Home Spirometry and Chronic Allograft Disease after Lung Transplantation—The Clinical Impact

Objective: Chronic allograft disease after lung transplantation (CLAD) remains one of the major problems in long-term cause of these patients. Home spirometry is routinely used for the assessment of acute pulmonary events and the development of CLAD. Nevertheless the evidence for home spirometry in lung transplantation is rare. The aim of this study was to analyze the clinical impact of home spirometry in patients with CLAD.

Methods: We analyzed the home spirometry data (62,180 measurements) of 37 patients after lung transplantation during a mean observation time of 27.6 months. Patient demographics, acute pulmonary events, and development auf CLAD on the basis of standard FEV1-Baseline (1 peak measurement) were evaluated. Additionally the development auf CLAD was calculated using an alternative FEV1-Baseline (arithmetic mean of the 10 best 3-day medians). To determine a clinical impact regression analysis was performed.

Results: The patients were 42.2 ± 16.3 years of age (62.5% male). Indications for lung transplantation were fibrosis (29.7%), cystic fibrosis (24.3%), COPD (32.4%), CLAD (5.4%, Re-Tx), Eisenmenger syndrome (5.4%, HLTX), and sarcoidosis (2.7%). Freedom of CLAD (≤ stadium 1) calculated with standard Baseline were 426.7 ± 103.8 days. Freedom of CLAD (≤ stadium 1) calculated with the alternative FEV1-Baseline were significantly (p = 0.003, 216%) longer (922.5 ± 141.3 days). In regression analysis, CLAD stadium calculated with the alternative FEV1-Baseline was the only significant risk factor for occurrence of acute pulmonary events (p=0,041) and poor recovery (p = 0.020) in our population.

Conclusion: Home spirometry is an important tool to assess CLAD in the long-term medical care after lung transplantation. A significant clinical impact is only detectable if our alternative FEV1-Baseline is used for calculating the CLAD stadium.