The Effect Of Enhanced External Counterpulsation On Endothelial Function And Arterial Stiffness In Patients With Unstable Angina Pectoris

Objective:To observe the the change between endothelial function and arterial stiffness in patients with unstable angina pectoris(UAP) treated with enhanced external couterpulsation(EECP), investigate the mechanism of EECP therapy deeply, then provide new evidence for the effects of EECP.Methods:100 patients with UAP randomly divided into two groups:50 patients in EECP treatment group and 50 patients in Drug treatment group. All of patients with UAP were given drug treatment. And patients in EECP treatment group underwent a standard 36-h course of EECP(lh daily,6 days a week,over 6 weeks).Then observing all patients with UAP’s CCS angina level、angina seizure frequency per week、duration of attack、amount of Nitroglycerin per week、the improvement of ECG before and after treatment.Some indexs which reflect endothelial function and arterial stiffness were respectively measured before the treatment and after 6 weeks treatment. The nitric oxide(NO) which reflect endothelial function was detected by Nitrate reductase method.Then we respectively measured brachial artery diameter at baseline, endothelial-dependent vasodilatation function(flow-mediated dilatation,FMD),and calculated the rate of brachial artery diameter at FMD compared baseline which reflect endothelial function.In addition,we also can get some popular arterial stiffness indexs such as brachial-ankele pulse velocity (baPWV) and Carotid-femoral pulse velocity(cfPWV) by arteriosclerosis monitoring unit.There were 30 healthy volunteers which choose from Health examination center in normal control.All volunteers in normal control were measured the above items.All subjects signed informed consent.Results:(1)Symptoms of angina episodes comparison:after treatment, the angina seizure frequency、 duration of attack、the amount of Nitroglycerin and the CCS angina levelthat in EECP treatment group and Drug treatment group were decreasing (P<0.01),which had Statistical significance. And the EECP treatment group whose angina attack frequency、duration of angina episodes、amount of Nitroglycerin、CCS angina level were reducing obviously compared with the Drug treatment group (P<0.05),which had Statistical significance.After 6 week’s treatment,the total Efficiency of ECG in EECP treatment group was 86%,the total Efficiency of ECG in drug treatment group was 74%,the difference between two groups had no Statistical significance(P>0.05).(2)Before treatment,the value of brachial artery FMD in EECP treatment group and Drug treatment group were 3.39±2.32%,3.68±2.27% respectively(P>0.05), there were no statistical significance.So two groups had Comparability. After treatment, the brachial artery FMD of EECP treatment group and Drug treatment group were increased(P<0.05),but EECP treatment group’s brachial artery FMD was increased obviously compared with Drug treatment group, P<0.05) which had statistical significance.(3)Before treatment,the value of NO in EECP treatment group and Drug treatment group were 55.06±19.63 μ mol/L VS 56.90±14.64 u mol/L respectively(P>0.05), there were no Statistical significance. So two groups had Comparability. After treatment, the value of NO in EECP treatment group and Drug treatment group were increasing(P<0.05),but EECP treatment group’s NO value increased obviously compared with Drug treatment group(P<0.05) which had statistical significance.(4)Before treatment,the value of baPWV in EECP treatment group and Drug treatment group were 15.29±2.41m/s VS 15.03±1.75m/s respectively(P>0.05), there had no statistical significance. So two groups had Comparability. After treatment, the value of baPWV in EECP treatment group gradually decreased(P<0.05)which had statistical significance,but the value of baPWV in Drug treatment group had no change(P>0.05).(5)Before treatment,the value of cfPWV in EECP treatment group and Drug treatment group were10.69±1.81m/s VS 10.24±1.70m/s respectively(P>0.05), there had no statistical significance. So two groups had Comparability. After treatment, the value of baPWV in EECP treatment group decreased(P<0.05) which had statistical significance,but the value of baPWV in Drug treatment group had no change(P>0.05).(6)Before the EECP treatment,all patients with UAP’s value of NO respectively had negative correlation with the value of baPWV and cfPWV(r=-0.835,P<0.01;r=-0.828,P<0.01);and the value of brachial artery FMD respectively had negative correlation with the value of baPWV and cfPWV(r=-0.383,P<0.01;r=-0.381,P<0.01).After the EECP treatment, the value of NO respectively had no significant correlation with the value of baPWV and cfPWV (r=-0.269,P=0.059;r=-0.267,P=0.061);and the value of brachial artery FMD respectively had no significant correlation with the value of baPWV and cfPWV(r=-0.273, P=0.055;r=-0.271,P=0.057).Conclusion:(1) EECP may improve the symptoms of patients with unstable angina pectoris whose activity were also increasing.(2)Endothelial dysfunction and arterial stiffness increased play a Critical role in unstable angina pectoris. The endothelial function of patients with unstable angina pectoris had negative correlation with arterial stiffness.(3) EECP therapy can significantly improve endothelial function and reduce arterial stiffness in patients with unstable angina pectoris,but the change of them after EECP had no parallel.