Effect of enhanced external counterpulsation on coronary microcirculation dysfunction (CMD) in patients with coronary artery disease (EECP-CMD II): study protocol of a single-centre, open-label, parallel group, randomised controlled trial.

INTRODUCTION: Coronary microcirculation dysfunction (CMD) is prevalent in patients with coronary artery disease (CAD). Current therapies for CMD are focused on pharmacotherapy, non-pharmacological treatments such as enhanced external counterpulsation (EECP) have shown favourable results in patients with CAD. However, whether EECP can improve CMD remains unknown. This study is designed to evaluate the effectiveness of EECP on CMD in patients with CAD, and to assess the feasibility of conducting a multicentre randomised controlled trial. METHODS AND ANALYSIS: This study is a single-centre, outcome-assessor-blinded, parallel randomised controlled trial. A total of 110 participants with CAD will be included and randomly assigned to either the intervention group (EECP plus optimal medical therapy (OMT)) or the control group (OMT alone). EECP will be administered by operators for 60 min, 5 times per week for 7 weeks (35 times in total). Outcomes include patients' retention rates, the primary outcome and secondary outcomes. The primary outcome is the change in Myocardial Perfusion Reserve Index with cardiac MRI from baseline to the end of follow-up. The planned study duration is from 2024 to 2026. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Ethics Committee of the Eighth Affiliated Hospital, Sun Yat-sen University (ID: 2023-045-03). The findings will be disseminated in peer-reviewed publications. TRIAL REGISTRATION NUMBER: ChiCTR2300076231.

Evaluation of enhanced external counterpulsation for diabetic foot based on a patient-specific 0D-1D cardiovascular system model.

BACKGROUND AND OBJECTIVE: Diabetic foot (DF) complications often lead to severe vascular issues. This study investigated the effectiveness of enhanced external counterpulsation (EECP) and its derived innovative compression strategies in addressing poor perfusion in DF. Although developing non-invasive and efficient treatment methods for DF is critical, the hemodynamic alterations during EECP remain underexplored despite promising outcomes in microcirculation. This research sought to address this gap by developing a patient-specific 0D-1D model based on clinical ultrasound data to identify potentially superior compression strategies that could substantially enhance blood flow in patients with DF complications. METHODS: Data were gathered from 10 patients with DF utilizing ultrasound for blood flow rate and computed tomography angiography (CTA) to identify lower limb conditions. Clinical measurements during standard EECP, with varying cuff pressures, facilitated the creation of a patient-specific 0D-1D model through a two-step parameter estimation process. The accuracy of this model was verified via comparison with the clinical measurements. Four compression strategies were proposed and rigorously evaluated using this model: EECP-Simp-I (removing hip cuffs), EECP-Simp-II (further removing the cuffs around the lower leg), EECP-Impr-I (removing all cuffs around the affected side), and EECP-Impr-II (building a loop circulation from the healthy side to the affected side). RESULTS: The predicted results under the rest and standard EECP states were generally closely aligned with clinical measurements. The patient-specific 0D-1D model demonstrated that EECP-Simp-I and EECP-Impr-I contributed similar enhancement to perfusion in the dorsal artery (DA) and were comparable to standard EECP, while EECP-Simp-II had the least effect and EECP-Impr-II displayed the most significant enhancement. Pressure at the aortic root (AO) remained consistent across strategies. CONCLUSIONS: EECP-Simp-I is recommended for patients with DF, emphasizing device simplification. However, EECP-Simp-II is discouraged as it significantly diminished blood perfusion in this study, except in cases of limb fragility. EECP-Impr-II showed superior enhancement of blood perfusion in DA to all other strategies but required a more complex EECP device. Despite increased AO pressure in all the proposed compression strategies, safety could be guaranteed as the pressue remained within a safe range.

A Randomized Controlled Study of Enhanced External Counterpulsation with Cardiac Rehabilitation in Patients with Nonobstructive Coronary Artery Disease and Coronary Microvascular Dysfunction.

Treatment with enhanced external counterpulsation (EECP) or cardiac rehabilitation (CR) benefits patients with coronary heart disease; this paper intends to explore the feasibility of EECP combined with CR in patients with nonobstructive coronary heart disease (NOCAD) and coronary microcirculation disorders (CMD).In January 2021-2022 month June our income NOCAD patients as the research object, the line of cardiac magnetic resonance (CMR), myocardial perfusion reserve (MPR) < 2.0 coronary microcirculation disorders (CMD, 80 cases). Random indicator method 80 CMD patients divided into two groups, 40 cases in each. Usual treatment group: conventional drugs and CR therapy. EECP treatment group: on the basis of standard treatment group, employ EECP therapy. Comparing the two groups before and after the treatment curative effect cardiac function index, endothelial unction index, adverse cardiovascular events, etc.After EECP treatment, the treatment group showed a higher effective rate compared to the usual treatment group (P < 0.05). EECP group curative effect, left ventricular ejection fraction,plasma NO and vascular endothelial growth factor levels higher than the usual group, the incidence of adverse cardiovascular events is lower than the usual group. The difference was statistically significant (P < 0.05).EECP combined with cardiac rehabilitation in patients with CMD symptoms has better effect and safety and provides reference for treatment of CMD patients.

Development of in vitro microfluidic models to study endothelial responses to pulsatility with different mechanical circulatory support devices.

Continuous-flow ventricular assist devices (CFVAD) and counterpulsation devices (CPD) are used to treat heart failure (HF). CFVAD can diminish pulsatility, but pulsatile modes have been implemented to increase vascular pulsatility. The effects of CFVAD in a pulsatile mode and CPD support on the function of endothelial cells (ECs) are yet to be investigated. In this study, two in vitro microfluidic models for culturing ECs are proposed to reproduce blood pressure (BP) and wall shear stress (WSS) on the arterial endothelium while using these medical devices. The layout and parameters of the two microfluidic systems were optimized based on the principle of hemodynamic similarity to efficiently simulate physiological conditions. Moreover, the unique design of the double-pump and double afterload systems could successfully reproduce the working mode of CPDs in an in vitro microfluidic system. The performance of the two systems was verified by numerical simulations and in vitro experiments. BP and WSS under HF, CFVAD in pulsatile modes, and CPD were reproduced accurately in the systems, and these induced signals improved the expression of Ca2+, NO, and reactive oxygen species in ECs, proving that CPD may be effective in normalizing endothelial function and replacing CFVAD to a certain extent to treat non-severe HF. This method offers an important tool for the study of cell mechanobiology and a key experimental basis for exploring the potential value of mechanical circulatory support devices in reducing adverse events and improving outcomes in the treatment of HF in the future.

Enhanced external counterpulsation treatment improves multi-organ hemodynamics for postoperative liver transplantation patient. A case report.

INTRODUCTION: Post liver transplantation (LT) patients endure high morbidity rate of multi-organ ischemic symptoms following reperfusion. We hypothesize that enhanced external counterpulsation (EECP) as a typical non-invasive assisted circulation procedure, which can efficiently inhibit the relative ischemic symptoms via the systemic improvement of hemodynamics. CASE PRESENTATION: A 51-year-old male patient, 76 kg, 172 cm, received orthotopic LT surgery for viral hepatitis B induced acute-on-chronic liver failure hepatic failure. His medical records revealed ischemic symptoms in multi-organ at the time of hospital discharge, including headache, refractory insomnia, abdominal paralysis, and lower limb pain. The EECP treatment was introduced for assisted rehabilitation and to improve the postoperative quality of life. Doppler Ultrasound examination showed significant augmentation of blood flow volume in the carotid arteries, the hepatic artery, the portal vein and the femoral artery during EECP intervention. A standard 35-hour EECP treatment led to significant improvement in quality of life, e.g. sleep quality and walking ability. CONCLUSION: We report a case of multi-organ ischemic symptoms in a post LT patient. EECP treatment can significantly improve the quality of life via the systematic promotion of hemodynamics.

Hemodynamics of ventricular-arterial coupling under enhanced external counterpulsation: An optimized dual-source lumped parameter model.

BACKGROUND AND OBJECTIVE: Enhanced external counterpulsation (EECP) is a mechanically assisted circulation technique widely used in the rehabilitation and management of ischemic cardiovascular diseases. It contributes to cardiovascular functions by regulating the afterload of ventricle to improve hemodynamic effects, including increased diastolic blood pressure at aortic root, increased cardiac output and enhanced blood perfusion to multiple organs including coronary circulation. However, the effects of EECP on the coupling of the ventricle and the arterial system, termed ventricular-arterial coupling (VAC), remain elusive. We aimed to investigate the acute effect of EECP on the dynamic interaction between the left ventricle and its afterload of the arterial system from the perspective of ventricular output work. METHODS: A neural network assisted optimization algorithm was proposed to identify the ordinary differential equation (ODE) relation between aortic root blood pressure and flow rate. Based on the optimized order of ODE, a lumped parameter model (LPM) under EECP was developed taking into consideration of the simultaneous action of cardiac and EECP pressure sources. The ventricular output work, in terms of aortic pressure and flow rate cooperated with the LPM, was used to characterize the VAC of ventricle and its afterload. The VAC subjected to the principle of minimal ventricular output work was validated by solving the Euler-Poisson equation of cost function, ultimately determining the waveforms of aortic pressure and flow rate. RESULTS: A third-order ODE can precisely describe the hemodynamic relationship between aortic pressure and flow rate. An optimized dual-source LPM with three energy-storage elements has been constructed, showing the potential in probing VAC under EECP. The LPM simulation results demonstrated that the VAC in terms of aortic pressure and flow rate yielded to the minimal ventricular output work under different EECP pressures. CONCLUSIONS: The ventricular-arterial coupling under EECP is subjected to the minimal ventricular output work, which can serve as a criterion for determining aortic pressure and flow rate. This study provides insight for the understanding of VAC and has the potential in characterizing the performance of the ventricular and arterial system under EECP.

A numerical study on the siphonic effect of enhanced external counterpulsation at lower extremities with a coupled 0D-1D closed-loop personalized hemodynamics model.

Enhanced external counterpulsation (EECP) is a treatment and rehabilitation approach for ischemic diseases, including coronary artery disease. Its therapeutic benefits are primarily attributed to the improved blood circulation achieved through sequential mechanical compression of the lower extremities. However, despite the crucial role that hemodynamic effects in the lower extremity arteries play in determining the effectiveness of EECP treatment, most studies have focused on the diastole phase and ignored the systolic phase. In the present study, a novel siphon model (SM) was developed to investigate the interdependence of several hemodynamic parameters, including pulse wave velocity, femoral flow rate, the operation pressure of cuffs, and the mean blood flow changes in the femoral artery throughout EECP therapy. To verify the accuracy of the SM, we coupled the predicted afterload in the lower extremity arteries during deflation using SM with the 0D-1D patient-specific model. Finally, the simulation results were compared with clinical measurements obtained during EECP therapy to verify the applicability and accuracy of the SM, as well as the coupling method. The precision and reliability of the previously developed personalized approach were further affirmed in this study. The average waveform similarity coefficient between the simulation results and the clinical measurements during the rest state exceeded 90%. This work has the potential to enhance our understanding of the hemodynamic mechanisms involved in EECP treatment and provide valuable insights for clinical decision-making.

A real-time patient-specific treatment strategy for enhanced external counterpulsation.

Diastolic/systolic blood pressure ratio (D/S) ≥ 1.2 is the gold standard of enhanced external counterpulsation (EECP) treatment, but it does not show a clear clinical correspondence with the configuration of the EECP mode. As such, a single target results in different treatment effects in different individuals. The local haemodynamic effect (wall shear stress, WSS) of EECP on vascular endothelial cells is conducive to promote the growth of collateral circulation vessels and restore the blood supply distal to the stenosis lesion. Considering the haemodynamic effects of WSS on human arteries, this study developed a real-time patient-specific treatment strategy of EECP for patients with cardio-cerebrovascular diseases. Based on patient-specific haemodynamic data from 113 individuals, an optimization algorithm was developed to achieve the individualization of a 0D lumped-parameter model of the human circulatory system, thereby simulating the patient-specific global haemodynamic effects. 0D/3D coupled cardio-cerebrovascular models of two subjects were established to simulate the local WSS. We then established statistical models to evaluate clinically unmeasurable WSS based on measurable global haemodynamic indicators. With the aim of attaining appropriate area- and time-averaged WSS (ATAWSS, 4-7 Pa), as evaluated by global haemodynamic indicators, a closed-loop feedback tuning method was developed to provide patient-specific EECP treatment strategies. Results showed that for clinical data collected from 113 individuals, the individualized 0D model can accurately simulate patient-specific global haemodynamic effects (average error <5%). Based on two subjects, the statistical models can be used to evaluate local ATAWSS (error <6%) for coronary arteries and for cerebral arteries. An EECP mode planned by the patient-specific treatment strategy can promote an appropriate ATAWSS within a 16 s calculation time. The real-time patient-specific treatment strategy of EECP is expected to improve the long-term outcome for each patient and have potential clinical significance.

Enhanced External Counterpulsation Improves Cognitive Function of Persons With Long COVID.

OBJECTIVE: The aim of this study is to determine the effects of enhanced external counterpulsation (EECP) in patients with long COVID and objectively assessed cognitive impairment. DESIGN: A retrospective evaluation of long COVID patients referred for EECP, with cognitive sequela, and having completed an objective digital assessment before and after therapy. Patients had either cognitive impairment or no cognitive impairment at baseline. We assessed changes in composite score using multifactor analysis of variance. Multiple linear and logistic regression analyses were conducted to evaluate several independent variables. RESULTS: Eighty long COVID patients (38 cognitive impairment vs. 42 no cognitive impairment) were included for analyses. All baseline characteristics were well matched. There was significant improvement in composite score post EECP in those with objective cognitive impairment at baseline. There were no notable documented safety concerns. CONCLUSIONS: This is the first study showing that EECP led to significant improvement in cognitive functioning of long COVID patients with objectively defined cognitive impairment. Although a lack of a negative control group is a limitation of this study, EECP seems to be highly safe and effective with the potential for widespread application.

Enhanced external counterpulsation improves sleep quality in chronic insomnia: A pilot randomized controlled study.

PURPOSE: To investigate the short-term efficacy of enhanced external counterpulsation (EECP) on chronic insomnia. METHODS: This is a pilot randomized, participant-blind, and sham-controlled study. Forty-six participants with chronic insomnia were randomly assigned in a 1:1 ratio to receive EECP or sham EECP intervention (total of 35 sessions with 45 min each). The primary outcome was Pittsburgh Sleep Quality Index (PSQI). The secondary outcomes included sleep diary, Hospital Anxiety and Depression Scale (HADS), Short-Form Health Survey (SF12), flow mediated dilation (FMD), serum biomarkers of melatonin, cortisol, interleukin-6, and high sensitivity C-reactive protein. Outcomes were assessed after treatment and at 3-month follow-up. RESULTS: The PSQI was significantly decreased in both EECP and sham groups after 35-session intervention (13.74 to 6.96 in EECP and 13.04 to 9.48 in sham), and EECP decreased PSQI more than sham EECP (p = 0.009). PSQI in two groups kept improved at 3-month follow-up. After treatment, the total sleep time, sleep efficiency, FMD value and SF12 mental component of EECP group were significantly improved, and group differences were found for these outcomes. At follow-up, total sleep time, sleep efficiency and SF12 mental component of EECP group remained improved, and group difference for SF12 mental component was found. Post-treatment and follow-up HADS-A significantly decreased in both groups, with no differences between groups. Post-treatment serum biomarkers showed no differences within and between groups. LIMITATION: Lack of objective sleep measurement. CONCLUSION: EECP could improve sleep quality and mental quality of life in chronic insomnia and the therapeutic effect maintained for 3 months.

Enhanced External Counterpulsation for the Treatment of Angina With Nonobstructive Coronary Artery Disease.

Angina and nonobstructive coronary artery disease (ANOCA) is associated with poor outcomes and limited treatment options. Enhanced external counterpulsation (EECP) is a noninvasive treatment that involves applying external inflatable cuffs to the lower extremities to increase blood flow during diastole, followed by deflation during systole. Although EECP is approved for treatment in patients with refractory angina due to obstructive coronary artery disease, its effectiveness in treating patients with ANOCA with refractory angina is limited to small studies. We assessed the efficacy of EECP treatment in patients with ANOCA (defined as ≤50% stenosis in any major epicardial vessels) with refractory anginaby measuring changes in Canadian Cardiovascular Society (CCS) angina class, 6-minute walk test, Duke Activity Status Index (DASI), Seattle Angina Questionnaire 7 (SAQ7), and weekly anginal episodes pre-EECP and post-EECP treatment. A total of 101 patients with ANOCA with CCS class III/IV angina completed a full course of EECP treatment at 2 large EECP centers. In 101 patients with ANOCA the mean age (SD) of 60.6 (11.3) years and 62.4% of the cohort were women. We found significant improvements post-EECP treatment in CCS angina class (mean (SD) 3.4 (0.5) to 2.4 (2.9), p <0.001), 6-minute walk test (median 1200 (IQR 972 to 1411) to 1358 (1170 to 1600), p <0.001), DASI (mean (SD) 15.2 (11.6) to 31.5 (16.3), p <0.001), SAQ7 (mean (DS) 36.2 (24.7) to 31.5 (16.3), p <0.001), and weekly anginal episodes (mean (SD) 5.3 (3.5) to 2.4 (2.9), p <0.001). After EECP treatment, 71 patients (70.3%) had an improvement of ≥1 CCS angina class, including 33 (32.7%) patients improving by ≥2 CCS classes. In conclusion, in patients with ANOCA, EECP therapy reduces CCS angina class and improves exercise tolerance and capacity; and should be considered a part of optimal medical therapy.

Enhanced external counterpulsation increases coronary flow reserve in coronary microvascular disease.

OBJECTIVES: To investigates the outcomes of enhanced external counterpulsation (EECP) among coronary microvascular disease (CMD) patients. METHODS: Coronary microvascular disease patients were separated into the EECP (n=41) and control cohorts (n=42). Prior to and following the 4-week EECP program, coronary flow reserve (CFR) was recorded using transthoracic Doppler echocardiography. The serum endothelial nitric oxide synthase (eNOS) and endothelin-1 (ET-1) contents were analyzed by ELISA. Quality of life (QoL) was assessed by the Seattle Angina Questionnaire (SAQ) and the Canadian Cardiovascular Society (CCS) angina class. RESULTS: After four weeks, CFR was substantially enhanced in the EECP versus control cohort (p<0.05). Endothelin-1 was strongly diminished whereas eNOS was considerably upregulated in the EECP cohort. EECP also enhanced patients' SAQ scores and decreased the CCS angina class. CONCLUSION: Enhanced external counterpulsation may improve CFR and enhance the CMD patient QoL.

Influence of enhanced external counterpulsation on endothelial function: a meta-analysis of randomized controlled trials.

OBJECTIVES: Enhanced external counterpulsation (EECP) is an effective and noninvasive treatment for patients with refractory angina and chronic heart failure. However, previous studies evaluating the influence of EECP on endothelial function showed inconsistent results. This systematic review and meta-analysis was conducted to evaluate the effects of EECP on endothelial function measured by brachial artery flow-mediated dilation (FMD). DESIGN: PubMed, Embase, Cochrane Library, CNKI, and Wanfang databases were searched for randomized controlled trials comparing the influence of EECP versus usual care on FMD in adult population. A random-effects model incorporating the potential influence of heterogeneity was used to pool the results. RESULTS: Nineteen studies with 1647 patients were included in the meta-analysis. Compared with usual care or conventional therapy, additional treatment with EECP for 3-7 weeks was associated with a significantly improved FMD (mean difference [MD]: 1.96%, 95% confidence interval [CI]: 1.57-2.36, p < 0.001, I2 = 52%). Subgroup analysis showed consistent results in patients with coronary artery disease and in patients with other diseases (p for subgroup difference = 0.21). Results of meta-regression analysis showed that the mean baseline FMD level was positively correlated with the influence of EECP on FMD (coefficient = 0.42, p < 0.001). Results of subgroup analysis suggested that the increment of FMD following EECP was larger in patients with baseline FMD ≥ 5% (MD: 2.69, 95% CI: 2.27-3.10, p < 0.001; I2 = 15%) compared to those with baseline FMD < 5% (MD: 1.49, 95% CI: 1.13-1.85, p < 0.001; I2 = 0%; p for subgroup difference < 0.001). CONCLUSIONS: EECP may be effective in improving endothelial function measured by FMD.

Enhanced external counterpulsation treatment regulates blood flow and wall shear stress metrics in femoral artery: An in vivo study in healthy subjects.

As a non-invasive assisted circulation therapy, enhanced external counterpulsation (EECP) has demonstrated potential in treatment of lower-extremity arterial disease (LEAD). However, the underlying hemodynamic mechanism remains unclear. This study aimed to conduct the first prospective investigation of the EECP-induced responses of blood flow behavior and wall shear stress (WSS) metrics in the femoral artery. Twelve healthy male volunteers were enrolled. A Doppler ultrasound-basedapproach was introduced for the in vivo determination of blood flow in the common femoral artery (CFA) and superficial femoral artery (SFA) during EECP intervention, with incremental treatment pressures ranging from 10 to 40 kPa. Three-dimensional subject-specific numerical models were developed in 6 subjects to quantitatively assess variations in WSS-derived hemodynamic metrics in the femoral bifurcation. A mesh-independence analysis was performed. Our results indicated that, compared to the pre-EECP condition, both the antegrade and retrograde blood flow volumes in the CFA and SFA were significantly augmented during EECP intervention, while the heart rate remained constant. The time average shear stress (TAWSS) over the entire femoral bifurcation increased by 32.41%, 121.30%, 178.24%, and 214.81% during EECP with treatment pressures of 10 kPa, 20 kPa, 30 kPa, and 40 kPa, respectively. The mean relative resident time (RRT) decreased by 24.53%, 61.01%, 69.81%, and 77.99%, respectively. The percentage of area with low TAWSS in the femoral artery dropped to nearly zero during EECP with a treatment pressure greater than or equal to 30 kPa. We suggest that EECP is an effective and non-invasive approach for regulating blood flow and WSS in lower extremity arteries.

The Effect of EECP on Ischemic Heart Failure: a Systematic Review.

PURPOSE OF REVIEW: Heart failure is a serious global health problem, and coronary artery disease is one of the main causes. At present, the treatment options for ischemic heart failure (IHF) are limited. This article mainly aims to explore the evidence of enhanced external counterpulsation (EECP) as a non-invasive cardiac rehabilitation method in patients with IHF and to make a preliminary exploration of its mechanisms. RECENT FINDINGS: According to the existing evidence, the standard course of EECP is safe in patients with IHF and can significantly improve the quality of life of these patients. The effect of EECP on systolic function is still unclear, while EECP has a significant improvement effect on cardiac diastolic function. At the same time, this treatment can reduce the re-hospitalization rate and emergency visit rate of patients within 6 months. In terms of mechanisms, in addition to the immediate hemodynamic effect, existing evidence mostly suggests that its improvement of cardiac function may come from its upregulation of shear stress to improve myocardial perfusion. EECP is safe to use in patients with stable ischemic heart failure, and it can improve the performance status of patients and may be beneficial to cardiac function and reduce the short-term re-hospitalization rate.

Treatment strategy of different enhanced external counterpulsation frequencies for coronary heart disease and cerebral ischemic stroke: A hemodynamic numerical simulation study.

BACKGROUND AND OBJECTIVES: Currently, enhanced external counterpulsation (EECP) devices mainly produce one counterpulsation per cardiac cycle. However, the effect of other frequencies of EECP on the hemodynamics of coronary and cerebral arteries is still unclear. It should be investigated whether one counterpulsation per cardiac cycle leads to the optimal therapeutic effect in patients with different clinical indications. Therefore, we measured the effects of different frequencies of EECP on the hemodynamics of coronary and cerebral arteries to determine the optimal counterpulsation frequency for the treatment of coronary heart disease and cerebral ischemic stroke. METHODS: We established 0D/3D geometric multi-scale hemodynamics model of coronary and cerebral arteries in two healthy individuals, and performed clinical trials of EECP to verify the accuracy of the multi-scale hemodynamics model. The pressure amplitude (35 kPa) and pressurization duration (0.6 s) were fixed. The global and local hemodynamics of coronary and cerebral arteries were studied by changing counterpulsation frequency. Three frequency modes, including one counterpulsation in one, two and three cardiac cycles, were applied. Global hemodynamic indicators included diastolic / systolic blood pressure (D/S), mean arterial pressure (MAP), coronary artery flow (CAF), and cerebral blood flow (CBF), whereas local hemodynamic effects included area-time-averaged wall shear stress (ATAWSS) and oscillatory shear index (OSI). The optimal counterpulsation frequency was verified by analyzing the hemodynamic effects of different frequency modes of counterpulsation cycles and full cycles. RESULTS: In the full cycle, CAF, CBF and ATAWSS of coronary and cerebral arteries were the highest when one counterpulsation per cardiac cycle was applied. However, in the counterpulsation cycle, the global and local hemodynamic indicators of coronary and cerebral artery reached the highest when one counterpulsation in one cardiac cycle or two cardiac cycles was applied. CONCLUSIONS: For clinical application, the results of global hemodynamic indicators in the full cycle have more clinical practical significance. Combined with the comprehensive analysis of local hemodynamic indicators, it can be concluded that for coronary heart disease and cerebral ischemic stroke, applying one counterpulsation per cardiac cycle may provide the optimal benefit.

Cerebral multi-autoregulation model based enhanced external counterpulsation treatment planning for cerebral ischemic stroke.

Enhanced external counterpulsation (EECP) treatment for cerebral ischemic stroke patients with differing severity of stenosis, is subject to uncertainties due to the varying effects of the cerebral autoregulation mechanism on haemodynamics. The current study reports the development of a cerebral multi-autoregulation (MR) mathematical model, based on cerebral arteriole regulation of neurogenic, vascular smooth muscle reflex and shear stress mechanisms which takes into account the severity of stenosis. The model was evaluated by comparison to authentic clinical measurements of cerebral autoregulatory efficiency. Then it was applied to a 0D/3D geometric multi-scale haemodynamic model of a cerebral artery. Haemodynamic indicators were calculated under different pressurization durations of EECP to evaluate the efficacy for different stenosis lesions. Moderate stenosis of 50% to 60% produced excessive time-averaged wall shear stress in the distal area of the stenosis (>7 Pa) during prolonged pressurization and may result in damage to vascular endothelial cells. However, prolonged pressurization did not result in haemodynamic risk for severe stenosis of 70% to 80%, indicating that the duration of pressurization may be extended with increasing severity of stenosis. The current MR model accurately simulated cerebral blood flow and has relevance to the simulation of cerebral haemodynamics in a clinical setting.