Heart failure. Cardiovascular rehabilitation. Expiratory muscle training. Inspiratory muscle training. Non-invasive ventilation
Key words: Heart failure. Cardiovascular rehabilitation. Expiratory muscle training. Inspiratory muscle training. Non-invasive ventilation
Introduction: Dyspnoea is one of the most common symptoms of chronic heart failure with reduced left ventricular ejection fraction (HFrEF) and relentlessly progresses with the progression of the disease, leading to reduced functional capacity and activities of daily living. Moreover, considering that ventilatory inefficiency in HF can also be aggravated as a consequence of expiratory muscle weakness, it is possible that the investigation of different modalities of adjuvant therapies may better guide clinical decision making, especially in patients with muscle dysfunction which is associated with a worse prognosis of HFrEF and can optimize the participation of these patients in Cardiovascular Rehabilitation (CR). Thus, we hypothesized that a mode of expiratory muscular training (EMT) concomitant with inspiratory muscle training (IMT) associated with CR may present superior effects to the use of Non-invasive ventilation (NIV) plus CR in relation to respiratory muscle improvement, quality of life and exercise tolerance. Objectives: to analyze the effects of EMT plus IMT plus CR versus CR plus NIV in exercise tolerance in patients with HFrEF. Methods: The research was divided into three stages. Initially, a study was carried out to determine if there is an additional benefit of concomitant IMT associated with aerobic exercise (AE) in HFrEF when compared to healthy individuals in 31 participants. In the second stage, we performed a randomized clinical trial involving 17 patients with CHF who were allocated in Group 1 CR-control (n = 6), Group 2 - CR + NIV (n = 5), Group 3 - = 6). All patients were assessed before and after 12 weeks of the structured supervised CR program three times a week. Group 1- CR supervised. Group 2 - CR + NIV with continuous airway pressure (CPAP), using the VPAP ™ Auto 25 ResMed System (ResMed® USA). The CPAP gradually adjusted to 8 cmH2O for 20 minutes. RC plus TMR for 30 minutes, with 15 minutes with inspiratory load up to 40% of MIP and 15 minutes with expiratory load between 5 and 15% of MEP, with EMT performed according to the protocol performed in the study by Cahalin et al. In the third step, we evaluated the effects of IMT on VO2 kinetics in patients with HF versus healthy subjects: a systematic review. Results: Combining IMT plus EMT plus AE training showed superior additional benefits in six minute walking distance (6MWD), MIP and MEP, between the groups when compared to the isolated AE; both in patients with HFrEF and in healthy individuals. However, when compared to NIV versus EMT + IMT, they were similar for 6MWD and VO2peak, but there was a significant difference in Minnesota Living with Heart Failure Questionnaire (MLHFQ) compared to control (24.6 vs. 19.2 in CR plus NIV, p= 0.0001 , and 26.6 vs. 19.2 in CR + EMT plus IMT, p <0.0001). RC plus NIV led to an additional increase in forced vital capacity (FVC). CR plus EMT + IMT showed additional benefit in maximal inspiratory and expiratory pressures with an increase of 83% in MIP and 48% in MEP. Conclusions: AE plus IMT plus EMT seems to contribute to the increase of MIP and MEP and to optimize exercise tolerance in both the ICrFE and healthy individuals. CR plus NIV versus CR plus EMT plus IMT may provide additional benefits on quality of life, improving lung function or performance of ventilatory muscles, and may contribute as alternatives to CR in CHF, but to confirm or refute these findings; new studies are needed.