Magnetic Resonance Measurements of Myocardial Function and Pathophysiology
We have an extremely vibrant research portfolio using Cardiovascular MRI (CMR) led by Gerry McCann. Projects have been funded by the MRC, BHF and NIHR through central grants and the NIHR Leicester Cardiovascular BRU.
Three main areas of research
CMR as an outcome measure in clinical trials
We have completed a number of clinical trials assessing the impact of different revascularization strategies on infarct size and myocardial salvage following STEMI. (J Am Coll Cardiol 2015;66:2713-24 and Eur Heart J 2016;37:1910-9). The CvLPRIt CMR study showed that complete revascularization at the time of Primary-PCI (PPCI) did not increase total infarct size, although there was a small increase in non-infarct related artery MI. The REFLO STEMI trial assessed whether either intracoronary adenosine or sodium nitroprusside could reduce MI size and microvascular obstruction at the time of PPCI. Neither drug was effective and there was a strong signal that routine adenosine administration may cause harm with larger infarct size and more adverse events see in this arm.
Further collaborative studies with industry are assessing whether novel treatments improve both clinical and subclinical (strain/strain rate, perfusion reserve) cardiac dysfunction.
Better understanding of the pathophysiology of heart disease using advanced CMR techniques
We have recently completed a multicenter study assessing whether myocardial perfusion reserve (MPR) can predict symptom development better than exercise testing in asymptomatic patients with aortic stenosis. MPR was significantly associated with symptom onset but did not predict outcome better than exercise testing. (Singh A et al Eur Heart J 2017) Interestingly scarring detected by late gadolinium enhancement did not predict the development of symptoms, despite being associated with mortality in previous studies.
We have recently completed a detailed phenotyping study in 170 patients with Heart Failure and preserved Ejection Fraction (HFpEF). The data are being analysed in relation to prognosis and results are expected to be published in 2017. We have also recruited and phenotyped over 100 patients in the BHF funded spontaneous coronary artery dissection study.
The role of CMR in the investigation of patients with known or suspected heart disease
Two of the largest ever CMR trials have been conducted at Glenfield. The BHF funded CEMARC-2 trial (led by Leeds) assessed whether patients with suspected chest pain of cardiac origin are better managed with 3T stress CMR than either SPECT or NICE guidance. 1200 patients were recruited in 6 sites across the UK and showed that the use of functional imaging (stress MRI or SPECT) was much more likely to result in unnecessary invasive coronary angiography than following NICE guidance (JAMA 2016;316:1051-60).
The MR-Inform study (led by King’s College London) assesses whether patient with angina can be as safely and more cost-effectively managed by stress CMR than invasive angiography in 918 patients. The results are being presented at the American College of Cardiology scientific sessions in March 2017.