Target lobe volume reduction and COPD outcome measures after endobronchial valve therapy.
Endobronchial valve (EBV) therapy may be associated with improvements in chronic obstructive pulmonary disease-related outcomes and may therefore be linked to improvements in the body mass index, airflow obstruction, dyspnoea, exercise capacity (BODE) index. Data from 416 patients with advanced emphysema and hyperinflation across Europe and USA, who were randomised to EBV (n=284) or conservative therapy (n=132) were analysed. Quantitative image analysis was used to compare the volume of the targeted lobe at baseline and at 6 months to determine target lobe volume reduction (TLVR). 44% of patients receiving EBV therapy (versus 24.7% of controls) had clinically significant improvements in the BODE index (p<0.001). BODE index was significantly reduced by mean ± sd 1.4 ± 1.8, 0.2 ± 1.3 and 0.1 ± 1.3 points in patients with TLVR >50%, 20%-50% and <20%, respectively (intergroup differences p<0.001), but increased by 0.3 ± 1.2 points in controls. Changes in BODE were predicted by baseline BODE and correlated significantly with lobar exclusion and lung volumes at 6 months. A greater proportion of patients in the treatment group than in the control group achieved a clinically meaningful improvement in BODE index; however, the likelihood of benefit was less than half in both groups. Patients in whom TLVR was obtained had greater improvements in clinical outcomes.