Anatomical And Functional Evaluation For Myocardial Bridge-Mural Coronary Artery Based On CT-FFR

Purpose:The purpose of this study was to investigate the anatomical characteristics of the parietal coronary artery through coronary artery CTA.Based on CT-FFR analysis system,functional characteristics of mural coronary artery were evaluated,and correlation between anatomy and function of mural coronary artery was analyzed and summarized,so as to provide reference for clinical diagnosis and treatment of myocardial bridge and related diseases.Methods:We retrospectively included 236 patients who underwent coronary CTA examination in the Department of Cardiology,Heilongjiang Agricultural Reclamation General Hospital from January 2017 to December 2021,and the results returned MB.Patients were divided into A and B groups according to whether they had angina pectoris of coronary heart disease.Group A: symptomatic group and group B:asymptomatic group.Demographic characteristics and clinical risk factors were recorded.Based on coronary CTA images,three-dimensional postprocessing was performed to measure the anatomical characteristics of myocardial bridge,including location,length,depth,muscle index,proximal myocardial bridge atherosclerosis and systolic and diastolic stenosis degree.The CT-FFR values at the proximal end of myocardial bridge 1 cm and the distal end 2-4 cm were measured by the CT-FFR software(deep pulse fraction)independently developed in China,and the difference between the two was △ CT-FFR.Correlation analysis was used to evaluate the relationship between anatomic characteristics and functional indicators of myocardial Bridges.Logistic regression was used to analyze independent predictions of clinical ischemia symptoms.Results:1.When comparing the main characteristics of symptomatic and asymptomatic groups,there was a statistically significant difference between smoking and LDL.2.A total of 313 myocardial Bridges were detected in the two groups,including 235 myocardial Bridges in the left anterior descending branch of the coronary artery(about75%),73 myocardial Bridges in the first diagonal branch(about 23.3%),and 5 myocardial Bridges in the circumflex branch(about 1.6%).No right coronary myocardial Bridges were found.3.The coronary artery depth,diastolic stenosis and proximal myocardial bridge plaque in symptomatic group were significantly higher than those in asymptomatic group.4.Compared with the control group,there were statistically significant differences in CT-FFR value at the distal end of myocardial bridge,attenuation degree of wall coronary artery from proximal to distal end(△CTFFR),CT-FFR value > 0.8 and CT-FFR < 0.75 in symptomatic group.5.logistics regression analysis showed that low-density lipoprotein,CT-FFR < 0.75 and diastolic stenosis degree were independent predicators of clinical myocardial ischemia symptoms in patients.6.CT-FFR + anatomic stenosis(degree of diastolic stenosis)+low density lipoprotein had the highest diagnostic efficacy,with area under line(AUC)of 94.4,sensitivity of 93.2%,specificity of 92.6%.Conclusions:1.Coronary artery CT-FFR can accurately identify myocardial pontoon coronary arteries and explain the anatomical characteristics of myocardial pontoon coronary arteries.The peripheral wall coronary arteries are covered by myocardial Bridges of different degrees and ranges,and the myocardial Bridges that cause clinical myocardial ischemia mostly occur in the middle of the wall coronary artery.2.There is a clear relationship between the anatomic features and functional features of mural coronary artery myocardial bridge,and the thickness and extent of myocardial bridge are negatively correlated with the function of mural coronary artery.