Advanced Analysis Of Coronary CT Angiography In Diagnosis Of Myocardial Ischemia In Female And Elderly Patients

Background and objective:Coronary angiography(CAG)is currently recognized as the “gold standard” in the diagnosis of Coronary Artery Disease(CAD).However,CAG as an invasive approach with high cost and operational risk is difficult to implement in all patients.Besides,the interpretation of CAG on the severity of coronary stenosis depends on Physician Visual Assessment(PVA)and clinical experience.Furthermore,diameter stenosis(DS)based on coronary anatomy is poorly related with physiology stenosis severity.Therefore,many studies have proposed non-invasive advanced analysis based on coronary computed tomography angiography(CCTA),which uses the computer image processing system and Computational Flow Dynamics(CFD)technology to obtain plaque quantitative parameters and wall shear stress(WSS)for determining myocardial ischemia.Until now,there are only a few studies that combine with parameters of three categories,including coronary anatomy(DS),plaque characteristics(plaque compositions,risk features),and hemodynamics(WSS)to optimize the diagnostic performance predicting ischemia based on CCTA,especially in groups of female and elderly.Based on the current situation and challenges,we conducted the following studies.First,we explored the influence of gender difference on PVA in the assessment of coronary DS by using quantitative coronary assessment(QCA)as the reference standard.Second,We established a precise non-invasive modeling of CCTA advanced analysis for diagnosis of myocardial ischemia in patients with suspected CAD.And then we estimated the benefits of this model for females.Finally,we further validated the application of advanced analysis of CCTA in the diagnosis of myocardial ischemia at elderly patients.Methods and results:(1)The influence of gender difference on PVA: coronary DS was measured by a QCA system and by PVA,separately.The mean difference between PVA and QCA in the assessment of diameter stenosis was compared between genders.The results showed that in females,the degree of overestimation of coronary DS by PVA was as high as 8.0 ± 10.9%.While in males,it was only 4.7 ± 10.9%.There was statistically significant(P = 0.03)between genders on the mean difference between PVA and QCA.(2)Advanced analysis of CCTA for the diagnosis of myocardial ischemia in females with suspected CAD: we quantitatively and qualitatively analyzed the plaque characteristics and calculated WSS based on CCTA image by using a computer image segmentation system and CFD technology.We obtained the information of coronary lesion,including diameter stenosis,the plaque burden,and WSS.The diagnostic performance of each parameter based on CCTA was expressed by the Area Under ROC Curve(AUC)(FFR ? 0.8 as the reference standard).In females,compared with the AUC(0.68)of DS ? 50% assessed by physician visual based on CCTA,the AUC of DS ? 50% + plaque burden and DS ? 50% + plaque burden +WSS was lifted to0.82(P = 0.075)and 0.90(P < 0.001),respectively.While in males,the AUC of DS ?50%,DS ? 50% + plaque burden and DS ? 50% + plaque burden +WSS is 0.64,0.77(P = 0.004)? 0.84(P < 0.001),respectively.Noted there was no significant difference of AUC by using single indictor of DS ? 50%,plaque burden(0.74 for females and0.75 for males,P > 0.05 for both)and WSS(0.85 for females and 0.76 for males,P >0.05 for both),respetctively.(3)Application of advanced analysis based on CCTA in the diagnosis of myocardial ischemia in elderly patients with suspected CAD: Based on the same method as the second part,we further explored the diagnosis performance of predicting myocardial ischemia by advanced analysis of CCTA in elderly.In elderly,compared with the AUC(0.67)of DS ? 50%,the AUC of DS ? 50% + plaque burden and DS ? 50% + plaque burden +WSS was increased to 0.79(P = 0.03)and 0.86(P <0.001),respectively.While in young,the AUC of DS ? 50%,DS ? 50% + plaque burden and DS ? 50% + plaque burden +WSS is 0.61,0.72(P = 0.066)and 0.82(P <0.001),respectively.Furthermore,only in young,we found that there was significant difference of AUC by using single indictor of WSS(0.80,P = 0.010)compared with DS ? 50%.Conclusions:(1)It revealed that Gender difference can affect the diagnosis accuracy of coronary stenosis assessed by PVA,and there is a higher potential risk that the diagnosis of CAD is overestimated in females,which may further influence treatment guiding.(2)An advanced analysis method based on CCTA was established to diagnose the myocaridal ischemia by integrating the information of DS,plaque burden,and WSS together for each lesion.And this method can more significantly improve the diagnosis performance in the female with suspected CAD.(3)In elderly(age ? 60),it is necessary to comprehensively analyze DS,plaque burden and WSS to significantly increase the diagnosis performance of CCTA in predicting myocardial ischemia.At the same time,in young(age < 60),the diagnosis performance of predicting myocardial ischemic only by WSS is much improved by comparing with DS ? 50%.(4)Based on the above findings,advanced analysis of CCTA is very effective for the diagnosis of CAD,which can significantly improve the diagnosis performance of CCTA in predicting myocardial ischemia,especially for the elderly and female with more benefit from precise diagnosis of myocardial ischemia and operational guidance.