The Beneficial Effects of Cardiac Rehabilitation on the Function and Levels of Endothelial Progenitor Cells

Potential preservative mechanisms of cardiac rehabilitation pathways on endothelial function in coronary heart disease

Cardiac rehabilitation, a comprehensive exercise-based lifestyle and medical management, is effective in decreasing morbidity and improving life quality in patients with coronary heart disease. Endothelial function, an irreplaceable indicator in coronary heart disease progression, is measured by various methods in traditional cardiac rehabilitation pathways, including medicinal treatment, aerobic training, and smoking cessation. Nevertheless, studies on the effect of some emerging cardiac rehabilitation programs on endothelial function are limited. This article briefly reviewed the endothelium-beneficial effects of different cardiac rehabilitation pathways, including exercise training, lifestyle modification and psychological intervention in patients with coronary heart disease, and related experimental models, and summarized both uncovered and potential cellular and molecular mechanisms of the beneficial roles of various cardiac rehabilitation pathways on endothelial function. In exercise training and some lifestyle interventions, the enhanced bioavailability of nitric oxide, increased circulating endothelial progenitor cells (EPCs), and decreased oxidative stress are major contributors to preventing endothelial dysfunction in coronary heart disease. Moreover, the preservation of endothelial-dependent hyperpolarizing factors and inflammatory suppression play roles. On the one hand, to develop more endothelium-protective rehabilitation methods in coronary heart disease, adequately designed and sized randomized multicenter clinical trials should be advanced using standardized cardiac rehabilitation programs and existing assessment methods. On the other hand, additional studies using suitable experimental models are warranted to elucidate the relationship between some new interventions and endothelial protection in both macro- and microvasculature.

Pulmonary rehabilitation and endothelial function in patients with chronic obstructive pulmonary disease: A prospective cohort study

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with subclinical atherosclerosis and endothelial dysfunction, thereby leading to increased cardiovascular risk. In the present study, we evaluated the changes in endothelium-dependent flow-mediated dilation (FMD) in a cohort of severe COPD patients undergoing pulmonary rehabilitation.

METHODS

Consecutive COPD patients referred to our Pulmonary Rehabilitation Unit were screened for inclusion. All study procedures were performed at hospital admission and discharge.

RESULTS

Of 78 patients screened for eligibility, a total of 40 participants (67.5% males, median age 72.5 years) were included. After pulmonary rehabilitation, a significant improvement in functional parameters, exercise capacity, and measures of disability and quality of life were documented. FMD changed from 3.25% (IQR: 2.31-4.26) to 4.95% (IQR: 3.57-6.02), corresponding to a 52.3% increase of its median value (P < 0.001). Significantly lower changes in FMD were documented in COPD patients with hypercholesterolemia as compared to those without (+0.33% ± 1.61 vs. +1.62% ± 1.59, P = 0.037). Changes in FMD (ΔFMD) were positively associated with changes in forced expiratory volume in 1 s (FEV1), when expressed both as absolute values (ΔFEV1) (r = 0.503, P = 0.002) and as percentages of predicted values (ΔFEV1%) (r = 0.608; P < 0.001). In multiple linear regressions, after adjusting for major cardiovascular risk factors, ΔFEV1 (β=0.342; P = 0.049) and ΔFEV1% (β=0.480; P = 0.015) were both confirmed as independent predictors of ΔFMD.

CONCLUSIONS

Results of our study suggest that endothelial function may improve in COPD after pulmonary rehabilitation. The potential beneficial effect in terms of cardiovascular risk prevention should be evaluated in ad hoc designed studies.

Longer-Term Effects of Cardiac Telerehabilitation on Patients With Coronary Artery Disease: Systematic Review and Meta-Analysis

BACKGROUND

Cardiac telerehabilitation offers a flexible and accessible model for patients with coronary artery disease (CAD), effectively transforming the traditional cardiac rehabilitation (CR) approach.

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the long-term effectiveness of cardiac telerehabilitation.

METHODS

We searched randomized controlled trials (RCTs) in 7 electronic databases: PubMed, Web of Science, EMBASE, the Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, the China National Knowledge Infrastructure, and WANFANG. The primary outcome focused on cardiopulmonary fitness. For secondary outcomes, we examined cardiovascular risk factors (blood pressure, BMI, and serum lipids), psychological scales of depression and anxiety, quality of life (QoL), cardiac telerehabilitation adherence, and adverse events.

RESULTS

In total, 10 RCTs fulfilled the predefined criteria, which were reviewed in our meta-analysis. The results showed that after cardiac telerehabilitation, there was a significant difference in the improvement in long-term peak oxygen uptake compared to center-based CR (mean difference [MD] 1.61, 95% CI 0.38-2.85, P=.01), particularly after 6-month rehabilitation training (MD 1.87, 95% CI 0.34-3.39, P=.02). The pooled effect size of the meta-analysis indicated that there were no significant differences in the reduction in cardiovascular risk factor control. There was also no practical demonstration of anxiety scores or depression scores. However, cardiac telerehabilitation demonstrated an improvement in the long-term QoL of patients (MD 0.92, 95% CI 0.06-1.78, P=.04). In addition, the study reported a high completion rate (80%) for cardiac telerehabilitation interventions. The incidence of adverse events was also low during long-term follow-up.

CONCLUSIONS

Cardiac telerehabilitation proves to be more effective in improving cardiopulmonary fitness and QoL during the long-term follow-up for patients with CAD. Our study highlights monitoring-enabled and patient-centered telerehabilitation programs, which play a vital role in the recovery and development of CAD and in the long-term prognosis of patients.

Mechanisms and Clinical Implications of Endothelial Dysfunction in Arterial Hypertension

The endothelium is composed of a monolayer of endothelial cells, lining the interior surface of blood and lymphatic vessels. Endothelial cells display important homeostatic functions, since they are able to respond to humoral and hemodynamic stimuli. Thus, endothelial dysfunction has been proposed as a key and early pathogenic mechanism in many clinical conditions. Given the relevant repercussions on cardiovascular risk, the complex interplay between endothelial dysfunction and systemic arterial hypertension has been a matter of study in recent years. Numerous articles have been published on this issue, all of which contribute to providing an interesting insight into the molecular mechanisms of endothelial dysfunction in arterial hypertension and its role as a biomarker of inflammation, oxidative stress, and vascular disease. The prognostic and therapeutic implications of endothelial dysfunction have also been analyzed in this clinical setting, with interesting new findings and potential applications in clinical practice and future research. The aim of this review is to summarize the pathophysiology of the relationship between endothelial dysfunction and systemic arterial hypertension, with a focus on the personalized pharmacological and rehabilitation strategies targeting endothelial dysfunction while treating hypertension and cardiovascular comorbidities.

Endothelial Progenitor Cell Response to Acute Multicomponent Exercise Sessions with Different Durations

It is widely accepted that exercise training has beneficial effects on vascular health. Although a dose-dependent relation has been suggested, little is known about the effects of different exercise durations on endothelial markers. This study aimed to assess the effect of single exercise sessions with different durations in the circulating levels of endothelial progenitor cells (EPCs) and endothelial cells (CECs) among adults with cardiovascular risk factors. Ten participants performed two multicomponent exercise sessions, one week apart, lasting 30 and 45 min (main exercise phase). Before and after each exercise session, blood samples were collected to quantify EPCs and CECs by flow cytometry. The change in EPCs was significantly different between sessions by 3.0% (95% CI: 1.3 to 4.7), being increased by 1.8 ± 1.7% (p = 0.009) in the 30 min session vs. −1.2 ± 2.0% (p > 0.05) in the 45 min session. No significant change was observed in CECs [−2.0%, 95%CI: (−4.1 to 0.2)] between the sessions. In conclusion, a multicomponent exercise session of 30 min promotes an acute increase in the circulating levels of EPCs without increasing endothelial damage (measured by the levels of CECs) among adults with cardiovascular risk factors.

The impact of different forms of exercise on endothelial progenitor cells in healthy populations

Circulating endothelial progenitor cells (EPCs) contribute to vascular healing and neovascularisation, while exercise is an effective means to mobilise EPCs into the circulation.

OBJECTIVES

to systematically examine the acute and chronic effects of different forms of exercise on circulating EPCs in healthy populations.

METHODS

Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed.

RESULTS

thirty-one articles met the inclusion criteria including 747 participants aged 19 to 76 years. All included trials used flow cytometry for identification of circulating EPCs. Eight and five different EPC phenotypes were identified in the acute and chronic trials, respectively. In the acute trials, moderate intensity continuous (MICON), maximal, prolonged endurance, resistance and high intensity interval training (HIIT) exercise protocols were utilised. Prolonged endurance and resistance exercise had the most profound effect on circulating EPCs followed by maximal exercise. In the chronic trials, MICON exercise, HIIT, HIIT compared to MICON and MICON compared to exergame (exercise modality based on an interactive video game) were identified. MICON exercise had a positive effect on circulating EPCs in older sedentary individuals which was accompanied by improvements in endothelial function and arterial stiffness. Long-stage HIIT (4 min bouts) appears to be an effective means and superior than MICON exercise in mobilising circulating EPCs. In conclusion, both in acute and chronic trials the degree of exercise-induced EPC mobilisation depends upon the exercise regime applied. In future, more research is warranted to examine the dose-response relationship of different exercise forms on circulating EPCs using standardised methodology and EPC phenotype.

Cardiopulmonary Exercise Performance and Endothelial Function in Convalescent COVID-19 Patients

BACKGROUND

Endothelial dysfunction has been proposed as the common pathogenic background of most manifestations of coronavirus disease 2019 (COVID-19). Among these, some authors also reported an impaired exercise response during cardiopulmonary exercise testing (CPET). We aimed to explore the potential association between endothelial dysfunction and the reduced CPET performance in COVID-19 survivors.

METHODS

36 consecutive COVID-19 survivors underwent symptom-limited incremental CPET and assessment of endothelium-dependent flow-mediate dilation (FMD) according to standardized protocols.

RESULTS

A significantly higher FMD was documented in patients with a preserved, as compared to those with a reduced, exercise capacity (4.11% ± 2.08 vs. 2.54% ± 1.85, p = 0.048), confirmed in a multivariate analysis (β = 0.899, p = 0.038). In the overall study population, FMD values showed a significant Pearson's correlation with two primary CPET parameters, namely ventilation/carbon dioxide production (VE/VCO2) slope (r = -0.371, p = 0.026) and end-tidal carbon dioxide tension (PETCO2) at peak (r = 0.439, p = 0.007). In multiple linear regressions, FMD was the only independent predictor of VE/VCO2 slope (β = -1.308, p = 0.029) and peak PETCO2 values (β = 0.779, p = 0.021). Accordingly, when stratifying our study population based on their ventilatory efficiency, patients with a ventilatory class III-IV (VE/VCO2 slope ≥ 36) exhibited significantly lower FMD values as compared to those with a ventilatory class I-II.

CONCLUSIONS

The alteration of endothelial barrier properties in systemic and pulmonary circulation may represent a key pathogenic mechanism of the reduced CPET performance in COVID-19 survivors. Personalized pharmacological and rehabilitation strategies targeting endothelial function may represent an attractive therapeutic option.

Exercise Training Improves Functions of Endothelial Progenitor Cells in Patients with Metabolic Syndrome

Fundamento

As células progenitoras endoteliais (CPEs) desempenham um papel importante na manutenção da função endotelial. A síndrome metabólica (SM) está associada à disfunção das CPEs. Embora o exercício físico tenha um impacto benéfico na atividade das CPEs, seu mecanismo ainda não está completamente esclarecido.

Objetivo

O objetivo deste estudo é investigar os efeitos do exercício físico nas funções das CPEs e os mecanismos subjacentes em pacientes com SM.

Métodos

Os voluntários com SM foram divididos em grupo exercício (n=15) e grupo controle (n=15). Antes e após 8 semanas de treinamento físico, as CPEs foram isoladas do sangue periférico. Foram feitos o ensaio de unidades formadoras de colônias (UFC), o ensaio de formação de tubos, a expressão proteica do óxido nítrico sintase endotelial (eNOS), da fosfatidilinositol-3-quinase (PI3-K) e da proteína quinase B (AKT). Considerou-se um valor de probabilidade <0,05 para indicar significância estatística.

Resultados

Após 8 semanas, o número de UFCs aumentou significativamente no grupo exercício em comparação com o grupo controle (p<0,05). Além disso, observamos uma diminuição significativa do modelo de avaliação da homeostase da resistência à insulina (HOMA-IR), endotelina-1, proteína C reativa de alta sensibilidade e dos níveis de homocisteína no grupo exercício. A intervenção com exercícios também pode aumentar a capacidade de formação de tubos de CPEs e aumentar o nível de fosforilação de eNOS, PI3-K e AKT.

Conclusão

O exercício físico aprimorou as funções das CPEs. O mecanismo pode estar relacionado ao exercício, ativando a via PI3-K/AKT/eNOS.

Metformin Inhibits the Expression of Biomarkers of Fibrosis of EPCs In Vitro

Endothelial progenitor cells (EPCs) are a group of circulating cells with important functions in vascular repair and treatment of cardiovascular diseases. However, in patients with atrial fibrillation (AF), the number and function of EPCs reportedly are decreased. TGF-β is highly expressed in AF patients. In this study, we examined the effect of TGF-β1 on EPCs and the therapeutic outcome of metformin treatment on TGF-β1-induced EPCs. EPCs were induced with TGF-β1 at different concentrations (5 ng/ml, 10 ng/ml, and 20 ng/ml) for 48 h followed by western blot, qPCR, and immunofluorescence analyses to investigate changes in the levels of the fibrosis-related proteins, α-SMA, Col I, Col III, CTGF, and MMP-1. Live-dead cell staining was used to evaluate cell apoptosis. Compared with the control, TGF-β1 treatment significantly (p < 0.05) enhanced the levels of α-SMA, Col I, Col III, CTGF, and MMP-1 in a dose-dependent manner. The most effective concentration of TGF-β1 (20 ng/ml) was then used to induce fibrosis biomarker expression in EPCs, followed by treatment with metformin at different concentrations (0.5, 1, and 2 mmol/l). Metformin treatment suppressed TGF-β-induced expression of all above factors, with the effect at 2 mmol/l being significant (p < 0.05). Live-dead cell staining showed no difference among the control, TGF-β1-treated, and metformin-treated groups. In conclusion, our study showed that TGF-β1 induces the expression of fibrosis biomarkers in EPCs, which is attenuated by treatment with metformin. Thus, metformin may have therapeutic potential for improving EPC function in cardiovascular diseases.

Stem/Progenitor Cells and Their Therapeutic Application in Cardiovascular Disease

Cardiovascular disease is the leading cause of death in the world. The stem/progenitor cell-based therapy has emerged as a promising approach for the treatment of a variety of cardiovascular diseases including myocardial infarction, stroke, peripheral arterial disease, and diabetes. An increasing number of evidence has shown that stem/progenitor cell transplantation could replenish damaged cells, improve cardiac and vascular functions, and repair injured tissues in many pre-clinical studies and clinical trials. In this review, we have outlined the major types of stem/progenitor cells, and summarized the studies in applying these cells, especially endothelial stem/progenitor cells and their derivatives, in the treatment of cardiovascular disease. Here the strategies used to improve the stem/progenitor cell-based therapies in cardiovascular disease and the challenges with these therapies in clinical applications are also reviewed.

Acute Exercise-Induced Circulating Haematopoietic Stem and Progenitor Cells in Cardiac Patients - A Case Series

BACKGROUND

Exercise-induced circulating haematopoietic stem and progenitor cell (HPC) number has been discussed in the context of regeneration in heart disease patients.

OBJECTIVE

The aim of this pilot study was to compare the effect of different exercise protocols usually applied in cardiac rehabilitation on the number of acute, exercise-induced HPCs, related to potential mediators, e.g. biomarkers of sympathetic and oxidative stress, and inflammation.

METHODS

This is a case series comprising seven patients suffering from coronary heart disease (CHD) undertaken at the Center for Ambulant Cardiac Rehabilitation. Patients (n=6) performed two exercise modes (constant-load, CLE; high-intensity interval, HIIE) in randomised order. Venous blood was drawn before and immediately after each test to assess CD34+/CD45+ HPC number by flow cytometry and biomarkers in blood plasma. The primary outcome was the change in HPC number, the secondary outcomes were changes in sympathetic/oxidative stress and markers of inflammation.

RESULTS

Both exercise modes resulted in a non-significant increase in HPC number after exercise, even when the results of both tests were combined. Overall, free norepinephrine increased significantly and was positively related to exercise-induced HPC number (r=0.70, p<0.05). Markers of sympathetic activation (fNE), oxidative stress (myeloperoxidase) and inflammation (interleukin-6) significantly increased after CLE and HIIE with no difference between tests.

CONCLUSIONS

Interestingly, acute CLE and HIIE did not stimulate significant HPC mobilisation in CHD, although both exercise modes elevated circulating concentrations of sympathetic activation. Haematopoietic stem and progenitor cell mobilisation could be blunted due to disease-related bone-marrow exhaustion.

A randomized controlled trial to evaluate utilization of physical activity recommendations among patients of cardiovascular healthcare centres in Eastern Slovakia: study design and rationale of the AWATAR study

Background

Guidelines on modifiable risk factors regarding cardiological patients are poorly implemented in clinical practice perhaps due to low health literacy. Several digital tools for improving lifestyle and behavioural intervention were developed. Our primary aim is to evaluate the effectiveness of a digital exercise prescription tool on the adherence to physical activity recommendations among patients with cardiovascular diseases.

Methods

A randomized controlled trial will be realized in cooperation with Cardiovascular Health Centres in Eastern Slovakia. Patients recruited through their cardiologists, will be randomised at 1:1 ratio to the three-months’ experimental condition or control condition. The experimental group will receive standard lifestyle consultation leading to individually optimized prescription of physical activity. The control group will receive standard, usual-cardio-care lifestyle counselling, also in the domain of physical activity. The digital system will be used for optimized exercise prescription. The primary outcome is a change in the patient’s adherence to exercise recommendations. Data will be collected in both groups prior to consultation and after 3 months.

Discussion

This study protocol presents background and design of a randomized control trial to investigate the effectiveness of a digital system-provide exercise prescription tool on the adherence to physical activity recommendations. An optimized exercise prescription that better reflects patient’s diagnosis, comorbidities and medication can have a significant impact on secondary prevention of cardiovascular disease. This trial can provide important evidence about the effectiveness of digital exercise guidance in everyday practice of cardiovascular healthcare.

Trial registration

The study was registered on 1st November, 2017 and is available online at ClinicalTrials.gov (ID:NCT03329053).

TPPU enhanced exercise-induced epoxyeicosatrienoic acid concentrations to exert cardioprotection in mice after myocardial infarction

Exercise training (ET) is a safe and efficacious therapeutic approach for myocardial infarction (MI). Given the numerous benefits of exercise, exercise-induced mediators may be promising treatment targets for MI. C57BL/6 mice were fed 1-trifluoromethoxyphenyl-3-(1-propionylpiperidine-4-yl) urea (TPPU), a novel soluble epoxide hydrolase inhibitor (sEHI), to increase epoxyeicosatrienoic acid (EET) levels, for 1 week before undergoing MI surgery. After 1-week recovery, the mice followed a prescribed exercise programme. Bone marrow-derived endothelial progenitor cells (EPCs) were isolated from the mice after 4 weeks of exercise and cultured for 7 days. Angiogenesis around the ischaemic area, EPC functions, and the expression of microRNA-126 (miR-126) and its target gene Spred1 were measured. The results were confirmed in vitro by adding TPPU to EPC culture medium. ET significantly increased serum EET levels and promoted angiogenesis after MI. TPPU enhanced the effects of ET to reduce the infarct area and improve cardiac function after MI. ET increased EPC function and miR-126 expression, which were further enhanced by TPPU, while Spred1 expression was significantly down-regulated. Additionally, the protein kinase B/glycogen synthase kinase 3β (AKT/GSK3β) signalling pathway was activated after the administration of TPPU. EETs are a potential mediator of exercise-induced cardioprotection in mice after MI. TPPU enhances exercise-induced cardiac recovery in mice after MI by increasing EET levels and promoting angiogenesis around the ischaemic area.