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

Introduction: The aim of endoscopic valve therapy in patients with emphysema 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. In this analysis baseline lung function parameters, exercise test and high resolution computed tomography (HRCT) variables were analyzed to identify predictors of clinical outcome following valve therapy.

Methods: Baseline clinical measures (VC, FEV1, 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 following valve therapy were assessed and examined for their impact on patient's outcome (changes of VC, FEV1, RV, 6-MWT from baseline to time point of atelectasis).

Results: LAV of target lobe to LAV of target lung predicts significantly FEV1 improvement in patients with complete lobar atelectasis following valve therapy. A 10% difference in that CT predictor was associated with a 82 ml improvement in FEV1 at the time of atelectasis (p = 0.006). For 6-MWT, LAV% of target lobe (p = 0.064) was found to be a CT predictor. A 10% difference in the LAV% of target lobe value was associated with a 7.7meters improvement in the 6MWT. Worse 6-MWT, low VC and high RV at baseline were associated significantly with greater improvement for the respective parameter (all p < 0.001).

Discussion: 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.

*Presenting author