Introduction: Connective tissue disease related PAH (CTD-PAH) patients are classified as Group 1 according to the World Symposium on pulmonary hypertension. Patients with CTD-PAH with significant interstitial lung disease (CTD-PAH-ILD) are classified as Group 3 and are shown to have worse outcomes than CTD-PAH patients, however the degree of fibrosis has not been reported in previous studies (Humbert et al., 2022).

Aim: Investigate whether patients with CTD-PAH-ILD with mild to moderate fibrosis (subgroup A, less than 30%) respond better to pulmonary vasodilator therapy (VDT) than their counterpart with severe fibrosis (subgroup B, more than 30%). 

Methods: Retrospective chart review of patients diagnosed with CTD-PAH and ILD who had right heart catheterization and were treated with VDT between January 2015-December 2021 in a tertiary center. Patients were divided into two subgroups based on visual scoring of fibrosis on chest CT.

Results:The median follow-up was 20 months. There was no difference in baseline modified clinical risk criteria or echocardiography RVSP (Table 1). Both groups had improvement in MPAP and PVR however degree of improvement was not statistically significant (Table 2). 

Conclusion:There was no statistically significant difference in clinical, hemodynamics improvement including escalation of VDT between the subgroups.