EXPOSURE (EUPAS19085) is an ongoing observational study of PAH patients in Europe and Canada who initiate PAH-specific therapy. A risk assessment with 4-strata was introduced in the 2022 ESC/ERS PH guidelines to guide treatment decision at follow-up.

This analysis presents characteristics, treatment patterns and outcomes of patients initiating selexipag between Sept 2017?Nov 2022, stratified by the 1-year mortality 4-strata ESC/ERS risk assessment (low, intermediate-low, intermediate-high and high strata).

By 30th Nov 2022, 535/698 selexipag-treated patients had data allowing for risk score assessment at selexipag initiation (Table). 14% of patients were in the low risk stratum, 31% in the intermediate-low, 34% in the intermediate-high and 20% in the high. In this prevalent population, the majority (74?81%) received selexipag as part of triple combination therapy. During the exposure period, 47% (7/15;n=12) of all hospitalisations were PAH-related in low risk patients, 54% (37/69; n=39) in intermediate-low, 53% (58/109; n=62) in intermediate-high, and 71% (51/72; n=46) in high risk; death occurred in 1 (1%), 7 (4%), 22 (12%) and 23 (21%) in the 4 risk strata, respectively.

Applying the recent ESC/ERS risk assessment indicated that in clinical practice, selexipag is initiated across all 4-risk strata, with about half of patients being at low or intermediate-low risk.