Phenotypic patterns and outcomes of connective tissue disease-associated pulmonary arterial hypertension: a Saudi single center experience.

BACKGROUND

CTD-PAH is a heterogeneous condition with poor prognosis. While systemic sclerosis predominates in Western cohorts, systemic lupus erythematosus is a major contributor in Saudi Arabia and other non-Western regions. However, data on phenotypes, outcomes, and longitudinal risk stratification in Middle Eastern CTD-PAH remain limited. This study characterized CTD-PAH in a Saudi cohort and identified predictors of adverse outcomes.

METHODS

We retrospectively analyzed adult patients with CTD-PAH from the SAUDIPH registry (2004-2024), comparing baseline characteristics and 2-year changes in REVEAL Lite 2 scores between SLE-PAH and other CTD-PAH subtypes.

RESULTS

Thirty-nine patients were included (24 with SLE-PAH and 15 with other CTD-PAH subtypes), with a mean age of 39 years at PAH diagnosis. Patients with SLE were diagnosed at a younger age (p = 0.011) and showed evidence of disease activity, including higher anti-dsDNA levels and lower complement C3 and C4. Although New York Heart Association functional class was worse in the non-SLE group (p = 0.02), both groups had predominantly high-risk REVEAL Lite 2.0 scores at baseline and demonstrated significant improvement after two years of therapy, regardless of SLE status or early immunosuppression. Multiorgan autoimmune involvement and lower C3 and C4 complement levels showed a trend toward higher REVEAL Lite 2 scores at 2-year follow-up, although not statistically significant.

CONCLUSIONS

In this Saudi cohort, SLE-PAH was the predominant CTD-PAH subtype. Despite clinical differences, there was no statistically significant difference in disease severity at diagnosis or in response to PAH-targeted therapy between SLE-PAH and non-SLE-PAH.