Cardiac Magnetic Resonance Imaging: New Pathological Insights and Their Functional and Clinical Significance in ST Elevation Acute Myocardial Infarction.
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Acute ST-elevation Myocardial Infarction
- Sponsor
- NHS National Waiting Times Centre Board
- Enrollment
- 324
- Locations
- 1
- Primary Endpoint
- Myocardial salvage
- Status
- Active, not recruiting
- Last Updated
- last year
Overview
Brief Summary
Heart imaging with magnetic resonance imaging (MRI) provides detailed insights into heart function and injury. The nature and significance of heart injury after a heart attack is incompletely understood. We propose a 'natural history' study of heart attack injury using contemporary MRI methods. In a large hospital in the West of Scotland, heart attack patients will be invited to have at least two MRI scans and also continue with life-long follow-up. The results from the MRI scans will be assessed with all of the other clinical information obtained at the time of the heart attack and during follow-up. The results of our study should provide new insights into heart attack injury and these results should help improve how heart attack patients should be treated.
Detailed Description
Magnetic resonance imaging (MRI) provides detailed insights into soft tissue characteristics and this technique has particular value for imaging patients with acute myocardial infarction (MI). Recent advances in MRI have the potential to reveal new insights into the evolution and functional significance of myocardial injury and repair. Here, we will study at least 300 consecutive patients with acute ST elevation MI (STEMI) and focus on oedema, scar and bleeding in the heart using MRI in patients managed by emergency percutaneous coronary intervention (PCI). Cardiac MRI scans will be performed at 1.5 Tesla (MAGNETOM, Siemens Healthcare). MRI will be used to assess initial heart function and injury. Myocardial salvage and haemorrhage are prioritised outcomes. Novel MRI methods will also be used to quantify the extent of myocardial jeopardy representing the initial area-at-risk (AAR), and the nature of this injury (strain, haemorrhage). The MRI methods will include T1, T2 and T2\* relaxometry (mapping). Secondly, we will assess coronary artery disease severity by angiography and coronary artery function at the time of the heart attack treatment using a pressure-sensitive coronary guidewire (St Jude Medical). This wire can be used instead of the usual coronary wire and can provide information on heart injury, which can be linked in turn to the MRI findings. All of this information will be linked with health outcomes in the longer term. We hypothesise that myocardial salvage, oedema, haemorrhage, and strain as revealed by MRI, have functional and prognostic significance. In all patients MRI will be performed at baseline (\~day 2) and again at 6 months. In a subgroup of 30 patients, MRI will be performed on days \<12 hours, and days 2, 7-10 days and 6 months post-MI. A blood and urine sample and quality of life will be obtained at baseline and at 6 months post-MI. Clinical outcomes (e.g. rehospitalisation, death) will be assessed at the end of the study (minimum 1 year) and again during longer term follow-up (minimum 3 years, maximum 20 years) by electronic linkage through central National Health Service (NHS) and government health records in order to determine the long-term prognostic significance of our initial observations with angiography, MRI and the pressure wire. The main statistical analyses will be conducted by an independent trials unit statistician.
Investigators
Colin Berry
Professor of Cardiology and Imaging
University of Glasgow
Eligibility Criteria
Inclusion Criteria
- •Acute STEMI
Exclusion Criteria
- •Major systemic illness (e.g. cancer limiting survival \< 6 months);
- •Metallic implant (e.g. cochlear implant);
- •Metallic foreign body
- •Pregnancy.
Outcomes
Primary Outcomes
Myocardial salvage
Time Frame: Baseline and 6 months after date of index hospitalisation for STEMI
Myocardial salvage (% left ventricular volume) was defined as the difference between the initial jeopardised area-at-risk revealed by T2-weighted MRI (1.5 Tesla, Siemens Healthcare) at baseline and final infarct size revealed by contrast-enhanced MRI at 6 months on the same MRI scanner.
Secondary Outcomes
- Myocardial salvage index(Baseline and 6 months)
- Myocardial haemorrhage(Baseline MRI scan)
- Left ventricular end-systolic volume(Baseline and follow-up MRI at 6 months)
- Index of microvascular resistance(Day 0 at initial hospital admission)
- Adenosine response(Baseline)
- First pass MVO(Baseline MRI)
- Area-at-risk(Baseline MRI scan)
- Myocardial T2 time(Baseline and follow-up MRI at 6 months)
- MACE(Minimum 12 months)
- Myocardial T1 time(Baseline and follow-up MRI at 6 months)
- MACCE(Minimum 12 months)
- Early MVO(Baseline MRI)
- Left ventricular end-diastolic volume(Baseline and follow-up MRI at 6 months)
- Quality of life(Baseline and 6 months)
- Recurrent myocardial infarction(6 months)
- Final infarct size(MRI scan at 6 months after index hospitalisation)
- Microvascular obstruction(Baseline MRI scan)
- Left ventricular ejection fraction(Baseline and follow-up MRI at 6 months)
- Serious adverse cardiovascular events.(Minimum 12 months)
- All-cause death or heart failure(Minimum 12 months from baseline)