RT Journal Article SR Electronic T1 Risk Factors for Inspiratory Muscle Weakness in Chronic Heart Failure JF Respiratory Care FD American Association for Respiratory Care SP respcare.06766 DO 10.4187/respcare.06766 A1 Naomi Kondo Nakagawa A1 Mariana Abreu Diz A1 Tatiana Satie Kawauchi A1 Geisa Nascimento de Andrade A1 Iracema Ioco Kikuchi Umeda A1 Fernanda Murata Murakami A1 Janaina Proença Oliveira-Maul A1 Juliana Araúo Nascimento A1 Newton Nunes A1 Júlio Yoshio Takada A1 Antonio de Padua Mansur A1 Lawrence Patrick Cahalin YR 2019 UL http://rc.rcjournal.com/content/early/2019/12/10/respcare.06766.abstract AB BACKGROUND: Chronic heart failure is commonly associated with inspiratory muscle weakness. However, few studies have investigated the risk factors for inspiratory muscle weakness in individuals with chronic heart failure and systolic dysfunction (left-ventricular ejection fraction [LVEF] <40%).METHODS: Seventy subjects were recruited in a cardiac center. We assessed clinical parameters, smoking history, peripheral muscle strength, pulmonary function, echocardiographic variables, and brain natriuretic peptide. The subjects were classified with inspiratory muscle weakness when the maximum inspiratory pressure was <70% of predicted values.RESULTS: Thirty-six subjects (51%) had inspiratory muscle weakness. The subjects with inspiratory muscle weakness and the subjects with no inspiratory muscle weakness were similar in age, sex, body mass index, medication use, and physical activity. However, the subjects with inspiratory muscle weakness had lower LVEF (P = .003), systolic blood pressure (P = .01), diastolic blood pressure (P = .042), quadriceps muscle strength (P = .02), lung function (P = .035), increased brain natriuretic peptide (P = .02), smoking history (P = .01), and pulmonary hypertension incidence (P = .03). Multivariate logistic regression analysis found a lower LVEF, increased smoking history, and lower systolic blood pressure as significant independent predictors for inspiratory muscle weakness.CONCLUSIONS: The combination of lower LVEF, lower systolic blood pressure, and smoking history predicted inspiratory muscle weakness. Patients with suspected inspiratory muscle weakness should be examined and, if inspiratory muscle weakness exists, then inspiratory muscle training should be provided. Reducing inspiratory muscle weakness has the potential to improve many of the deleterious effects of chronic heart failure.