Enhanced External Counterpulsation Improves Endothelial Function And Elevates Exercise Tolerance In Patients With Chronic Coronary Syndrome

Background:Coronary atherosclerotic heart disease(CHD)is not only a common clinical disease,but also one of the major diseases affecting human health.With the understanding of the disease,the European Society of Cardiology issued the Guidelines for the Management of Chronic Coronary Syndrome in 2019.The new term "Chronic Coronary Syndrome(CCS)" was proposed to replace the previous "stable coronary artery disease" At present,the prevalence and mortality of CCS are on the rise,and scientific and standardized management is very important.Numerous studies have shown that the vascular endothelial system is involved in multiple pathological processes of coronary artery disease,such as oxidative stress,inflammation,angiogenesis and remodeling,regulation of vascular tone,etc.Improving endothelial function is of great significance in the prevention and treatment of coronary heart disease.Enhanced external counterpulsation(EECP)is a new non-drug treatment for coronary artery disease(CAD).However,the long-term effect of EECP on endothelial dysfunction and exercise tolerance,and the relationship between the changes in the endothelial dysfunction and exercise tolerance in the patients with coronary heart disease are still unclear.In our experiment,240 patients with chronic coronary syndrome were divided into two groups according to the ratio of 1:1,given different intervention measures,and followed up for 1 year to record the changes of hemodynamics,endothelial factor,and cardiopulmonary function.To explore the possible mechanism of EECP improving endothelial dysfunction in coronary heart disease and its impact on long-term exercise capacity of patients.Methods:A total of 240 patients with CAD were randomly divided into EECP group(n=120)and control group(n=120).All patients received routine treatment of CAD as the basic therapy.Patients in the EECP group received 35 1-h daily sessions of EECP during 7 consecutive weeks while the control group received the same treatment course,but the cuff inflation pressure was 0-10 mmHg.PSV,EDV,RI,and ID of the right carotid artery were examined using a Color Doppler Ultrasound and used to calculate the FSS.Serum levels of VEGF,VEGFR2,and Ang II were determined by ELISA.Exercise load time,VO2max,METs,AT,VO2max/HR were assessed using cardiopulmonary exercise tests.Results:Statistical analysis showed the EDV(P<0.001),PSV(P<0.001),ID(P<0.001)and FSS(P<0.01)after 1 year of follow-up;this is very important.in the high EECP group.The changes in EDV,PSV,and ID in the EECP group were significantly greater than those in the control group(all P<0.001).However,no significant change in RI was observed in either group(P<0.05).After EECP treatment,the levels of VEGF and VEGFR2 were significantly elevated compared to untreated patients(P<0.001).Additionally,the level of Ang II in the EECP group is significantly decreased.The EECP group also experienced significant improvements in exercise tolerance,including exercise time,VO2max,VO2max/HR,AT,and METs.In contrast,the control group only showed improvements in maximal oxygen uptake(P<0.05)and MET(P<0.001)after drug treatment alone.Correlation analysis showed that the levels of VEGF and VEGFR2 were positively correlated with the changes of FSS(P<0.001).Linear regression showed that,among all variables,age(P<0.001),the use of ACEI/ARB drug(P=0.015),history of diabetes(p=0.028),VEGF change(P<0.001)and VEGFR2(P=0.023)were factors affecting the extent of METs improvement.Conclusion:The data of our study suggested that EECP is a useful therapeutic measurement for amelioration of endothelial dysfunction and long-term elevation of exercise tolerance for patients with chronic coronary syndrome.