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

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.

Effectiveness of Exercise-Based Cardiac Rehabilitation for Heart Transplant Recipients: A Systematic Review and Meta-Analysis

Background:

Heart Transplant (HTx) is the ultimate chance of life for end stage Heart Failure (HF). Exercise training has consistently shown the potential to improve functional capacity in various chronic heart diseases. Still, the evidence in HTx recipients is scarcer. This study aims to systematically review the literature to evaluate the effectiveness and safety of Exercise-based Cardiac Rehabilitation (EBCR) in HTx recipients and to identify possible moderators of success.

Methods:

We conducted a systematic review and meta-analysis of randomized controlled trials on the effect and safety of EBCR in adult HTx recipients. The primary outcome was functional capacity, measured by Peak Oxygen Uptake (pVO2). We searched CENTRAL, MEDLINE, Embase, Scopus, and Web of Knowledge databases until December 2020, reviewed references of relevant articles and contacted experts. Usual care (UC), the different dosages of exercise regimens and alternative settings were allowed as comparators. A quantitative synthesis of evidence was performed using random-effects meta-analyses.

Results:

A total of 11 studies with 404 patients were included. Nine studies comprising 306 patients compared EBCR with usual care. They showed that EBCR improved pVO2 compared to usual care (Mean Difference [MD] 3.03 mL/kg/min, 95% CI [2.28-3.77]; I² = 32%). In the subgroup analysis, including length of intervention and timing of enrollment after HTx, no significant moderator was found. Two trials, with 98 patients total, compared High Intensity Interval Training (HIIT) and Moderate Intensity Continuous Training (MICT). HIIT attained a significant edge over MICT (MD 2.23 mL/kg/min, 95% CI [1.79-2.67]; I² = 0%). No major adverse events associated with EBCR were reported.

Conclusion:

We found moderate quality evidence suggesting EBCR has a significant benefit on functional capacity improvement HTx recipients at the short-term. HIIT showed superiority when compared to MICT. Research focusing long term outcomes and standardized protocols are needed to improve evidence on EBCR effectiveness.

Body composition and maximal exercise capacity after heart transplantation

Aims

Maximal exercise capacity as measured by peak oxygen consumption (pVO₂) in cardiopulmonary exercise testing (CPET) of heart transplant recipients (HTR) is limited to a 50–70% level of healthy age‐matched controls. This study investigated the relationship between body composition and pVO₂ during the first decade post‐transplant.

Methods and results

Body composition was determined by dual‐energy X‐ray absorptiometry (DXA) and pVO₂ by CPET in 48 HTR (n = 38 males; mean age 51 ± 12 years). A total of 95 assessments were acquired 1–9 years post‐transplant, and the results of four consecutive periods were compared [Period 1: 1–2 years (n = 25); 2: 3–4 years (n = 23); 3: 5–6 years (n = 23); 4: 7–9 years (n = 24)]. Linear regression analysis analysed the correlation between pVO₂ and pairs of appendicular lean mass (ALM) and fat mass (FM). The relation between ALM and daily dose of calcineurin inhibitor (CNI) was explored using partial correlation controlling for age, gender, and height. pVO₂ increased from 0.98 (0.34) to 1.35 (0.35) L/min (P < 0.01) between Periods 1 and 4 corresponding to 54.5–63.3% of predicted value. Peak heart rate (HR) raised from 115 ± 19 to 131 ± 23 b.p.m. (P = 0.05), and anaerobic threshold (AT = VO₂ achieved at AT) increased from 0.57 (0.18) to 0.83 (0.35) L/min (P < 0.01) between Periods 1 and 3. Median FM normalized to height² (FMI) always remained elevated (>8.8 kg/m²). ALM normalized to body mass index increased from 0.690 (0.188) to 0.848 (0.204) m² (P = 0.02) between Periods 1 and 4, explaining 45% of the variance of pVO₂ (R² = 0.455; P < 0.001). Eighty‐one per cent of the variance of pVO₂ (R² = 0.817; P < 0.001) in multiple regression was explained by AT (β = 0.488), ALM (β = 0.396), peak HR (β = 0.366), and FMI (β = −0.181). ALM was negatively correlated with daily CNI dose (partial R = −0.258; P = 0.01).

Conclusions

After heart transplantation, the beneficial effect of peripheral skeletal muscle gain on pVO₂ is opposed by increased FM. Our findings support lifestyle efforts to fight adiposity and CNI dose reduction in the chronic stable phase to favour positive adaptation of peripheral muscle mass.

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.

Cardiac rehabilitation program improves exercise capacity in heart transplantation recipients regardless of marginal donor factors

Cardiac rehabilitation (CR) is recommended to improve exercise capacity after heart transplantation (HTx); however, the effects of marginal donor factors are unclear. Forty-one recipients participated in a 3-month CR program early after HTx (mean age 39 ± 14 years; 88% male). Patients were divided into marginal (≥ 2 marginal donor factors; n = 24) and control groups (< 2 marginal donor factors; n = 17). We examined donor and recipient factors related to change in peak oxygen uptake (peak VO₂) during the CR program using multiple linear regression analysis. Baseline characteristics were similar between groups, although the mean age was higher in the marginal group (43 ± 13 vs. 34 ± 14 years, p = 0.043). Peak VO₂ and knee extensor muscular strength (KEMS) improved significantly in both groups (p < 0.05), but there were no observed inter-group differences. Multiple analysis revealed change in KEMS (β = 0.52, 95% CI = 0.023-1.01) as an independent predictor of change in peak VO₂ after adjustment for recipients' age, sex, and CR attendance frequency (adjusted R² = 0.25, p = 0.0084), whereas marginal donor factors were not a predictor (p = 0.76). The CR program improved exercise capacity in HTx recipients regardless of marginal donor factors, suggesting that recipients of marginal donor hearts should be referred to CR programs.

Exercise and cardiac health: physiological and molecular insights

The cardiac benefits of exercise have been recognized for centuries. Studies have undisputedly shown that regular exercise is beneficial for the cardiovascular system in young, old, healthy and diseased populations. For these reasons, physical activity has been recommended worldwide for cardiovascular disease prevention and treatment. Although the benefits of exercise are clear, understanding of the molecular triggers that orchestrate these effects remains incomplete and has been a topic of intense research in recent years. Here, we provide a comprehensive review of the cardiac effects of physical activity, beginning with a brief history of exercise in cardiovascular medicine and then discussing seminal work on the physiological effects of exercise in healthy, diseased and aged hearts. Later, we revisit pioneering work on the molecular mechanisms underlying the cardiac benefits of exercise, and we conclude with our view on the translational potential of this knowledge as a powerful platform for cardiovascular disease drug discovery.

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.

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.

Importance of physical capacity and the effects of exercise in heart transplant recipients

One of the most important prognostic factors in heart failure patients is physical capacity. Patients with very poor physical performance and otherwise eligible, may be listed as candidates for heart transplantation (HTx). After such surgery, life-long immunosuppression therapy is needed to prevent rejection of the new heart. The dark side of immunosuppression is the increased risk of infections, kidney failure, cancer and advanced atherosclerosis (cardiac allograft vasculopathy), with the two latter conditions as the main causes of later mortality. In a worldwide perspective, 50% of the HTx patients survive past 10 years. Poor aerobic capacity prior to graft deterioration is not only limited to the failing heart, but also caused by peripheral factors, such as limited function in the skeletal muscles and in the blood vessels walls. Exercise rehabilitation after HTx is of major importance in order to improve physical capacity and prognosis. Effects of high-intensity interval training (HIT) in HTx recipients is a growing field of research attracting worldwide focus and interest. Accumulating evidence has shown that HIT is safe and efficient in maintenance HTx recipients; with superior effects on physical capacity compared to conventional moderate exercise. This article generates further evidence to the field by summarizing results from a decade of research performed at our center supported by a broad, but not strict formal, literature review. In short, this article demonstrates a strong association between physical capacity measured after HTx and long-term survival. It describes the possible “HIT-effect” with increased levels of inflammatory mediators of angiogenesis. It also describes long-term effects of HIT; showing a positive effect in development of anxiety symptoms despite that the improved physical capacity was not sustained, due to downregulation of exercise and intensity. Finally, our results are linked to the ongoing HITTS study, which investigates safety and efficiency of HIT in de novo HTx recipients. Together with previous results, this study may have the potential to change existing guidelines and contribute to a better prognosis for the HTx population as a whole.

Improvements in exercise capacity following cardiac transplantation in a patient born with double inlet left ventricle

A 32-year-old man born with double inlet left ventricle (DILV) and other significant cardiac abnormalities underwent surgical palliation at 1 day, 2 years and 20 years, before receiving a donor heart at 29 years. To our knowledge, there are no case reports or cohort studies of the effect of exercise training on exercise capacity and peak oxygen uptake (VO₂peak) following heart transplantation (HTx) for individuals born with DILV. The patient accessed our clinical exercise physiology service for assessment, advice and support for exercise training over a 7-year period spanning pre-HTx and post-HTx. An individualised exercise plan, together with careful assessment and monitoring, and the patient’s own motivation have contributed to him achieving an outstanding post-HTx doubling of VO₂peak and exercise capacity.

Exercise-based cardiac rehabilitation in heart transplant recipients

BACKGROUND

Heart transplantation is considered to be the gold standard treatment for selected patients with end-stage heart disease when medical therapy has been unable to halt progression of the underlying pathology. Evidence suggests that aerobic exercise training may be effective in reversing the pathophysiological consequences associated with cardiac denervation and prevent immunosuppression-induced adverse effects in heart transplant recipients.

OBJECTIVES

To determine the effectiveness and safety of exercise-based rehabilitation on the mortality, hospital admissions, adverse events, exercise capacity, health-related quality of life, return to work and costs for people after heart transplantation.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO) and Web of Science Core Collection (Thomson Reuters) to June 2016. We also searched two clinical trials registers and handsearched the reference lists of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of parallel group, cross-over or cluster design, which compared exercise-based interventions with (i) no exercise control (ii) a different dose of exercise training (e.g. low- versus high-intensity exercise training); or (iii) an active intervention (i.e. education, psychological intervention). The study population comprised adults aged 18 years or over who had received a heart transplant.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all identified references for inclusion based on pre-specified inclusion criteria. Disagreements were resolved by consensus or by involving a third person. Two review authors extracted outcome data from the included trials and assessed their risk of bias. One review author extracted study characteristics from included studies and a second author checked them against the trial report for accuracy.

MAIN RESULTS

We included 10 RCTs that involved a total of 300 participants whose mean age was 54.4 years. Women accounted for fewer than 25% of all study participants. Nine trials which randomised 284 participants to receive exercise-based rehabilitation (151 participants) or no exercise (133 participants) were included in the main analysis. One cross-over RCT compared high-intensity interval training with continued moderate-intensity training in 16 participants. We reported findings for all trials at their longest follow-up (median 12 weeks).Exercise-based cardiac rehabilitation increased exercise capacity (VO_2peak) compared with no exercise control (MD 2.49 mL/kg/min, 95% CI 1.63 to 3.36; N = 284; studies = 9; moderate quality evidence). There was evidence from one trial that high-intensity interval exercise training was more effective in improving exercise capacity than continuous moderate-intensity exercise (MD 2.30 mL/kg/min, 95% CI 0.59 to 4.01; N = 16; 1 study). Four studies reported health-related quality of life (HRQoL) measured using SF-36, Profile of Quality of Life in the Chronically Ill (PLC) and the World Health Organization Quality Of Life (WHOQoL) - BREF. Due to the variation in HRQoL outcomes and methods of reporting we were unable to meta-analyse results across studies, but there was no evidence of a difference between exercise-based cardiac rehabilitation and control in 18 of 21 HRQoL domains reported, or between high and moderate intensity exercise in any of the 10 HRQoL domains reported. One adverse event was reported by one study.Exercise-based cardiac rehabilitation improves exercise capacity, but exercise was found to have no impact on health-related quality of life in the short-term (median 12 weeks follow-up), in heart transplant recipients whose health is stable.There was no evidence of statistical heterogeneity across trials for exercise capacity and no evidence of small study bias. The overall risk of bias in included studies was judged as low or unclear; more than 50% of included studies were assessed at unclear risk of bias with respect to allocation concealment, blinding of outcome assessors and declaration of conflicts of interest. Evidence quality was assessed as moderate according to GRADE criteria.

AUTHORS' CONCLUSIONS

We found moderate quality evidence suggesting that exercise-based cardiac rehabilitation improves exercise capacity, and that exercise has no impact on health-related quality of life in the short-term (median 12 weeks follow-up), in heart transplant recipients. Cardiac rehabilitation appears to be safe in this population, but long-term follow-up data are incomplete and further good quality and adequately-powered trials are needed to demonstrate the longer-term benefits of exercise on safety and impact on both clinical and patient-related outcomes, such as health-related quality of life, and healthcare costs.

Exercise-based cardiac rehabilitation in heart transplant recipients

BACKGROUND

Heart transplantation is considered to be the gold standard treatment for selected patients with end-stage heart disease when medical therapy has been unable to halt progression of the underlying pathology. Evidence suggests that aerobic exercise training may be effective in reversing the pathophysiological consequences associated with cardiac denervation and prevent immunosuppression-induced adverse effects in heart transplant recipients.

OBJECTIVES

To determine the effectiveness and safety of exercise-based rehabilitation on the mortality, hospital admissions, adverse events, exercise capacity, health-related quality of life, return to work and costs for people after heart transplantation.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCO) and Web of Science Core Collection (Thomson Reuters) to June 2016. We also searched two clinical trials registers and handsearched the reference lists of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of parallel group, cross-over or cluster design, which compared exercise-based interventions with (i) no exercise control (ii) a different dose of exercise training (e.g. low- versus high-intensity exercise training); or (iii) an active intervention (i.e. education, psychological intervention). The study population comprised adults aged 18 years or over who had received a heart transplant.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all identified references for inclusion based on pre-specified inclusion criteria. Disagreements were resolved by consensus or by involving a third person. Two review authors extracted outcome data from the included trials and assessed their risk of bias. One review author extracted study characteristics from included studies and a second author checked them against the trial report for accuracy.

MAIN RESULTS

We included 10 RCTs that involved a total of 300 participants whose mean age was 54.4 years. Women accounted for fewer than 25% of all study participants. Nine trials which randomised 284 participants to receive exercise-based rehabilitation (151 participants) or no exercise (133 participants) were included in the main analysis. One cross-over RCT compared high-intensity interval training with continued moderate-intensity training in 16 participants. We reported findings for all trials at their longest follow-up (median 12 weeks).Exercise-based cardiac rehabilitation increased exercise capacity (VO2peak) compared with no exercise control (MD 2.49 mL/kg/min, 95% CI 1.63 to 3.36; N = 284; studies = 9; moderate quality evidence). There was evidence from one trial that high-intensity interval exercise training was more effective in improving exercise capacity than continuous moderate-intensity exercise (MD 2.30 mL/kg/min, 95% CI 0.59 to 4.01; N = 16; 1 study). Four studies reported health-related quality of life (HRQoL) measured using SF-36, Profile of Quality of Life in the Chronically Ill (PLC) and the World Health Organization Quality Of Life (WHOQoL) - BREF. Due to the variation in HRQoL outcomes and methods of reporting we were unable to meta-analyse results across studies, but there was no evidence of a difference between exercise-based cardiac rehabilitation and control in 18 of 21 HRQoL domains reported, or between high and moderate intensity exercise in any of the 10 HRQoL domains reported. One adverse event was reported by one study.Exercise-based cardiac rehabilitation improves exercise capacity, but exercise was found to have no impact on health-related quality of life in the short-term (median 12 weeks follow-up), in heart transplant recipients whose health is stable.There was no evidence of statistical heterogeneity across trials for exercise capacity and no evidence of small study bias. The overall risk of bias in included studies was judged as low or unclear; more than 50% of included studies were assessed at unclear risk of bias with respect to allocation concealment, blinding of outcome assessors and declaration of conflicts of interest. Evidence quality was assessed as moderate according to GRADE criteria.

AUTHORS' CONCLUSIONS

We found moderate quality evidence suggesting that exercise-based cardiac rehabilitation improves exercise capacity, and that exercise has no impact on health-related quality of life in the short-term (median 12 weeks follow-up), in heart transplant recipients. Cardiac rehabilitation appears to be safe in this population, but long-term follow-up data are incomplete and further good quality and adequately-powered trials are needed to demonstrate the longer-term benefits of exercise on safety and impact on both clinical and patient-related outcomes, such as health-related quality of life, and healthcare costs.

Supervised exercise training versus usual care in ambulatory patients with left ventricular assist devices: A systematic review

Implantation of left ventricular assist devices (LVAD) has increased because of improved safety profile and limited availability of heart transplantation. Although supervised exercise training (ET) programs are known to improve exercise capacity and quality of life (QoL) in heart failure (HF) patients, similar data is inconclusive in LVAD patients. Thus, we performed a systematic review on studies that incorporated supervised ET and measured peak oxygen uptake in LVAD patients. A total of 150 patients in exercise and 55 patients in control groups were included from 8 studies selected from our predefined criteria. Our systematic review suggests supervised ET has an inconsistent effect on exercise capacity and QoL when compared to control groups undergoing usual care. A quantitative sub-analysis was performed with 4 studies that provided enough data to compare peak oxygen uptake and QoL at baseline and at follow-up. After at least 6 weeks of training, LVAD patients undergoing supervised ET demonstrated significant improvement in exercise capacity (standardized mean difference [SMD] = 0.735, 95% Confidence Interval-[CI], 0.31-1.15 units of the standard deviation, P = 0.001) and QoL scores (SMD = 1.58, 95% CI 0.97-2.20 units of the standard deviation, P <0.001) when compared to the usual care group, with no serious adverse events with exercise. These results suggest that supervised ET is safe and can improve patient outcomes in LVAD patients when compared to the usual care.

Association Between Early Cardiac Rehabilitation and Long-term Survival in Cardiac Transplant Recipients

OBJECTIVE

To determine whether participation in early cardiac rehabilitation (CR) after heart transplant (HTx) affects long-term survival.

PATIENTS AND METHODS

A retrospective review was conducted in 201 patients who underwent HTx at Mayo Clinic between June 1, 2000, and July 31, 2013. Patients were excluded with multiorgan transplant, no CR data, and follow-up less than 90 days after HTx. Demographic and exercise data at baseline before HTx were collected. Post-HTx exercise capacity, biopsy, CR data, and medications were collected at 1 through 5 and 10 years.

RESULTS

Overall survival at 1, 5, and 10 years was 98%, 88%, and 82%, respectively; 29 patients died. Number of CR sessions attended in the first 90 days after HTx predicted survival in multivariate regression, controlling for baseline post-HTx 6-minute walk test (6MWT) results and rejection episodes (hazard ratio, 0.90; 95% CI, 0.82-0.97; P=.007). Additional univariate predictors of survival included pre-HTx 6MWT results, weight at HTx, and body mass index and systolic blood pressure at CR enrollment. Pre-HTx 6MWT results, body mass index, and post-HTx were associated with improvement in peak oxygen consumption.

CONCLUSION

This report demonstrates, for the first time, an association between CR and long-term survival in patients after HTx. Further work should clarify the most beneficial aspects of CR.

Design and rationale of the HITTS randomized controlled trial: Effect of High-intensity Interval Training in de novo Heart Transplant Recipients in Scandinavia

There is no consensus on how, when, and at what intensity exercise should be performed and organized after heart transplantation (HTx). Most rehabilitation programs are conducted in HTx centers, which might be impractical and costly. We have recently shown that high-intensity interval training (HIT) is safe, well tolerated, and efficacious in maintenance HTx recipients, but there are no studies among de novo patients, and whether HIT is feasible and superior to moderate training in HTx recipients is unclear. A total of 120 clinically stable HTx recipients older than 18 years will be recruited from 3 Scandinavian HTx centers. Participants are randomized to HIT or moderate training, shortly after surgery. All exercises are supervised in the patients' local communities. Testing at baseline and follow-up includes the following: VO2peak (primary end point), muscle strength, body composition, quality of life, myocardial performance, endothelial function, biomarkers, and progression of cardiac allograft vasculopathy. A subgroup (n = 90) will also be tested at 3-year follow-up to assess long-term effects of exercise. So far, the HIT intervention is well tolerated, without any serious adverse events. We aim to test whether decentralized HIT is feasible, safe, and superior to moderate training, and whether it will lead to significant improvement in exercise capacity and less long-term complications.

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.

Effect of high-intensity training versus moderate training on peak oxygen uptake and chronotropic response in heart transplant recipients: a randomized crossover trial

In heart transplant (HTx) recipients, there has been reluctance to recommend high-intensity interval training (HIIT) due to denervation and chronotropic impairment of the heart. We compared the effects of 12 weeks' HIIT versus continued moderate exercise (CON) on exercise capacity and chronotropic response in stable HTx recipients >12 months after transplantation in a randomized crossover trial. The study was completed by 16 HTx recipients (mean age 52 years, 75% males). Baseline peak oxygen uptake (VO2peak ) was 22.9 mL/kg/min. HIIT increased VO2peak by 4.9 ± 2.7 mL/min/kg (17%) and CON by 2.6 ± 2.2 mL/kg/min (10%) (significantly higher in HIIT; p < 0.001). During HIIT, systolic blood pressure decreased significantly (p = 0.037) with no significant change in CON (p = 0.241; between group difference p = 0.027). Peak heart rate (HRpeak ) increased significantly by 4.3 beats per minute (p = 0.014) after HIIT with no significant change in CON (p = 0.34; between group difference p = 0.027). Heart rate recovery (HRrecovery ) improved in both groups with a trend toward greater improvement after HIIT. The 5-month washout showed a significant loss of improvement. HIIT was well tolerated, had a superior effect on oxygen uptake, and led to an unexpected increase in HRpeak accompanied by a faster HRrecovery . This indicates that the benefits of HIIT are partly a result of improved chronotropic response.

Association of depression symptoms with quality of life and chronic artery vasculopathy: a cross-sectional study in heart transplant patients

OBJECTIVE

Depression represents a relevant co-morbidity in patients with chronic heart disease and may diminish the overall success for long-term survival after heart transplantation (HTx). This study aimed to assess the prevalence of depression symptoms in long-term HTx survivors, and to compare depressive patients to those without depression with respect to chronic artery vasculopathy (CAV).

METHODS

A sample of 203 HTx patients, median 11.5 (IQR 7-17) years after transplant, provided detailed data of depression symptoms, and other psychosocial symptoms including anxiety, family support, professional re-integration, and health-related quality of life (HRQoL). Data were analyzed for an association with CAV.

RESULTS

Overall, 14.8% patients (95% CI: 10.2-20.4) showed relevant depression symptoms. No significant differences were seen between non-depressed vs. depressed patients with respect to demographics, clinical variables, and cardiovascular risk factors. Anxiety was prevalent in 9.0% (95% CI: 5.4-13.9) of the sample. Depression symptoms showed impaired HRQoL in the SF-36 physical (P=.012) and psychosocial (P=.0001) components. CAV was prevalent in 34.0% (95% CI: 27.5-41.0), and depression symptoms and CAV were not significantly associated. CAV-patients did not report their physical HRQoL being lower relative to those without CAV (P=.40). Multivariate analysis revealed overweight BMI (OR=2.20; P=.04), longer time since transplant (OR=1.10; P=.001), and older age (OR=1.04; P=.01) being associated with CAV.

CONCLUSION

Depression symptoms are prevalent in long-term survivors after HTx, and psychological impairments decrease patients' perceptions of HRQoL. More research seems necessary to identify the inter-relationship between depression symptoms and CAV, in order to develop targeted interventions to overcome this problem.

Exercise after heart transplantation: An overview

While life expectancy is greatly improved after a heart transplant, survival is still limited, and compared to the general population, the exercise capacity and health-related quality of life of heart transplant recipients are reduced. Increased exercise capacity is associated with a better prognosis. However, although several studies have documented positive effects of exercise after heart transplantation (HTx), little is known about the type, frequency and intensity of exercise that provides the greatest health benefits. Moreover, the long-term effects of exercise on co-morbidities and survival are also unclear. Exercise restrictions apply to patients with a denervated heart, and for decades, it was believed that the transplanted heart remained denervated. This has since been largely disproved, but despite the new knowledge, the exercise restrictions have largely remained, and up-to-date guidelines on exercise prescription after HTx do not exist. High-intensity, interval based aerobic exercise has repeatedly been documented to have superior positive effects and health benefits compared to moderate exercise. This applies to both healthy subjects as well as in several patient groups, such as patients with metabolic syndrome, coronary artery disease or heart failure. However, whether the effects of this type of exercise are also applicable to heart transplant populations has not yet been fully established. The purpose of this article is to give an overview of the current knowledge about the exercise capacity and effect of exercise among heart transplant recipients and to discuss future exercise strategies.

Effects of an acute, outpatient physiotherapy exercise program following pediatric heart or lung transplantation

This prospective interventional study investigated the impact of a three-month, ambulatory HA or HB, semi-individualized, PT-prescribed exercise program following pediatric HTx or LTx. SMW distance, strength, and flexibility were assessed at start and completion of the program and one yr after enrollment. Subjects received either an HB or HA exercise program three times per week. The cohort demonstrated clinically and statistically significant improvements in SMW distances at three months (425.7 ± 109.4-500.6 ± 93.6 m, p < 0.001) and at one yr (528.5 ± 66.6 m, p = 0.001), although there was no difference between the two groups at any time. Similar improvements were also observed in strength and flexibility measures. Correlates with higher SMW distance at three months and one yr included older age, male gender, and underlying diagnosis other than CHD. Male gender and diagnosis other than CHD were associated with a slower improvement in the SMW distance. This is the first report of institutionally based, outpatient exercise rehabilitation in the recovery following pediatric thoracic transplantation. We found similar improvements to HB interventions up to one yr after surgery. Further study of the role of exercise rehabilitation and long-term fitness outcomes is needed.

One year of high-intensity interval training improves exercise capacity, but not left ventricular function in stable heart transplant recipients: a randomised controlled trial

BACKGROUND

Heart transplant recipients have lower exercise capacity and impaired cardiac function compared with the normal population. High-intensity interval training (HIIT) improves exercise capacity and cardiac function in patients with heart failure and hypertension, but the effect on cardiac function in stable heart transplant recipients is not known. Thus, we investigated whether HIIT improved cardiac function and exercise capacity in stable heart transplant recipients by use of comprehensive rest- and exercise-echocardiography and cardiopulmonary exercise testing.

DESIGN AND METHODS

Fifty-two clinically stable heart transplant recipients were randomised either to HIIT (4 × 4 minutes at 85-95% of peak heart rate three times per week for eight weeks) or to control. Three such eight-week periods were distributed throughout one year. Echocardiography (rest and submaximal exercise) and cardiopulmonary exercise testing were performed at baseline and follow-up.

RESULTS

One year of HIIT increased VO 2peak from 27.7 ± 5.5 at baseline to 30.9 ± 5.0 ml/kg/min at follow-up, while the control group remained unchanged (28.5 ± 7.0 vs. 28.0 ± 6.7 ml/kg per min, p < 0.001 for difference between the groups). Systolic and diastolic left ventricular functions at rest and during exercise were generally unchanged by HIIT.

CONCLUSIONS

Whereas HIIT is feasible in heart transplant recipients and effectively improves exercise capacity, it does not alter cardiac systolic and diastolic function significantly. Thus, the observed augmentation in exercise capacity is best explained by extra-cardiac adaptive mechanisms.

Factors associated with low physical activity levels following pediatric cardiac transplantation

BACKGROUND

Objectively measured MVPA levels following pediatric cardiac transplantation are unknown despite physical health implications. We sought to determine factors associated with MVPA in a pediatric cohort who had undergone cardiac transplantation.

METHODS

Study assessments included maximal exercise testing (VO(2) max), accelerometry, and physical activity (HAES) and functional health status (CHQ-PF50) questionnaires.

RESULTS

Participants (n = 20, 60% male, age: 11.8 ± 3.0 yr old) had a VO(2) max of 28.5 ± 6.8 mL/kg/min (%-predicted: 65 ± 14%) and maximal heart rate of 154 ± 16 beats/min (%-predicted: 73 ± 7.5%). Participants performed a median of 7.6 min/day (Q1 4.0 min/day, Q3 11.0 min/day) of MVPA. Each additional year of age at transplantation was associated with a decrease of 1.9 [1.0] min/day of MVPA (p = 0.07). Predicted VO(2) max, maximal power output, male sex, and age at study enrollment were not associated with an increase in MVPA. Parents' perception of their child's functional health status (CHQ-PF50) was lower on general health (p < 0.01) and family activity (p < 0.01) domains relative to a population-based cohort of parents reporting on healthy children.

CONCLUSION

Pediatric cardiac transplantation recipients may be indicated to participate in cardiac rehabilitation to optimize physical activity levels.

High-intensity interval training improves peak oxygen uptake and muscular exercise capacity in heart transplant recipients

Heart transplant (HTx) recipients usually have reduced exercise capacity with reported VO(2peak) levels of 50-70% predicted value. Our hypothesis was that high-intensity interval training (HIIT) is an applicable and safe form of exercise in HTx recipients and that it would markedly improve VO(2peak.) Secondarily, we wanted to evaluate central and peripheral mechanisms behind a potential VO(2peak) increase. Forty-eight clinically stable HTx recipients >18 years old and 1-8 years after HTx underwent maximal exercise testing on a treadmill and were randomized to either exercise group (a 1-year HIIT-program) or control group (usual care). The mean ± SD age was 51 ± 16 years, 71% were male and time from HTx was 4.1 ± 2.2 years. The mean VO(2peak) difference between groups at follow-up was 3.6 [2.0, 5.2] mL/kg/min (p < 0.001). The exercise group had 89.0 ± 17.5% of predicted VO(2peak) versus 82.5 ± 20.0 in the control group (p < 0.001). There were no changes in cardiac function measured by echocardiography. We have demonstrated that a long-term, partly supervised and community-based HIIT-program is an applicable, effective and safe way to improve VO(2peak) , muscular exercise capacity and general health in HTx recipients. The results indicate that HIIT should be more frequently used among stable HTx recipients in the future.

Health-related quality of life and exercise tolerance in recipients of heart transplants and left ventricular assist devices: a prospective, comparative study

BACKGROUND

The aim of this study was to evaluate and compare health-related quality of life (HRQoL) and physical exercise tolerance in patients after heart transplantation (HTx) or implantation of a left ventricular assist device (LVAD).

METHODS

A prospective, comparative design was used to characterize changes over time in HRQoL (SF-36) and exercise tolerance in patients after HTx (n = 54) and during LVAD support (n = 36). Nine LVAD patients were lost for follow-up. The majority of patients in both groups were male (97%); the LVAD cohort tended to be younger (p = 0.06).

RESULTS

HRQoL improved significantly in HTx patients in the SF-36 physical (p = 0.02), but not in the psychosocial (p = 0.27) component score during follow-up. In the LVAD group, HRQoL showed improvements for both the SF-36 physical and psychosocial component scores (both p = 0.04). Between-group comparisons revealed better HRQoL for the HTx cohort than the LVAD cohort for 2 of 8 SF-36 subscales. Age-, gender- and body mass index (BMI)-adjusted exercise tolerance (workload; VO(2max)) showed significant improvements for both HTx (p = 0.01) and LVAD (p = 0.01) patients. Adjusted maximum oxygen consumption was higher for HTx patients (p = 0.05) relative to LVAD patients at 8 ± 1 months after implant.

CONCLUSION

HRQoL and exercise capacity increased in both groups over the time-course of the study. After adjusting for relevant variables, HTx patients showed a higher exercise tolerance compared with the LVAD group during follow-up. Thus, future large-scale intervention studies should emphasize the specific needs of these patient cohorts.

The current status of heart transplantation and the development of "artificial heart systems"

BACKGROUND

In view of the major technical advances in ventricular assist devices (VAD) in recent years, the authors discuss the question whether these "artificial hearts" are still no more than a temporary measure for patients awaiting heart transplantation (HTx), or whether they can already be used as an independent form of long-term treatment.

METHODS

Statistics from Eurotransplant regarding heart transplantations and transplant waiting lists in Germany are presented. Technical developments in cardiac support systems, the variation in results depending on the indication, and the findings with respect to quality of life are all discussed on the basis of a selective review of the literature and the authors' own clinical experience.

RESULTS

The waiting list for heart transplantation in Germany has grown to a record size of nearly 800 patients, while fewer than 400 hearts are transplanted each year. Technical advances have improved outcomes in VAD therapy, but the outcome depends on the patient's preoperative condition. The physical performance of patients who have received VAD is comparable to that of HTx patients; nonetheless, HTx patients have a better quality of life.

CONCLUSIONS

Chronic VAD therapy has become a clinical reality. Because of the greater number of patients awaiting HTx, many will not receive their transplants in time. When the decision to treat with VAD is made early, it can be used as an alternative form of treatment with a comparable one-year survival (>75%).

Health-enabling technologies for pervasive health care: on services and ICT architecture paradigms

BACKGROUND

Progress in information and communication technologies (ICT) is providing new opportunities for pervasive health care services in aging societies.

OBJECTIVES

To identify starting points of health-enabling technologies for pervasive health care. To describe typical services of and contemporary ICT architecture paradigms for pervasive health care.

METHODS

Summarizing outcomes of literature analyses and results from own research projects in this field.

RESULTS

Basic functions for pervasive health care with respect to home care comprise emergency detection and alarm, disease management, as well as health status feedback and advice. These functions are complemented by optional (non-health care) functions. Four major paradigms for contemporary ICT architectures are person-centered ICT architectures, home-centered ICT architectures, telehealth service-centered ICT architectures and health care institution-centered ICT architectures.

CONCLUSIONS

Health-enabling technologies may lead to both new ways of living and new ways of health care. Both ways are interwoven. This has to be considered for appropriate ICT architectures of sensor-enhanced health information systems. IMIA, the International Medical Informatics Association, may be an appropriate forum for interdisciplinary research exchange on health-enabling technologies for pervasive health care.

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.

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.