Effect of High-Intensity Training Versus Moderate Training on Peak Oxygen Uptake and Chronotropic Response in Heart Transplant Recipients: A Randomized Crossover Trial

Abstract

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 (VO 2peak ) was 22.9 mL/kg/min. HIIT increased VO 2peak by 4.9 AE 2.7 mL/min/kg (17%) and CON by 2.6 AE 2.2 mL/ kg/min (10%) (significantly higher in HIIT; p < 0.001). During HIIT, systolic blood pressure decreased significantly (p ¼ 0.037) with no significant change in CON (p ¼ 0.241; between group difference p ¼ 0.027). Peak heart rate (HR peak ) increased significantly by 4.3 beats per minute (p ¼ 0.014) after HIIT with no significant change in CON (p ¼ 0.34; between group difference p ¼ 0.027). Heart rate recovery (HR recovery ) 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 HR peak accompanied by a faster HR recovery . This indicates that the benefits of HIIT are partly a result of improved chronotropic response.Abbreviations: absolute VO 2peak , peak oxygen uptake (mL/min); bpm, beats per minute; CON, continued moderate exercise; DBP, diastolic blood pressure; HIIT, high-intensity interval training; HR, heart rate; HR peak , peak heart rate; HR recovery , heart rate recovery; HR reserve , heart rate reserve; HR rest , resting heart rate; HTx, heart transplant; RER, respiratory exchange ratio; SBP, systolic blood pressure; SET, strength and endurance training; VO 2peak , peak oxygen uptake (mL/min/kg)

Peak oxygen uptake and self‐reported physical health are strong predictors of long‐term survival after heart transplantation

“…This beneficial trend in anxiety development together with no negative trends in other secondary end points, support the statements of HIT as a safe exercise modality in HF patients (99), and in maintenance HTx patients (18,24,30). The long-term difference in anxiety between the HIT group and the control group is considered a valuable finding, as anxiety is a frequent health issue after HTx, especially in the long-term follow-up (67).…”

“…These results are recently mentioned in the updated recommendations from 2013 (45). As well as the increase in exercise capacity, the HIT group also improved their chronotropic response index (CRI) (18,30), endothelial function (24) and had less CAV development after a long-term exercise intervention (46).…”

“…The chronotropic incompetence is most prominent the first months after HTx and tends to be largely normalized in the majority of patients after 12 months (44) as illustrated in figure 4 (unpublished data). Recent randomized controlled trials (RCT), have investigated the effect of HIT in the maintenance HTx recipients and have to a large extend overruled the traditional approach with MICT (18,24,30). These studies showed that HIT increased VO2peak significantly compared to the control groups, and that a HIT intervention was safe and well tolerated.…”

“…While HIT already is an established exercise modality in patients with HF (37) and CAD (38), and more recently in maintenance HTx (18,24,30), the upcoming results from the HITTS study will contribute to fill the gap of knowledge related to the effect of HIT among de novo HTx recipients. In addition to exercise capacity measurement, other important secondary outcomes are; development of CAV, improvements in chronotropic response and changes in cardiac and endothelial function.…”

Dynamic of Physical Capacity and Quality of Life After Heart Transplantation

“…Более того, одним из факторов, влияющих на динамику ЧСС, является регулярное выполнение ФН в связи с улучшением хронотропного ответа [27]. Наши дан-ные показали, что через 1 год после ТС ЧСС на пике ФН у физически активных пациентов была выше, чем у ведущих сидячий образ жизни.…”