Mild pulmonary hemodynamic alterations in patients with systemic sclerosis: relevance of the new 2022 ESC/ERS definition of pulmonary hypertension and impact on mortality

Abstract

Background and objective: The definition of pre-capillary pulmonary hypertension (PH) has been modified, with lowering of the mean pulmonary arterial pressure (mPAP) threshold from 25 to 20 mmHg and addition of a mandatory criterion of pulmonary vascular resistance (PVR) ≥ 2 Wood units (WU). Our objectives were: 1/ to estimate the proportion of patients reclassified as having pre-capillary PH when using the new 2022 ESC/ERS hemodynamic criteria (i.e. mPAP 21-24 mmHg and PVR ≥ 2 WU), and to describe their clinical characteristics and outcome; and 2/ to study the relationship between PVR and survival in patients with mPAP > 20 mmHg. Methods: We retrospectively analyzed consecutive SSc patients included in our National Reference Center for a first right-heart catheterization between 2003 and 2018. The association between survival and PVR was studied using smoothing splines. Results: We included 126 SSc patients with mPAP > 20 mmHg. Among them, 16 (13%) had a baseline mPAP value between 21 and 24 mmHg and PVR ≥ 2 mmHg and were reclassified as pre-capillary PH; 10 of which (62%) raised their mPAP ≥ 25 mmHg during follow-up. In patients with mPAP > 20 mmHg, we observed a linear relation between PVR and mortality for values < 6 WU. Conclusion: A significant proportion of SSc patients is reclassified as having pre-capillary PH with the new 2022 ESC/ERS hemodynamic definition. Lowering the PVR threshold from 3 to 2 WU captures patients at risk of raising their mPAP > 25 mmHg, with a possibly less severe disease.