Free-breathing, non-contrast, three-dimensional whole-heart coronary magnetic resonance imaging for the identification of culprit and vulnerable atherosclerotic plaque

Detection of vulnerable coronary plaque can predict future myocardial infarctions. We have developed a novel, non-contrast cardiovascular magnetic resonance sequence (iT2prep-BOOST), enabling simultaneous, co-registered coronary angiography and plaque detection. To validate iT2prep-BOOST in patients with non-ST-segment elevation myocardial infarction (NSTEMI). 41 patients with suspected NSTEMI were recruited. Invasive coronary angiography ± intravascular imaging was used to classify coronary segments into the following categories: normal, non-culprit and culprit segments; stenosed segments as well as segments with vulnerable plaque features (lipid, calcium, fibroatheroma, thin cap fibroatheroma (TCFA), plaque-rupture and thrombus). The plaque/myocardial signal intensity ratio (PMR) in each coronary segment was analyzed on iT2prep-BOOST. The mean ± standard deviation PMR of culprit segments was significantly higher than non-culprit segments and normal segments (1.01 ± 0.14 vs. 0.67 ± 0.18 vs. 0.35 ± 0.24, P<0.001, respectively). Coronary segments with lipid, calcium, and fibroatheroma had a significantly higher PMR compared to normal coronary segments (P<0.001), but significantly lower than segments with plaque-rupture and intraluminal thrombus (P<0.05). There was a progressive increase in PMR with increasing coronary segment stenosis (P<0.001). There was a significant association on multivariable analysis between HbA1c as well as family history of coronary artery disease and mean PMR (P = 0.05 and P = 0.04, respectively). iT2prep-BOOST has the potential to simultaneously visualize coronary artery lumen and plaque and differentiate normal segments from non-culprit and culprit plaque segments non-invasively and without contrast. The prognostic value of PMR needs to be investigated in a prospective multicenter study. 1. A patient who presented with chest pain, peak high sensitivity troponin of 13459 ng/L and ST-segment depression in the inferior electrocardiogram leads. A -Bright-blood coronary angiography from iT2Prep-BOOST showing a stenosis in the proximal RCA (white arrow). B -Co-registered fusion image of iT2Prep-BOOST bright-blood and black-blood datasets showing increased signal from the proximal RCA lesion (white arrow). C -Invasive coronary angiography showing a subtle stenosis in the proximal RCA (white arrow). D -Dark-blood late gadolinium enhancement short axis image showing a partial thickness infarction affecting the basal inferior wall (white arrows). E -Pre-contrast T2 mapping showing increased signal in the basal inferior wall (white arrows). F -Optical coherence tomography of the proximal RCA lesion demonstrating acute plaque rupture and intraluminal thrombus (yellow arrows). 2. Dot strip plot showing the per-segment analysis of the mean ± standard deviation PMR of normal segments, bystander non-culprit segments and culprit segments as identified iT2Prep-BOOST. PMR plaque to myocardial signal intensity ratio, RCA right coronary artery, SD standard deviation.