Lung volumes predict survival in patients with chronic lung allograft dysfunction
23 February 2017 (online)
Identification of disease phenotypes might improve understanding and care of patients with chronic lung allograft dysfunction (CLAD). The aim of the study was to assess the impact of pulmonary restriction and pulmonary hyperinflation by lung volume measurements at the onset of CLAD.
396 consecutive bilateral lung transplant recipients were analysed. At onset, CLAD was further categorized based on plethysmography. A restrictive CLAD (R-CLAD) was defined as a loss of total lung capacity (TLC) of baseline. Pulmonary hyperinflation (H-CLAD) was defined as an increased ratio of residual volume (RV) to TLC. Outcome was survival after CLAD onset. Patients with insufficient clinical information were excluded (n = 95).
Out of 301 lung transplant recipients 94 (31.2%) developed CLAD. Patients with R-CLAD (n = 20) and H-CLAD (n = 21), respectively had a significantly worse survival (p < 0.001) than patients with non-R/H-CLAD. Both R-CLAD and H-CLAD were associated with increased mortality when controlling for baseline characteristics, time to CLAD and severity of CLAD at onset (HR = 5.69 [2.32; 13.96]; p < 0.001 and HR = 5.19 [2.17; 12.38]; p < 0.001). Further, measurement of static lung volumes was associated with a strong diagnostic accuracy for the clinical syndrome of CLAD and useful to identify patients with combined phenotypes.
Measurement of lung volumes in the long-term follow-up of lung transplant recipients allows identification of patients who are at risk for worse outcome and warrant special consideration.