Clinical Value Of Three-dimensional Visible Coronary Artery Model And New Techniques Of Echocardiography In Quantitative Analysis Of Myocardial Motion And Cardiac Function Before And After Percutaneous Coronary Intervention

BackgroundCoronary heart disease (CHD) is threatening human health seriously. And theincidence of CHD is rising. Percutaneous coronary intervention (PCI) is one of the primarymeans of revascularization. Its safety and effectiveness have been fully recognized.Coronary angiography (CAG) is the gold standard for CHD diagnosis. It is also used infollowing up after treatment. But CAG also brings a certain degree of complication.Therefore, to explore a non-invasive coronary imaging diagnosis and follow-up method isvaluable. Recently, the development of new techniques of transthoracic echocardiography(TTE) is rapid. Real-time three dimensional echocardiography (RT3DE) can supply thesynchronization data of segmental motion of left ventricular (LV) and analyze segmentalmovements of LV quantitatively. Speckle tracking imaging (STI) is able to accuratelymeasure the deformation of LV myocardium in different directions. So it can evaluatesegmental function of LV. Both of RT3DE and STI can quantitatively assess segmentalmovement of LV. They are expected to reflect significant value in the diagnosis andpostoperative evaluation of coronary heart disease. However, these two kinds of ultrasonictechniques can not directly show the diseased coronary artery. At the same time, there areno detailed series reports about the application of RT3DE and STI in diagnosis of coronaryartery disease and evaluation after PCI yet, including myocardial motion and cardiacfunction changes. This study established three-dimensional visible coronary artery model,and combined it with TTE to study the corresponding relations of coronary artery and itsbranches, with17segments of LV. So we could provide detailed anatomical reference fornew techniques of TTE to evaluate CHD. Based on it, we could also diagnose abnormalcoronary lesions in patients with CHD by RT3DE and STI, analyze global and segmental movement of LV before and after PCI. Our purpose is to discuss the value of RT3DE andSTI in diagnosis of CHD and following up before and after PCI.Objectives:1. To establish three-dimensional visible coronary artery models and combine it withTTE in order to confirm corresponding relations of coronary artery and branches with LVsegments.2. To discuss the value of RT3DE and STI in diagnosing CHD and evaluating efficacyof PCI.Methods:1. Establishment of three-dimensional visible coronary artery models andcombination of the models with TEEConsecutive thin sectional cardiac images of the Chinese Visible Human datasets anddual-source CTA images with no cardiac diseases were used to establish three-dimensionalvisible coronary artery models in volume rendering and surface rendering with AMIRAsoftware. Two-dimensional images of50healthy adults were acquired to establish databaseof TTE. Images of TTE were simulated by virtual cutting in the three-dimensional visiblecoronary artery model. Then contrastive research was made to comfirm correspondingrelations of coronary artery and its branches with LV17segments ordained by AmericanCollege of Cardiology (ACC).2. Diagnosis of CHD and evaluation of PCI by RT3DE and STI50healthy people (33males and17females, aged from22to38(28.6±7.8) years)were enrolled in control group. There were170patients (95males and75females, agedfrom40to82(61.3±8.9) years) who were from Department of Cardiology of SouthwestHospital affiliated to the Third Military Medical University. They had unambiguous CHDhistory or been clinically suspected as patients with CHD. Electrocardiography of themshowed ST-T changes.2D and3D images of TTE were acquired by using philips iE33colorDoppler ultrasound machine and saved in DICOM format. The patients underwent CAG inthe second day after examination of TTE. Negative patients according to the result of CAGwere excluded, and the positive patients were devided into two groups. Patients with degreeof coronary artery stenosis＜75%were enrolled in the mild and moderate stenosis group(98patients). Patients with degree of coronary artery stenosis≥75%were enrolled in thesevere stenosis group.36patients of severe stenosis group who had PCI after CAG were enrolled in PCI group. PCI group was examined by TTE in the third day, second month andsixth month after PCI.Images of all the160patients before CAG were analyzed to get Illustration of the BullEye (IBE), time-volume curve, longitudinal time–strain curve. The abnormal segmentshad been classified as pathological segments. The TTE result was combined withthree-dimensional visible coronary artery model. And the number of positive and negativepatients was counted according to TTE. After CAG, the number of positive and negativepatients according to CAG was compared with RT3DE and STI. The severe stenosis group,mild and moderate stenosis group were analyzed for next step in order to evaluate theaccuracy of these two kinds of ultrasonic techniques in diagnosing CHD. After that, the LVsystolic function, contraction synchrony, myocardial strain data of control group and PCIgroup were acquired by RT3DE and STI. The data were compared with each other in orderto discuss the value of RT3DE and STI in following up after PCI.Results:1. The three-dimensional visible coronary artery model we have established couldclearly show the human coronary artery trunk and its main branch. It could combinethree-dimensional structure of coronary artery with the gross anatomy of heart. The modelcould be also cutted virtually by stimulating TTE images. So the corresponding relations ofcoronary artery and17segments of LV could be clearly comfirmed. The model provided adetailed, intuitive anatomical reference for TTE and its new techniques for diagnosingcoronary artery stenosis by evaluating abnormal segment of LV.2. There was no significant difference between TTE and CAG about the number ofpositive and negative patients (P>0.05). Specific branches stenosis of coronary artery inRT3DE and STI also had no significant difference with CAG (P>0.05). Contrasted withresult of CAG, the sensitivity and specificity of RT3DE were>72%and>97%whendiagnosing single-vessel disease, the sensitivity and specificity of RT3DE were>87%and>78%when diagnosing multi-vessel disease. Similarily, the sensitivity and specificity ofSTI were>63%and>94%when diagnosing single-vessel disease, the sensitivity andspecificity of STI were>80%and>57%when diagnosing multi-vessel disease.3. RT3DE: LV global systolic function and synchronization improved significantlyafter PCI. Most of the indices increased in the third day, and improved significantly in thesecond month after PCI (P<0.05). In the sixth month after PCI, the indices were relatively stable. Systolic function parameters had no significant difference with control group in thethird day and the sixth month after PCI (P>0.05), but synchronization indices hadsignificant difference with control group at the same time (P<0.05). STI: The capacity ofcured segmental myocardial strain was remarkably improved after PCI. In the third dayafter PCI, the peak myocardial systolic longitudinal strain and strain rate values increasedto a certain extent compared with preoperation, but the difference was not statisticallysignificant (P>0.05). In the second month after PCI, the peak myocardial systolic strain andstrain rate values of all the directions were significantly higher than the value before PCI(P<0.05).In the sixth month after PCI, the indices were stable and had no significantdifference with before (P>0.05).Conclusion1. In this study, we established the three-dimentional visible coronary artery modeland also made comparative research between the model and TTE to accurately display thecoronary artery and its branches of LV17segments. The study provided a detailed, accuratereference of anatomy for TTE and new techniques of TTE to diagnose CHD. The model is abridge and tool for ultrasound techniques to diagnose coronary artery stenosis directly byfinding abnormal segments.2. RT3DE was able to diagnose CHD by IBE and time-volume curves of17segments,especially for the single-vessel disease. STI also could do it by longitudinal time-straincurves of17segments, but its sensitivity and specificity were less than RT3DE. These twotechniques of TTE have advantages of non-invasiveness and convenience. They wereexpected to become non-invasive and accurate diagnostic methods in diagnosis of CHD.3. RT3DE and STI were able to obtain the data of LV global systolic function,synchronization and myocardial strain (rate). They proved that it was the second monthafter PCI treatment that was most suitable testing time for restoring perfusion with ischemicmyocardium. RT3DE and STI were non-invasive, reproducible and easy to be accepted bypatients. So they were conducive to long term follow-up after PCI and had importantclinical significance for evaluation of LV global and segmental function.