Clinical Evaluation of Magnetic Resonance Imaging in Coronary Heart Disease-2

The study is a randomized controlled trial of non-invasive imaging to determine diagnosis and management of patients presenting with suspected stable angina. Despite the widespread availability of non-invasive imaging and guideline-enshrined use of optimal medical therapy (OMT), patients with suspected coronary heart disease (CHD) often end up having invasive coronary angiography early in their disease course. Currently >50% of elective invasive coronary angiograms performed in the UK and US do not lead on to a revascularisation procedure (data from 2008-09 UK Hospital Episode Statistics; American College of Cardiology National Cardiovascular Data Registry (Patel MR, et al., N Engl J Med 2010;362:886-95)). The UK NICE guidelines for the management of chest pain of recent onset (CG95; 2010) could increase this proportion even further. This is inefficient for patients and also of healthcare resources.

More widespread use of non-invasive functional imaging could reduce the rates of unnecessary angiography. We have shown in the CE-MARC study (Lancet 2012) that cardiovascular magnetic resonance (CMR) at 1.5Tesla has a higher diagnostic accuracy for the detection of CHD than single-photon emission computed tomography (SPECT). CE-MARC 2 will be a three-way randomised controlled trial of patient management in 1200 patients with known or suspected CHD, comparing 3Tesla CMR to SPECT-guided care or NICE guidelines-based management. The primary endpoint will be the reduction of unnecessary invasive angiography (defined by invasive FFR) at 12 months - identified by our expert patients as an important 'patient focused' clinical outcome measure. The secondary objectives will include: 1) assessment of safety of a CMR-guided management strategy 2) cost effectiveness analysis of these strategies.

Inclusion criteria

• Patient ≥30yrs
• Patient has suspected stable angina (CHD) that requires further investigation
• Has a defined risk of 10-90% (according to NICE guidelines CG95; 2010)
• Suitable for revascularisation if required
• Given informed written consent

Exclusion criteria

• Non-anginal chest pain
• Clinically unstable
• Previous MI or biomarker positive ACS
• Previous revascularisation with coronary artery bypass surgery or PCI
• Contraindication to CMR imaging (pacemaker, intra-orbital debris, intra-auricular implants, intracranial clips, severe claustrophobia)
• Contraindication to adenosine infusion (regular adenosine antagonist medication, significant reversible airways disease, second or third degree atrio-ventricular heart block, sino-atrial disease)
• Known adverse reaction to Adenosine or Gadolinium contrast agent
• Obesity (where body girth exceeds scanner diameter)
• Pregnancy or breast feeding
• Inability to give informed consent
• Known chronic renal failure (eGFR <30mL/min/1.73m2)