Rapid three-dimensional quantification of high-intensity plaques from coronary atherosclerosis T1-weighted characterization to predict periprocedural myocardial injury.

BACKGROUND: High-intensity plaque (HIP) on magnetic resonance imaging (MRI) has been documented as a powerful predictor of periprocedural myocardial injury (PMI) following percutaneous coronary intervention (PCI). Despite the recent proposal of three-dimensional HIP quantification to enhance the predictive capability, the conventional pulse sequence, which necessitates the separate acquisition of anatomical reference images, hinders accurate three-dimensional segmentation along the coronary vasculature. Coronary atherosclerosis T1-weighted characterization (CATCH) enables the simultaneous acquisition of inherently coregistered dark-blood plaque and bright-blood coronary artery images. We aimed to develop a novel HIP quantification approach using CATCH and to ascertain its superior predictive performance compared to the conventional two-dimensional assessment based on plaque-to-myocardium signal intensity ratio (PMR). METHODS: In this prospective study, CATCH MRI was conducted before elective stent implantation in 137 lesions from 125 patients. On CATCH images, dedicated software automatically generated tubular three-dimensional volumes of interest on the dark-blood plaque images along the coronary vasculature, based on the precisely matched bright-blood coronary artery images, and subsequently computed PMR and HIP volume (HIPvol). Specifically, HIPvol was calculated as the volume of voxels with signal intensity exceeding that of the myocardium, weighted by their respective signal intensities. PMI was defined as post-PCI cardiac troponin-T > 5 × the upper reference limit. RESULTS: The entire analysis process was completed within 3 min per lesion. PMI occurred in 44 lesions. Based on the receiver operating characteristic curve analysis, HIPvol outperformed PMR for predicting PMI (C-statistics, 0.870 [95% CI, 0.805-0.936] vs. 0.787 [95% CI, 0.706-0.868]; p = 0.001). This result was primarily driven by the higher sensitivity HIPvol offered: 0.886 (95% CI, 0.754-0.962) vs. 0.750 for PMR (95% CI, 0.597-0.868; p = 0.034). Multivariable analysis identified HIPvol as an independent predictor of PMI (odds ratio, 1.15 per 10-µL increase; 95% CI, 1.01-1.30, p = 0.035). CONCLUSIONS: Our semi-automated method of analyzing coronary plaque using CATCH MRI provided rapid HIP quantification. Three-dimensional assessment using this approach had a better ability to predict PMI than conventional two-dimensional assessment.

Relationship between coronary high-intensity plaques on T1-weighted imaging by cardiovascular magnetic resonance and vulnerable plaque features by near-infrared spectroscopy and intravascular ultrasound: a prospective cohort study.

BACKGROUND: This study aimed to compare the coronary plaque characterization by cardiovascular magnetic resonance (CMR) and near-infrared spectroscopy (NIRS)-intravascular ultrasound (IVUS) (NIRS-IVUS), and to determine whether pre-percutaneous coronary intervention (PCI) evaluation using CMR identifies high-intensity plaques (HIPs) at risk of peri-procedural myocardial infarction (pMI). Although there is little evidence in comparison with NIRS-IVUS findings, which have recently been shown to identify vulnerable plaques, we inferred that CMR-derived HIPs would be associated with vulnerable plaque features identified on NIRS-IVUS. METHODS: 52 patients with stable coronary artery disease who underwent CMR with non-contrast T1-weighted imaging and PCI using NIRS-IVUS were studied. HIP was defined as a signal intensity of the coronary plaque-to-myocardial signal intensity ratio (PMR) ≥ 1.4, which was measured from the data of CMR images. We evaluated whether HIPs were associated with the NIRS-derived maximum 4-mm lipid-core burden index (maxLCBI4mm) and plaque morphology on IVUS, and assessed the incidence and predictor of pMI defined by the current Universal Definition using high-sensitive cardiac troponin-T. RESULTS: Of 62 lesions, HIPs were observed in 30 lesions (48%). The HIP group had a significantly higher remodeling index, plaque burden, and proportion of echo-lucent plaque and maxLCBI4mm ≥ 400 (known as large lipid-rich plaque [LRP]) than the non-HIP group. The correlation between the maxLCBI4mm and PMR was significantly positive (r = 0.51). In multivariable logistic regression analysis for prediction of HIP, NIRS-derived large LRP (odds ratio [OR] = 5.41; 95% confidence intervals [CIs] 1.65-17.8, p = 0.005) and IVUS-derived echo-lucent plaque (OR = 5.12; 95% CIs 1.11-23.6, p = 0.036) were strong independent predictors. Furthermore, pMI occurred in 14 of 30 lesions (47%) with HIP, compared to only 5 of 32 lesions (16%) without HIP (p = 0.005). In multivariable logistic regression analysis for prediction of incidence of pMI, CMR-derived HIP (OR = 5.68; 95% CIs 1.53-21.1, p = 0.009) was a strong independent predictor, but not NIRS-derived large LRP and IVUS-derived echo-lucent plaque. CONCLUSIONS: There is an important relationship between CMR-derived HIP and NIRS-derived large LRP. We also confirmed that non-contrast T1-weighted CMR imaging is useful for characterization of vulnerable plaque features as well as for pre-PCI risk stratification. Trial registration The ethics committee of Juntendo Clinical Research and Trial Center approved this study on January 26, 2021 (Reference Number 20-313).

Additional Effect of Coronary High-Intensity Plaque on T1-Weighted Magnetic Resonance Imaging With Circulating Malondialdehyde-Modified Low-Density Lipoprotein on Cardiac Events.

BACKGROUND: Although elevated levels of oxidized low-density lipoprotein (LDL) could play a critical role in vulnerable plaque, there are no studies that have compared coronary high-intensity plaque (HIP) and circulating malondialdehyde-modified (MDA)-LDL levels for the prediction of cardiac events.Methods and Results:A total of 139 patients with coronary artery stenosis (>70%) were examined with non-contrast T1-weighted magnetic resonance imaging (MRI) (HIP: n=64, non-HIP: n=75). Scheduled percutaneous coronary intervention (PCI) for culprit lesions was performed within 48 h after MRI. HIP was defined as a signal intensity of coronary plaque to cardiac muscle ratio (PMR) ≥1.4. We evaluated the subsequent major adverse cardiac events (MACE) during the follow-up period (5.6±1.3 years). MDA-LDL levels were independently associated with the presence of HIP (P<0.0001). The incidence of MACE was 15%, and it was significantly higher in patients with HIP (27%) than in those without HIP (5%; P=0.011). Cox proportional hazard analysis showed MDA-LDL levels (P=0.007) and PMR (P=0.016) were significantly associated with MACE. For MACE prediction, C-statistic values for MDA-LDL, PMR, and PMR+MDA-LDL were 0.724, 0.791, and 0.800, respectively. Compared with MDA-LDL alone, the addition of PMR to MDA-LDL increased net reclassification improvement by 0.78 (P=0.012). CONCLUSIONS: MDA-LDL levels might be associated with the presence of HIP in patients with coronary artery disease. Furthermore, adding PMR to MDA-LDL levels markedly improved prediction of subsequent MACE after PCI.

[Optimal Conditions for 3D Non-contrast T1-weighted Magnetic Resonance Imaging Segmented Turbo Fast Low-angle Shot for Tissue Characterization of Coronary Plaques].

In three-dimensional (3D) T1-weighted magnetic resonance imaging used for tissue characterization of coronary plaques, the contrast for electrocardiographic synchronization may vary according to the R-R interval (RR). The coronary artery plaque image shows suppression of the fluid compartment signal for the coronary artery luminal blood as well as the fat signal in the region of interest; in addition, it is necessary to ensure that the value of the plaque-to-muscle signal intensity ratio (PMR) does not change according to the difference in RR. In the current study, the phantom review and clinical data suggested that the PMR changes that occur due to the differences in RR can be minimized by adjusting the inversion time (TI) in the range of the required black blood effect. Moreover, the signal-to-noise ratio (SNR), which varies according to the difference between the RR and the TI, was determined to identify the maximum value flip angle (FA) value that would lead to improvement in the SNR. Thus, signal suppression of the PMR, SNR, and the fluid compartment of the coronary artery luminal blood can be controlled using different RRs with the relational expressions for calculating optimal TI and FA.

Clinical utility of non-contrast T1-weighted magnetic resonance imaging in percutaneous coronary intervention: A case report.

Coronary high-intensity plaques (HIPs) visualized by non-contrast T1-weighted imaging (T1WI) in cardiac magnetic resonance (CMR) are associated with slow-flow phenomena during percutaneous coronary intervention (PCI). We report a case of a 52-year-old man who had undergone left anterior descending artery stent implantation for unstable angina 5 years previously. He underwent CMR imaging for screening of vulnerable plaques. A lesion in the proximal right coronary artery showed HIP on non-contrast T1WI. Invasive coronary angiography showed progressive stenosis and PCI was performed. Non-contrast T1WI indicated a high risk for a slow-flow phenomenon. A distal protection device (Parachute™ (Tri-Med, Osaka, Japan)) was deployed at the distal site of the lesion. Following balloon dilation, a filter no-reflow phenomenon developed. Coronary flow was improved with removal of the Parachute™ after debris aspiration. Histological examination revealed aspirated debris composed of white thrombi, foamy macrophages, and cholesterol crystals. .

Differences of plaque characterization of high-intensity and non high-intensity plaques on non-contrast T1-weighted magnetic resonance imaging using angioscopy and optical coherence tomography.

Coronary high-intensity plaques (HIPs) visualized by non-contrast T1-weighted imaging (T1WI) in cardiac magnetic resonance (CMR) were associated with coronary events. We report a case of a 68-year-old man with an old myocardial infarction. He had undergone CMR to exclude new coronary artery disease, because he sometimes had an atypical chest symptom. The moderate stenosis in the right coronary artery (RCA) showed non HIP on non-contrast T1WI. We observed HIP in the proximal left anterior descending artery (LAD) without significant stenosis. Non HIP lesion in the RCA showed fibrous and calcified plaque without thrombus by optical coherence tomography (OCT) and angioscopy. On the other hand, the HIP lesion in the LAD showed lipid plaque with thrombus by OCT, and yellow plaque with mobile mixed thrombus by angioscopy. .