The Study Of The Overestimation Of The Severity Of Left Main Ostial Lesion Stenosis In Coronary Angiography Confirmed By Intravascular Ultrasound

Objective To investigate the cause of overestimation of the severity of left main coronary artery ostium(LMCA ostial)stenosis measured by quantitative coronary angiography(QCA)compared with intravascular ultrasound(IVUS).Methods A retrospective study was performed on 62 cases of patients with coronary heart disease who were diagnosed severe stenosis in LMCA ostial(visual diameter stenosis≥50%)by coronary angiography in the Department of Cardiology of the General Hospital of the Northern Theater from January 2018 to January 2021.According to the minimum lumen area(MLA)of LMCA ostial measured by IVUS,the subjects were further divided into overestimated group(OE,n=37)with MLA≥6mm~2and Non-overestimated group(NOE,n=25)with MLA<6mm~2.The QCA measurement results of the two groups were compared,including the minimum vessel diameter,stenosis degree and reference segment vessel diameter of LMCA ostial;IVUS measurement results,including MLA,minimum lumen diameter,plaque load,remodeling index,eccentricity index,cross-sectional anatomical shape of LMCA ostial and reference segment related parameters.Results(1)Comparison of QCA related parameters:the diameter of left main artery(LMCA)reference segment in OE group was significantly higher than that in NOE group(3.89±0.96mm vs 3.35±0.71mm,P<0.05),while there was no significant difference in the size of LMCA ostial minimum lumen diameter,degree of stenosis and whether there was contrast medium reflux;(2)Comparison of IVUS related parameters:LMCA ostial MLA(9.22±2.6mm~2vs 4.34±1.13mm2),external elastic membrane area(20.01±4.56mm~2vs 15.81±5.34mm~2)in OE group were higher than those in NOE group,centripetal index(0.67±0.12 vs 0.75±0.14)and plaque burden(53±11%vs 69±14%)were lower than those in NOE group(P<0.05);There was no significant difference in the characteristics of LMCA ostial plaque between groups.Multivariate logistic regression analysis showed that vascular remodeling(OR=0.15,95%CI 0.029～0.788,P=0.025),circular ostium(OR=0.065,95%CI 0.006～0.701,P=0.024)and LMCA reference vessel diameter(OR=5.75,95%CI 1.553～21.288,P=0.009)were independent influencing factors for overestimation of LMCA ostial stenosis.Conclusion This study confirmed by IVUS analysis that for patients with visual LMCA ostial stenosis≥50%,the closer the ostial shape is to the circle,the more accurate the judgment of LMCA ostial stenosis is;The milder the plaque burden and the larger the diameter of the reference segment,the more likely it is to overestimate the degree of LMCA ostial stenosis.