Outcomes and temporal trends among high-risk patients after lung transplantation in the United States

Introduction: Although several studies have evaluated risk factors for death after lung transplantation (LTx), few studies have focused on the highest-risk recipients. We undertook this study to evaluate the effect of high lung allocation scores (LAS), ventilator support, and extracorporeal membrane oxygenation (ECMO) support on outcomes after LTx. Methods: We retrospectively reviewed all LTx recipients in the United Network for Organ Sharing database. Primary stratification was by recipient acuity at the time of LTx. The 3 strata consisted of (1) recipients in the highest LAS quartile (LAS < 48.4), (2) those requiring ventilator support, and (3) those requiring ECMO support. The primary outcome was 1-year mortality. Sub-group analysis focused on temporal trends. Results: From May 2005 to June 2011, 9,267 adults underwent LTx. Before LTx, 1,874 (20.2%) were in the highest LAS quartile, 526 (5.7%) required ventilator support, and 122 (1.3%) required ECMO support. Unadjusted analysis showed decreased 1-year survival associated with ventilator (67.7%) and ECMO support (57.6%) compared with the highest LAS quartile (81.0%; p < 0.001 for each comparison). These differences persisted on adjusted analysis for ventilator support (hazard ratio, 1.99, p < 0.001) and ECMO support (hazard ratio, 3.03; p < 0.001). Increasing annual center volume was associated with decreased mortality. In patients bridged to LTx with ECMO support, 1-year survival improved over time (coefficient, 8.03% per year; p = 0.06). Conclusions: High-acuity LTx recipients, particularly those bridged with ventilator or ECMO support, have increased short-term mortality after LTx. However, since the introduction of the LAS, high-risk patients have demonstrated improving outcomes, particularly at high-volume centers.