PIMR and Pulmonary Vascular Disease

Pulmonary Index of Microcirculatory Resistance (PIMR),Right Ventricle Index of Microcirculatory Resistance (RV-IMR),OCT-derived pulmonary artery wall thickness,OCT-derived thickness-diameter ratio,OCT-derived wall-area ratio

The findings from this innovative, first-in-man, prospective pilot study will elucidate the
 role of PIMR and RV-IMR in pre-capillary PH. The study cohort will consist of patients with
 pulmonary pressures ranging from normal (advanced lung disease patients undergoing lung
 transplant evaluation) to severe PH (PAH and CTEPH patients), and thus will allow for
 identification of a PIMR cutoff. Participants will include: 1) advanced lung disease patients
 undergoing bilateral heart catheterization as part of their pre-lung transplant work-up, and
 2) newly referred patients to PAH and CTEPH clinics undergoing bilateral heart
 catheterization as part of standard of care work-up. All participants will undergo PIMR
 testing, and those with pre-capillary PH will also undergo pulmonary OCT and measurement of
 RV-IMR. The study seeks to define the relationship between PIMR and PH and to establish the
 PIMR threshold that identifies pulmonary microvascular dysfunction as well as to evaluate the
 association of PIMR and pulmonary vascular remodeling on OCT in patients with pre-capillary
 PH. In addition, the study will assess the relationship between RV-IMR and RV pressure
 overload among patients with pre-capillary PH.