The Value Of Transluminal Attenuation Gradient Indices Of Coronary Artery To Predict Myocardial Bridge With Systolic Compression

Objective:To study the diagnostic value of transluminal attenuation gradient(TAG)indices of myocardial bridge(MB)in left anterior descending artery(LAD)measured by dual-source computed tomography coronary angiography(DSCTCA)in predicting significant systolic compression of MB.Methods:81 Patients with confirmed MB of LAD who underwent DSCTCA were included.TAG?the standardized TAG(TAGs)?corrected mural coronary opacification(CMCO)difference?MB length and MB depth were measured and calculated in systolic and diastolic phase.The difference of systolic parameters and diastolic parameters were compared among the groups with significant systolic compression(SC)?mild systolic compression and none systolic compression.ROC curve was used to analyze the difference of TAGs and CMCO difference as well as the combined index in predicting significant systolic compression of MB.Results: Both in systolic and diastolic phase,there was statistical difference in TAG,TAGs and CMCO difference between the group of significant-SC and mild-SC(P < 0.05),also between the group of significant-SC and none-SC(P < 0.05),but there was no statistical difference in MB length and MB thickness among the three groups(P>0.05).ROC analysis showed that the sensitivity of TAGs,CMCO difference and their combined indexes in predicting significant systolic compression of MB was 76.0%,84.0%,84.0% in systolic phase and 68.0%,80.0%,80.0% in diastolic phase,the specificity was 82.1%,85.7%,89.3% in systolic phase and 80.1%,82.1%,82.1% in diastolic phase,and the area under the curve was 0.80,0.81,0.86 in systolic phase and 0.79,0.81,0.87 in diastolic phase.Conclusion: DSCTCA is a noninvasive,intuitive and accurate method for the diagnosis and evaluation of MB.The systolic compression of MB can last to diastole.There was no correlation between the length,the thickness and the degree of systolic compression of MB.TAG,TAGs and CMCO difference are related to the extent of dynamic compression of MB and have a relatively good diagnostic efficacy in predicting significant systolic compression of MB.TAGs combined with CMCO difference can improve the diagnostic value of MB with significant compression,and provide more clinical treatment information.