Does your working phenotype for ‘new PAH after LT’ (occult POPH vs PAH unmasked after HPS resolution vs distinct post-LT vasculopathy) change what you actually do—specifically, who you screen more aggressively and when you initiate PAH therapy?

In pre-liver transplant patients with known hepatopulmonary syndrome (HPS), we do pay greater post-transplant attention to those considered to have "large intrapulmonary shunts," marked lung-brain uptake with technetium-99m macroaggregated albumin (⁹⁹ᵐTc-MAA) scanning (>30%) or poor response to 100% inspired oxygen (PaO₂ < 300 mmHg). These are just suggested parameters leading us to more careful screening echocardiography studies post-transplant (even 4 weeks after transplant) for the development of pulmonary artery hypertension (PAH). In all liver transplant recipients, we routinely obtain transthoracic echocardiograms (TTEs) at 4 and 12 months post-transplant. Following an abnormal echocardiogram (right ventricular systolic pressure [RVSP...