Respiratory muscle training to improve exercise capacity and quality of life in people with pulmonary arterial hypertension

A randomised controlled study of respiratory muscle training for adults with pulmonary artery hypertension. The control group (Arm 1) will continue with usual/standard care. The training group (Arm 2) will undergo an 10 week respiratory muscle training program that includes 2 supervised sessions per week. The respiratory muscle training group will be asked to attend hospital twice a week to undertake approximately 20 minutes of supervised training for 10 weeks. These sessions will be supervised by an Exercise Physiologist with expertise in respiratory muscle training. Training involves the participant breathing through a handheld device which provides resistance to their inhalation breaths. On one other day of the week participants will be asked to do 20 minutes of respiratory muscle training at home. Any costs incurred for travel to hospital will be reimbursed. Individuals in the control group will NOT participate in the Respiratory muscle training program. Respiratory muscle training is performed using a threshold loading inspiratory muscle trainer (Threshold IMT; Respironics, Cedar Grove, NJ, USA). The participant will be seated and can lean forward and fix their arms on a chair or table if desired. The target inspiratory training load will initially be 30% of the maximum inspiratory pressure measured during assessment. The training will consist of: 1-minute warm-up at 50% of the target inspiratory training load 2 minutes of inspiratory muscle training at the target load followed by 1 minute rest This 2-minute training plus 1-minute rest will be repeated seven times giving a total of 14 minutes of inspiratory muscle training and a total session time of 21 minutes. . The training load will be increased based on maintaining the participant’s symptoms of perceived exertion at 3-4 (‘moderate’ to ‘somewhat heavy’) on the modified Borg 0-10 category-ratio rate of perceived exertion (RPE) scale. Participants will be asked to keep a diary to record their home training sessions to monitor adherence.