Endobronchial Valve Therapy in Patients with Homogeneous Emphysema: Results from the IMPACT Study

Abstract

Abstract Rationale Endobronchial valves (EBVs) have been successfully used in patients with severe heterogeneous emphysema to improve lung physiology. Limited available data suggest that EBVs are also effective in homogeneous emphysema. Objectives To evaluate the efficacy and safety of EBVs in patients with homogeneous emphysema with absence of collateral ventilation assessed with the Chartis system. Methods Prospective, multicenter, 1:1 randomized controlled trial of EBV plus standard of care (SoC) or SoC alone. Primary outcome was the percentage change in FEV1 (liters) at 3 months relative to baseline in the EBV group versus the SoC group. Secondary outcomes included changes in FEV1, St. George’s Respiratory Questionnaire (SGRQ), 6-minute-walk distance (6MWD), and target lobe volume reduction. Measurements and Main Results Ninety-three subjects (age, 63.7 ± 6.1 yr [mean ± SD]; FEV1, % predicted, 29.3 ± 6.5; residual volume, % predicted, 275.4 ± 59.4) were allocated to either the EBV group (n = 43) or the SoC group (n = 50). In the intention-to-treat population, at 3 months postprocedure, improvement in FEV1 from baseline was 13.7 ± 28.2% in the EBV group and −3.2 ± 13.0% in the SoC group (mean between-group difference, 17.0%; P = 0.0002). Other variables demonstrated statistically and clinically significant changes from baseline to 3 months (EBV vs. SoC, respectively: SGRQ, −8.63 ± 11.25 vs. 1.01 ± 9.36; and 6MWD, 22.63 ± 66.63 m vs. −17.34 ± 52.8 m). Target lobe volume reduction at 3 months was −1,195 ± 683 ml (P < 0.0001). Of the EBV subjects, 97.2% achieved volume reduction in the target lobe (P < 0.0001). Procedure-related pneumothoraces occurred in 11 subjects (25.6%). Five subjects required removal/replacement of one or more valves. One subject experienced two valve migration events requiring removal/replacement of valves. Conclusions EBV in patients with homogeneous emphysema without collateral ventilation results in clinically meaningful benefits of improved lung function, exercise tolerance, and quality of life.