Conflict of interest: P. Brenot reports lecture honoraria from MSD, outside the submitted work. D. Montani reports grants from Acceleron, Janssen and MSD, consulting fees from Acceleron, and lecture honoraria from Bayer, Janssen and MSD, outside the submitted work. L. Savale reports grants from Acceleron, Janssen and MSD, lecture honoraria from Janssen and MSD, and travel support from Janssen, outside the submitted work. O. Sitbon reports grants from Acceleron, Janssen, MSD and GSK, consulting fees from Gossamer Bio, Janssen and MSD, lecture honoraria from AOP Orphan, Janssen, Ferrer and MSD, travel support from Janssen, and advisory board participation from Acceleron, Janssen and MSD, outside the submitted work. A. Boucly reports grants from Acceleron, Janssen and MSD, payment or honoraria for lectures, manuscript writing or educational events from Janssen, Merck and AOP Orphan, and support for attending meetings and/or travel from Janssen. E. Fadel reports lecture honoraria from MSD, outside the submitted work. G. Simonneau reports grants from Acceleron, Janssen and MSD, consulting fees and advisory board participation with Acceleron, Janssen, MSD and Bayer, lecture honoraria from Bayer, Janssen and MSD, and travel support from Janssen, outside the submitted work. M. Humbert reports grants and consulting fees from Acceleron, Janssen and MSD, lecture honoraria from Janssen and MSD, advisory board participation with Acceleron, Janssen, MSD and United Therapeutics, and has an interest in the Investissement d'Avenir programme managed by the French National Research Agency under the grant contract ANR-18-RHUS-0006 (DESTINATION 2024), outside the submitted work. X. Jaïs reports grants from Acceleron, Janssen and MSD, lecture honoraria from Janssen and MSD, and travel support from Janssen, outside the submitted work. The remaining authors have no potential conflicts of interest to disclose.