The 70 year Odyssey of exercise training based cardiac rehabilitation with respect to medical innovations in heart failure.

Exercise training (ET) based cardiac rehabilitation (ExCR) is considered as a ‘pillar’ of heart failure (HF) management, alongside drug and medical device treatment improving health related quality of life and reducing hospitalizations. However, it is reported that the large beneficial effects of optimal medical therapy (OMT) and device therapy may have reduced the potency of ExCR in patients with HF and reduced ejection fraction (HFrEF), associated with a non-clear benefit in mortality, as well as, with modest changes in aerobic capacity, at least compared to the pre-OMT era. The present review explores a ‘hypothesis of an OMT associated attenuation of ET effectiveness’. It investigates the evolvement and potency of ExCR during the last 70 years with respect to medical innovations in patients with HFrEF and focuses on the three largest multicenter ET randomized controlled trials, HF-ACTION, SMARTEX-HF, ARISTOS-HF, investigating ‘breakthrough’ interventions such as moderate continuous aerobic training, high intensity interval training and aerobic/resistance/inspiratory training outcomes, respectively. It is suggested that ET delivery using ‘poly-muscle training’ and a ‘high ET dosage’ may improve the effectiveness of ET programs in the era of OMT, although further confirmation is required.