Limitations of the pulmonary arterial hypertension hypoxia model
There are some limitations to the human hypoxia model for investigating pulmonary arterial hypertension that must be carefully addressed. Whilst arterial hypoxia and increased pulmonary vascular resistance can be effectively modelled, other disease characteristics are less reproducible. The duration of the experimental hypoxic exposition will not be long enough to induce relevant pulmonary remodelling in healthy participants. Trials should therefore aim to investigate acute responses in the vasculature liker oxygen metabolism, and the hypoxia-induced inflammation and fibrosis. Furthermore, pulmonary arterial hypertension related comorbidities should be carefully considered. Patients with chronic pulmonary arterial hypertension may develop right heart insufficiency, which proceeds to alter the physiology of the whole cardio-circulatory system. Healthy participants will maintain right heart function with higher cardiac outputs than pulmonary arterial hypertension patients.