Ehara Shoichi, Mizutani Kazuki, Yamazaki Takanori, Matsumoto Kenji, Okai Tsukasa, Yamaguchi Tomohiro, Izumiya Yasuhiro, Naruko Takahiko, Yoshiyama Minoru
Department of Cardiovascular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
Department of Cardiology, Osaka City General Hospital, Osaka, Japan.
Am Heart J Plus. 2021 Oct 6;10:100047. doi: 10.1016/j.ahjo.2021.100047. eCollection 2021 Oct.
Although intraplaque hemorrhage (IPH) has been identified as a key feature of rupture-prone plaques, noninvasive imaging-based features for its detection in coronary artery have not been clearly established. The aim of this study was to investigate the relationship of the ratio between the signal intensities of coronary plaque and cardiac muscle (PMR) on non-contrast T1-weighted imaging (T1WI) in magnetic resonance with IPH in the directional coronary atherectomy (DCA) specimens.
Fifteen lesions from 15 patients, who underwent DCA and T1WI, were prospectively enrolled. The snap-frozen samples obtained by DCA were used for immunohistochemical staining against a protein specific to erythrocyte membranes (glycophorin A) and macrophages. The percentage of glycophorin A and macrophages was graded using a scale from 0 to 4, with higher scores indicating higher percentages.
PMR showed a strong positive correlation with glycophorin A scores (ρ = 0.772, < 0.001), whreas, there was a weak correlation between the PMR and macrophage scores (ρ = 0.626, < 0.05). The receiver-operating characteristic curve analysis showed that the optimal PMR cutoff value for predicting glycophorin A scores ≥grade 2 (glycophorin A-positive area ≥5% of the plaque) was 1.2 (area under the curve; 0.91, 95% confidence interval; 0.73-1.00), and this PMR value had a sensitivity of 8/9 (89%), specificity of 6/6 (100%), positive predictive value of 8/8 (100%), and negative predictive value of 6/7 (86%).
In patients with ischemic heart disease, a high PMR on T1WI is a predictor of coronary IPH as assessed by DCA specimens.
尽管斑块内出血（IPH）已被确定为易破裂斑块的一个关键特征，但基于非侵入性成像在冠状动脉中检测IPH的特征尚未明确确立。本研究的目的是探讨磁共振非对比T1加权成像（T1WI）上冠状动脉斑块与心肌的信号强度比值（PMR）与定向冠状动脉斑块旋切术（DCA）标本中IPH的关系。
前瞻性纳入15例接受DCA和T1WI检查的患者的15个病变。通过DCA获得的速冻样本用于针对红细胞膜特异性蛋白（血型糖蛋白A）和巨噬细胞的免疫组织化学染色。血型糖蛋白A和巨噬细胞的百分比采用0至4级评分，分数越高表明百分比越高。
PMR与血型糖蛋白A评分呈强正相关（ρ = 0.772，<0.001），而PMR与巨噬细胞评分之间的相关性较弱（ρ = 0.626，<0.05）。受试者操作特征曲线分析表明，预测血型糖蛋白A评分≥2级（血型糖蛋白A阳性面积≥斑块的5%）的最佳PMR截断值为1.2（曲线下面积；0.91，95%置信区间；0.73 - 1.00），该PMR值的敏感性为8/9（89%），特异性为6/6（100%），阳性预测值为8/8（100%），阴性预测值为6/7（86%）。
在缺血性心脏病患者中，T1WI上高PMR是DCA标本评估的冠状动脉IPH的预测指标。
