The effect of inspiratory muscle training on fatigue and dyspnea in patients with heart failure: A randomized, controlled trial

Abstract

Aim Fatigue and dyspnea are debilitating symptoms in patients with heart failure (HF). The purpose of this study was to evaluate the effects of inspiratory muscle training (IMT) on dyspnea, fatigue and the New York Heart Association (NYHA) functional classification in patients with HF. Methods In this prospective, randomized, controlled trial, 84 patients with HF (NYHA classes II‐III/IV) with a mean age of 56.62 ± 9.56 years were randomly assigned to a 6‐week IMT (n = 42) or a sham IMT (n = 42) program. The IMT was performed at 40% of the maximal inspiratory pressure (MIP) in the IMT group and at 10% in the sham group. The main outcomes were assessed at baseline and after the intervention and included dyspnea severity scale (Modified Medical Research Council [MMRC], Fatigue Severity Scale [FSS] and the NYHA functional classification (based on the presenting symptoms). Results The between‐group analysis showed significant improvements in dyspnea, fatigue and the NYHA functional classification in the IMT group compared to the sham group (P < .05). The within‐group analysis showed significant improvements in dyspnea (from 2.63 ± 0.79 to 1.38 ± 0.66, P < .001), fatigue (from 43.36 ± 8.5 to 28.95 ± 9.11, P < .001) and the NYHA functional classification (from 2.73 ± 0.5 to 2.1 ± 0.6, P = .001) in the IMT group, while fatigue and dyspnea increased significantly in the sham group. Conclusions The 6‐week home‐based IMT was found to be an effective and safe tool for reducing dyspnea and fatigue and improving the NYHA functional classification.

Inspiratory Muscle Training in Patients with Heart Failure

“…To date, 26 articles have examined the effects of IMT in patients with HF ( Table 1 ) [ 20 , 30 , 31 , 35 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , 69 ]. Twenty-one of these studies were randomized clinical trials [ 20 , 30 , 31 , 35 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 59 , 60 , 61 , 62 , 63 , 66 , 67 , 68 , 69 ] ( Table 1 a,b), four studies were quasi-experimental studies [ 48 , 58 , 64 , 65 ], and one study was a clinical case [ 59 ] (…”

“…To date, 26 articles have examined the effects of IMT in patients with HF (Table 1) [20,30,31,35,. Twenty-one of these studies were randomized clinical trials [20,30,31,35,[49][50][51][52][53][54][55][56][57][59][60][61][62][63][66][67][68][69] (Table 1a,b), four studies were quasi-experimental studies [48,58,64,65], and one study was a clinical case [59] ( Table 1c). The sample size for most of these studies was small.…”

“…The sample size for most of these studies was small. Most of the studies were carried out in patients with HFrEF [20,30,31,35,[48][49][50][51][52][53][54][55][59][60][61][62][63][64][65][66][67][68][69]. In addition, patients of the study carried out by Cahalin et al [65] were waiting for a heart transplant.…”

“…IMT effects on dyspnea were measured in 15 studies [30,31,35,[51][52][53][54]61,[63][64][65][66][67][68][69] and demonstrated that IMT may be a useful treatment to reduce dyspnea at both rest and during exercise performance. All these studies showed a significant improvement (p < 0.05) in dyspnea except for the study carried out by Johnson et al [66].…”

“…Nevertheless, Mancini et al [64] did not observe statistically significant improvements for dyspnea; patients walked a greater distance with the same dyspnea sensation and concluded that HF patients were able to increase working charge without dyspnea sensation increase. Three studies used the Modified Medical Research Council (MMRC) scale [51,54,61] showing statistically significant improvements with respect to the control group, except for the study carried out by Marco et al [54], which did not show statistical significance. Two additional studies measured the dyspnea index [35] and the Mahler transition index [63].…”