ABC | Volume 110, Nº5, May 2018

Original Article Oliveira et al Exercise in acute heart failure Arq Bras Cardiol. 2018; 110(5):467-475 groups (ET+Sham and ET+NIV) had a lower number of patients receiving dobutamine infusion compared to the control group (Table 2). From D1 to D10, there was a significant reduction in NT-proBNP (∆NT-proBNP: -892 ± 112  ρ g/mL [Control]; -1184 ± 299  ρ g/mL [ET+Sham]; -1002 ± 356  ρ g/mL [ET+NIV]) and hs-CRP levels (∆hs-CRP: -4 ± 2 mg/L [Control]; -4 ± 3 mg/L [ET+Sham]; -5±3 mg/L [ET+NIV]), but without differences among groups. In addition, there was a similar reduction in body weight from D1 to D10 between the three groups studied (∆weight: -3.3 ± 2.2 kg [Control]; -5.3 ± 3.9 kg [ET+Sham]; -5.0 ± 2.0 kg [ET+NIV]). No differences in small airway obstruction, MIP and blood lactate were found between the groups at D1 and at D10 (Table 2). Follow-up None of the patients of the exercise groups needed to be transferred to the intensive care unit. In addition, more patients in the ET+NIV and ET+Sham groups had an early hospital discharge compared to the control group. Of note, the control group had a significantly greater length of stay compared to the exercise groups. In addition, the ET+NIV group had a shorter length of stay compared to the ET+Sham group (Table 1). Interestingly, total exercise time performed in both groups (ET+Sham and ET+NIV) was inversely related to length of stay (Figure 3). Discussion To the best of our knowledge, this is the first study to assess the role of aerobic exercise training in acute/ decompensated HF (NYHA class IV). The main and new findings of this study are that exercise in acute/ decompensated HF (i) is safe, since neither ET+Sham nor ET+NIV groups showed worse symptoms during exercise or signs of requiring exercise interruption and (ii) reduces the length of hospital stay. In addition, the exercise increases the 6MWT distance. Studies have demonstrated that early mobilization therapy in intensive care unit patients can significantly reduce the length of stay. 19 It has also been demonstrated that rehabilitation immediately following an acute exacerbation of chronic obstructive pulmonary disease is associated with a reduced frequency of re-exacerbation and with an increase in quadriceps muscle strength. 20,21 In the same line, a recently study demonstrated that functional electrical stimulation improved exercise tolerance and muscle strength in acute HF patients. 28 Our study extends the knowledge about approaches to be used during hospitalization to treat decompensated HF patients. It suggests that aerobic exercise training per se is a safe and effective tool to reduce length of hospital stay in acute HF patients. It should be emphasized that none of the patients who performed exercise had worsening of symptoms during exercise or exhibited any signs of exercise intolerance. Table 2 – Characteristics of the “exercise training + non-invasive ventilation (ET + NIV)”, “ET + Sham” and Control groups at hospital admission and after study protocol Day 1 Day 10 Control ET+Sham ET+NIV Control ET+Sham ET+NIV NYHA II, n (%) - - - 3 (33%) 5 (55%)* 8 (72%)* III, n (%) - - - 4 (44%) 3 (33%)* 2 (18%)* IV, n (%) 9 (100%) 9 (100%) 11 (100%) 2 (22%) 1 (11%)* 1 (10%)* Dobutamine, n (%) 5 (55%) 4 (44%) 6 (54%) 3 (33%) 2 (22%)* ‡ 2 (18%)* ‡ Exercise tolerance Total exercise time, min - - - - 92 (60 – 120) 128 (90 – 160) † 6MWT, m 221 ± 58 238 ± 51 224 ± 30 266 ± 83 311 ± 67* ‡ 345 ± 61* †‡ ∆6MWT, m - - - 45 ± 32 73 ± 26* 120 ± 72* † Pulmonary function MIP, cmH 2 O -65 ± 20 -53 ± 20 -60 ± 11 -64 ± 31 -61 ± 36 -63 ± 15 MIP, % predicted 73 ± 25 77 ± 33 72 ± 24 72 ± 32 75 ± 42 77 ± 22 FEV 1 , % predicted 57 ± 21 59 ± 20 61 ± 22 68 ± 29 60 ± 20 65 ± 21 FEV 1 /FVC 0.72 ± 0.18 0.79 ± 0.10 0.75 ± 0.12 0.74 ± 0.17 0.78 ± 0.18 0.76 ± 0.10 Definition of abbreviations: NYHA: New York Heart Association; 6MWT: six minute walk test; MIP: maximal inspiratory pressure; FEV 1 : forced expiratory volume in 1 second; FVC: forced vital capacity. Values are expressed in mean ± standard deviation; median (interquartile range) and frequency (n and %). Repeated-measures ANOVA with the appropriate Bonferroni corrections was applied to variables described as mean ± standard deviation and the chi-square test was used to assess categorical data differences in frequency variables; * p < 0.05 vs. Control; † p < 0.05 vs. ET+Sham; ‡ p < 0.05 vs. Day 1 470