Pulmonary vascular dysfunction in systemic sclerosis.

Purpose: This study aimed to determine if any cases of pulmonary arterial hypertension (PAH) were missed using routine screening of systemic sclerosis (SSc). We assessed the potential benefits of adding the DETECT algorithm and invasive hemodynamic exercise testing into the local screening process in a Danish single-center cohort without known PAH. Methods: Seventy-three patients with SSc (aged 60 ± 10 years; 56 (77%) females) underwent echocardiography. Among them, 24/73 had an elevated step 2 score of whom 3 had a high risk of pulmonary hypertension on echocardiographic assessment. Four patients declined right heart catheterization. Twenty patients (aged 62 ± 10 years, 13 (65%) females) underwent invasive hemodynamic assessment at rest. Nineteen patients participated in invasive hemodynamic exercise testing. Results: At rest, 3/20 patients met the 2022 ESC guidelines for PAH (mean pulmonary arterial pressure (mPAP) >20 mm Hg, pulmonary arterial wedge pressure (PAWP) ≤15 mm Hg, and pulmonary vascular resistance >2 Wood units). According to the 2015 ESC guidelines, only 1/19 patients had PAH. During exercise, 18/19 experienced an mPAP of >30 mm Hg, with the majority (13/19) showing an abnormal pulmonary pressure-flow relationship >3 mm Hg/liter/min. Interestingly, 7 out of 9 patients with no pulmonary hypertension (PH) at rest had exercise-induced pulmonary hypertension. One-quarter of the patients had pulmonary hypertension associated with left ventricular dysfunction (group 2 PH, WHO classification). Conclusions: In a Danish cohort of 73 patients with SSc already undergoing bi-annual PAH screening, applying the DETECT algorithm identified 3 patients meeting the 2022 ESC/ERS guideline criteria for PAH at rest, 1 of whom demonstrated increased PAWP with exercise. However, many patients exhibited an abnormal pulmonary vascular response to exercise and/or signs of group 2 PH.