Regular physical exercise improves endothelial function in heart transplant recipients

Prevention and rehabilitation after heart transplantation: A clinical consensus statement of the European Association of Preventive Cardiology, Heart Failure Association of the ESC, and the European Cardio Thoracic Transplant Association, a section of ESOT

Little is known either about either physical activity patterns, or other lifestyle-related prevention measures in heart transplantation (HTx) recipients. The history of HTx started more than 50 years ago but there are still no guidelines or position papers highlighting the features of prevention and rehabilitation after HTx. The aims of this scientific statement are (i) to explain the importance of prevention and rehabilitation after HTx, and (ii) to promote the factors (modifiable/non-modifiable) that should be addressed after HTx to improve patients' physical capacity, quality of life and survival. All HTx team members have their role to play in the care of these patients and multidisciplinary prevention and rehabilitation programmes designed for transplant recipients. HTx recipients are clearly not healthy disease-free subjects yet they also significantly differ from heart failure patients or those who are supported with mechanical circulatory support. Therefore, prevention and rehabilitation after HTx both need to be specifically tailored to this patient population and be multidisciplinary in nature. Prevention and rehabilitation programmes should be initiated early after HTx and continued during the entire post-transplant journey. This clinical consensus.

Prevention and Rehabilitation After Heart Transplantation: A Clinical Consensus Statement of the European Association of Preventive Cardiology, Heart Failure Association of the ESC, and the European Cardio Thoracic Transplant Association, a Section of ESOT

Little is known either about either physical activity patterns, or other lifestyle-related prevention measures in heart transplantation (HTx) recipients. The history of HTx started more than 50 years ago but there are still no guidelines or position papers highlighting the features of prevention and rehabilitation after HTx. The aims of this scientific statement are (i) to explain the importance of prevention and rehabilitation after HTx, and (ii) to promote the factors (modifiable/non-modifiable) that should be addressed after HTx to improve patients' physical capacity, quality of life and survival. All HTx team members have their role to play in the care of these patients and multidisciplinary prevention and rehabilitation programmes designed for transplant recipients. HTx recipients are clearly not healthy disease-free subjects yet they also significantly differ from heart failure patients or those who are supported with mechanical circulatory support. Therefore, prevention and rehabilitation after HTx both need to be specifically tailored to this patient population and be multidisciplinary in nature. Prevention and rehabilitation programmes should be initiated early after HTx and continued during the entire post-transplant journey. This clinical consensus statement focuses on the importance and the characteristics of prevention and rehabilitation designed for HTx recipients.

The Exercise aNd hEArt transplant (ENEA) trial - a registry-based randomized controlled trial evaluating the safety and efficacy of cardiac telerehabilitation after heart transplant

BACKGROUND

Heart transplant (HTx) is gold-standard therapy for patients with end-stage heart failure. Cardiac rehabilitation (CR) is a multidisciplinary intervention shown to improve cardiovascular prognosis and quality of life. The aim in this randomized controlled trial is to explore the safety and efficacy of cardiac telerehabilitation after HTx. In addition, biomarkers of rehabilitation outcomes will be identified, as data that will enable treatment to be tailored to patient phenotype.

METHODS

Patients after HTx will be recruited at IRCCS S. Maria Nascente - Fondazione Don Gnocchi, Milan, Italy (n = 40). Consenting participants will be randomly allocated to either of two groups (1:1): an intervention group who will receive on-site CR followed by 12 weeks of telerehabilitation, or a control group who will receive on-site CR followed by standard homecare and exercise programme. Recruitment began on 20th May 2023 and is expected to continue until 20th May 2025. Socio-demographic characteristics, lifestyle, health status, cardiovascular events, cognitive function, anxiety and depression symptoms, and quality of life will be assessed, as well as exercise capacity and muscular endurance. Participants will be evaluated before the intervention, post-CR and after 6 months. In addition, analysis of circulating extracellular vesicles using Surface Plasmon Resonance imaging (SPRi), based on a rehabilomic approach, will be applied to both groups pre- and post-CR.

CONCLUSION

This study will explore the safety and efficacy of cardiac telerehabilitation after HTx. In addition, a rehabilomic approach will be used to investigate biomolecular phenotypization in HTx patients.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT05824364.

Exercise training in heart transplantation

Heart transplantation remains the gold standard in the treatment of end-stage heart failure (HF). Heart transplantation patients present lower exercise capacity due to cardiovascular and musculoskeletal alterations leading thus to poor quality of life and reduction in the ability of daily self-service. Impaired vascular function and diastolic dysfunction cause lower cardiac output while decreased skeletal muscle oxidative fibers, enzymes and capillarity cause arteriovenous oxygen difference, leading thus to decreased peak oxygen uptake in heart transplant recipients. Exercise training improves exercise capacity, cardiac and vascular endothelial function in heart transplant recipients. Pre-rehabilitation regular aerobic or combined exercise is beneficial for patients with end-stage HF awaiting heart transplantation in order to maintain a higher fitness level and reduce complications afterwards like intensive care unit acquired weakness or cardiac cachexia. All hospitalized patients after heart transplantation should be referred to early mobilization of skeletal muscles through kinesiotherapy of the upper and lower limbs and respiratory physiotherapy in order to prevent infections of the respiratory system prior to hospital discharge. Moreover, all heart transplant recipients after hospital discharge who have not already participated in an early cardiac rehabilitation program should be referred to a rehabilitation center by their health care provider. Although high intensity interval training seems to have more benefits than moderate intensity continuous training, especially in stable transplant patients, individualized training based on the abilities and needs of each patient still remains the most appropriate approach. Cardiac rehabilitation appears to be safe in heart transplant patients. However, long-term follow-up data is incomplete and, therefore, further high quality and adequately-powered studies are needed to demonstrate the long-term benefits of exercise training in this population.

Cardiac Rehabilitation in German Speaking Countries of Europe-Evidence-Based Guidelines from Germany, Austria and Switzerland LLKardReha-DACH-Part 2

Background: Scientific guidelines have been developed to update and harmonize exercise based cardiac rehabilitation (ebCR) in German speaking countries. Key recommendations for ebCR indications have recently been published in part 1 of this journal. The present part 2 updates the evidence with respect to contents and delivery of ebCR in clinical practice, focusing on exercise training (ET), psychological interventions (PI), patient education (PE). In addition, special patients’ groups and new developments, such as telemedical (Tele) or home-based ebCR, are discussed as well. Methods: Generation of evidence and search of literature have been described in part 1. Results: Well documented evidence confirms the prognostic significance of ET in patients with coronary artery disease. Positive clinical effects of ET are described in patients with congestive heart failure, heart valve surgery or intervention, adults with congenital heart disease, and peripheral arterial disease. Specific recommendations for risk stratification and adequate exercise prescription for continuous-, interval-, and strength training are given in detail. PI when added to ebCR did not show significant positive effects in general. There was a positive trend towards reduction in depressive symptoms for “distress management” and “lifestyle changes”. PE is able to increase patients’ knowledge and motivation, as well as behavior changes, regarding physical activity, dietary habits, and smoking cessation. The evidence for distinct ebCR programs in special patients’ groups is less clear. Studies on Tele-CR predominantly included low-risk patients. Hence, it is questionable, whether clinical results derived from studies in conventional ebCR may be transferred to Tele-CR. Conclusions: ET is the cornerstone of ebCR. Additional PI should be included, adjusted to the needs of the individual patient. PE is able to promote patients self-management, empowerment, and motivation. Diversity-sensitive structures should be established to interact with the needs of special patient groups and gender issues. Tele-CR should be further investigated as a valuable tool to implement ebCR more widely and effectively.

Effect of exercise on endothelial function in heart transplant recipients: systematic review and meta-analysis

Endothelial dysfunction is associated with increased cardiovascular risk and death in heart transplant recipients (HTx). Although the measurement of peripheral endothelial function is considered a significant predictor of cardiovascular events in several populations, few studies have investigated this outcome after therapeutic strategies, including different exercise types, duration, and intensity. This systematic review and meta-analysis aimed to investigate the effects of continuous moderate exercise (CON) or high-intensity interval training (HIIT) to improve endothelial function (EF) in HTx. The search was conducted in Cochrane Central Registry of Controlled Trials (CENTRAL), MEDLINE (via PubMed), Web of Science and Scopus/Elsevier, CINAHL/Ebsco, Physiotherapy Evidence Database (PEDro), LILACS/BIREME, and SciELO databases. Quality of the evidence was assessed using the Grading of Recommendations Assessment Development and Evaluation (GRADE). The search strategy retrieved 5192 titles. A total of four articles met the inclusion criteria and were included for the qualitative analysis. Meta-analysis showed that exercises improved EF ([mean difference-MD] 3.48 95% CI - 0.29 to 7.25, p = 0.007) when compared with the control. However, there was a poor quality of evidence to demonstrate that CON or HIIT is better than usual care to improve EF. Exercise training provides benefits to patients, but the poor quality of evidence does not allow us to state that exercise is related to endothelial function improvement in HTx.

Exercise after Heart Transplantation: Typical Alterations, Diagnostics and Interventions

For the treatment of terminal heart failure, heart transplantation is considered to be the gold standard, leading to significantly improved quality of life and long-time survival. For heart transplant recipients, the development and maintenance of good functional performance and adequate exercise capacity is crucial for renewed participation and integration in self-determined live. In this respect, typical transplant-related alterations must be noted that play a significant role, leading to restrictions both centrally and peripherally. Before patients begin intensive and structured exercise training, a comprehensive diagnosis of their exercise capacity should take place in order to stratify the risks involved and to plan the training units accordingly. Particularly endurance sports and resistance exercises are recommended to counter the effects of the underlying disease and the immunosuppressive medication. The performance level achieved can vary considerably depending on their individual condition, from gentle activity through a non-competitive-level to intensive competitive sports. This paper includes an overview of the current literature on heart transplant recipients, their specific characteristics, as well as typical cardiovascular and musculoskeletal alterations. It also discusses suitable tools for measuring exercise capacity, recommendations for exercise training, required precautions and the performance level usually achieved.

Secondary prevention through comprehensive cardiovascular rehabilitation: From knowledge to implementation. 2020 update. A position paper from the Secondary Prevention and Rehabilitation Section of the European Association of Preventive Cardiology

Secondary prevention through comprehensive cardiac rehabilitation has been recognized as the most cost-effective intervention to ensure favourable outcomes across a wide spectrum of cardiovascular disease, reducing cardiovascular mortality, morbidity and disability, and to increase quality of life. The delivery of a comprehensive and 'modern' cardiac rehabilitation programme is mandatory both in the residential and the out-patient setting to ensure expected outcomes. The present position paper aims to update the practical recommendations on the core components and goals of cardiac rehabilitation intervention in different cardiovascular conditions, in order to assist the whole cardiac rehabilitation staff in the design and development of the programmes, and to support healthcare providers, insurers, policy makers and patients in the recognition of the positive nature of cardiac rehabilitation. Starting from the previous position paper published in 2010, this updated document maintains a disease-oriented approach, presenting both well-established and more controversial aspects. Particularly for implementation of the exercise programme, advances in different training modalities were added and new challenging populations were considered. A general table applicable to all cardiovascular conditions and specific tables for each clinical condition have been created for routine practice.

The Role of Cardiac Rehabilitation in Reducing Major Adverse Cardiac Events in Heart Transplant Patients

BACKGROUND

Methods for reducing major adverse cardiac events (MACE) in patients after heart transplantation (HTx) are critical for long-term quality outcomes.

METHODS AND RESULTS

Patients with cardiopulmonary exercise testing prior to HTx and at least 1 session of cardiac rehabilitation (CR) after HTx were included. Exercise sessions were evaluated as ≥ 23 or < 23 sessions based on recursive partitioning. We included 140 patients who had undergone HTx (women: n = 41 (29%), age: 52 ± 12 years, body mass index: 27 ± 5 kg/m²). Mean follow-up was 4.1 ± 2.7 years, and 44 patients (31%) had a MACE: stroke (n = 1), percutaneous intervention (n = 5), heart failure (n = 6), myocardial infarction (n = 1), rejection (n = 16), or death (n = 15). CR was a significant predictor of MACE, with ≥ 23 sessions associated with a ∼ 60% reduction in MACE risk (hazard ratio [HR]: 0.42, 95% CI: 0.19-0.94, P = 0.035). This remained after adjusting for age, sex and history of diabetes (HR: 0.41, 95% CI: 0.18-0.94, P = 0.035) as well as body mass index and pre-HTx peak oxygen consumption (HR: 0.40, 95% CI: 0.18-0.92, P = 0.031).

CONCLUSIONS

After adjustment for covariates of age, sex, diabetes, body mass index, and pre-HTx peak oxygen consumption, CR attendance of ≥ 23 exercise sessions was predictive of lower MACE risk following HTx. In post-HTx patients, CR was associated with MACE prevention and should be viewed as a critical tool in post-HTx treatment strategies.

Oxidative Stress-Related Endothelial Damage in Vascular Depression and Vascular Cognitive Impairment: Beneficial Effects of Aerobic Physical Exercise

Oxidative stress- (OS-) related endothelial damage is involved in the occurrence and progression of several disorders, such as vascular depression and dementia. It has been reported that moderate, aerobic, physical exercise could reduce OS and inflammation, thus limiting the cardiovascular risk factors while improving endothelial homeostasis, mood, and cognition. In this review, we will discuss about the role of OS and OS-related endothelial damage in vascular depression and vascular cognitive impairment. Then, we will comment on the effects of physical exercise on both disorders.

Cardiac reinnervation affects cardiorespiratory adaptations to exercise training in individuals with heart transplantation

PURPOSE

The purpose of this study was to investigate the hemodynamic and cardiorespiratory adaptations to exercise in individuals with heart transplantation with evidence of cardiac reinnervation (cardiac reinnervation group) versus without evidence of cardiac reinnervation (no cardiac reinnervation group).

METHODS

Sedentary individuals with heart transplantation (age = 45.5 ± 2.2 years; time elapsed since surgery = 6.7 ± 0.7 years) were divided into the cardiac reinnervation (n = 16) and no cardiac reinnervation (n = 17) groups according to their heart rate response to cardiopulmonary exercise testing. The 24-hour ambulatory blood pressure, carotid-femoral pulse wave velocity, and cardiorespiratory fitness were assessed before and after 12 weeks of a thrice-weekly exercise program (five minutes of warm-up, 30 min of endurance exercise, one set of 10-15 reps in five resistance exercises, and five minutes of cool-down).

RESULTS

The cardiac reinnervation group had reduced (p < 0.01) 24-hour systolic/diastolic blood pressure (7/9 mm Hg), daytime systolic/diastolic blood pressure (9/10 mm Hg) and nighttime diastolic blood pressure (6 mm Hg) after training. The no cardiac reinnervation group reduced (p < 0.05) only 24-hour (5 mm Hg), daytime (5 mm Hg) and nighttime (6 mm Hg) diastolic blood pressure after training. Hourly analysis showed that the cardiac reinnervation group reduced systolic/diastolic blood pressure for 10/21 h, while the no cardiac reinnervation group reduced systolic/diastolic blood pressure for only 3/11 h. The cardiac reinnervation group also improved both maximal oxygen consumption (10.8%) and exercise tolerance (13.4%) after training, but the no cardiac reinnervation group improved only exercise tolerance (9.9%). Pulse wave velocity did not change in both groups.

CONCLUSION

There were greater improvements in ambulatory blood pressure and maximal oxygen consumption in the cardiac reinnervation than the no cardiac reinnervation group. These results suggest that cardiac reinnervation associates with hemodynamic and cardiorespiratory adaptations to exercise training in individuals with heart transplantation.

Endothelial dysfunction in cardiovascular disease and Flammer syndrome-similarities and differences

The endothelium has increasingly been recognized as a smart barrier and a key regulator of blood flow in micro- and macrovascular beds. Endothelial dysfunction marks a stage of atherosclerosis and is an important prognostic marker for cardiovascular disease. Yet, some people who tend to be slim and physically active and with rather low blood pressure show a propensity to respond to certain stimuli such as emotional stress with endothelial-mediated vascular dysregulation (Flammer syndrome). This leads to characteristic vascular symptoms such as cold hands but also a risk for vascular-mediated diseases such as normal-tension glaucoma. It is the aim of this review to delineate the differences between Flammer syndrome and its "counterpart" endothelial dysfunction in the context of cardiovascular diseases.

Effect of walking speed in heart failure patients and heart transplant patients

BACKGROUND

Chronic heart failure patients present higher cost of transport and some changes in pattern of walking, but the same aspects have not yet been investigated in heart transplant patients.

METHODS

The aim of this study was to investigate both metabolic and mechanicals parameters, at five different walking speeds on treadmill, in chronic heart failure and heart transplant patients. Twelve chronic heart failure patients, twelve healthy controls and five heart transplant patients participated in the study. Tridimensional kinematics data and oxygen uptake were collected simultaneously.

FINDINGS

In both experimental groups the self-selected walking speed was lower than in controls, and lower than the expected optimal walking speed. At that speed all groups showed the best ventilatory efficiency. On contrary, chronic heart failure and heart transplant patients reached the minimum cost of transport and the maximum recovery at greater speeds than the self-selected walking speed. Their mechanical efficiency was lower than in controls, while their metabolic cost and mechanical work were on average larger.

INTERPRETATION

We conclude that actions, like a physical training, that could increase the self-selected walking speed in these patients, could also increase their economy and optimize the mechanical parameters of walking. We propose a rehabilitation index, based on the theoretical optimal walking speed, to measure the improvements during a physical rehabilitation therapy. These results have an important clinical relevance and can help to improve the quality of life of heart failure and transplant patients.

Electromyography and economy of walking in chronic heart failure and heart transplant patients

Background Patients with chronic heart failure frequently report intolerance to exercise and present with changes in walk pattern, but information about heart transplant patients is lacking. Alterations of the gait pattern are related to interaction changes between the metabolism, neurological system and the mechanical demands of the locomotor task. The aim of this study was to investigate the electromyographic cost, coactivation and cost of transport of walking of chronic heart failure and heart transplant patients. Design This research was of an exploratory, cross-sectional design. Methods Twelve chronic heart failure patients, twelve healthy controls and five heart transplant patients participated in the study. Electromyographic data and oxygen uptake were collected simultaneously at five walking speeds. Results In the experimental groups, the electromyographic cost, percentage of coactivation in the leg and cost of transport were higher than in controls. The electromyographic cost was in line with the cost of transport. The minimum electromyographic cost matched with the self-selected walking speed in controls, while in chronic heart failure and heart transplant patients, it was reached at speeds higher than the self-selected walking speed. Conclusion The largest postural isometric activation and antagonist activation resulted in the highest metabolic demand. These findings are of great clinical relevance because they support the concept that interventions in order to improve the muscle performance in these patients can increase the self-selected walking speed and therefore the metabolic economy of walking.

Hypertension and arterial stiffness in heart transplantation patients

OBJECTIVES

Post-transplantation hypertension is prevalent and is associated with increased cardiovascular morbidity and subsequent graft dysfunction. The present study aimed to identify the factors associated with arterial stiffness as measured by the ambulatory arterial stiffness index.

METHODS

The current study used a prospective, observational, analytical design to evaluate a group of adult heart transplantation patients. Arterial stiffness was obtained by monitoring ambulatory blood pressure and using the ambulatory arterial stiffness index as the surrogate outcome. Multivariate logistic regression analyses were performed to control confounding.

RESULTS

In a group of 85 adult heart transplantation patients, hypertension was independently associated with arterial stiffness (OR 4.98, CI 95% 1.06-23.4) as well as systolic and diastolic blood pressure averages and nighttime descent.

CONCLUSIONS

Measurement of ambulatory arterial stiffness index is a new, non-invasive method that is easy to perform, may contribute to better defining arterial stiffness prognosis and is associated with hypertension.

Prescribing and Regulating Exercise with RPE after Heart Transplant: A Pilot Study

PURPOSE

The objective of this study is to analyze the use of the 6-20 RPE scale for prescribing and self-regulating heated water-based exercise (HEx) and land-based exercise (LEx) in heart transplant recipients.

METHODS

Fifteen (five females) clinically stable heart transplant recipients (time since surgery = 4.0 ± 2.5 yr) age 46.7 ± 11.8 yr underwent a symptom-limited maximal graded exercise test on a treadmill to determine their HR at anaerobic threshold (HRAT), respiratory compensation point (HRRCP), and maximal effort (HRmax). After a week, patients were randomized to perform 30 min of both HEx (walking inside the pool) and LEx (treadmill walking) sessions at a pace between 11 and 13 on the 6-20 RPE scale and had their HR measured every 4 min. The interval between sessions was 48-72 h.

RESULTS

No significant differences between sessions were found in the average HR during HEx and LEx. Patients showed a delay in HR increase during both interventions, with the stabilization beginning after 8 min of exercise. Exercise HR was maintained between the HRAT and HRRCP (in the aerobic exercise training zone) for the most part of both HEx (72% of HR measurements) and LEx (66% of HR measurements). Only a few HR measurements stayed below HRAT (HEx = 9%, LEx = 13%) or above HRRCP (HEx = 19%, LEx = 21%) during both exercise sessions.

CONCLUSION

Exercise HR was maintained in the aerobic exercise training zone (between HRAT and HRRCP) for the most part of both sessions, suggesting that the 6-20 RPE scale may be an efficient tool for prescribing and self-regulating HEx and LEx in heart transplant recipients.

Exercise modalities and endothelial function: a systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND

Regular exercise is associated with enhanced nitric oxide (NO) bioavailability. Flow-mediated dilation (FMD) is used widely to assess endothelial function (EF) and NO release.

OBJECTIVES

The aims of this systematic review and meta-analysis were to (i) investigate the effect of exercise modalities (aerobic, resistance or combined) on FMD; and (ii) determine which exercise and participant characteristics are most effective in improving FMD.

METHODS

We searched the MEDLINE, Embase, Cochrane Library, and Scopus databases for studies that met the following criteria: (i) randomized controlled trials of exercise with comparative non-exercise, usual care or sedentary groups; (ii) duration of exercise intervention ≥4 weeks; (iii) age ≥18 years; and (iv) EF measured by FMD before and after the intervention. Weighted mean differences (WMDs) with 95% confidence interval were entered into a random effect model to estimate the pooled effect of the exercise interventions.

RESULTS

All exercise modalities enhanced EF significantly: aerobic (WMD 2.79, 95% CI 2.12-3.45, p = 0.0001), resistance (WMD 2.52, 95% CI 1.11-3.93, p = 0.0001) and combined (WMD 2.07, 95% CI 0.70-3.44, p = 0.003). A dose-response relationship was observed between aerobic exercise intensity and improvement in EF. A 2 metabolic equivalents (MET) increase in absolute exercise intensity or a 10% increase in relative exercise intensity resulted in a 1% unit improvement in FMD. There was a positive relationship between frequency of resistance exercise sessions and improvement in EF (β 1.14, CI 0.16-2.12, p = 0.027).

CONCLUSIONS

All exercise modalities improve EF significantly and there was a significant, positive relationship between aerobic exercise intensity and EF. Greater frequency, rather than intensity, of resistance exercise training enhanced EF.

Exercise training improves ambulatory blood pressure but not arterial stiffness in heart transplant recipients

BACKGROUND

Hypertension is the most prevalent comorbidity after heart transplantation (HT). Exercise training (ET) is widely recommended as a key non-pharmacologic intervention for the prevention and management of hypertension, but its effects on ambulatory blood pressure (ABP) and some mechanisms involved in the pathophysiology of hypertension have not been studied in this population. The primary purpose of this study was to investigate the effects of ET on ABP and arterial stiffness of HT recipients.

METHODS

40 HT patients, randomized to ET (n = 31) or a control group (n = 9) underwent a maximal graded exercise test, 24-hour ABP monitoring, and carotid-femoral pulse wave velocity (PWV) assessment before the intervention and at a 12-week follow-up assessment. The ET program was performed thrice-weekly and consisted primarily of endurance exercise (40 minutes) at ~70% of maximum oxygen uptake (Vo2MAX).

RESULTS

The ET group had reduced 24-hour (4.0 ± 1.4 mm Hg, p < 0.01) and daytime (4.8 ± 1.6 mm Hg, p < 0.01) systolic ABP, and 24-hour (7.0 ± 1.4 mm Hg, p < 0.001) daytime (7.5 ± 1.6 mm Hg, p < 0.001) and nighttime (5.9 ± 1.5 mm Hg, p < 0.001) diastolic ABP after the intervention. The ET group also had improved Vo2MAX (9.7% ± 2.6%, p < 0.001) after the intervention. However, PWV did not change after ET. No variable was changed in the control group after the intervention.

CONCLUSIONS

The 12-week ET program was effective for reducing ABP but not PWV in heart transplant recipients. This result suggests that endurance ET may be a tool to counteract hypertension in this high-risk population.

The effect of physical activity or exercise on key biomarkers in atherosclerosis--a systematic review

OBJECTIVE

This systematic review aimed to summarize published papers on the effect of physical activity (PA)/exercise on key atherosclerotic factors in patients with risk factors for or established cardiovascular disease (CVD).

METHODS

Studies involving PA and cytokines, chemokines, adhesion molecules, CRP and angiogenic factors were searched for in Medline and Cochrane library. Original human studies of more than 2 weeks of PA intervention were included. Study quality was assessed according to the GRADE system of evidence.

RESULTS

Twenty-eight papers fulfilled the inclusion criteria. PA decreases the cytokines, tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), and interferon-y IFN-y (high, moderate and low evidence, respectively). The effect of PA on chemokines; stromal derived factor-1 (SDF-1), interleukin-8 (IL-8) (insufficient evidence) and monocyte chemoattractant protein-1 (MCP-1) (low evidence) was inconclusive. Aerobic exercise decreased the adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) (moderate and high evidence, respectively), while effects of PA on E- and P-selectin were inconclusive. PA decreases C-reactive protein (CRP) (high evidence). The angiogenic actors, endothelial progenitor cells (EPCs) are increased (high evidence) and VEGF is decreased (moderate evidence) by PA. The effect of PA on these factors seems to depend on the type and duration of exercise intervention and patient factors, such as presence of ischemia.

CONCLUSION

As presented in this review, there is a high level of evidence that physical activity positively affects key players in atherosclerosis development. These effects could partly explain the scientifically proven anti-atherogenic effects of PA, and do have important clinical implications.

Exploring relationships among distress, psychological growth, motivation, and physical activity among transplant recipients

PURPOSE

To examine relationships among transplant-specific psychological growth and distress, motivational regulations and health-enhancing physical activity (HEPA) among transplant recipients.

METHODS

Participants (N = 138; Mage = 48 years; 58% male), who were primarily heart, liver, lung, and kidney transplant recipients, completed scientifically-supported questionnaires. The associations among transplant-specific emotional health, motivation, and HEPA were examined in a path model.

RESULTS

In the path model (Χ(2)(3) = 2.12, RMSEA = 0.02, CFI = 0.98, NNFI = 0.97, SRMR = 0.04), distress was significantly related to introjected regulation and psychological growth was associated with autonomous self-regulation (a combined score of identified and intrinsic regulations), which was a significant correlate of HEPA (R(2)= 0.12). There were no significant direct associations between distress, psychological growth, and HEPA.

CONCLUSION

Transplant-specific distress and psychological growth may be factors to target in clinical intervention and rehabilitation. Furthermore, exercise motivation regulations are modifiable factors that relate to HEPA among transplant recipients and could be targeted in the development of rehabilitation strategies aimed at enhancing physical activity in this population.

IMPLICATIONS FOR REHABILITATION

Organ transplant recipients should maintain a healthy lifestyle in order to prevent rejection and other risk factors associated with transplantation. Physical activity is a promising lifestyle factor linked to many health benefits. This study shows how a mix of stress and growth following transplantation is related to physical activity motivation and behavior.

The relationship between physical activity and heart rate variability in orthotopic heart transplant recipients

AIMS AND OBJECTIVES

To investigate the relationship between physical activity and heart rate variability in orthotopic heart transplant recipients, to compare the difference in heart rate variability between patients one year after orthotopic heart transplant and healthy adults matched to the heart transplant recipients in terms of age, gender and physical activity levels.

BACKGROUND

Although physical activity affects the heart rate variability in patients with heart disease, there is a paucity of literature discussing the correlation between physical activity and heart rate variability among heart transplant recipients.

DESIGN

This was a descriptive and cross-sectional study.

METHODS

A total of 120 eligible subjects were divided into the orthotopic heart transplant recipient group (n = 60) and the healthy adult group (n = 60). The Seven-day Physical Activity Recall questionnaire was used to record the subjects' amount of physical activity per week. Heart rate variety parameters were determined by separate frequency domain components.

RESULTS

Results indicated heart transplant recipients' heart rate variety was significantly lower than that of healthy adults in terms of mean, sdr, total power (ms(2)), low frequency (ms(2)), low frequency (nu), high frequency (ms(2)) and low frequency/high frequency. Heart transplant recipients' heart rate variety including total power (ms(2)), low frequency (ms(2)) and high frequency (ms(2)) was 18·2, 2 and 7·2% of healthy controls, respectively; the amount of absolutely and relatively moderate physical activity was positively related to high frequency (ms(2)) and high frequency (nu), but was negatively related to low frequency/high frequency. High frequency (nu) increases while the total amount of weekly physical activity increases.

CONCLUSIONS

Results confirmed that the more the moderate physical activity performed, the better the patient's heart rate variability.

RELEVANCE TO CLINICAL PRACTICE

We suggest that clinical care providers have to encourage heart transplant recipients to engage in moderate physical activity.

Vascular function and the role of oxidative stress in heart failure, heart transplant, and beyond

Using flow-mediated vasodilation (FMD), reactive hyperemia, and an acute oral antioxidant cocktail (AOC; vitamins C and E and α-lipoic acid), this study aimed to provide greater insight into altered vascular function and the role of oxidative stress in chronic heart failure patients with reduced ejection fraction (HFrEF) and at several time points beyond heart transplantation (HTx). A total of 61 age-matched subjects (12 healthy controls, 14 New York Heart Association class II and III HFrEF, and 35 HTx recipients [<3 years post-HTx, 5-10 years post-HTx, and >14 years post-HTx]) ingested either placebo (PL) or an AOC before FMD and reactive hyperemia testing of the brachial artery. Vascular function, as measured by FMD, was not different among the controls (6.8±1.9%), recent <3-year post-HTx group (8.1±1.2%), and the 5- to 10-year post-HTx group (5.5±1.0%). However, PL FMD was lower in the HFrEF (4.5±0.7%) and in the >14-year post-HTx group (2.9±0.8%). The AOC increased plasma ascorbate levels in all of the groups but only increased FMD in the controls (PL, 6.8±1.9%; AOC, 9.2±1.0%) and >14-year post-HTx recipients (PL, 2.9±0.8%; AOC, 4.5±1.3%). There were no differences in reactive hyperemia in any of the groups with PL or AOC. This cross-sectional study reveals that, compared with controls, vascular function is blunted in HFrEF, is similar soon after HTx, but is decreased with greater time post-HTx with free radicals implicated in this progression.

Effects of exercise training in heart transplant recipients: a meta-analysis

OBJECTIVES

Muscle wasting and exercise intolerance are common in heart transplant recipients. Most studies on the effects of exercise training have used relatively small sample sizes and are heterogeneous in nature. The purpose of this meta-analysis was to systematically review the relevant studies and investigate the effects of exercise training on exercise capacity and muscle strength in heart transplant recipients.

METHODS

A systematic search was adopted from electronic databases and relevant references, using medical subject heading key words related to heart transplantation and exercise. Only randomized controlled trials with exercise intervention versus usual care were included. The data were expressed as the weighted mean differences with 95% confidence intervals (CIs).

RESULTS

Altogether 6 studies were included. Peak oxygen consumption (VO(2)) was reported in 4 trials (117 patients), and muscle strength was reported in 3 trials (67 patients). Peak VO(2) was significantly increased by 2.34 ml/kg/min (95% CI 0.63-4.05). One-repetition maxima of the chest press (23.28 kg, 95% CI 0.64-45.91) and leg press (28.84 kg, 95% CI 5.70-51.98) were significantly improved by exercise training.

CONCLUSION

Exercise training is recommended for heart transplant recipients to improve peak VO(2) and muscle strength despite the small number of trials included in this meta-analysis.

Effects of Aerobic Exercise vs. Resistance Training on Endothelial Function in Women with Type 2 Diabetes Mellitus

BACKGROUND

There is controversy over whether aerobic or resistance exercise is more effective for improving endothelial function in type 2 diabetes mellitus (T2DM). This study was aimed to investigate the effects of an aerobic and resistance training program on endothelial function, and the influences of glycemic control, body weight changes, and aerobic capacity in T2DM.

METHODS

Total 40 overweight women with T2DM were assigned into 3 groups: an aerobic exercise group (AEG, n=13), resistance exercise group (REG, n=12), and control group (CG, n=15), and followed either brisk walking for the AEG or resistance band training for the REG, 60 minutes per day, 5 days per week for 12 weeks with monitoring daily activity using accelerometers. We assessed endothelial function by flow-mediated dilation (FMD), and aerobic capacity by oxygen uptake at anaerobic threshold (AT_VO(2)) at baseline and following training program.

RESULTS

The mean participants' age was 57.0±6.8 years, and body mass index (BMI) was 27.0±2.3 kg/m(2). After intervention, FMD increased by 2.2±1.9% in AEG, which differed from REG and CG (P=0.002), despite of decreased body weight (BW) in both AG and RG (2.8±2.5%, P=0.002; 1.6±2.0%, P=0.017, respectively). A significant increased AT_VO(2) and decreased HbA1c were found only in AEG. In all participants, FMD was changed with the significant relations to the AT_VO(2) (r=0.348, P=0.035), but not to HbA1c levels or BW.

CONCLUSION

Aerobic exercise appears to be more beneficial than resistance exercise for improving endothelial function in T2DM. In addition, aerobic capacity could be a better predictor of changes in FMD than BW and glycemic control.

Effect of high intensity exercise on peak oxygen uptake and endothelial function in long-term heart transplant recipients

Coronary allograft vasculopathy is a well-known long-term complication after cardiac transplantation. Endothelial dysfunction is involved and may be prevented by aerobic exercise. The purpose of this study was to examine whether high intensity aerobic exercise improves peak oxygen uptake (VO(2 peak) ) and endothelial function in heart transplant (HT) recipients. Twenty-seven long-term HT recipients were randomized to either 8-weeks high intensity aerobic exercise or no training. Flow mediated dilation of the brachial artery (FMD) was measured by ultrasound and VO(2 peak) by the analysis of expired air. Blood pressure and biomarkers were measured before and after 8 weeks. VO(2 peak) increased significantly in the exercise group (VO(2 peak) 23.9 ± 1.79 to 28.3 ± 1.63 mL/kg/min compared to controls (VO(2 peak) 24.6 ± 1.38 to 23.4 ± 1.58, p < 0.001 exercise vs. control).FMD increased in the exercise group compared to controls (8.3 ± 1.1% to 11.4 ± 1.2% vs. 5.6 ± 1.0% to 5.3 ± 1.7%, p = 0.024). No increase in nitroglycerin-induced vasodilation was observed. Systolic blood pressure fell in the exercise group (142 ±4.2 mmHg to127 ± 3.4 mmHg, p = 0.01) and was unchanged in controls (141 ± 4.2 mmHg to 142 ±6.4 mmHg, NS). High intensity aerobic exercise reduces systolic blood pressure and improves endothelial function in HT recipients.

L-arginine supplementation improves exercise capacity after a heart transplant

BACKGROUND

Endothelial dysfunction is associated with the decreased exercise capacity observed in heart-transplant (HTx) recipients. L-arginine supplementation (LAS) stimulates the nitric oxide (NO) pathway and restores endothelial function.

OBJECTIVE

We compared exercise capacity in healthy subjects and HTx patients and investigated whether chronic LAS might improve exercise capacity and NO/endothelin balance after an HTx.

DESIGN

Clinical, echocardiographic, and exercise characteristics were measured in 11 control subjects and 22 HTx recipients. In a prospective, double-blind study, the 22 HTx recipients performed a 6-min exercise [6-min-walk test (6MWT)] and a maximal bicycle exercise test before and after a 6-wk period of placebo intake or LAS. Endothelial function was measured by analyzing blood NO metabolites, endothelin, and the resulting NO/endothelin balance.

RESULTS

Exercise capacity decreased after transplantation. Unlike with the placebo intake, 6 wk of LAS improved quality of life in HTx recipients (mean +/- SEM Minnesota Score: from 15.3 +/- 1.3 to 10.6 +/- 1.1; P < 0.001) and their submaximal exercise capacity. The distance walked during the 6MWT increased (from 525 +/- 20 to 580 +/- 20 m; P = 0.002), and the ventilatory threshold during the incremental test was delayed by 1.2 min (P = 0.01). Central factors such as resting stroke volume, systolic pulmonary arterial pressure, cardiac systolodiastolic functions, and heart-rate reserve were not modified, but LAS significantly increased the NO:endothelin ratio (from 2.49 +/- 0.38 to 3.31 +/- 0.39; P = 0.03).

CONCLUSION

Oral LAS may be a useful adjuvant therapeutic to improve quality of life and exercise tolerance in HTx recipients.

Impact of inactivity and exercise on the vasculature in humans

The effects of inactivity and exercise training on established and novel cardiovascular risk factors are relatively modest and do not account for the impact of inactivity and exercise on vascular risk. We examine evidence that inactivity and exercise have direct effects on both vasculature function and structure in humans. Physical deconditioning is associated with enhanced vasoconstrictor tone and has profound and rapid effects on arterial remodelling in both large and smaller arteries. Evidence for an effect of deconditioning on vasodilator function is less consistent. Studies of the impact of exercise training suggest that both functional and structural remodelling adaptations occur and that the magnitude and time-course of these changes depends upon training duration and intensity and the vessel beds involved. Inactivity and exercise have direct "vascular deconditioning and conditioning" effects which likely modify cardiovascular risk.

Assessment of peripheral endothelial-dependent vasodilatation within the first year after heart transplantation

BACKGROUND

Peripheral endothelial dysfunction (ED) has been found in patients with severe heart failure. Whether ED improves after heart transplantation (HTx) is still a matter of controversy.

METHODS

Forearm endothelium-dependent vasoreactivity was assessed in 40 patients after HTx. Flow-mediated vasodilatation (FMD) was measured by high-resolution brachial artery ultrasound to assess endothelial function at 1, 6, and 12 months after HTx. Cardiac allograft vasculopathy (CAV) was assessed by coronary angiography at 1 and 12 months and by intravascular ultrasound (IVUS) at 1 year.

RESULTS

Mean FMD at 1 month was 1.9% +/- 2.6%, improving to 3.3% +/- 3.2% at 6 months (p < 0.005) and to 5.1% +/- 3.4% at 1 year (p < 0.0001). FMD was significantly impaired in 33 patients (82%) at 1 month, in 27 (67%) at 6 months, and in 19 (47%) at 1 year after HTx. CAV was diagnosed by IVUS in 19 patients (63%) at 1 year. Patients without peripheral ED at 1 month had lower incidence of increased intimal thickness of 0.5 mm or more at 1 year after HTx (20% vs 75%, p < 0.01).

CONCLUSIONS

Impairment of peripheral FMD was highly prevalent soon after HTx and was present in nearly 50% of patients at 1 year. Patients without peripheral ED at 1 month were associated with lower probability of CAV. Although more studies are needed, the evaluation of peripheral endothelial function at 1 month after HTx could be potentially useful to identify patients at lower risk of CAV.

Standards for the use of cardiopulmonary exercise testing for the functional evaluation of cardiac patients: a report from the Exercise Physiology Section of the European Association for Cardiovascular Prevention and Rehabilitation

Cardiopulmonary exercise testing (CPET) is a methodology that has profoundly affected the approach to patients' functional evaluation, linking performance and physiological parameters to the underlying metabolic substratum and providing highly reproducible exercise capacity descriptors. This study provides professionals with an up-to-date review of the rationale sustaining the use of CPET for functional evaluation of cardiac patients in both the clinical and research settings, describing parameters obtainable either from ramp incremental or step constant-power CPET and illustrating the wealth of information obtainable through an experienced use of this powerful tool. The choice of parameters to be measured will depend on the specific goals of functional evaluation in the individual patient, namely, exercise tolerance assessment, training prescription, treatment efficacy evaluation, and/or investigation of exercise-induced adaptations of the oxygen transport/utilization system. The full potentialities of CPET in the clinical and research setting still remain largely underused and strong efforts are recommended to promote a more widespread use of CPET in the functional evaluation of cardiac patients.

Effects of exercise training on forearm and calf vasodilation and proinflammatory markers in recent heart transplant recipients: a pilot study

BACKGROUND

Aerobic exercise training improves vasodilatory capacity of peripheral resistance vasculature and modifies plasma proinflammatory markers in chronic heart failure patients. It is, however, currently unknown whether aerobic exercise has a similar effect in heart transplant recipients (HTR).

DESIGN AND METHODS

Eight weeks after transplantation, 14 HTR were randomly assigned to 12 weeks of supervised aerobic exercise training (TRAINED; n=8) or attention-time control (CONTROL; n=6) in addition to posttransplantation medical care. Peak forearm blood flow and calf blood flow (CBF) during reactive hyperemia after 5 min of limb ischemia was used as a measure of endothelium-dependent vasodilation of limb resistance arteries. Plasma C-reactive protein, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), soluble intercellular adhesion molecule-1 (sICAM-1), and exercise capacity were measured at baseline and again after 12 weeks in both groups.

RESULTS

Peak CBF increased 22% in the TRAINED (25.9+/-5.8-31.6+/-7.9 ml/min/100 ml, P<0.05), but there was no change in peak CBF after 12 weeks in CONTROL. Plasma C-reactive protein, IL-6, TNF-alpha, sICAM-1 did not change in TRAINED, but there was a significant increase in TNF-alpha (1.66+/-1.02 vs. 3.07+/-1.10 pg/ml, P<0.05), and sICAM-1 (205.9+/-59.1 vs. 245.0+/-47.9 ng/ml, P<0.01) in CONTROL after 12 weeks. Furthermore, exercise test duration improved 51.7% (P<0.01) and there was a trend toward an increase in peak VO2 (P=0.05) in TRAINED after 12 weeks but neither changed in CONTROL.

CONCLUSION

A program of supervised aerobic exercise improves endothelium-dependent vasodilation of the calf, but not forearm resistance arteries, and may attenuate a progressive increase in selected proinflammatory markers in HTR.

Acute effects of a single dose of phosphodiesterase type 5 inhibitor (sildenafil) on systemic arterial blood pressure during exercise and 24-hour ambulatory blood pressure monitoring in heart transplant recipients

BACKGROUND

Arterial systemic hypertension (SH) can be associated with a decrease in endothelium-dependent nitric oxide (NO). Sildenafil increases cyclic guanosine monophosphate (cGMP), a mediator of NO. However, little is known about the effects of PDE5 inhibition on 24-hour ambulatory pressure (ABP) and exercise blood pressure, noreprinephrine (Nor), and exercise capacity, especially after orthotopic heart transplantation (OHT).

METHODS

We studied 22 OHT patients who on the 1st day underwent a cardiopulmonary (CP) self-controlled treadmill 6' walk test (6') and, then, an ECG monitored CP treadmill maximal exercise test (Ex) within 60 and 90 minutes after oral Sildenafil (Sil; 50 mg) or placebo (Pl) given at random, and ABP. We determined at basal position (b), in the last minute of the 6' and at the peak Ex, the HR (bpm), Systolic blood pressure (SBP), and diastolic blood pressure (DBP), (mm Hg), VO2 (mL/kg/min), Slope VE/VCO2, exercise time (ET, min), distance (D; miles), and Nor (pg/mL). Also, after CP tests, 24-h SBP and DBP, the measurements were repeated on the 2nd day when the cross-over was done.

RESULTS

Sil significantly reduced blood pressure in the basal position and during exercise. It also promoted a significant reduction in SBP and DBP during 24 hours, daytime and nighttime. Sil did not change exercise capacity.

CONCLUSION

The NO-cGMP pathway seems to play a role in blood pressure control in OHT. In addition to antihypertensive therapy, PDE5 inhibition may have potential beneficial effects on hypertensive OHT.

Exercise training attenuates progressive decline in brachial artery reactivity in heart transplant recipients

BACKGROUND

Heart transplantation normalizes central hemodynamics, but endothelial dysfunction persists after transplantation.

METHODS

To investigate the effects of aerobic exercise on arterial function, oxidative stress, lipid profile, and sympathetic nervous system activity, 20 heart transplant recipients (age, 54.3 +/- 9.1 years; 17 men, 3 women) were randomly assigned to 12 weeks of supervised treadmill exercise (Trained; n = 10) or standard medical care (Control; n = 10). Supervised exercise was initiated at 8 weeks after transplant. Brachial artery reactivity was assessed using flow-mediated dilation.

RESULTS

The VO2 peak increased 26% in the Trained patients (15.4 +/- 4.3 vs 19.4 +/- 5.5 ml/kg/min; p < or = 0.05) but did not change in the Controls (16.2 +/- 5.2 vs 16.8 +/- 2.8 ml/kg/min; p > or = 0.05). Brachial artery flow-mediated dilation (10.1% +/- 6.1% vs 9.6% +/- 6.2%) and absolute brachial diameter (0.48 +/- 0.22 vs 0.42 +/- 0.24 mm) did not change in Trained patients, but brachial flow-mediated dilation (10.5% +/- 2.8% vs 7.9% +/- 5.1%) and the absolute change in brachial diameter (0.48 +/- 0.16 vs 0.36 +/- 0.24 mm) decreased significantly (p < or = 0.05) in the Control patients. Resting norepinephrine decreased significantly (p < or = 0.05) after training (0.32 +/- 0.19 vs 0.22 +/- 0.22 ng/ml), but there was a nonsignificant trend toward increased norepinephrine in the Controls (0.26 +/- 0.17 vs 0.53 +/- 0.41 ng/ml; p = 0.07). The lipid profile and marker of oxidative stress did not differ between the groups before or after the intervention.

CONCLUSIONS

To our knowledge, this is the first prospective, randomized study to investigate the effects of heart transplantation and aerobic exercise on peripheral artery function in the same cohort of heart transplant recipients. Brachial artery flow-mediated dilation increased early in the post-operative period. Aerobic exercise preserved but did not improve brachial artery flow-mediated dilation. Heart transplant recipients who did not participate in supervised exercise showed a progressive decline in brachial artery flow-mediated dilation.

Comparison of hospital-supervised exercise versus home-based exercise in patients after orthotopic heart transplantation: effects on functional capacity, quality of life, and psychological symptoms

In heart transplant patients it is common to observe a reduced exercise capacity and diminished quality of life. The objective of this study was to compare the effectiveness of a hospital-based exercise program versus that of a home-based exercise program on the functional capacity, quality of life, and psychological symptoms among heart transplant patients.

METHODS

Thirty-eight heart transplant patients were randomly placed into two groups: a hospital-based exercise program (group 1, n = 15) or a home-based exercise program (group 2, n = 13). All patients performed flexibility, stretching, aerobic, strengthening, breathing, and relaxation exercise programs for 8 weeks. We performed estimates of functional capacity (maximal oxygen consumption-pVO2), quality of life (Short Form-36-SF36), and psychological symptoms (Beck Depression Inventory-BDI, the State-Trait Anxiety Inventory-STAI).

RESULTS

In group 1, significant increases were observed in pVO2 and all SF36 subgroups, with the exception of vitality and social function subgroups (P < .05). Significant increases were not observed on the BDI or STAI (P > .05). Group 2 failed to show significant improvements in any variable, with the exception of the score on the bodily pain subgroup of the SF36 (P > .05).

CONCLUSION

Based on our clinical results, we recommend a well-organized exercise program performed in a rehabilitation unit to improve postoperative exercise capacity and quality of life among heart transplant patients.

Six months of aerobic exercise does not improve microvascular function in type 2 diabetes mellitus

AIMS/HYPOTHESIS

Adults with type 2 diabetes mellitus have impaired microvascular function. It has been hypothesised that microvascular function may be restored through regular exercise. The aim of this study was to investigate whether 6 months of regular aerobic exercise would improve microvascular function in adults with type 2 diabetes.

MATERIALS AND METHODS

Fifty-nine patients with type 2 diabetes (32 males, age 62.9+/-7.6 years, HbA(1c) 6.8+/-0.9%) were randomised to either a 6-month aerobic exercise programme (30 min, three times a week, 70-80% of maximal heart rate) or a 'standard care' control group. Before and after the intervention period, microvascular function was assessed as the maximum skin hyperaemia to local heating and endothelial and non-endothelial responsiveness following the iontophoretic application of acetylcholine and sodium nitroprusside. Maximal oxygen uptake, as an index of aerobic fitness, was assessed using a maximal exercise test.

RESULTS

No significant improvement was seen in the exercise group compared with the control group for any of the variables measured: maximal oxygen uptake (control pre: 1.73+/-0.53 [means+/-SD] vs post: 1.67+/-0.40; exercise pre: 1.75+/-0.56 vs post: 1.87+/-0.62 l/min, p=0.10); insulin sensitivity (insulin tolerance test) (control pre: -0.17+/-0.06 vs post: -0.17+/-0.06; exercise pre: -0.16+/-0.1 vs post: -0.17+/-0.07 mmol l(-1) min(-1), p=0.97); maximal hyperaemia (control pre: 1.49+/-0.43 vs post: 1.52+/-0.57; exercise pre: 1.42+/-0.36 vs post: 1.47+/-0.33 V, p=0.85); peak response to acetylcholine (control pre: 1.37+/-0.47 vs post: 1.28+/-0.37; exercise pre: 1.27+/-0.44 vs post: 1.44+/-0.23 V, p=0.19) or to sodium nitroprusside (control pre: 1.09+/-0.50 vs post: 1.10+/-0.39; exercise pre: 1.12+/-0.28 vs post: 1.13+/-0.40 V, p=0.98).

CONCLUSIONS/INTERPRETATION

In this group of type 2 diabetic patients with good glycaemic control a 6-month aerobic exercise programme did not improve microvascular function or aerobic fitness.

A proinflammatory state is detectable in obese children and is accompanied by functional and morphological vascular changes

BACKGROUND

Obesity is generally accepted as a risk factor for premature atherosclerosis. Subclinical inflammation as quantified by blood levels of C-reactive protein (CRP) contributes to the development and progression of atherosclerosis. We hypothesized that inflammation in obese children is related to functional and early morphological vascular changes.

METHODS AND RESULTS

Blood levels of high sensitivity (hs) CRP, hsIL-6, the soluble intercellular adhesion molecule1 (ICAM-1), vascular cell adhesion molecule (VCAM)-1, and E-selectin were measured in 145 severely obese (body mass index [BMI], 32.2+/-5.8 kg/m2) and 54 lean (BMI, 18.9+/-3.2 kg/m2) children 12+/-4 years old. Flow-mediated dilation (FMD) of the brachial artery and carotid intima-media thickness (IMT) measured by high-resolution ultrasound as markers of early vascular changes were assessed in 92 (77 obese and 15 lean) and 59 (50 obese and 9 lean) children, respectively. Obese children had significantly higher levels of hsCRP, hsIL-6, and E-selectin than healthy controls (4.1+/-4.8 versus 0.9+/-1.5 mg/L, P<0.001 for hsCRP; 1.99+/-1.30 versus 1.42+/-1.01 pg/mL, P=0.05 for hsIL-6; and 78+/-38 versus 59+/-29 ng/mL, P=0.01 for E-selectin). There were no differences in the levels of ICAM-1 and VCAM-1 between groups. Obese children had lower peak FMD response (7.70+/-6.14 versus 11.06+/-3.07%, P=0.006) and increased IMT (0.37+/-0.04 versus 0.34+/-0.03 mm, P=0.03) compared with controls. Morbidly obese children (n=14, BMI 44.1+/-3.9 kg/m2) had highest levels of hsCRP (8.7+/-0.7 mg/L), hsIL-6 (3.32+/-1.1 pg/mL), and E-selectin (83+/-40 ng/mL).

CONCLUSIONS

A proinflammatory state is detectable in obese children, which is accompanied by impaired vascular endothelial function and early structural changes of arteries, even in young subjects at risk. It remains to be determined whether high hsCRP in obese children predicts cardiovascular events.

Variability of flow-mediated dilation measurements with repetitive reactive hyperemia

To capture the response of an acute intervention, multiple post intervention measurements of flow-mediated dilation (FMD) must be performed. The effect of repetitive reactive hyperemia on endothelial function and the measurement of FMD are unknown. The purpose of this investigation was (1) to examine the effect of repetitive reactive hyperemia on brachial artery FMD and (2) to determine whether brachial artery FMD is stable during a 2-h morning period. We investigated FMD in 20 apparently healthy college students on three randomized treatment days every 30 min (T30), 60 min (T60), and 120 min (T120) throughout a 2-h morning period (08.00 h to 10.00 h). An ANOVA (p > 0.05) and ICC (> 0.40) were both needed to confirm no difference among repetitive reactive hyperemia treatments. In response to repetitive reactive hyperemia, there was no difference (p = 0.307; ICC > 0.40) within the first and last FMD measurements of each treatment condition or between treatment conditions (p = 0.344; ICC > 0.40). FMD was similar (p = 0.348) throughout the 2-h morning period. In conclusion, repetitive reactive hyperemia over a 2-h period has no effect on FMD measurements in apparently healthy college students. In addition, this study found no time trends for FMD measurements during the 2-h morning period to allow for pre/post intervention FMD measurements.

Exercise training improves low-density lipoprotein oxidability in untrained subjects with coronary artery disease

Exercise training improves low-density lipoprotein oxidability in untrained subjects with coronary artery disease.

OBJECTIVE

To test the hypothesis that regular exercise alters low-density lipoprotein (LDL) oxidability in patients with coronary artery disease.

DESIGN

Longitudinal study.

SETTING

General hospital and community.

PARTICIPANTS

Thirteen patients.

INTERVENTIONS

Training program comprising running bouts twice weekly over 2 months.

MAIN OUTCOME MEASURES

Plasma lipid profile, oxidized LDL, and rate (Ox(rate)) and amount (Ox(amount)) of LDL reaction products were measured at baseline and after 2 months of training. Brachial artery endothelium-dependent and -independent vasodilation was assessed by use of ultrasound.

RESULTS

Lipid profile and oxidized LDL remained unchanged, but mean Ox(rate) and Ox(amount) +/- standard deviation were reduced from 2.5+/-1.5nmol.mgLDL(-1).min(-1) and 120.3+/-75.3nmol/mgLDL at baseline to 0.4+/-0.2nmol.mgLDL(-1).min(-1) and 21.3+/-11.4nmol/mgLDL after training (P<.05), respectively. Brachial artery vasodilation was suggested to be improved, but statistical significance was not reached in the small cohort under study.

CONCLUSIONS

Aerobic training enhances the resistance of LDL to oxidation in patients with coronary artery disease, which may play a role in the favorable effects of exercise.

Adherence to the Therapeutic Regimen in Heart, Lung, and Heart-Lung Transplant Recipients

Optimal outcome after heart, lung, and heart-lung transplantation can only be obtained if patients are supported in adhering to a lifelong therapeutic regimen. The transplant patient's therapeutic regimen consists of a lifelong medication regimen, including immunosuppressive drugs; monitoring for signs and symptoms related to complications; avoidance of risk factors for cardiovascular disease and cancer (ie, diet and exercise prescriptions, nonsmoking); avoidance of abuse/dependence of alcohol or illegal drugs, as well as attending regular clinical checkups. Nonadherence to all aspects of this regimen is substantial. Nonadherence has been related to negative clinical outcome in view of acute rejections, graft vasculopathy, higher costs, and mortality. This review focuses on the prevalence, correlates, and consequences of nonadherence to the therapeutic regimen in heart, lung, and heart-lung transplantation. The current state of the-art on adherence-enhancing interventions is reported. Priorities for future research are outlined.

Time course of physical reconditioning during exercise rehabilitation late after heart transplantation

BACKGROUND

Exercise rehabilitation improves physical capacity in heart transplant recipients. The time course of physical reconditioning and skeletal muscle adaptation late after transplantation are unknown.

METHODS

Twenty-one heart transplant recipients, at 5.2 +/- 2.1 years after transplantation, completed 1 year of an individually tailored home ergometer-training program (2.1 +/- 0.7 sessions weekly with matched heart rates, intensity at 10% below anaerobic threshold). We analyzed time course of physical reconditioning data for each home-training session (n = 2,396). Constant-load tests with consistent blood lactate concentrations were performed quarterly (n = 105) to estimate the time course of skeletal muscle adaptation. Nine heart transplant recipients served as a control group (CG).

RESULTS

After 12 months, exercise capacity for matched heart rates (112 +/- 11 beats/min; CG, 114 +/- 8 beats/min) increased by 35% +/- 19% (from 43 +/- 14 to 58 +/- 18 W; p < 0.001; CG, 53 +/- 18 to 54 +/- 18 W); 24% of the increase was caused by improved skeletal muscle function and 11% by central functioning. Physical reconditioning showed its greatest increase within the first 3 months (+18%; p < 0.001); 50% of the increase consisted of better skeletal muscle or central functioning. Between the 4(th) and 12(th) months, exercise capacity increased continuously (+15%; p < 0.001), mainly because of better skeletal muscle functioning.

CONCLUSIONS

The persistent improvement in exercise capacity along with consistent lactate concentrations during 12 months of training indicates that exercise training could counteract the negative side effects of immunosuppressive treatment on skeletal muscles. Even late after heart transplantation, physical training should be performed regularly to prevent the accelerated decrease in exercise capacity and in skeletal muscle function.

Improving exercise capacity, 6 wk training tends to reduce circulating endothelin after heart transplantation

Short-term survival is no longer the pivotal issue after heart transplantation but, most heart-transplant (Htx) patients still present with increased circulating endothelin-1 (ET) and reduced exercise capacity. ET-1 limits both exercise-induced vasodilation and blood flow redistribution toward acting muscles and might be accessible to training. This study was performed to investigate the effect of training on ET-1 and whether an eventual training-induced improvement in exercise capacity may be related to reduced baseline or exercise circulating ET-1 in Htx patients. Five Htx patients performed a maximal bicycle exercise test and an endurance exercise test before and after a training program of 18 exercises sessions during 6 wk. ET-1 was determined by radioimmunoassay at rest, end endurance exercise and 30 min recovery, before and after training. Training improved significantly Htx's maximal oxygen uptake (+13.1 +/- 4.8%; p < 0.05) and also reduced significantly the endurance exercise-induced heart rate increase. Resting ET-1 was increased in Htx (5.98 +/- 1.88 vs. 1.61 +/- 0.25 pmol/L in controls; p < 0.01) but although ET-1 modulation might participate in training-induced beneficial effects, training failed to modulate either resting or exercise ET-1 plasma level. Training-induced improvement in exercise capacity might not mainly due to decreased ET-1 after heart transplantation. Further supporting the usefulness of training, these preliminary data suggest that improved exercise capacity may not be mainly due to decreased ET-1 in Htx patients. Further, larger scale studies will be needed to investigate whether an impaired nitric oxide pathway stimulation might explain such results and whether a longer training program can reduce local ET-1, arising from working muscles after heart transplantation.

Effect of high-volume and -intensity endurance training in heart transplant recipients

BACKGROUND

A recommended component of heart transplant recipients (HTR) is endurance-oriented exercise therapy. However, the trainability of HTR after transplantation is vague. We examined the effect of high-volume and -intensity exercise training on exercise performance in HTR, compared with HTR undergoing regular rehabilitation training, and sedentary healthy subjects (SHS).

METHODS

We studied four groups of individuals; of those, three groups were HTR. Subjects were a regularly trained HTR group of denervated (HTR-D; N = 15), reinnervated (HTR-R; N = 26) hearts, a high-volume and -intensity endurance-training group (training time 7-20 h.wk(-1); HTR-ET; N = 12), and a group of sedentary healthy subjects (SHS; N = 21). All participants performed cardiopulmonary exercise testing.

RESULTS

The HTR-ET achieved a significantly higher performance (255 +/- 47 W, VO(2max) of 45.2 +/- 6.9 mL.kg(-1).min(-1)) in contrast to all other groups (HTR-D: 119 +/- 17 W, VO(2max) of 17.4 +/- 4.5 mL.kg(-1).min(-1); HTR-R: 119 +/- 17 W, VO(2max) of 16.9 +/- 3.7 mL.kg(-1).min(-1); SHS: 184 +/- 19 W, VO(2max) of 35.0 +/- 6.9 mL.kg(-1).min(-1)). The HR at maximal power output in the HTR-ET was 169 +/- 17 bpm and similar to SHS (164 +/- 17 bpm), but significantly higher than HTR-D (125 +/- 16) and HTR-R (142 +/- 10). Maximal lactate concentration (LAmax) of HTR-ET was 9.9 +/- 2.2 mmol.L(-1), comparable to SHS (9.2 +/- 2.1 mmol.L(-1)), and significantly higher than HTR-D (5.5 +/- 1.5 mmol.L(-1)) and HTR-R (5.1 +/- 1.0 mmol.L(-1)).

CONCLUSIONS

Data suggest that HTR can perform high-volume and -intensity exercise training, reaching exercise performance comparable to or even exceeding values of sedentary or moderately trained healthy subjects.