Functional Status and Time Since Primary Lung Transplant Predict Survival after Redo Lung Transplant

Abstract

Survival is worse after redo lung transplant (LTx) compared to primary LTx. We hypothesize that functional status and time since primary LTx predict survival after redo LTx. From the Scientific Registry of Transplant Recipients (SRTR) database, 681 adult and pediatric patients underwent primary LTx before redo LTx from 01/01/2005-9/1/2018. Pre-LTx characteristics, Karnofsky Performance Status (KPS), time between primary and redo LTx, intra-operative variables, LTx complications, and survival were evaluated. Those with en bloc, lobar, multivisceral or heart-lung transplants, or without preoperative KPS were excluded. Paired comparisons were used to compare pre-transplant variables. Survival analysis was used to examine mortality after redo LTx, and risk factors for survival within a Cox PH regression model including recipient center as a random effect, while time between transplants was considered using time-dependent coefficients at follow-up times of 3, 6, and 12 months. All analysis was performed in R (ver. 3.6.0) RESULTS: KPS was grouped into 3 categories:10-40%, 50-60%, 70-100%. Compared to their first transplant, KPS prior to redo LTx was significantly worse (37% vs 64% with a KPS of 10-40%). Prior to their redo LTx, patients were more likely to require ventilation support (9% vs 37%) and ICU admission (13% vs 37%). Following redo LTx, survival was worse in the KPS 10-40% group, compared to the 50-60% and 70-100% groups (Figure 1, log-rank p=0.017). This effect was lessened in the multivariate model, but survival for the 70-100% group was still better than for KPS 10-40%. The effect of decreased time between transplants is most prominent in the early postoperative period. Higher functional status and increased time between the primary and redo LTx predict improved survival after redo LTx. Increased mortality risk with early redo LTx is most dramatic in the early postoperative period after redo LTx.