Treatment outcomes of endoscopic lung volume reduction with valves in advanced lung emphysema patients are largely independent of body mass index: Data from the German Lung Emphyema Registry

a) Background Endoscopic lung volume reduction (ELVR) via valves is a proven therapeutic option for patients with advanced chronic obstructive pulmonary disease (COPD) and emphysema without collateral ventilation. Body mass index (BMI), a simple measure of adiposity, has a complex relationship with COPD. A lower BMI is associated with increased mortality in this patient population. However, the influence of BMI on the outcome of ELVR remains unclear. b) Study design and methods This analysis was conducted with data from the Lung Emphysema Registry (www.lungenemphysemregister.de), a national, prospective, multicentric, producer-independent, open-label clinical trial. The aim of this study was to evaluate the impact of baseline BMI on treatment outcomes after ELVR. Patients were grouped according to their BMI as follows: underweight (BMI <20kg/m², n =76), normal weight (20-24.9kg/m², n=282), overweight (BMI 25-30kg/m², n=146), and obese (BMI >30 kg/m², n=45). c) Results Baseline parameters were characteristic of patients with advanced lung emphysema. Emphysema scores and heterogeneity indices of the target lobe were greater in patients with lower BMI. Patients with a lower BMI had worse lung function parameters (FEV1, RV, DLCO, pCO2) and a higher CAT score. All groups showed significant improvements after ELVR at the 3-month follow-up in terms of lung function parameters, exercise capacity and quality of life. Treatment outcomes were comparable across BMI groups, with the notable exception of more pronounced improvement in CAT scores among underweight patients. The complication rates were low and comparable among the groups, although obese patients had a higher rate of ICU admissions. d) Discussion This study suggests that ELVR provides meaningful clinical benefits regardless of BMI in patients with advanced lung emphysema, particularly when dyspnea is primarily attributable to pulmonary pathology. The findings suggest that BMI should be considered as a reflection of disease phenotype and clinical state rather than serving as a predictor for treatment response after ELVR.