BACKGROUND Pulmonary hypertension (PH) adversely impact patient´s exercise capacity in interstitial lung disease (ILD). Pulmonary vascular and right ventricular (RV) dysfunction impact, however, have traditionally been thought to be mild, and clinically relevant principally in advanced lung disease states. We sought to evaluate the relative contributions of pulmonary mechanics, pulmonary vascular and RV function to the ILD exercise limit. METHODS 49 ILD patients that underwent resting right heart catheterization followed by invasive exercise testing were evaluated. Patients with PH at rest (ILD+rPH) and with PH diagnosed exclusively during exercise (ILD+ePH) were contrasted to ILD patients without PH (ILD non-PH). RESULTS Peak oxygen consumption (VO2) was reduced in ILD+rPH (61±10 %predicted) and ILD+ePH (67±13 %predicted) compared to ILD non-PH (81±16 %predicted; p<0.001 and p=0.016, respectively). Each ILD hemodynamic phenotype presented distinct patterns of dynamic changes of pulmonary vascular compliance relative to pulmonary vascular resistance from rest to peak exercise. Peak RV stroke work index was increased in ILD+ePH (24.7±8.2 g.m2/beat) and ILD+rPH (30.9±6.1 g.m2/beat) compared to ILD non-PH (18.3±6.4 g.m2/beat; p=0.020 and p=0.014, respectively). Ventilatory reserve was reduced in ILD+rPH compared to the other groups at the anaerobic threshold, but it was similar between ILD+ePH and ILD non-PH at the anaerobic threshold (0.32±0.13 vs. 0.30±0.11, p=0.921) and at peak exercise (0.70±0.17 vs. 0.73±0.24, p=0.872). CONCLUSIONS ILD with resting and exercise PH is associated with increased exercise RV work, reduced pulmonary vascular reserve and reduced peak VO2. The findings highlight the role of pulmonary vascular and RV burden to ILD exercise limit.

中文翻译：

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运动期间间质性肺疾病的肺血管和右心室负荷

背景 肺动脉高压 (PH) 对间质性肺病 (ILD) 患者的运动能力有不利影响。然而，传统上认为肺血管和右心室 (RV) 功能障碍的影响是轻微的，并且主要与晚期肺病状态具有临床相关性。我们试图评估肺力学、肺血管和 RV 功能对 ILD 运动极限的相对贡献。方法 对 49 名接受静息右心导管插入术和侵入性运动试验的 ILD 患者进行评估。将静息 PH (ILD+rPH) 和仅在运动期间诊断为 PH (ILD+ePH) 的患者与没有 PH 的 ILD 患者 (ILD 非 PH) 进行对比。结果 与 ILD 非 PH（预测的 81±16%；p<0.001 和 p=）相比，ILD+rPH（预测的 61±10%）和 ILD+ePH（预测的 67±13%）的峰值耗氧量 (VO2) 降低0.016，分别）。每个 ILD 血流动力学表型呈现出不同的肺血管顺应性相对于肺血管阻力从休息到运动峰值的动态变化模式。与 ILD 非 PH (18.3±6.4 g.m2/beat) 相比，ILD+ePH (24.7±8.2 g.m2/beat) 和 ILD+rPH (30.9±6.1 g.m2/beat) 的峰值 RV 卒中指数增加；分别为 p=0.020 和 p=0.014）。与处于无氧阈值的其他组相比，ILD+rPH 组的通气储备降低，但在无氧阈值的 ILD+ePH 和 ILD 非 PH 组之间的通气储备相似（0.32±0.13 vs. 0.30±0.11，p=0.921）和在运动高峰期（0.70±0.17 对 0.73±0.24，p=0.872）。结论 静息和运动 PH 的 ILD 与运动 RV 工作增加、肺血管储备减少和峰值 VO2 降低有关。研究结果强调了肺血管和 RV 负担对 ILD 运动限制的作用。