Acute hemodynamic effects of enhanced external counterpulsation

Introduction In the United States, there are about 17.6 million patients suffer from symptomatic coronary artery disease （CAD）, affecting 7.9% of adults ≥ 20 years of age.1 An estimated 10.2 million patients have angina, and 500,000 patients will develop new angina pectoris each year. 1 A subset of angina patients are categorized as refractory when symptoms continue despite optimal medical therapy and revascularization.Routine daily activities become impossible without experiencing chest pain in this patient population.2

Reduced peripheral vascular reactivity in refractory angina pectoris:Effect of enhanced external counterpulsation

Objective To examine if the skin microvascular bed is altered and can be modified by enhanced external counterpulsation(EECP)in patients with chronic refractory angina.Methods Twenty patients diagnosed with refractory angina were divided into EECP(n=10)or no EECP(n=10)groups.The data were compared to matched healthy subjects(n=20).The cutaneous forearm microvascular blood flow was measured by Laser-Doppler flowmetry.The vascular responsiveness to iontophoretic administration of acetylcholine(ACh),sodium nitroprusside(SNP)and local skin warming were studied.Measurements of Canadian Cardiovascular Society(CCS)-class,blood pressure and plasma samples were registered.Results EECP patients showed reduced CCS-class compared to no EECP(P<0.05).Both EECP and no EECP(P<0.05)groups had decreased systolic blood pressure(SBP)as compared to SBP at baseline(P<0.05).There was no difference in resting blood flow between the two refractory groups at baseline as well as after EECP and seven weeks of follow-up.Responses to heating,the responses to ACh and SNP in the cutaneous microcirculation were lower in both groups of refractory angina patients as compared to healthy subjects(P<0.05).EECP patients corresponded positively to the treatment shown by reduced plasma level of soluble interleukin-2 receptor and CCS-class.Conclusions Refractory angina patients have reduced responsiveness in their cutaneous microcirculation to ACh,SNP and heat compared to healthy subjects.Although EECP reduced the CCS-class,this effect was not associated with improvements in responsiveness of the cutaneous microcirculation.

Enhanced external counterpulsation promotes growth cytokines-mediated myocardial angiogenesis in a porcine model of hypercholesterolemia

Background Enhanced external counterpulsation （EECP） improves ischemia in patients with refractory angina pectoris but the mechanism remains unclear. To explore the mechanisms of EECP action, we detected progenitor cells presenting any of the following markers CD34^＋, CD29^＋, and CD106^＋. Methods Growth cytokines-mediated progenitor cell mobilization and associated angiogenesis potential were assessed in a porcine model of hypercholesterolemia. Twenty-four male domestic swines were randomly assigned to 4 groups： normal diet （control, n=6）, hypercholesterolemic diet （CHOL, n=-6）, hypercholesterolemic diet with administration of recombinant human granulocyte colony-stimulating factor （rhG-CSF） （rhG-CSF, n=6）, and hypercholesterolemic diet with EECP treatment （EECP, n=6）. EECP was applied 2 hours every other day for a total of 36 hours. Serum levels of vascular endothelial growth factor （VEGF） and granulocyte colony-stimulating factor （G-CSF）, peripheral blood progenitor cell counts, level of regional angiogenesis, and expression of VEGF and stromal cell derived factor l a （SDF-1α） in porcine myocardium were assessed, respectively. Results A porcine model of hypercholesterolemia-induced arteriosclerosis was successfully established. There was no significant difference in serum levels of VEGF among the four groups. The serum levels of G-CSF in the EECP group increased significantly at week 15 and week 18 （（38.3±5.6） pg/ml at week 15 vs （26.2±3.7） pg/ml at week 12, P 〈0.05, and （46.9±6.1） pg/ml at week 18 vs （26.2±3.7） pg/ml at week 12, P 〈0.01）. The serum levels of G-CSF in group 3 increased also significantly after receiving rhG-CSF injection for five days （（150±13.9） pg/ml at week 18 vs （24.8±5.4） pg/ml at week 12, P 〈0.01）. Compared to other groups and other time points, progenitor celt counts increased significantly after 2-hour EECP treatment （108±13 vs 26±6 per 10^5 leukocytes, P 〈0.01）, but not at week 18. The progenitor cell counts also increased significantly after subcutaneous injection of rhG-CSF for five days compared to the week 12 （baseline） （180±21 vs 25±7 per 10s leukocytes, P 〈0.01）. There was no significant difference among the four groups at other time points. Moreover, the expression of VEGF and SDF-1α and the level of regional angiogenesis in myocardium increased significantly in both EECP and rhG-CSF groups. Conclusions The results demonstrated that EECP could facilitate angiogenesis in the myocardium of atherosclerotic swines by increasing endogenous G-CSF, inducing an enhanced mobilization of progenitor cells and augmenting myocardial expression of VEGF and SDF-1α.

Short-term effects of enhanced external counterpulsation on coronary slow flow and cardiac function in patients with acute myocardial infarction during primary percutaneous coronary intervention

Background Coronary slow flow（CSF） during primary percutaneous coronary intervention（PCI） is closely related to the prognosis of patients with acute myocardial infarction（AMI）. Whether Enhanced External CounterPulsation（EECP） could improve the phenomenon and enhance cardiac function in these patients has not been studied. Methods Seventy-eight AMI patients undergoing primary PCI were enrolled and divided into 2 groups, EECP group and sham group. In EECP group, the patients were treated with EECP for 30 min after coronary artery stent implantation; and in sham group, the patients after coronary artery stent implantation were treated with cuffs wrapped for 30 min. Hemodynamics and corrected TIMI Frame Count（c TFC） were recorded at different time points in both groups. CRP, HCY, NT-pro BNP and Killip class were also detected before operation and after treatment. Results In EECP group, compared to pre-and post-EECP treatment, the systolic blood pressure（SBP） was much lower（P〈0.05）, diastolic blood pressure（DBP） and mean arterial blood pressure（MBP）were much higher（P〈0.05）. The heart rate（HR） was not changed during EECP treatment（P〉0.05）. In sham group, SBP, DBP, MBP and HR were not significantly changed during these period（P〉0.05）. In EECP group,the c TFC of patients with CSF decreased significantly after treatment（P〈0.05）; and there was no difference in sham group（P〉0.05）. Compared with pre-EECP treatment, CRP and HCY were increased in post-EECP treatment of both groups（P〈0.05）, while, they were much lower in EECP group（P〈0.05）. The expression of NTpro BNP was decreased after treatment in both groups（P〈0.05）, and it was much lower in EECP group than in sham group（P〈0.05）. The Killip class was much lower after treatment than before operation in EECP group（P〈0.05）, and there was no change in sham group（P〉0.05）. Conclusions The results suggest that EECP is helpful in a short time to the improvement of CSF and recovery of cardiac function in AMI patients during primary PCI,and that CRP and HCY may be involved in this process.

Enhanced External Counterpulsation Inducing Arterial Hemodynamic Variations and Its Chronic Effect on Endothelial Function

To make clear the precise hemodynamic mechanism underlying the anti-atherogenesis benefit of enhanced external couterpulsation(EECP) treatment, and to investigate the proper role of some important hemodynamic factors during the atherosclerotic progress, a comprehensive study combining long-term animal experiment and numerical solving was conducted in this paper. An experimentally induced hypercholesterolemic porcine model was developed and the chronic EECP intervention was subjected. Basic hemodynamic measurement was performed in vivo, as well as the arterial endothelial samples were extracted for physiological examination. Meanwhile, a numerical model was introduced to solve the complex hemodynamic factors such as WSS and OSI. The results show that EECP treatment resulted in significant increase of the instant levels of arterial WSS, blood pressure, and OSI. During EECP treatment, the instant OSI level of the common carotid arteries over cardiac cycles raised to a mean value of 8.58 ×10-2±2.13 ×10-2. Meanwhile, the chronic intervention of EECP treatment significantly reduced the atherosclerotic lesions in abdominal aortas and the endothelial cellular adherence. The present study suggests that the unique blood flow pattern induced by EECP treatment and the augmentation of WSS level in cardiac cycles may be the most important hemodynamic mechanism that contribute to its anti-atherogenesis effect. And as one of the indices that cause great concern in current hemodynamic study, OSI may not play a key role during the initiation of atherosclerosis.

The effects of enhanced external counterpulsation on the serum level of C-reactive protein and endothelin-1 in patients with ischemic stroke

Objective To explore the effects of enhanced external counterpulsation(EECP)on the serum level of C-reactive protein and endothelin-1 in patients with cerebral ischemic stroke,to provide clinical evidence for the treatment and secondary prevention of patients with serebral ischemic stroke.Methods Total 187 patients with ischemic stroke and enrolled measure the serum level