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)
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 106
- 试验地点
- 1
- 主要终点
- Correspondence between FFR and myocardial perfusion revealed by adenosine stress perfusion MRI.
研究概览
简要总结
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.
详细描述
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).
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •(1) Participation in the FAMOUS NSTEMI clinical trial (NCT registration 01764334); (2) age >18 years; (3) written informed consent.
排除标准
- •Contra-indications to MRI including metallic devices and severe kidney disease (i.e. an estimated glomerular filtration rate <30 ml/min/1.73 m2).
结局指标
主要结局
Correspondence between FFR and myocardial perfusion revealed by adenosine stress perfusion MRI.
时间窗: 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.
次要结局
- Myocardial Infarction(Baseline MRI scan)
- Myocardial area-at-risk(Baseline MRI scan)
- Adenosine response(Baseline)
- Left ventricular ejection fraction(Baseline and follow-up MRI (average 12 months))
- Myocardial salvage(Baseline and follow-up MRI (average 12 months))
- Culprit artery assignment(Baseline MRI scan)
- Microvascular obstruction(Baseline MRI scan)
- Myocardial haemorrhage(Baseline MRI)
- Myocardial salvage index(Baseline and follow-up MRI (average 12 months))
- Regional myocardial strain(Baseline and follow-up MRI (average 12 months))
研究者
Colin Berry
Professor of Cardiology and Imaging
NHS National Waiting Times Centre Board