Clinical Response Rate to Endobroncial valve treatment of Chronic Obstructive Pulmonary Disease; A retrospective cohort study

<bold>Background:</bold> Endobronchial valve (EBV) treatment stands as a viable option for managing emphysema. Despite randomized controlled trials, not all treated patients experience an improvement of symptoms or lung function. This study aims to assess the proportion of EBV-treated patients, who experience an improvement exceeding the minimum clinically important difference (MCID) for lung function and exercise capacity. <bold>Method:</bold> This retrospective cohort study includes patients treated with EBV between 2017-2023 at Aarhus University Hospital in Denmark. Information from baseline and three months were retrieved from the medical records. MCIDs chosen from literature search were: FEV1 +12 %, RV -7.5 %, MRC -1 and 6MWD +26 m. <bold>Results:</bold> Among 109 included patients, 80 attended the 3-month visit. Mean age was 64.4 years (±7.62), BMI 24 (± 4.34) and 54% were male. Increase in FEV1% (3.3 %pt., p=0.054), RV reduction(30.9 %pt., p=0.0001), MRC improvement(0.51 , p=0.0046) and 6MWT distance increase (27.3 m, p=0.2789) were observed. Response rate were: FEV1% 37%, RV 65%, MRC 46% and 6MWT 41.5%. <bold>Conclusion:</bold> Though, the results showed inconsistent benefit of EBV treatment regarding FEV1, RV, MRC and 6MWD, approximately 1-2 out of 3 patients experienced positive treatment response.