NonST Elevation Myocardial Infarction Clinical Trial
Official title:
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.
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.
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| Status | Clinical Trial | Phase | |
|---|---|---|---|
| Active, not recruiting |
NCT01764334 -
Fractional Flow Reserve Versus Angiographically Guided Management to Optimise Outcomes in Unstable Coronary Syndromes
|
Phase 4 |