冠状动脉CT血管造影测量管腔密度梯度预测心肌桥收缩期压迫程度

The value of transluminal attenuation gradient measured by coronary computed tomography angiography in predicting the degree of systolic compression of myocardial bridge

目的:探讨冠状动脉CT血管造影(coronary computed tomography angiography,CCTA)测量的管腔密度衰减梯度(transluminal attenuation gradient,TAG)对预测心肌桥(myocardial bridge,MB)收缩期压迫程度的有关价值。方法:收集2017年1月至2019年12月,进行冠状动脉CT血管造影(CCTA)检查,且于前后1个月内实行有创性冠状动脉造影(invasive coronary angiography,ICA)检查,确诊为心肌桥的患者的临床资料并进行回顾性分析。经ICA影像学诊断,将受试患者分成:无心肌桥收缩压迫、心肌桥收缩压迫程度<50%以及心肌桥收缩压迫程度≥50%三组。TAG被定义为造影剂浓度的衰减和冠状动脉管腔长度之间的线性回归系数。通过测量心肌桥的长度和深度,以及心肌桥血管的TAG,探寻这三者与在ICA检查中检测出的收缩期压迫程度之间的联系。结果:共纳入分析244例患者。TAG在无心肌桥收缩压迫的患者、心肌桥收缩压迫<50%以及心肌桥收缩压迫≥50%三组中线性相关(r=-0.53,P<0.001),其数值分别为[(-9.56±4.11)HU/10 mm,P<0.001],[(-13.35±5.82)HU/10 mm,P<0.001]以及[(-17.48±6.97)HU/10 mm,P<0.001]。反观MB长度或深度与心肌桥血管收缩期压迫程度未见明显相关性。经ROC曲线分析可得TAG最佳临界值取值为-14.8 HU/10 mm时,其曲线下面积最大即0.801,诊断准确性为82.0%,高于其他两组。结论:冠状动脉CTA上测量的TAG能预测MB收缩期压迫情况,而MB长度或深度对预测MB收缩压迫程度的诊断准确度不佳。

Objective:To investigate the value of transluminal attenuation gradient(TAG)measured by coronary computed tomography angiography(CCTA)in predicting systolic compression of myocardial bridge(MB).Methods:Between January 2017 and December 2019,clinical data of patients diagnosed with MB by both CCTA and invasive coronary angiography(ICA)within one month were collected and analyzed retrospectively.According to their ICA findings,patients were divided into three groups:patients without systolic compression,patients with systolic compression<50%,and patients with systolic compression≥50%.TAG was defined as the linear regression coefficient between the contrast agent concentration of the luminal attenuation in the coronary artery and the length from the vessel ostium.By measuring the length and depth of MB,as well as the TAG of MB vessels,the relationship between these three parameters and the degree of systolic compression detected by ICA was explored.Results:Totally,244 patients meeting the inclusion criteria were included.TAG showed a linear correlation(r=-0.53,P<0.001)in the three groups of patients without MB systolic compression,MB systolic compression<50%and MB systolic compression≥50%,with values of[(-9.56±4.11)HU/10 mm,P<0.001],[(-13.35±5.82)HU/10 mm,P<0.001]and[(-17.48±6.97)HU/10 mm,P<0.001].In contrast,there was no significant correlation between the length or depth of MB and the degree of the systolic compression of MB.When the best cut-off value of TAG was determined by ROC curve analysis as-14.8 HU/10 mm,area under curve was 0.801,and its diagnostic accuracy(82.0%)were higher than those of the other two control groups.Conclusions:TAG measured by coronary CTA can predict systolic compression of myocardial bridge.However,the length or depth of MB is not very accurate in predicting the degree of the systolic compression of myocardial bridge.