NCT05812976

Novel Index (PIMR) in PAH

Impact of the Pulmonary Index of Microcirculatory Resistance in Pulmonary Arterial Hypertension

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 22 (actual)
• Sponsor: University of California, Los Angeles · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The chief regulator of resistance in pulmonary arterial hypertension (PAH) is the small arteries. In the heart, the invasive measurement of the resistance of the small arteries has been shownto be safe, easy, reliable, and prognostic. This study is intended to translate prior work in heart arteries to the PAH space and invasively measure the resistance of the small arteries of the lung (pulmonary index of microcirculatory resistance \[PIMR\]) and the coronary artery supplying the right ventricle (acute marginal of the RCA; RV-IMR). Importantly, these measurements will be made during standard of care cardiac catheterizations (right heart catheterization \[RHC\] +/- left heart catheterization). The correlation between these new indices and the standard ones measured during RHC typically used to determine the severity of pulmonary hypertension will be analyzed. In addition, among newly diagnosed patients, the study will evaluate how these indices change 6 months after starting treatment. Finally, the association of these indices with clinical outcomes at 1 year will be assessed. The findings from this study may deliver an immediate impact to patient care by identifying a new metric to help better identify those who may benefit from a more intensive, personalized treatment regimen.

Conditions

• Pulmonary Hypertension

Interventions

Type	Name	Description
OTHER	Pulmonary Index of Microcirculatory Resistance	PIMR measurement involves placing a coronary pressure wire in the pulmonary arteries and making pressure/time measurements during maximal flow down the artery.
OTHER	Right Ventricle Index of Microcirculatory Resistance	RV-IMR measurement involves placing a coronary pressure wire in the acute marginal branch of the right coronary artery and making pressure/time measurements during maximal flow down the artery.

Timeline

• Start date: 2023-02-01
• Primary completion: 2025-04-08
• Completion: 2025-04-08
• First posted: 2023-04-14
• Last updated: 2025-08-01

Locations

1 site across 1 country: United States