The Clinical Study Of Carotid Arteries’ Elasticity For Diabetic Patients By Ultrasound RF-data And X-strain Techniques

Background and ObjectivesPatients diagnosed with diabetes have a higher risk of developing atherosclerosis,while hypertension accelerates the chronic process. About one-third of type2diabetespatients present with hypertension. As mutual predisposing factors, high glucose level andhypertension increase the incidence and mortality of cardiovascular events.Atherosclerotic diseases, though known as chronic disorders, it is possible that nosymptoms would be shown at an early stage. Consequently, early detection andintervention for vascular dysfunctions are critical inpredicting cardiovascular events.Carotid artery as one of the largest elastic arteries is the window for viewing systemicatherosclerosis lesions. This research adopts ultrasound radio frequency and vector strain techniques to giveus insights into structural and functional parameters of carotid arteries for patientsdiagnosed with diabetes. Through analysis of the above two parameters between the threeexperimental groups, our goal is to explore the values of these technologies in assessmentof vascular elasticity at an early stage, and to screen out sensitive parameters for clinicalevaluations of cardiovascular risk in patients with diabetes.Method1. Subjects:From March2011to March2012,65diabetic patients admitted into Tangdu hospitalwere selected into the experiment as subjects. All these subjects are divided into2groupsbased on whether they presented with hypertension or not. Finally,32patients were in thediabetes group. Other33patients were assigned to the diabetes&hypertension group.35healthy subjects matched with above two groups in gender and age were included ascontrol group. Diabetes mellitus and Hypertension were diagnosed in reference to theWHO Standard published in1999. Ultrasonography for heart function andelectrocardiogram was done for every candidate. Ultrasonography for heart function andelectrocardiogram were done for every candidate. Patients with diseases such as coronaryheart disease and heart dysfunction etc. are excluded.2. Data collectionEsaote Mylab-twice color Doppler ultrasound diagnostic equipment with Mylab Deskanalysis workstation was the main platform used in this research. LA523blood vesselprobe with the radio frequency of4-13MHz was adopted. The intima-mediathickness(IMT) of bilateral common carotid artery were measured by QIMT technique;Parameters of blood vessel stiffness such as pulse wave velocity(PWV), compliancecoefficient(CC), Stiffness parameter β were acquired through QAS technique;Cardiovascular coupling curvewas drawn automatically based on the expansion wave andthe patients’ blood pressure and the turning point (T1) was able to be picked. On the basisof displacement of two-dimensional short and long axis view of the common carotid artery,Strain vector (X-Strain) technology was started to capture raw pictures by sampling points posted on vascular intima-media and external walls by a well-trained performer. Real-timetracking the movement trajectory was recorded automatically, endothelial and epicardialcircumferential strain and strain rate (EN-CS, EN-CSR, EP-CS, EP-CSR), longitudinalstrain and strain rate (EN-LS, EN-LSR) were acquired accordingly.3. Statistical analysisStatistical analysis was performed using the SPSS16.0. Data were shown as mean±standard error. The difference between the two groups was determined by student t test.Correlation analysis between the parameters was performed by Pearson correlationprotocol. The results with a P value smaller than0.05were considered statisticallysignificant for all analyses.Results1. Comparison between diabetes alone group and control group: T1turning point was putforward significantly in comparison to control group; PWV, Stiffness parameter β areincreased significantly in comparison to control group; CC, EN-CS, EN-CSR, EP-CS,EP-CSR decreased; while IMT showed no significant difference compared with controlgroup.2. In comparison to patients with control group, for those with diabetes and hypertension,T1point happened earlier; PWV, Stiffness parameter β is increased; CC, EN-CS, EN-CSR,EP-CS, EP-CSR decreased; IMT increased significantly.3. In comparison to patients with diabetes alone, for those with diabetes and hypertension,T1point happened earlier; PWV, Stiffness parameter β is increased; CC, EN-CS, EN-CSR,EP-CS, EP-CSR decreased; IMT increased significantly.4. No significant difference was found for Longitudinal strain(LS) and strain rate(LSR)indexes between the three groups.5.Correlations between the three groups: IMT was positively related with age(r=0.341; P=0.001), PWV was positively related with Stiffness parameter β and Local systolicpressure(r=0.574, P <0.001; r=0.916, P <0.001) but negatively related with CC, T1,EN-CS, EP-CS(r=-0.764, P <0.001; r=-0.393, P <0.001; r=-0.437, P <0.001; r=-0.414, P <0.001). Conclusions1. Data acquired through ultrasound radio frequency such as PWV, CC, β, T1and throughvector strain technique such as EN-CS, EN-CSR, EP-CS, EP-CSR had statisticalsignificance compared between the three groups. Characterized by: with the increase ofcardiovascular disease risk factors (blood glucose and blood pressure), the vascularelasticity is impaired as the stiffness increases.2. For diabetic patients, vascular structural parameter (IMT) shows no difference with thatof people without diabetes, while functional parameters such as PWV, CC, β, T1, EN-CS,EN-CSR. Consequently structural impairment follows functional changes.3. All the parameters are closely related to PWV, which has been established as a keyparameter for vascular stiffness evaluation. So, all these parameters above couldpotentially be applied for early evaluation of vascular elasticity.