Baseline lung allograft dysfunction is associated with impaired survival after double-lung transplantation

Abstract

The prognostic value of defining normal vs abnormal baseline post-transplant lung function (or baseline lung allograft dysfunction [BLAD]) has not been studied using standardized reference values of percent predicted of the population. Our aim was to assess the association between BLAD and survival in double-lung transplant recipients and assess for potential pre-transplant donor and recipient risk factors for BLAD. We conducted a retrospective cohort study of double-lung transplant recipients in our program during the period 2004 to 2009. We defined normal baseline function as both forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) ≥80% predicted on at least 2 consecutive tests ≥3 weeks apart; we defined BLAD as failure to meet these criteria. We used a Cox regression model to assess the association between BLAD and survival. We used logistic regression to assess potential pre-transplant donor and recipient factors associated with BLAD. Of 178 patients double-lung transplant recipients eligible for study, 75 (42%) met the criteria for BLAD. BLAD was associated with impaired survival (hazard ratio [HR] 2.23, 95% confidence interval [CI] 1.41 to 3.54]) via Cox regression compared to patients with normal baseline, and lower baseline was associated with greater risk of death in a dose-dependent fashion. Pre-transplant factors associated with BLAD included interstitial lung disease (ILD) as an indication for transplant (odds ratio [OR] 2.66, 95% CI 1.17 to 6.15) and heavy donor smoking history (OR 3.07, 95% CI 1.17 to 8.43). BLAD is dynamic risk state associated with impaired survival after double-lung transplantation, and should be considered when physiologically phenotyping patients.