Study On The Distribution Of Plaque Lesions And The Relationship Between Bifurcation Angle And Hemodynamics In Coronary Bifurcation

Objective To explore the distribution of plaque lesions at the bifurcation of the coronary arteries and the relationship between plaque lesions and bifurcation angles,and to create a computational fluid dynamics model of solid coronary bifurcation based on CCTA images to explore the hemodynamics of the bifurcation.The relationship between the wall shear stress(WSS)and its distribution area and bifurcation angle.Methods Retrospective analysis of 300 patients with clinically suspected coronary heart disease from December 2017 to June 2018,and CCTA examination.Sixty patients with enrollment conditions were selected.Coronary bifurcation angle and plaque were measured on CCTA images.The block distribution quadrant,the distance from the center of the plaque to the bifurcation reference plane.In the end,a total of 62 bifurcations met the screening conditions,31 at the LAD-D bifurcation,28 at the LAD-LCX bifurcation,2 at the LCX-OM bifurcation,and only 1 at the RCA-PDA bifurcation.Only the LAD-LCX bifurcation was selected for the study.The LAD-LCX bifurcation of 20 patients without plaque was randomly selected for late fluid dynamics analysis,and 20 plaque-free patients were set as non-plaque group;bifurcation based on the mean value of the plaque component fork angle.The division is divided into a large angle group and a small angle group,and is separately counted;the influence of the region and the angle on the patch distribution is analyzed.The coronary ct data of 20 plaque-free dicom formats were imported into MIMICS,3-MATIC,ANAYS ICEM CFD and FLUENT to obtain a fluid mechanics model.The wall shear stress(WSS)distribution was analyzed and the angles of the bifurcations were different.The WSS value of the region is measured,and the relationship between different regions of the bifurcation and different angles and wss values is analyzed.Results(1)There were 23 in the third quadrant of the LAD-LCX bifurcation,3 in the II quadrant,2 in the first quadrant,and 0 in the IV quadrant.(2)The 28 plaque component fork angle ranged from 42.2° to 123.7° with an average of(76.31±20.35)°;the 20 plaque-free group had a bifurcation angle range of 33.4°~121.2°,with an average of 71.86.±18.90)°.There was a statistically significant difference in the number of plaques between?76° and <76° groups(?2=4.898,P=0.027).(3)WSS fluid mechanics cloud image shows a low WSS region on the side wall of the bifurcation,and a slightly high WSS region appears on the inner side wall of the bifurcation.(4)The 20 LAD-LCX bifurcation side wall WSS values range from 0.1124995 to 0.6484985,with an average of 0.4086134±0.1206135;WSS value of the inner wall of the bifurcation ranged from 0.9675585 to2.3246920,and the average value was 1.6970531±0.344806.The difference between the two groups was statistically significant(t=-16.111,p<0.001).(5)LAD-LCX bifurcation on the side wall low WSS.The WSS value decreases with the increase of the bifurcation angle.(6)Multivariate analysis of variance is performed on WSS values ??by A factor(different regions of bifurcation)and B factor(bifurcation angle).The main effect of A factor(F=202.385,P<0.001)was statistically significant.The main effect of B factor(F=1.596,P=0.215)was not statistically significant.The interaction between A factor and B factor(F=0.906,P=0.348)was not statistically significant.The effect diagram shows that the interaction between the two factors is small.Conclusion (1)The plaque at the LAD-LCX bifurcation is mostly distributed in the ? quadrant(ie,the opposite side wall of the branch opening).(2)For the LAD-LCX bifurcation,the mean value of the bifurcation angle of the plaque group is larger;the probability of plaque formation in the smaller angle group of the large angle group is higher.(3)Obtain a coronary artery bifurcation model based on CCTA image and realize quantitative analysis of fluid dynamic parameters to realize the feasibility of estimating vascular WSS value with CCTA data.(4)By hydrodynamic analysis,the LAD-LCX bifurcation has a lower WSS value than the inner side of the bifurcation.It can be considered that the low WSS of the LAD-LCX bifurcation on the side wall is an important factor in the formation of atherosclerotic plaque;The WSS value of the opposite side of the LAD-LCX bifurcation has a tendency to decrease with the increase of the angle.It can be considered that the larger the bifurcation angle is,the more easily the atherosclerotic plaque is formed;however,it is not considered that the bifurcation angle has a WSS value when acting alone.influences.