Efficacy of Inspiratory Muscle Training in Patients With Acute Decompensated Heart Failure.

Background: Inspiratory muscle training (IMT) is supported for outpatients with stable chronic heart failure, but its efficacy in hospitalized patients with acute decompensated heart failure (ADHF) remains unclear. The aim of the present study was to clarify IMT efficacy and safety in hospitalized ADHF patients.

Methods and results: Patients with inspiratory muscle weakness who underwent cardiac rehabilitation (CR) were analyzed. The control group was historical control data of patients admitted to the same facility. IMT was performed at 30% maximal inspiratory mouth pressure (15 reps/set, 2 sets/day, 5 times/week) with usual CR. Associations between IMT and changes in the 2-min walking distance (2MWD) were assessed using a linear mixed model. In total, 31 and 29 patients in the IMT and control groups (median age 83 [71-88] vs. 86 [77-88] years), respectively, were analyzed. After adjustment for covariates and propensity scores, calculated on the basis of heart-failure severity, frailty, physical function, nutritional status, and inspiratory muscle strength, the 2MWD was significantly higher in the IMT group than in the control group (F=4.697; P=0.035; ∆2MWD; +31.9 vs. +16.3 m). Among 348 IMT sessions, no adverse cardiovascular events or absolute termination criteria were identified. Eleven (3.2%) IMT sessions met relative termination criteria.

Conclusions: Adding IMT to usual CR improves the 2MWD, can be safely performed in hospitalized patients with ADHF, and may represent a novel CR approach in patients with ADHF.