High-intensity interval training and health-related quality of life in de novo heart transplant recipients - results from a randomized controlled trial.

BACKGROUND: Studies on the effect of high-intensity interval training (HIT) compared with moderate intensity continuous training (MICT) on health-related quality of life (HRQoL) after heart transplantation (HTx) is scarce. No available studies among de novo HTx recipients exists. This study aimed to investigate the effect of HIT vs. MICT on HRQoL in de novo recipients. METHODS: The HITTS study randomized eighty-one de novo HTx recipients to receive either HIT or MICT (1:1). The HIT intervention were performed with 2-4 interval bouts with an intensity of 85-95% of maximal effort. The MICT group exercised at an intensity of 60-80% of their maximal effort with a duration of 25 min. HRQoL was assessed by the Short Form-36 version 2 (SF-36v2) and the Hospital Anxiety and Depression Scale, mean 11 weeks after surgery and after a nine months' intervention. The participants recorded their subjective effect of the interventions on their general health and well-being on a numeric visual analogue scale. Clinical examinations and physical tests were performed. Differences between groups were investigated with independent Student t-tests and with Mann-Whitney U tests where appropriate. Within-group differences were analyzed with Paired-Sample t-tests and Wilcoxon Signed Rank tests. Correlations between SF-36 scores and VO2peak were examined with Pearson's correlations. RESULTS: Seventy-eight participants completed the intervention. Both exercise modes were associated with improved exercise capacity on the physical function scores of HRQoL. Mental health scores remained unchanged. No differences in the change in HRQoL between the groups occurred except for Role Emotional subscale with a larger increase in the HIT arm. Better self-reported physical function was associated with higher VO2peak and muscle strength. CONCLUSION: HIT and MICT resulted in similar mean changes in HRQoL the first year after HTx. Both groups experienced significant improvements in the physical SF-36v2. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT01796379 Registered 18 February 2013.

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.

Interval training does not modulate diastolic function in heart transplant recipients.

OBJECTIVES: This study investigates the effect of aerobic interval training on diastolic function at rest and during exercise in stable heart transplant (HTx) recipients. DESIGN: Twenty-three stable HTx recipients (74% males, mean age 50 ± 14.9 years) were recruited to a training programme. Intervention was 8 weeks intensive training or control in a randomized controlled design. RESULTS: At baseline, participants had normal or mild diastolic dysfunction at rest. During exercise, mean E/e' increased from 9.0 (± 2.8) to 12.8 (± 7.7) (p = 0.09), E/A increased from 2.1 (± 0.6) to 2.6 (± 0.7) (p = 0.02), and deceleration time decreased by over 50 ms, all markers of increased filling pressure. There were no correlations between diastolic function and VO 2 peak at baseline. After intervention VO 2 peak increased from 23.9 (± 4.5) to 28.3(± 6) ml/kg/min in the training group (difference between groups p = 0.0018). No consistent pattern of improvement in diastolic function at rest or during exercise was seen. CONCLUSION: The study does not support a role of diastolic dysfunction in the limited exercise capacity of HTx recipients and suggests that in these patients peripheral factors are of greater importance.

Effect of High-Intensity Interval Training on Inhaled Corticosteroid Dose in Asthma Patients: A Randomized Controlled Trial.

BACKGROUND: Inhaled corticosteroids (ICS) are the cornerstone of asthma treatment. However, ICS has side effects, and dose reduction is recommended when possible. Physical exercise improves asthma control, but it is unknown whether it reduces the reliance on ICS. OBJECTIVE: To assess whether supervised high-intensity interval training reduces the need for ICS in untrained asthma patients. METHODS: An assessor-blinded single-center randomized controlled trial, Copenhagen, Denmark. One hundred fifty untrained ICS-treated adults with symptomatic asthma were randomly assigned (2:1) to 6 months of supervised exercise 3 times weekly or a lifestyle as usual control group. Every second month, a clinical algorithm based on symptom control was applied in both groups to adjust ICS dose. Primary outcome was the proportion who had their ICS dose reduced by 25% or more after 6 months. Secondary outcomes included actual ICS dosage in micrograms per day. RESULTS: Between October 2017 and December 2019, 102 patients were allocated to exercise intervention (86% completed) and 48 to the control (85% completed). At the 6-month visit, 63% versus 50% met the primary outcome in the exercise and control groups, respectively (adjusted risk difference 9.6% [95% CI -3.8 to 18.8]; P = .15). Daily ICS dose was reduced in favor of the exercise group, with a mean difference of -234 µg (95% CI -391 to -77; P = .0037), corresponding to a 24% reduction from baseline. This effect was sustained at 12 months. The intervention was safe and well tolerated. CONCLUSIONS: Six months of regular exercise results in reduction in daily ICS dose without compromising asthma control.

Clinical features and determinants of VO2peak in de novo heart transplant recipients.

AIM: To study exercise capacity and determinants of early peak oxygen consumption (VO2peak) in a cohort of de novo heart transplant (HTx) recipients. METHODS: To determine possible central (chronotropic responses, cardiopulmonary and hemodynamic function) and peripheral factors (muscular exercise capacity and body composition) predictive of VO2peak, a number of different measurements and tests were performed, as follows: Cardiopulmonary exercise testing (CPET) was performed mean 11 wk after surgery in 81 HTx recipients > 18 years and was measured with breath by breath gas exchange on a treadmill or bicycle ergometer. Metabolic/respiratory measures include VO2peak and VE/VCO2 slope. Additional measures included muscle strength testing, bioelectrical impedance analysis, echocardiography, blood sampling and health-related quality of life. Based on the VO2peak (mL/kg per minute) median value, the study population was divided into two groups defined as a low-capacity group and a high-capacity group. Potential predictors were analyzed using multiple regression analysis with VO2peak (L/min) as the dependent variable. RESULTS: The mean ± standard deviation (SD) age of the total study population was 49 ± 13 years, and 73% were men. This de novo HTx cohort demonstrated a median VO2peak level of 19.4 mL/kg per min at 11 ± 1.8 wk post-HTx. As compared with the high-capacity group, the low-capacity group exercised for a shorter time, had lower maximal ventilation, O2 pulse, peak heart rate and heart rate reserve, while the VE/VCO2 slope was higher. The low-capacity group had less muscle strength and muscular exercise capacity in comparison with the high-capacity group. In order of importance, O2 pulse, heart rate reserve, muscular exercise capacity, body mass index, gender and age accounted for 84% of the variance in VO2peak (L/min). There were no minor or major serious adverse events during the CPET. CONCLUSION: Although there is great individual variance among de novo HTx recipients, early VO2peak measures appear to be influenced by both central and peripheral factors.

Effect of moderate- versus high-intensity exercise on vascular function, biomarkers and quality of life in heart transplant recipients: A randomized, crossover trial.

BACKGROUND: Growing evidence in long-term treatment of heart transplant (HTx) recipients indicates effects of high-intensity interval training (HIIT) on several parameters, including oxygen uptake, vascular function and psychological distress. In this study we compare the effect of HIIT vs continued moderate training (CON) on vascular function, biomarkers and health-related quality of life (HRQoL) in HTx recipients. METHODS: A randomized, controlled crossover trial of stable HTx recipients >12 months after transplantation was done on patients with 12 weeks of HIIT or 12 weeks of CON, followed by a 5-month washout and crossover. Outcomes included endothelial function, arterial stiffness, biomarkers, HRQoL and markers of anxiety and depression. RESULTS: Sixteen HTx recipients (mean age 52 years, 75% male) completed the study. HIIT increased VO(2peak) more than CON (between-group difference, p < 0.001). The physical component score of the 36-item Short Form (SF-36) was increased significantly in HIIT patients (p = 0.02) and borderline increased in CON patients (p = 0.07), whereas there was no significant effect of exercise on the mental component. Depression score decreased significantly in HIIT patients (p = 0.04) with no change in CON patients (p = 0.75), whereas anxiety score decreased significantly in both HIIT (p < 0.01) and CON (p < 0.05) patients. There were no between-group differences in any of the measures (all p > 0.05). Arterial stiffness and biomarkers were not changed, nor did endothelial function change after HIIT (p = 0.08) or CON (p = 0.68). CONCLUSIONS: HIIT and CON are both well tolerated and induce similar improvements in physical components of HRQoL and in markers of anxiety. Effects of either training modality on vascular function and biomarkers could not be confirmed.