Results: A total of 292 patients with SLE- associated PAH were enrolled.

Patients with associated PAH were significantly more likely to be postmenopausal compared to controls.

Conclusions: CPET is a safe and valuable method in the non-invasive detection of SSc- associated PAH.

We prospectively studied 69 consecutive patients with CTD- associated PAH.

Baseline data for patients with SLE- associated PAH and SLE patients without PAH were collected and compared.

African American and Hispanic patients are more likely to present with associated PAH compared to non-Hispanic whites.

We assessed the diagnostic accuracy of key parameters derived from cardiopulmonary exercise testing (CPET) for detecting and ruling out SSc- associated PAH.

Mass fraction of the fine particles associated PAHs was found to be positively correlated with fuel density and moisture, and negatively correlated with combustion efficiency.