FAMOUS-NSTEMI MRI Sub-Study

October 27, 2024 updated by: Colin Berry, NHS National Waiting Times Centre Board

Fractional Flow Reserve Versus Angiographically Guided Management to Optimise Outcomes in Unstable Coronary Syndromes - a 3.0 Tesla Stress Perfusion MRI Sub-Study (FAMOUS-NSTEMI MRI)

BACKGROUND: Non-ST-segment elevation myocardial infarction (NSTEMI) is the commonest type of acute coronary syndrome (ACS) and has a poor long-term prognosis. Guidewire-based coronary pressure measurement of the myocardial fractional flow reserve (FFR) is validated for measuring the severity of a coronary lesion narrowing in patients with stable angina. FFR measurement in patients with a recent ACS has theoretical limitations and is not fully validated.

AIM: To prospectively assess heart muscle blood flow and injury with guide-wire based methods at the time of the clinically-indicated angiogram and compare these results with those from a stress perfusion MRI scan in medically-stabilised NSTEMI..

HYPOTHESIS: 1) FFR measured invasively will correspond closely with findings from stress perfusion MRI, 2) MRI will provide clinically-relevant information on heart muscle injury, function and salvage, 3) Guidewire-derived measurements of coronary microvascular function will be associated with the MRI findings.

DESIGN: The MRI study will be performed in patients who give informed consent in the FAMOUS-NSTEMI clinical trial (NCT registration 01764334). All of the clinical data for these participants will be available to link with the MRI results.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

BACKGROUND: Non-ST elevation myocardial infarction (NSTEMI) is the commonest type of acute coronary syndrome (ACS) and has a poor long-term prognosis. Guidewire-based coronary pressure measurement of the myocardial fractional flow reserve (FFR) is a prognostically-validated invasive method for measuring coronary lesion severity in patients with stable coronary artery disease. FFR measurement in patients with unstable coronary disease has theoretical limitations and is not fully validated in NSTEMI.

AIM: To prospectively evaluate ischaemia and infarction with adenosine stress perfusion cardiac MRI in medically-stabilised NSTEMI patients in whom FFR has been measured.

METHODS: In the FAMOUS-NSTEMI clinical trial (NCT registration 01764334), medically-stabilised patients with recent NSTEMI will have lesion-level ischaemia measured with FFR in all coronary artery stenoses amenable to revascularisation, as clinically appropriate.

Consecutive study participants will be invited to have an adenosine (140 µg/kg/min) stress 3.0 Tesla cardiac MRI scan to assess myocardial perfusion on up to three occasions: 1) before coronary angiography, 2) within 10 days post coronary angiography and finally, 3) 6 months after hospital admission. MRI will also assess myocardial pathophysiology including ischaemia, oedema, haemorrhage and infarct scar. MRI will provide the reference dataset. Guidewire-derived parameters were obtained and assessed blind to the MRI results.

The primary outcome is the correspondence between the presence or absence of an inducible-myocardial perfusion defect and FFR ≤ or > 0.80 in the MRI scans at baseline or post-angiography. Secondary outcomes include the correlation between measures of infarct severity as revealed by MRI (infarct size, myocardial salvage, microvascular obstruction, myocardial haemorrhage, myocardial strain) and invasive measures of coronary function (1) coronary collateral supply (fractional coronary collateral supply), (2) microcirculatory resistance (index of microvascular resistance), and (3) vasodilator capacity (resistive reserve ratio).

The project was funded by the British Heart Foundation and Chief Scientist Office. The pressure wires were provided through a restricted grant from St Jude Medical. The funders of the study have no involvement in the study design, analysis, interpretation, or presentation of the results.

VALUE: This study will provide clinically important information on the relationships between coronary artery and microcirculatory function measured invasively and ischaemia and MI pathologies, as revealed by non-invasively by MRI.

Study Type

Observational

Enrollment (Actual)

106

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United Kingdom
    • Strathclyde
      • Glasgow, Strathclyde, United Kingdom, G12 8TA
        • BHF Glasgow Cardiovascular Research Centre

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Medically stabilised patients with recent non-ST elevation myocardial infarction.

Description

Inclusion Criteria:

  • (1) Participation in the FAMOUS NSTEMI clinical trial (NCT registration 01764334); (2) age >18 years; (3) written informed consent.

Exclusion Criteria:

  • 1) Contra-indications to MRI including metallic devices and severe kidney disease (i.e. an estimated glomerular filtration rate <30 ml/min/1.73 m2).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Non-ST elevation myocardial infarction
Natural history study of non-ST elevation myocardial infarction and coronary physiology
Device: Fractional flow reserve
Guidewire-based index of coronary artery stenosis severity measured when coronary microvascular resistance is minimised by administration of a vasodilator drug.
Other Names:
  • FFR
Other: Magnetic resonance imaging
Cardiac magnetic resonance imaging at 3.0 Tesla, including perfusion MRI at rest and during pharmacological stress with intravenous adenosine (140-210 ug/kg/min).
Other Names:
  • MRI

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Correspondence between FFR and myocardial perfusion revealed by adenosine stress perfusion MRI.
Time Frame: MRI at baseline
FFR is a guidewire based measurement of lesion-level flow limitation during hyperaemia. An MRI perfusion defect is classified as significant according to the presence of ischaemia in 2 segments of a 32 segment model i.e: > 60 degrees in either the basal or the mid-ventricular slices or > 90 degrees in the apical slice or any transmural defect or two adjacent slices. FFR and MRI will be correlated in corresponding coronary artery territories based on coronary anatomy. The analysis is for diagnostic accuracy of FFR vs. myocardial perfusion as assessed by MRI in temporally associated assessments at baseline.
MRI at baseline

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Myocardial Infarction
Time Frame: Baseline MRI scan
Presence and extent (% left ventricular volume) of infarction, as revealed by late gadolinium contrast enhancement.
Baseline MRI scan
Myocardial area-at-risk
Time Frame: Baseline MRI scan
The myocardial ischaemic area-at-risk revealed by non-contrast MRI methods (T1 mapping, T2 mapping, T2-weighted MRI).
Baseline MRI scan
Myocardial salvage
Time Frame: Baseline and follow-up MRI (average 12 months)
Myocardial salvage is estimated by subtraction of infarct size from the initial area-at-risk. Salvage may be estimated at baseline with initial infarct size or at follow-up (final infarct size).
Baseline and follow-up MRI (average 12 months)
Myocardial salvage index
Time Frame: Baseline and follow-up MRI (average 12 months)
Myocardial salvage index is estimated by indexing infarct size to the initial area-at-risk. Salvage may be estimated at baseline with initial infarct size or at follow-up with final infarct size.
Baseline and follow-up MRI (average 12 months)
Left ventricular ejection fraction
Time Frame: Baseline and follow-up MRI (average 12 months)
Left ventricular ejection fraction (LVEF) is an index of left ventricular systolic function, and a surrogate outcome measure of treatment efficacy and patient outcome.
Baseline and follow-up MRI (average 12 months)
Culprit artery assignment
Time Frame: Baseline MRI scan
Magnetic resonance imaging of myocardial ischaemic injury with non-contrast MRI methods should theoretically identify the culprit artery in patients with a recent non-ST elevation myocardial infarction. The MRI methods to be used in this study include T1 mapping (MOLLI, Siemens Healthcare), T2 mapping (bSSFP, Siemens Healthcare) and T2-STIR (dark blood oedema MRI). The diagnostic accuracy of these three methods will be compared using a combination of clinical parameters (ECG, coronary angiogram, invasive adjunctive diagnostic methods, contrast enhanced MRI) which together represent the reference dataset for culprit artery assignment in individual patients.
Baseline MRI scan
Microvascular obstruction
Time Frame: Baseline MRI scan
Microvascular obstruction revealed by MRI is due to a failure of gadolinium contrast to diffuse into the infarct zone because of extrinsic compression (e.g. oedema) and intrinsic obstruction (e.g. microvascular thrombosis).
Baseline MRI scan
Myocardial haemorrhage
Time Frame: Baseline MRI
Myocardial haemorrhage is a consequence of vascular damage and is related to the duration of ischaemia, infarct severity and coronary reperfusion. Transverse (T2) and T2* magnetisation are destroyed by the paramagnetic effects of deoxyhaemoglobin. Signal loss in T2*-weighted images have high positive predictive accuracy for myocardial haemorrhage. T2 and T2* mapping methods, and STIR (dark blood MRI) will be used to assess the incidence of haemorrhage.
Baseline MRI
Regional myocardial strain
Time Frame: Baseline and follow-up MRI (average 12 months)
Myocardial strain is an intrinsic property of myocardial contractility. Left ventricular (LV) thickening and inward LV motion (which is how LVEF is calculated) are passive phenomena secondary to active circumferential shortening and sources of artefact (such as through plane motion) can misrepresent actual LV contractility. Strain-encoded cardiac MRI with DENSE will be used to assess regional strain in the left ventricle, segmented according to the American Heart Association model. The mid-ventricular level will be a particular region of interest.
Baseline and follow-up MRI (average 12 months)
Adenosine response
Time Frame: Baseline
FFR and perfusion MRI require systemic vasodilatation. In this study, systemic hyperaemia is induced by administration of intravenous adenosine (140 ug/kg/min - 210 ug/kg/min). The patient response (symptoms, haemodynamics, MRI) will be assessed prospectively.
Baseline

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

NHS National Waiting Times Centre Board

Collaborators

British Heart Foundation
NHS Greater Glasgow and Clyde
University of Glasgow
NHS Lanarkshire

Investigators

  • Principal Investigator: Colin Berry, MB ChB BSc FRCP FACC, University of Glasgow

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 1, 2011

Primary Completion (Actual)

June 10, 2014

Study Completion (Actual)

December 10, 2016

Study Registration Dates

First Submitted

February 19, 2014

First Submitted That Met QC Criteria

February 25, 2014

First Posted (Estimated)

February 27, 2014

Study Record Updates

Last Update Posted (Actual)

October 29, 2024

Last Update Submitted That Met QC Criteria

October 27, 2024

Last Verified

October 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • NRS-11-CA56, PG/11/55/28999
  • PG/11/55/28999 (Other Grant/Funding Number: British Heart Foundation PG/11/55/28999)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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