Comparison Between DSCTCA And MPI On Simple Myocardial Bridge Of Anterior Descending Coronary Artery

Objective:Based on dual source CT coronary angiography(DSCTCA)and myocardial perfusion imaging(MPI)performed in patients of myocardial bridge,this retrospective study is to investigate the correlation among the multiple parameters measured by DSCTCA and the results of MPI examination.Therefore,it is deserved to improve understanding of myocardial bridge and to give more suggestions for the clinical diagnosis and treatment.Methods:According to the inclusion criteria,diagnosed as simple anterior descending myocardial bridge by DSCTCA and underwent MPI examination within 1 months,a total of 30 patients were enrolled.Data were collected from all eligible patients.DSCTCA was used to assess the type and location of the myocardial bridge,as well as to measure the thickness of the myocardial bridge and the length and stenosis rate of the mural coronary artery.MPI was used to assess the presence or absence of myocardial ischemia.Fisher's exact probability and t test were used to analyze the differences in type,site,length,thickness and stenosis rate between positive and negative MPI groups.The statistically significant parameters of myocardial bridge and mural coronary artery were selected,associated with myocardial ischemia.Draw the ROC curve of the relevant parameters,and select the appropriate cut-off points.Results:Of the 30 patients with simple myocardial bridge confirmed by DSCTCA,14 patients were positively diagnosed as myocardial ischemia by MPI examination.We found that the location of myocardial bridge and the length of mural coronary artery were not significantly associated with the risk of myocardial ischemia(P=1.0000,P>0.05 and t=0.07132,P>0.05).There were significantly statistical differences in the type of myocardial bridge and the thickness and stenosis rate of myocardial bridge between positive and negative MPI groups(P=0.0169,t=3.178 and 7.549,respectively,P<0.05).When the cut-off value was 1.7mm for the thickness of myocardial bridge,the specificity was relatively high(93.75%)for myocardial ischemia prediction.When artery stenosis rate of 30%was selected as the cut-offvalue,high specificity and sensitivity(93.75%and 92.86%-100%,respectively)were obtained to predict myocardial ischemia.Conclusion:The location and length of myocardial bridge may not be related to the risk of myocardial ischemia,but the type and thickness of myocardial bridge and the stenosis rate of mural coronary artery should have statistical influence on myocardial ischemia.Especially,when the thickness of myocardial bridge is more than 1.7mm or the stenosis rate of mural coronary artery is more than 30%,subsequently we should pay more attention to these patients for the risk of myocardial ischemia.