Author + information
- Derek Tran,
- Phillip Munoz,
- Edmund Lau,
- Jennifer Alison,
- Martin Brown,
- Yizhong Zheng,
- Patricia Corkery,
- Keith Wong,
- Steven Lindstrom,
- David Celermajer,
- Glen Davis and
- Rachael Cordina
Exercise intolerance is an important symptom of pulmonary arterial hypertension (PAH) and is associated with poor prognosis and reduced quality of life. Although the mechanisms of reduced exercise capacity are multifactorial, respiratory muscle dysfunction may be a significant contributing factor. Whether improving respiratory muscle function will result in increased exercise capacity remains unclear. The purpose of this study was to investigate the effects of inspiratory muscle training (IMT) in PAH.
Adults with PAH were prospectively recruited and randomized into an IMT or control group. Assessment of respiratory muscle strength (maximal inspiratory and expiratory pressures), cardiorespiratory fitness, pulmonary function and 6-minute walk distance were performed, before and after IMT. The IMT group performed two cycles of 30 breaths at 30–40% of their maximal inspiratory pressure, 5 days per week over 8 weeks.
Twelve patients were recruited and randomized (aged 60 ± 14 years, 83% females) with group I PAH (n = 11) or chronic thromboembolic pulmonary hypertension (n = 1). There was no significant difference in maximal inspiratory pressure (78.2 ± 29.3 vs 67.3 ± 17.3 cmH2O, p = 0.45) or six-minute walk distance (495 ± 154 vs 550 ± 61 meters, p = 0.44) at baseline between the IMT (n = 6) and control (n = 6) groups. Following IMT, the training group demonstrated significantly improved maximal inspiratory muscle strength compared to controls (30.8 ± 15.4 vs 10.3 ± 8.3 cmH2O, p = 0.02). Six-minute walk distance improved in the IMT group by 25 ± 18 meters compared to the control group, which fell by 12 ± 31 meters (p = 0.03). There was no significant difference in peak oxygen uptake post-intervention between groups (1.9 ± 1.3 vs 1.5 ± 2.7 ml/kg/min, p = 0.77). There were no significant changes between groups in pulmonary function testing parameters or maximal expiratory pressure (p > 0.05).
In this small study, inspiratory muscle training compared to usual care improved inspiratory muscle strength and six-minute walk distance in people with PAH.
Sunday, March 29, 2020, 9:04 a.m.-9:14 a.m.
Session Title: Highlighted Original Research: Pulmonary Hypertension and the Year in Review
Abstract Category: 35. Pulmonary Hypertension
Presentation Number: 904-12
- 2020 American College of Cardiology Foundation