Pulmonary function test parameters before liver transplantation predict post-transplant survival and respiratory-related death.

Abstract

Pulmonary function tests (PFTs) are performed ahead of listing for liver transplantation (LT) to assess respiratory fitness for transplantation. We aimed to establish whether pre-transplant PFTs were associated with post-LT overall survival and respiratory cause of death. A single-center retrospective study of patients transplanted between 2014 and 2023 was performed. Cox regression was used to analyze the relationship between PFT parameters, normalized for age, sex, ethnicity, and overall post-transplant survival. Competing risks regression was used to analyze the relationship between PFT parameters and respiratory death post-LT. Pre-transplant PFTs from 772 LT recipients were studied (33% female, median age 58 y, indication for transplant: alcohol-associated liver disease in 28.3%, metabolic dysfunction-associated steatotic liver disease in 18.0%). When combined with clinical variables, PFT parameters were predictive of post-transplant overall survival and respiratory death. Lower forced expiratory volume in 1 second (FEV1) (aHR 0.85, 95% CI 0.73-0.99, p =0.04), increased age at transplant (aHR 1.03, 95% CI 1.01-1.05, p =0.01), and current smoking at time of assessment (aHR 1.95, 95% CI 1.08-3.54, p =0.03) were independently associated with poorer post-transplant survival. Whereas both single-breath diffusing capacity of the lung (DLCO SB) (aSHR 0.66, 95% CI 0.52-0.82, p <0.001) and increasing age (aSHR 1.08, 95% CI 1.03-1.14, p =0.001) were independent predictors of post-LT respiratory cause of death. In conclusion, a lower FEV1 z -score was independently associated with poorer post-LT overall survival, and a lower DLCO SB z -score was associated with respiratory cause of death post-LT, supporting the routine use of PFTs in pre-liver transplant assessment.