Characterization of Baseline Lung Allograft Dysfunction in Single Lung Transplant Recipients

Background. Baseline lung allograft dysfunction (BLAD) is characterized by the failure to achieve normal baseline lung function after double lung transplantation (DLTX) and is associated with a high risk of mortality. In single lung transplant (SLTX) recipients, however, cutoff values and associated factors have not been explored. Here, we aimed to define BLAD in SLTX recipients, investigate its impact on allograft survival, and identify potential risk factors for BLAD in SLTX recipients. Methods. We performed a retrospective, single-center analysis of the LTX cohort of LMU Munich between 2010 and 2018. In accordance with DLTX cutoffs, BLAD in SLTX recipients was defined as failure to achieve percentage of forced expiratory volume in 1 s and percentage of forced vital capacity of >60% on 2 consecutive tests >3 wk apart. Survival analysis and regression analysis for potential predictors of BLAD were performed. Results. In a cohort of 141 SLTX recipients, 43% of patients met BLAD criteria. SLTX recipients with BLAD demonstrated impaired survival. Native lung hyperinflation was associated with BLAD in obstructive disease, whereas donor/recipient lung size mismatch was associated with BLAD in both obstructive and restrictive underlying diseases. Pulmonary function testing at 3 mo after lung transplantation predicted normal baseline lung function in SLTX recipients with obstructive lung disease. Conclusions. BLAD in SLTX recipients is as relevant as in DLTX recipients and should generally be considered in the follow-up of LTX recipients. Risk factors for BLAD differed between underlying obstructive and restrictive lung disease. A better understanding of associated factors may help in the development of preventive strategies.