A comparison of exercise capacity, respiratory functions, and quality of life in heart failure patients with and without inspiratory muscle weakness and healthy controls

<bold>Introduction and aim:</bold> Inspiratory muscle weakness (IMW) is observed in 30-50% of patients with heart failure (HF). However, it has not been known whether IMW effects functional exercise capacity, pulmonary function, peripheral muscle strength, dyspnea, fatigue, quality of life, and physical activity level in HF patients. To compare aforementioned outcomes in HF patients with/without IMW and healthy controls. <bold>Methods:</bold> Forty-one HF patients with IMW (NYHAII/III: 26/15), 30 HF patients without IMW (NYHAII/III: 20/10), 41 controls were compared. Functional exercise capacity (6-minute walk test; 6MWT), respiratory muscle strength (MIP, MEP), pulmonary function (spirometry), peripheral muscle strength (dynamometer), dyspnea (Modified Medical Research Council dyspnea scale; MMRC), fatigue (Fatigue Severity Scale; FSS), quality of (SF-36 questionnaires) and physical activity level (International Physical Activity Questionnaire; IPAQ) were evaluated. <bold>Results:</bold> The 6MWT distance, FEV1/FVC, FEF25-75%, shoulder abductor muscle strength of HF patients with IMW were significantly lower, MMRC scores were higher than patients without IMW and controls (p<0.017). FVC%, FEV1%, PEF%, quadriceps femoris muscle strength, SF-36 physical and mental health, IPAQ scores of patients with IMW were significantly lower, and FSS scores were higher than healthy controls (p<0.05). <bold>Conclusion:</bold> Functional exercise capacity and pulmonary function are impaired, peripheral muscles are weakened, dyspnea is increased more in HF patients with IMW than those without IMW. Effects of rehabilitation programs should be investigated in HF patients with and without IMW.