Identification of optimal portal pressure decrease to control ascites while minimizing HE after TIPS: A multicenter study

BACKGROUND AND AIMS: Clinically significant portal hypertension in patients with liver cirrhosis can lead to refractory ascites. A TIPS treats clinically significant portal hypertension but may cause overt hepatic encephalopathy (oHE). Our aim was to determine the optimal reduction of the portal pressure gradient (PPG) through TIPS to control ascites without raising oHE risk. APPROACH AND RESULTS: This multicenter study screened 1509 patients from 3 European centers (Hannover, Vienna, and Hamburg) undergoing TIPS implantation between 2000 and 2023. Patients with TIPS indications other than refractory ascites/hepatic hydrothorax, vascular liver disease, HCC, or insufficient PPG data were excluded. PPG was measured before and after TIPS insertion. Outcome data were assessed up to 1 year after TIPS insertion. Analyses were conducted utilizing a modern machine learning model, namely a competing-risk random survival forest, partial dependence plots, and competing risk analyses with liver transplantation/death as competitors. The cohort was divided into a 60% derivation and 40% validation cohort. Overall, 729 patients (median MELD: 13 [IQR 10-16], 66% male, 23% oHE before TIPS) were analyzed. The derivation cohort comprised 438 patients, and the validation cohort comprised 291 patients. The optimal PPG reduction, determined by maximally selected Gray statistic and PDP of the random survival forest, was 60%-80%. In this range, patients showed significantly fewer hepatic decompensations due to ascites (HDA) (subdistribution hazard ratio [sHR]: 0.7 [0.52-0.96]) with similar oHE incidences (sHR: 0.92 [0.67-1.27]). The PPG range was confirmed in the validation cohort (HDA: sHR: 0.66 [0.46-0.96]; oHE: sHR: 0.89 [0.61-1.32]). CONCLUSIONS: A targeted PPG reduction of 60%-80% showed significantly reduced HDA without increased oHE risk. Therefore, PPG reduction within this range could be a valid reduction target.