Identify and Characterize Populations at Risk for Developing Pulmonary Arterial Hypertension (PAH)

The goal of the project is to identify and characterize populations at risk for developing pulmonary arterial hypertension (PAH). The project will establish a PAH subphenotype core cohort (CORE) to evaluate mechanistic pathways and test novel therapeutic agents. This core cohort serves as a resource for the Translational Program Project grant, Vascular Subphenotypes of Lung Disease (Mark Gladwin, PI). In order to construct the CORE, we have chosen to recruit COPD and HIV patients, two populations with advanced lung and systemic diseases that are enriched for PAH. We have selected these as prototypic conditions because: A) both COPD patients and HIV-infected patients develop PAH at a rate significantly greater than the general population, B) morbidity and mortality are greatly increased in dually-affected persons, C) mechanisms responsible for development of the PAH "subphenotype" are not well-understood, D) clinical and genetic characteristics of the subgroup with PAH are not known, and E) effects of PAH therapies in subphenotypes are incompletely studied. There is also some overlap between COPD and HIV, with HIV-infected patients having accelerated COPD even with effective antiretroviral therapy. Participants with COPD, HIV, or HIV-uninfected controls will be recruited to the study based on entry criteria of elevated N-terminal pro-brain natriuretic peptide (NT-proBNP) and/or an abnormal echocardiogram. These subjects will then undergo a 6-minute walk test, blood collection, questionnaire, medical record review, and echocardiography (if not previously performed). Selected subjects will then be recruited to undergo right heart catheterization. The goals of the study are to establish a pulmonary hypertension cohort for translational investigations, to determine the utility of NT-proBNP as a biomarker of PAH, to determine clinical characteristics and relationship of lung function to PAH in COPD and HIV, and to establish a biorepository for mechanistic studies of PAH phenotypes.