This study showed that 3 of 5 patients (60.0%) with high-risk PAH reached PVR ≤ 4 WU and/or mPAP ≤ 40 mmHg by receiving intensive parenteral treprostinil therapy with significant improvements in 6MWD and NT-proBNP levels, and successfully transitioned to oral selexipag. We proposed that transition strategies from parenteral treprostinil to selexipag aiming at hemodynamic targets.