Hussein J Hassan, Mario Naranjo, Nour Ayoub, Traci Housten, Steven Hsu, Aparna Balasubramanian, Catherine E Simpson, Rachel L Damico, Stephen C Mathai, Todd M Kolb, Paul M Hassoun

To date, it remains unclear whether recent changes in the management of patients with systemic sclerosis-associated pulmonary hypertension (SSc-PH) have improved survival. To describe a cohort of SSc-PH patients and compare their characteristics and survival between the last two decades. SSc-PH patients prospectively enrolled in the Johns Hopkins PH Center Registry were grouped into two cohorts based on the date of diagnostic right heart catheterization: cohort A included patients diagnosed between 1999 and 2010, and cohort B included those diagnosed between 2010 and 2021. Patients' characteristics were compared between the two cohorts. Of 504 SSc-PH patients distributed almost equally between the two cohorts, 308 (61%) had World Symposium on Pulmonary Hypertension (WSPH) Group 1, 43 (9%) had Group 2, and 151 (30%) had Group 3. Patients with Group 1 disease in cohort B had significantly better clinical and hemodynamic characteristics at diagnosis, were more likely to receive upfront combination pulmonary arterial hypertension therapy, and had a nearly 4-year increase in median transplant-free survival in univariable analysis compared to those in cohort A (P<0.01). Improved transplant-free survival was still observed after adjusting for patients' baseline characteristics. In contrast, for Group 2 or 3 SSc-PH patients, there were no differences in baseline clinical, hemodynamic, or survival characteristics between the two cohorts. This is the largest single-center study that compares clinical characteristics of SSc-PH patients between the last two decades. Transplant-free survival has improved significantly for those with Group 1 disease over the last decade, possibly secondary to earlier detection and better therapeutic management. Conversely, those with Group 2 or 3 disease continue to have dismal prognosis.