Predictors of clinical outcome in emphysema patients with atelectasis following endoscopic valve therapy

Background: The aim of endoscopic valve therapy in emphysema patients is a complete lobar atelectasis of the most emphysematous destroyed lobe. Despite radiological advent of atelectasis, a great variability in the clinical outcome can be observed. Objective: Baseline lung function, exercise test and high resolution computed tomography (HRCT) variables were analysed to identify predictors of clinical outcome following valve therapy. Methods: Baseline clinical measures (VC, FEV 1 , RV, 6-MWT) and HRCT variables (low attenuation volume (LAV) of target lobe, LAV% of target and of ipsilateral untreated lobe, LAV of target lobe to LAV of target lung and to LAV of total lung) of 77 patients with complete lobar atelectasis after valve therapy were examined for their impact on outcome (changes of VC, FEV 1 , RV, 6-MWT from baseline to time point of atelectasis). Results: LAV of target lobe to LAV of target lung predicts significantly FEV 1 improvement in patients with complete lobar atelectasis following valve therapy. A 10% difference in that CT predictor was associated with a 82ml improvement in FEV 1 at the time of atelectasis (p=0.006). For 6-MWT, LAV% of target lobe (p=0.064) was found to be a predictor. A 10% difference in the LAV% of target lobe was associated with a 7.7meters improvement. Worse 6-MWT, low VC and high RV at baseline were associated significantly with greater improvement for the respective parameter (all p Conclusion: LAV of target lobe to LAV of target lung and baseline clinical measures seem to predict significantly clinical outcome in patients with complete lobar atelectasis following valve treatment. Data have to be confirmed in a larger prospective study.