Airway oscillometry parameters in baseline lung allograft dysfunction: Associations from a multicenter study

BACKGROUND: Baseline lung allograft dysfunction (BLAD), the failure to achieve >= 80%-predicted spirometry after lung transplant (LTx), is associated with impaired survival. Physiologic abnormalities in BLAD are poorly understood. Airway oscillometry measures respiratory system mechanics and may provide insight into understanding the mechanisms of BLAD.OBJECTIVES: This study aims to describe and measure the association between airway oscillome-try parameters [Reactance (Xrs5, Ax), Resistance (Rrs5, Rrs5-19)] (1) stable LTx recipients, com-paring those with normal spirometry and those with BLAD; and (2) in recipients with chronic lung allograft dysfunction (CLAD), comparing those with normal baseline spirometry and those with BLAD.METHODS: A multi-center cross-sectional study was performed including bilateral LTx between January 2020 and June 2021. Participants performed concurrent airway oscillometry and spirometry. Multivariable logistic regression was performed to measure the association between oscillometry parameters and BLAD.RESULTS: A total of 404 LTx recipients performed oscillometry and 253 were included for analysis. Stable allograft function was confirmed in 149 (50.2%) recipients (92 (61.7%) achieving normal spi-rometry and 57 (38.3%) with BLAD). Among stable LTx recipients, lower Xrs5 Z-Score (aOR 0.50 95% CI 0.37-0.76, p = 0.001) was independently associated with BLAD. CLAD was present in 104 (35.0%) recipients. Among recipients with CLAD, lower Xrs5 Z-Score (aOR 0.73 95% CI 0.56-0.95, p = 0.02) was associated with BLAD.CONCLUSIONS: Oscillometry provides novel physiologic insights into mechanisms of BLAD. The independent association between Xrs5 and BLAD, in both stable recipients and those with CLAD suggests that respiratory mechanics, in particular abnormal elastance, is an important physiologic feature. Further longitudinal studies are needed to understand the trajectory of oscillometry parameters in relation to allograft outcomes. J Heart Lung Transplant 2023;42:767-777 (c) 2023 International Society for Heart and Lung Transplantation. All rights reserved.

Automated summary

This study aims to describe and measure the association between airway oscillometry parameters and baseline lung allograft dysfunction (BLAD). The results showed that lower Xrs5 Z-score was independently associated with BLAD in stable lung transplant recipients. Lower Xrs5 Z-score was also associated with BLAD in recipients with chronic lung allograft dysfunction (CLAD).