Abnormal one-year post-lung transplant spirometry is a significant predictor of increased mortality and chronic lung...

The prognostic value of evaluating spirometry at a fixed time point using standardized population reference has not previously been evaluated. Our aim was to assess the association between spirometric phenotype at 12 months (Spiro_12M), survival and incidence of chronic lung allograft dysfunction (CLAD) in bilateral lung transplant recipients.

We conducted a retrospective cohort study of bilateral lung transplant recipients transplanted between January 2003 and September 2012. We defined Spiro_12M as the mean of the 2 prebronchodilator FEV₁ measurements 12-month post-transplant. Normal spirometry was defined as FEV₁/FVC ≥0.7 and FEV1≥80% and FVC≥80% predicted population-based values for that recipient. Abnormal spirometry was defined as failure to attain normal function by 12-months. We used a Cox regression model to assess the association between Spiro_12M, survival, and CLAD. We used logistic regression to assess potential pretransplant donor and recipient factors associated with abnormal Spiro_12M RESULTS: One hundred and eleven (51%) lung transplant recipients normalized their Spiro_12M. Normal Spiro_12M was associated improved survival (hazard ratio [HR] 0.60, 95% confidence interval [CI] 0.41-0.88], p = 0.009. Each 10% decrement in FEV₁ increased the risk of death in a stepwise fashion. Additionally, CLAD was reduced in those with normal Spiro_12M (HR:0.65, 95%CI:0.46-0.92, p = 0.016). Donor smoking history (OR:2.93, 95% CI:1.21-7.09; p = 0.018) and mechanical ventilation time in hours (OR:1.03, 95% CI:1.004-1.05; p = 0.02) were identified as independent predictors of abnormal Spiro_12M.

Abnormal Spiro_12M is associated with increased mortality and the development of CLAD. The effect is dose dependent with increased dysfunction corresponding to increased risk. This assessment of phenotype at 12-months can easily be incorporated into standard of care.