High-Intensity Interval Training Improves Peak Oxygen Uptake and Muscular Exercise Capacity in Heart Transplant Recipients

Abstract

Heart transplant (HTx) recipients usually have reduced exercise capacity with reported VO 2peak levels of 50-70% predicted value. Our hypothesis was that highintensity 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.Key words: Aerobic exercise, chronotropic response, heart transplantation, maximum oxygen uptake, muscle strength, VO 2peak Abbreviations: % HR max , percent of age-predicted maximum heart rate; AT, anaerobic threshold (ventilatory threshold); BIA, bioelectrical impedance analysis; CG, control group; CO, cardiac output; CRI, chronotropic response index; CRP, C-reactive protein; DXA, dual-emission X-ray absorptiometry; EG, exercise group; eGFR, estimated glomerular filtration rate; Hb, hemoglobin; HF, heart failure; HIIT, high-intensity interval training; HR, heart rate; HR max , maximum heart rate; HRQoL, health-related quality of life; HTx, heart transplant; J, Joule; LV, left ventricle; LVe', left ventricle early diastolic mitral annular velocity; LVEF, left ventricle ejection fraction; Nm, Newtonmeter; NT-proBNP, N-terminal prohormone of brain natriuretic peptide; RER, respiratory exchange ratio; RPE, rated perceived exertion; VAS scale, visual analog scale; VE max , maximum ventilation; VO 2peak , peak oxygen uptake.

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

“…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.…”

“…VO2peak is frequently used as the primary outcome measure in exercise intervention studies after HTx (15). Carter et al(17), Dall et al(18), Ewert et al(19), Givertz et al(20), Gullestad et al(21), Habedank et al(22), Haykowski et al (23), Hermann et al(24), Hognestad et al(25), Karpolat et al(26), Kavanagh et al(27), Kemp et al(28), Kobashigawa et al(29), Nytrøen et al (30), Osada et al(12), Renlund et al(31), Schwaiblmair et al(32), Squires et al(33), Tegtbur et al(34), Wu et al(35).…”

“…peripheral factors as the main mechanisms; by improvement in skeletal muscle exercise capacity (30), endothelial function and vasodilatation (24), rather than an increased CO (51).…”

Trening etter hjertetransplantasjon – gamle prinsipper for fall

“…Siden 2009 er det publisert tre studier av høyin-tensiv intervalltrening hos hjertetransplanterte, der alle viste overlegne resultater sammenliknet med kontrollgrupper og hva som tidligere er vist ved annen type trening (10)(11)(12). Ingen av studiene har rapportert om uønskede hendelser i forbindelse med den intensive treningen.…”