Severe pulmonary hypertension in chronic obstructive pulmonary disease – From clinical perspective to histological evidence

Fig. 1. a) Multivariate Cox regression analysis by pulmonary vascular resistance (PVR) groups (cut-off: PVR >5.0 WU) accounting for age, sex and forced expiratory volume in 1 s (FEV1) (n = 138; HR 2.59, 95 % CI 1.58–4.27; p < 0.001). b) Multivariate Cox regression analysis by mean pulmonary arterial pressure (mPAP) groups (cut-off: mPAP ⩾33 mmHg) accounting for age, sex and FEV1 (n = 139; HR 2.26, 95 % CI 1.37–3.71; p = 0.001). c) Univariate Cox regression analysis by mPAP and PVR groups with mPAP cut-off ⩾33 mmHg and PVR cut-off >5.0 WU (n = 138; p = 0.001; reference category: mPAP <33 mmHg and PVR ⩽5.0 WU (green curve); versus mPAP ⩾33 mmHg and PVR ⩽5.0 WU (yellow curve): HR 2.02, 95 % CI 1.04–3.93; versus mPAP <33 mmHg and PVR >5.0 WU (orange curve): HR 3.45, 95 % CI 1.25–9.52; versus mPAP ⩾33 mmHg and PVR >5.0 WU (red curve): HR 3.35, 95 % CI 1.95–6.06). For data in panels a and c, n = 138 as pulmonary arterial wedge pressure and therefore PVR was not available in one patient. Reproduced with permission of the ERS 2024: European Respiratory Journal 58 (2) 2100944; DOI: 10.1183/13993003.00944-2021 Published 26 August 2021

Fig. 2. Cox-regression survival analysis for patients with COPD based on severity of airflow limitation and PH. Red curve indicates good prognosis, consisting of GOLD stages 1 or 2 and no or moderate PH. Blue curve indicates intermediate prognosis, including either GOLD stages 3 or 4 or severe PH. Gray curve indicates poor prognosis, with the combination of GOLD stages 3 or 4 and severe PH. ©Chest. Kovacs et al., 2022, https://doi.org/10.1016/j.chest.2022.01.031page 208, Fig. 2), reprinted with permission.

Fig. 3. Comparison of small pulmonary arterial remodeling between donors, IPAH, noPH COPD, mildPH COPD, and sevPH COPD. (A) Systematic analysis of all orthogonal cuts of pulmonary arteries and arterioles <200 μm of all probes. (B) Representative pulmonary arteries and arterioles in the different groups (hematoxylin-eosin staining). For significant differences between groups please see Table 2. COPD, chronic obstructive pulmonary disease; IPAH, idiopathic PAH; MildPH-COPD, COPD with mild PH; NoPH-COPD, COPD without PH; SevPH-COPD, COPD with severe PH.

Fig. 4. Correlation between mean septal distance and mPAP in patients with COPD with no PH, mild PH, and severe PH. The significant negative Pearson correlation (r = −0.556) suggests that a higher degree of pulmonary vascular remodeling is associated with a lesser degree of lung emphysema (p < 0.001). mPAP, mean pulmonary arterial pressure; MildPH-COPD, COPD with mild PH; NoPH-COPD, COPD without PH; SevPH-COPD, COPD with severe PH.

Fig. 5. Central illustration of COPD patients with Severe PH, demonstrating the clinical and histopathologic changes in COPD patients with severe PH. PAS: Periodic Acid Shiff, FEV1: Forced Expiratory Volume in 1 s, WHO FC: World Health Organization Functional Class, mPAP: mean pulmonary arterial pressure, PVR: pulmonary vascular resistance, FVC: Forced Vital Capacity.