Prognostic factors in pulmonary arterial hypertension: assessing the course of the disease.

The practical management of pulmonary arterial hypertension (PAH) requires an accurate assessment of disease severity and prognosis. A number of prognostic indicators are known to be associated with patient outcome, and recent treatment guidelines advocate using such parameters to guide management decisions. Although PAH is characterised by the presence of pulmonary vasculopathy, it is the response of the right ventricle to an increased afterload that is the greatest determinant of a patient's symptoms and survival; thus, measurements that capture right ventricular function provide the best potential to assess PAH severity. One challenge is to understand how the tests we use in everyday clinical practice relate to right heart function in PAH patients, and how current measures can be improved and developed to optimise assessment of disease status and progress. Future research in the field of PAH should focus on how best to assess right heart function, and which measures or combination of measures provide the most relevant information for the individual patient.