Survival among patients with systemic sclerosis‐associated pulmonary arterial hypertension in the Australian scleroderma cohort study

BACKGROUND AND AIMS: Systemic sclerosis (scleroderma; SSc) patients can develop pulmonary arterial hypertension (PAH), which is a leading cause of death. We sought to evaluate severity, therapeutic strategy and survival of SSc-PAH in the Australian Scleroderma Cohort Study (ASCS). METHODS: Among patients with 2013 American College of Rheumatology/European League Against Rheumatism-defined SSc, PAH was defined as mean pulmonary artery pressure (mPAP) ≥20 mmHg, pulmonary arterial wedge pressure (PAWP) ≤15 mmHg and pulmonary vascular resistance (PVR) >2 WU. Characteristics of those with and without PAH and those with incident PAH in 2014-2020 versus 2007-2013 were compared using descriptive statistics. Survival was evaluated using the Kaplan-Meier method and a multivariable Cox regression model. RESULTS: Among 1612 patients, 71 (4.4%) had incident PAH prior to censoring on 13 February 2024. Significantly more patients received PDE5i monotherapy in the first 12 months after PAH diagnosis in the later epoch (30 (63.8%) vs 6 (25.0%), P = 0.002). Dual therapy (any endothelin reception antagonist (ERA) and any PDE5i) was more common in the later epoch (26 (55.3%) vs 4 (16.7%), P = 0.002). Overall survival of those diagnosed with PAH between 2007 and 2013 was 91.67%, 87.50% and 56.88% at 1, 3 and 5 years. Overall survival of those diagnosed between 2014 and 2020 was 100.00%, 77.62% and 48.98% at 1, 3 and 5 years (P = 0.414). CONCLUSIONS: Despite increased use of dual therapy in the more recent epoch, we observed no significant improvement in overall survival in SSc-PAH in our cohort. Our cohort's 1-, 3- and 5-year mortality is comparable to those reported for other contemporary SSc-PAH cohorts.