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
Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
Division of Cardiovascular Medicine, Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee, USA.
Pulm Circ. 2016 Sep;6(3):313-21. doi: 10.1086/688516.
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.
尽管毛细血管后和毛细血管前合并性肺动脉高压（Cpc-PH）患者很常见，但人们对其肺血管特性了解甚少。肺血管阻力与顺应性的乘积，即阻力-顺应性（RC）时间，是衡量肺血管生理功能的指标。虽然毛细血管后肺动脉高压患者的RC时间低于毛细血管前肺动脉高压患者，但Cpc-PH患者的RC时间以及肺楔压（PWP）对RC时间的影响尚不清楚。我们检验了以下假设：与单纯毛细血管后肺动脉高压（Ipc-PH）患者相比，Cpc-PH患者的RC时间更类似于肺动脉高压（PAH）患者。我们分析了2004年至2013年因右心导管检查（RHC）接受液体负荷试验的282例连续PH患者的血流动力学情况（队列A），以及1998年至2014年接受RHC以进行验证的4382例患者（队列B）。在两个队列中，Cpc-PH患者的基线RC时间均高于Ipc-PH患者，低于PAH患者（P<0.001）。在队列A中，Ipc-PH患者在液体负荷试验后RC时间降低，而PAH或Cpc-PH患者则未降低（P<0.001）。在队列B中，Cpc-PH患者肺血管顺应性与阻力的反比关系以及RC时间与PWP的反比关系与PAH患者相似，与Ipc-PH患者不同。我们的研究结果表明，Cpc-PH患者的肺血管生理功能更类似于PAH患者，而不是Ipc-PH患者。有必要进一步研究以确定血管重塑的决定因素，并评估这一PH亚组的治疗反应。
