The Clinical Study On Evaluation Of Left Ventricular Function And Systolic Synchrony In Patients With Coronary Artery Disease After PCI By RT-3DE

Research backgroundThe incidence of coronary artery disease(CAD) has increased and at an earlier age with the increased standard of living and changes in diet, a report shows that the incidence of CAD have increased to 67% between 1993 and 2007 in China, with an average annual increase of 1.7%. Development and incidence of CAD is associated with many factors, atherosclerotic plaque and its subsequent lesions are the pathogenesis of CAD. The treatment for CAD includes medical treatment, PCI and coronary artery bypass graft(CABG). PCI can relieve patient’s pain through reascularization and improve LV function in a short time. The most common medical treatment for CAD is fibrinolysis, PCI is more effective in achieving patency of the infarct-related artery and reducing risk of mortality, re-infarction, and stroke than fibrinolysis. In addition, PCI is less aggressive and costly than CABG, can be done just after coronary angiography(CAG), needs less hospitalization and fewer complications, so PCI is a perfect therapeutic method for CAD. The postoperative effect evaluation method after PCI is usually GAG or CTA, because of the invasive examination, and the radiation on the human body, CTA and CAG are not suitable for our examination. The function and synchrony of involved myocardium were declining after myocardial ischemia or infarction, so quantitative analysis the function and synchrony of involved myocardium is important for PCI curative effect analysis. The most common evaluation method after PCI is two-dimensional echocardiography(2-DE), although 2-DE is a widely used technique in clinic, it has several limitations, including the necessity for LV geometric assumptions and the conventional visual interpretation of 2DE images relies on the reader’s experience and ability to effectively integrate spatial and temporal information, so it has a high degree of inter-observer and intra-observer variability. In the past decade, the development of real-time three-dimensional echocardiography using advanced technology of super matrix probe, full volume data processing system and three-dimensional space positioning system, can provide 3D dynamic cardiac images completely, directly display of the three-dimensional structure of left ventricle and the movement in left ventricular long axis, short axis and annular. Overcomes the limitations of two-dimensional ultrasound can only analysis of each segment in the different not in the same cardiac cycle. RT-3DE can be displayed as multiple 2D short-axis slices covering the entire LV, and automated tracking the boundary of the endocardial, it is thus ideal for daily performance and for serial follow-up examinations of LV systolic function and synchrony. Accurate determination of left ventricular(LV) volume, ejection fraction(EF) and segmental wall motion abnormalities is important for percutaneous coronary intervention(PCI) follow-up assessment. RT-3DE can fully display left ventricular structure and the regional volume changes over time, we can assess PCI curative effect by compare parameters before and after PCI from time-volume curves(VTC) and illustration of the bull’s eye(IBE). PCI is a successful treatment for CAD, but the incidence rate of coronary stent restenosis is up to 5-46%. Currently Drug-eluting stents (DES) are used to reduce restenosis rates in a variety of patients with significant coronary artery stenosis. Compared to bare-metal stents (BMS), DES has an obvious reduction in restenosis rates, it has reduced the ISR to 5-9%. In past decades doctors always use CTA or CAG to estimate stents’condition, there is less report about application of real-time three-dimensional echocardiography in assess of stents’condition and in diagnosis of in-stent restenosis(ISR)s so it is worthy of further research. The aim of this study was to assess the value of RT-3DE to detect LV systolic synchrony and function of patients after PCI. Using coronary CT angiography(CTA) as the gold standard, we explore RT-3DE parameters which can indicate the happen of in-stent restenosis(ISR).Research objectives: ①To assess the left ventricular function and synchrony in patients with coronary heart disease before and after PCI by Real-time three-dimensional echocardiography.②To discuss the value of diagnosing in-stent restenosis in patients with percutaneous coronary intervention by real-time three-dimensional echocardiography.Research methods and resultsPart one50 subjects were in hospital from May 2013 to March 2014. PCI group consists of 30 patients(18 men,12 women; age,56.2±8.2 years)with left anterior descending (LAD) stenosis alone, criteria for exclusion included old myocardial infarction, severe bradycardia or tachycardia, complete left bundle branch block, severe lesions of mitral valve or aortic valve, severe heart failure, all kinds of cardiomyopathy and congenital cardiovascular disease.7 cases, the stenosis rate is between 50%-75%; 23 cases,the stenosis rate is more than 75%. During the same period 20 cases of hospitalized patients with chest pain, coronary angiography confirmed senosis< 30% as control group(11 men,9 women; age,52±6 years). There is no significant difference (P>0.05) between control group and PCI group in age and gender. All subjects were examined with RT-3DE. The 17-segmental time-volume curve and the illustration of the bull’s eye were analyzed, the global and regional function parameters including end diastolic volume(EDV), ejection fraction(EF), regional end diastolic volume(rEDV’), regional ejection fraction (rEF’), peak filing rate(PFR), and synchronic parameters including minimum of time difference in maximum, standard deviation and correction(Tmsv-16dif, Tmsv-16sd, Tmsvl6-dif%, Tmsv-16sd%), Emax, Emin, Ea, Esd, Esd/Ea, dyssynchrony segments(DS), ischemic or infarction segments(IIS) were obtained. Besides these parameters the correlations between rEF’and EF, Tmsv-16sd% and Esd/Ea, EF and Esd/Ea, PFR and IIS were also analyzed in this research.Results:1.Before PCI, EDV, rEDV’, Tmsvl6-dif, Tmsvl6-sd, Tmsv16-dif%, Tmsv16-sd%, Emax, Esd, Esd/Ea, DS, IIS of PCI group were larger than those of control group(t=2.24～3.19,all P<0.05), EF, rEF’, PFR, Ea, Emin were lower than those of control group(t=-3.07～-2.12, all P<0.05).2.In PCI group, all parameters showed no significant changes by comparison with the cardiac conditions 3 days after PCI and 3 days before PCI(all P>0.05). EDV, rEDV’, Tmsv-16dif, Tmsv-16sd, Tmsv-16dif%, Tmsv-16sd%, Emax, Esd, Esd/Ea, IIS, DS of 3 months after PCI were significantly lower than those of before PCI, but EF, rEF’, PFR, Emin, Ea were larger than those before PCI(F=3.79-17.28, all P<0.05).3.In PCI group, before and after PCI, the rEF’and EF, Tmsv-16sd% and Esd/Ea had positive correlations(r=0.793,0.478, P<0.01), Esd/Ea and EF, PFR and IIS had negative correlations(r=-0.454, r=-0.739, P<0.01).Part two100 cases of patients (56 men,44 women; age,57.6±7.8 years), who were in hospital from May 2013 to Jun 2014 with the diagnosis of the clinical suspected diagnosis of coronary artery disease were studied. Criteria for exclusion included old myocardial infarction, severe bradycardia or tachycardia, complete left bundle branch block, severe lesions of mitral valve or aortic valve, severe heart failure, all kinds of cardiomyopathy, congenital cardiovascular disease. All patients enrolled in this protocol were having only LAD stenosis and received PCI therapy(in 12 hours). These patients also classified into two groups according to the CTA results. Non-ISR group has 72 patients who have no ISR(40 men,32 women; age,52.4±2.8 years), ISR group has 28 patients who have ISR(16 men,12 women; age,59.8±7.5 years). There is no significant difference (P>0.05) between ISR group and non-ISR group in age and gender.3 days and half a year after PCI all patients received RT-3DE examination. RT-3DE was performed by using Philips IE33 with X3-1 probe. The 17-segmental time-volume curve(VTC) and the illustration of the bull’s eye(IBE) were obtained by the Qlab software. All parameters contain:mean regional end diastolic volume(rEDV’), mean regional systolic volume(rESV), dyssynchrony segments(DS), the ratio of mean regional end diastolic volume(rEDV’%), the ratio of mean regional end systolic volume(rESV’%), the ratio of dyssynchrony segments(DS%). Using computed tomography angiography(CTA) results as the gold standard, we analyzed the sensitivity, specificity, and receiver operating characteristic(ROC) curves of RT-3DE for diagnosis ISR.Results1. The difference between rEDV’, rESV’of ISR group before and after PCI has no statistical significance(t= 1.698,1.772, P>0.05), the difference between rEDV’、rESV’of normal group before and after PCI has statistical significance(t=2.125,2.347, P<0.05).2. The difference between rEDV’%、rESV’%、DS% of ISR group and normal group has statistical significance, these parameters of ISR group were larger than the non-ISR group(t=2.454,2.336,2.721, P<0.05).3. ROC analysis shown that the optimal cut-off for rEDV’% was 0.82(sensitivity 75%, specificity 88%, AUC 0.85) and for rESV’% was 0.79(sensitivity 70%, specificity 65%, AUC 0.77) and for DS% was 0.80(sensitivity 66%, specificity 69%, AUC 0.68) for diagnosis of ISR after PCI.Conclusion1.Real-time three-dimensional echocardiography can quantitatively assess left ventricular function and synchrony in patients with coronary artery disease, which can be applied as a noninvasive method for evaluating the effect of PCI.2.The systolic function and synchrony of involved myocardium were improved after PCI, in addition PCI can improve the diastolic function of involved myocardium, which can predict the extent of the ischemic myocardium’s recovery.3.The correlation analysis reveals that the restoration of LAD-related myocardium has contributed much to the whole LV function.4.The correlation analysis reveals validated that excursion index (El) is as good as systolic dyssychrony index (SDI) in assessing LV systolic synchrony.5.1n patients with PCI, the recordings of rEDV’% and rESV’% by RT-3DE are effective parameters for estimate ISR after PCI.