How do you distinguish portopulmonary hypertension from group 3 or mixed-etiology PH in liver transplant candidates with COPD/ILD and elevated mPAP—what additional testing (PFTs/DLCO, CT, V/Q, ABG, repeat RHC maneuvers) or hemodynamic interpretation do you rely on before listing?

Certainly, PFTS and Chest CT help decide if another (possible group 3) major issue is evolving along in the setting of suspected or proven portopulmonary hypertension (POPH) by right heart cath. In my experience, the severity of the pulmonary hypertension (mPAP and PVR) is helpful. Rarely have I see...