Hemodynamic Evidence of Vascular Remodeling in Combined Post- and Precapillary Pulmonary Hypertension. (September 2016)

• Record Type: Journal Article
• Authors: Assad, Tufik R.; Brittain, Evan L.; Wells, Quinn S.; Farber-Eger, Eric H.; Halliday, Stephen J.; Doss, Laura N.; Xu, Meng; Wang, Li; Harrell, Frank E.; Yu, Chang; Robbins, Ivan M.; Newman, John H.; Hemnes, Anna R.
• Is Part Of: Pulmonary circulation. Volume 6:Number 3(2016)
• Page Start: 313
• Page End: 321
• Publication Date: 2016-09
• Subjects: pulmonary vascular resistance -- pulmonary vascular compliance -- resistance-compliance time -- pulmonary hypertension -- precapillary -- postcapillary; Pulmonary circulation -- Periodicals; Pulmonary circulation; Electronic journals -- Sciences; Periodicals; 616.24005
• DOI: 10.1086/688516
• Languages: English
• ISSNs: 2045-8932

Abstract

Although commonly encountered, patients with combined postcapillary and precapillary pulmonary hypertension (Cpc-PH) have poorly understood pulmonary vascular properties. The product of pulmonary vascular resistance and compliance, resistance-compliance (RC) time, is a measure of pulmonary vascular physiology. While RC time is lower in postcapillary PH than in precapillary PH, the RC time in Cpc-PH and the effect of pulmonary wedge pressure (PWP) on RC time are unknown. We tested the hypothesis that Cpc-PH has an RC time that resembles that in pulmonary arterial hypertension (PAH) more than that in isolated postcapillary PH (Ipc-PH). We analyzed the hemodynamics of 282 consecutive patients with PH referred for right heart catheterization (RHC) with a fluid challenge from 2004 to 2013 (cohort A) and 4, 382 patients who underwent RHC between 1998 and 2014 for validation (cohort B). Baseline RC time in Cpc-PH was higher than that in Ipc-PH and lower than that in PAH in both cohorts ( P < 0.001). In cohort A, RC time decreased after fluid challenge in patients with Ipc-PH but not in those with PAH or Cpc-PH ( P < 0.001). In cohort B, the inverse relationship of pulmonary vascular compliance and resistance, as well as that of RC time and PWP, in Cpc-PH was similar to that in PAH and distinct from that in Ipc-PH. Our findings demonstrate that patients with Cpc-PH have pulmonary vascular physiology that resembles that of patients with PAH more than that of Ipc-PH patients. Further study is warranted to identify determinants of vascular remodeling and assess therapeutic response in this subset of PH.