction (MVO) quantified by Cardiac MRI at T-CMR (3-5 days)
Longitudinal Stability of In-Stent pFFR and UFR (Culprit Vessel Evolution)
To compare the temporal stability of pFFR and UFR values measured within the stented segment of the Culprit Vessel from T0 (post-PCI) to T2 (1-year follow-up).
Prognostic Value of T1 NCV Functional Status on 1-Year MACE
To evaluate the predictive value of the NCV's functional status at T1 (pFFR ≤ 0.80) on 1-year Major Adverse Cardiovascular Events (MACE). MACE is defined as cardiac death, target vessel MI, and clinically-driven revascularization.
Click on the lead sponsor to view all of their trials.
This trial is not recruiting at the moment. You can still explore other options:
