Prognostic Value of First Post-Transplant Lung Function

PurposeNormalization of lung function after transplant is an important milestone and determinant of survival. We tested the relationship between first post-transplant lung function and the maximal (baseline) function, as well the association with future lung dysfunction phenotypes, survival and potential pretransplant predictors.MethodsWe analyzed patients who underwent double lung transplant at our center between 2004 and 2016, assessing their first and maximum (baseline) forced expiratory volume in 1 second (FEV1) percent predicted. We tested the relationship between first and maximum FEV1% predicted via correlation coefficient. We secondarily analyzed the relationship between first FEV1% predicted and the future risk of baseline lung allograft dysfunction (BLAD) via logistic regression and time to chronic lung allograft dysfunction (CLAD) onset and overall survival via Cox regression. We assessed for pretransplant factors associated with first FEV1% predicted by t-tests and correlation coefficients.ResultsWe analyzed 446 patients with a mean first FEV1 of 2.14L (SD 0.70) and FEV1% predicted of 63.8% (SD 16.8), performed at a median of 23 days post-transplant (IQR 16-38). First function was strongly associated with maximal baseline function (corr coeff 0.5955, p<0.0001; figure 1). First FEV1% < 80% predicted strongly increased the risk of BLAD (odds ratio 7.89 (95% CI 3.91-18.20, p<0.0001), but not of death or time to CLAD onset. Grade 3 PGD and longer ventilation, ICU stay and hospitalization were all associated with lower first function, but time to first function was not. Pre- and peritransplant factors associated with first function < 80% predicted were: younger recipient age, older and female donors, use of cardiopulmonary bypass and use of IL2RA induction.ConclusionFirst FEV1% predicted is an important milestone associated with future baseline lung function, but not with future risk of death or CLAD onset. Future work into whether this early value is modifiable would be of use. Normalization of lung function after transplant is an important milestone and determinant of survival. We tested the relationship between first post-transplant lung function and the maximal (baseline) function, as well the association with future lung dysfunction phenotypes, survival and potential pretransplant predictors. We analyzed patients who underwent double lung transplant at our center between 2004 and 2016, assessing their first and maximum (baseline) forced expiratory volume in 1 second (FEV1) percent predicted. We tested the relationship between first and maximum FEV1% predicted via correlation coefficient. We secondarily analyzed the relationship between first FEV1% predicted and the future risk of baseline lung allograft dysfunction (BLAD) via logistic regression and time to chronic lung allograft dysfunction (CLAD) onset and overall survival via Cox regression. We assessed for pretransplant factors associated with first FEV1% predicted by t-tests and correlation coefficients. We analyzed 446 patients with a mean first FEV1 of 2.14L (SD 0.70) and FEV1% predicted of 63.8% (SD 16.8), performed at a median of 23 days post-transplant (IQR 16-38). First function was strongly associated with maximal baseline function (corr coeff 0.5955, p<0.0001; figure 1). First FEV1% < 80% predicted strongly increased the risk of BLAD (odds ratio 7.89 (95% CI 3.91-18.20, p<0.0001), but not of death or time to CLAD onset. Grade 3 PGD and longer ventilation, ICU stay and hospitalization were all associated with lower first function, but time to first function was not. Pre- and peritransplant factors associated with first function < 80% predicted were: younger recipient age, older and female donors, use of cardiopulmonary bypass and use of IL2RA induction. First FEV1% predicted is an important milestone associated with future baseline lung function, but not with future risk of death or CLAD onset. Future work into whether this early value is modifiable would be of use.