Home-based Inspiratory Muscle Training in Pulmonary Hypertension

The main objective of this study is to determine whether an 8-week inspiratory muscle training (IMT) programme, delivered at home through telerehabilitation, improves ventilatory efficiency (VE/VCO2 slope) compared with a sham (placebo) training programme in adults with pulmonary hypertension. Secondary objectives are to analyse its effects on airway inflammation, inspiratory muscle strength, lung function, ventilatory pattern and mechanical efficiency during exercise, dyspnoea and health-related quality of life. Forty participants will be randomly allocated (1:1) to active IMT or sham IMT. Both groups will train twice a day, 5 days a week, for 8 weeks, with biweekly load adjustments and supervision through video calls. Participants, therapists, outcome assessors and the statistician will be blinded to group allocation.

Inclusion Criteria: * Age 18 years or older. * Medical diagnosis of pulmonary hypertension group 1 (pulmonary arterial hypertension) or group 4 (chronic thromboembolic pulmonary hypertension) according to the 2022 ESC/ERS guidelines. * Transthoracic echocardiography performed within the previous 6 months. * Clinical stability: no hospitalizations, changes in PH-specific treatment or worsening of functional class in the previous 3 months. * Sufficient functional capacity to perform cardiopulmonary exercise testing and the other study assessments. * Signed informed consent. Exclusion Criteria: * Absolute contraindications to cardiopulmonary exercise testing according to current guidelines. * Neuromuscular disease or conditions with primary diaphragmatic involvement. * Thoracic or abdominal surgery in the previous 3 months. * Severe comorbidities unrelated to PH pathophysiology (e.g., severe COPD or unstable ischaemic heart disease). * Current participation in cardiopulmonary rehabilitation, or participation in the previous 3 months. * Pregnancy or breastfeeding. * Inability to understand or follow the telerehabilitation programme.