Inspiratory Muscle Training May Benefit Patients With PAH

Compared with usual care, inspiratory muscle training (IMT) may improve inspiratory muscle strength and 6-minute walk distance (6MWD) among individuals with pulmonary arterial hypertension (PAH), according to findings of a new study.

To reach this conclusion, the researchers studied data on 11 patients with group I PAH and on 1 patient with chronic thromboembolic pulmonary hypertension. The patients—aged 60 ± 14 years, 83% women—were randomly assigned to follow IMT or usual care.

At baseline, the 2 groups had no significant difference in maximal inspiratory pressure or 6MWD. The 6 participants in the IMT group had maximal inspiratory pressure of 78.2 ± 29.3 cmH2O and a 6MWD of 495 ± 154 m. The 6 participants in the control group had maximal inspiratory pressure of 67.3 ± 17.3 cmH2O and a 6MWD of 550 ± 61 m.

The IMT group participants had to perform 2 cycles of 30 breaths at 30% to 40% of their maximal inspiratory pressure, 5 days per week over 8 weeks.

Both before and after IMT, respiratory muscle strength (maximal inspiratory and expiratory pressures), cardiorespiratory fitness, pulmonary function, and 6MWD were assessed.

After IMT, the training group showed significant improvements in maximal inspiratory muscle strength (30.8 ± 15.4 cmH2O) compared with the controls (10.3 ± 8.3 cmH2O). 

The training group also showed improvement in their 6MWD compared with the controls; the 6MWD decreased by 25 ± 18 m among the IMT participants and by 12 ± 31 meters among the controls. 

Meanwhile, the groups displayed no significant difference in peak oxygen uptake post-intervention. Between the groups, there were also no significant changes in pulmonary function testing parameters or maximal expiratory pressure.

—Colleen Murphy


Tran D, Munoz P, Lau E, et al. Inspiratory muscle training improves six-minute walk distance in adults with pulmonary arterial hypertension. Paper available through: 2020 American College of Cardiology/World Congress of Cardiology virtual meeting; March 28-30, 2020. Accessed April 2, 2020.!/8992/presentation/11654.