Exercise Training in Patients with Heart Failure: From Pathophysiology to Exercise Prescription

Abstract

Heart failure (HF) is a chronic, progressive, and inexorable syndrome affecting worldwide billion of patients (equally distributed among men and women), with prevalence estimate of 1-3% in developed countries. HF leads to enormous direct and indirect costs, and because of ageing population, the total number of HF patients keep rising, approximately 10% in patients $>$ 65 years old. Exercise training (ET) is widely recognized as an evidence-based adjunct treatment modality for patients with HF, and growing evidence is emerging among elderly patients with HF. We used relevant data from literature search (PubMed, Medline, EMBASE) highlighting the epidemiology of HF; focusing on central and peripheral mechanisms underlying the beneficial effect of ET in HF patients; and on frail HF elderly patients undergoing ET. Since many Countries ordered a lockdown in early stages pandemic trying to limit infections, COVID-19 pandemic, and its limitation to exercise-based cardiac rehabilitation operativity was also discussed. ET exerts both central and peripheral adaptations that clinically translate into anti-remodeling effects, increased functional capacity and reduced morbidity and mortality. Ideally, ET programs should be prescribed in a patient-tailored approach, particularly in frail elderly patients with HF. In conclusion, given the complexity of HF syndrome, combining, and tailoring different ET modalities is mandatory. A procedural algorithm according to patient's baseline clinical characteristics [i.e., functional capacity, comorbidity, frailty status (muscle strength, balance, usual daily activities, hearing and vision impairment, sarcopenia, and inability to actively exercise), logistics, individual preferences and goals] has been proposed. Increasing long-term adherence and reaching the frailest patients are challenging goals for future initiatives in the field.

Keywords: COVID-19; cardiac rehabilitation; continuous training; elderly; exercise training; frailty; functional electrical stimulation; heart failure; inspiratory muscle training; interval training; mortality; preserved ejection fraction; respiratory training; strength training.

Fig. 1.

Effects of exercise training in Heart failure. BNP, brain natriuretic peptide; LV, left ventricular; LVEDD, left ventricular end diastolic diameter; NO, nitric oxide; peakVO2, peak oxygen consumption.

Fig. 2.

Procedural algorithm of exercise training in Heart failure (continue on next page). 6MWT, 6-Minute Walking Test; AHF, acute heart failure; CHF, chronic heart failure; CPET, cardiopulmonary exercise testing; CR, cardiac rehabilitation; CT, continuous training; ExT, Exercise Training; HIT, high intensity interval training; IMT, inspiratory muscle training; IT, interval training; LIT, low intensity interval training; RST, resistance strength training; VO₂ peak, peak oxygen consumption. * (yellow): consider it in active lifestyle patients. ** (blue): consider it only if respiratory muscle weakness is present.

Fig. 3.

Patients Reported Outcomes (PROs) and training modalities according to Frailty degree. 6MWD, 6-minute walking distance; ADL, activities of daily living and iADL, instrumental activities of daily living; CPET, cardio-pulmonary exercise test; CT, continuous training; HIIT, high intensity interval training; LIIT, low intensity interval training; RST, resistance/strength training; RT, respiratory training; SPPB, short physical performance battery.