A randomised controlled study of Bronchoscopic Lung Volume Reduction with endobronchial valves for patients with Heterogeneous emphysema and Intact interlobar Fissures: the BeLieVeR-HIFi study

Background: Despite optimal therapy many patients with emphysema remain significantly breathless and limited. Bronchoscopic lung volume reduction (BLVR), using valves placed to allow air to leave but not enter the worst-affected areas of the lung, has been proposed as a way to improve lung function in these patients, but response is variable because interlobar collateral ventilation prevents the devices from working. Based on retrospective analysis of clinical trials, patients with heterogeneous emphysema and intact interlobar fissures are most likely to benefit. Objectives: To establish whether or not it is possible to identify patients prospectively who will reliably benefit from endobronchial valve placement. Design: Prospective, randomised, parallel-group, double-blind, sham-controlled trial. Setting: The study was performed at a single specialist centre. Participants: Adult patients with heterogeneous emphysema and a target lobe with intact interlobar fissures were eligible if they had significant gas trapping (total lung capacity > 100% predicted, residual volume > 150% predicted), breathlessness [Medical Research Council (MRC) dyspnoea score of ≥ 3] and exercise limitation (6-minute walk distance of