The isobaric pulmonary arterial compliance in pulmonary hypertension

Denis Chemla; Emmanuelle Berthelot; Jason Weatherald; Edmund M T Lau; Laurent Savale; Antoine Beurnier; David Montani; Olivier Sitbon; Pierre Attal; David Boulate; Patrick Assayag; Marc Humbert; Philippe Hervé

doi:10.1183/23120541.00941-2020

The isobaric pulmonary arterial compliance in pulmonary hypertension

ERJ Open Res. 2021 May 31;7(2):00941-2020. doi: 10.1183/23120541.00941-2020. eCollection 2021 Apr.

Authors

Denis Chemla^{1

2

3}, Emmanuelle Berthelot^{2

4}, Jason Weatherald⁵, Edmund M T Lau⁶, Laurent Savale^{2

3

7}, Antoine Beurnier^{1

2

4}, David Montani^{2

3

7}, Olivier Sitbon^{2

3

7}, Pierre Attal^{1

8}, David Boulate⁹, Patrick Assayag^{2

3

4}, Marc Humbert^{2

3

7}, Philippe Hervé^{3

9}

Affiliations

¹ Service d'explorations fonctionnelles multidisciplinaires bi-site Antoine Béclère - Kremlin Bicêtre, GHU Paris Sud, DMU-CORREVE, AP-HP, Le Kremlin-Bicêtre, France.
² Université Paris-Sud, Faculté de Médecine, Université Paris-Saclay, Le Kremlin-Bicêtre, France.
³ INSERM UMR_S 999, Hôpital Marie Lannelongue, Le Plessis Robinson, France.
⁴ Service de cardiologie, GHU Paris Sud, AP-HP, Le Kremlin-Bicêtre, France.
⁵ Dept of Medicine, Division of Respirology, University of Calgary, and Libin Cardiovascular Institute, Calgary, AB, Canada.
⁶ Dept of Respiratory Medicine, Royal Prince Alfred Hospital, University of Sydney, Camperdown, NSW, Australia.
⁷ Service de Pneumologie, Hôpital Bicêtre, AP-HP, Le Kremlin-Bicêtre, France.
⁸ Dept of Otolaryngology - Head and Neck Surgery, Shaare-Zedek Medical Center and Hebrew University Medical School, Jerusalem, Israel.
⁹ Departement de Chirurgie Thoracique, Vasculaire et de Transplantation Pulmonaire, Hopital Marie Lannelongue, Le Plessis Robinson, France.

Abstract

Pulmonary hypertension is associated with stiffening of pulmonary arteries which increases right ventricular pulsatile loading. High pulmonary artery wedge pressure (PAWP) in postcapillary pulmonary hypertension (Pc-PH) further decreases pulmonary arterial compliance (PAC) at a given pulmonary vascular resistance (PVR) compared with precapillary pulmonary hypertension, thus responsible for a higher total arterial load. In all other vascular beds, arterial compliance is considered as mainly determined by the distending pressure, due to non-linear stress-strain behaviour of arteries. We tested the applicability, advantages and drawbacks of two comparison methods of PAC depending on the level of mean pulmonary arterial pressure (mPAP; isobaric PAC) or PVR. Right heart catheterisation data including PAC (stroke volume/pulse pressure) were obtained in 112 Pc-PH (of whom 61 had combined postcapillary and precapillary pulmonary hypertension) and 719 idiopathic pulmonary arterial hypertension (iPAH). PAC could be compared over the same mPAP range (25-66 mmHg) in 792 (95.3%) out of 831 patients and over the same PVR range (3-10.7 WU) in only 520 (62.6%) out of 831 patients. The main assumption underlying comparisons at a given PVR was not verified as the PVR×PAC product (RC-time) was not constant but on the contrary more variable than mPAP. In the 788/831 (94.8%) patients studied over the same PAC range (0.62-6.5 mL·mmHg^-1), PVR and thus total arterial load tended to be higher in iPAH. Our study favours comparing PAC at fixed mPAP level (isobaric PAC) rather than at fixed PVR. A reappraisal of the effects of PAWP on the pulsatile and total arterial load put on the right heart is needed, and this point deserves further studies.