VITRO score dynamics after liver transplantation predict portal-hypertensive events and post-transplant mortality

BACKGROUND AIMS: Portal hypertension (PH) after liver transplantation (LT) is rare but associated with complications and mortality. The VITRO score - combining von Willebrand Factor antigen (vWF) divided by platelet count (PLT) - reflects PH severity in cirrhosis, yet its prognostic value after LT remains unknown. METHODS: VITRO score dynamics and clinical outcomes were evaluated in 272 consecutive adult patients with available vWF-Ag measurements undergoing LT between 2016 and 2022 at the Medical University of Vienna. Laboratory parameters were assessed at listing, pre-LT, and at 3-6 and 12 months post-LT. Endpoints included overall mortality and a composite endpoint of PH events and/or liver-related death within 12 months post-LT. RESULTS: At listing, 89% of patients presented with clinically significant portal hypertension (CSPH), with markedly elevated vWF levels (median: 369%, IQR: 262-420) and VITRO scores (median: 3.3, IQR: 2.1-4.8). Following LT, PLT normalized in most cases, with vWF levels decreasing to 206% (IQR: 141-296) and VITRO scores improving to 1.1 (IQR: 0.9-1.5) at 3-6 months post-LT. ΔVITRO was significantly associated with both overall mortality (HR: 1.57, 95% CI: 1.28-1.93, p<0.001) and the composite endpoint of PH events/liver-related death (HR: 1.53, 95% CI: 1.24-1.88, p<0.001) within 12 months post-LT. In multivariable analysis adjusted for albumin, MELD dynamics, and age, ΔVITRO emerged as an independent predictor of mortality (aHR: 1.90, 95% CI: 1.40-2.57, p<0.001), alongside albumin (aHR 0.89, p=0.001) and post-LT MELD decrease (aHR 0.36, p=0.026). These findings remained robust in landmark sensitivity analyses from month 3 post-LT and after bootstrap-based internal validation. CONCLUSION: Post-LT VITRO score dynamics independently predict liver-related mortality and PH-related complications. Integration of ΔVITRO monitoring into post-LT care may facilitate individualized risk stratification after liver transplantation.