Endoscopic Valve Therapy in COPD Patients with Hypercapnia

Abstract

<b><i>Background:</i></b> Endoscopic valve therapy has been established as a therapeutic option for patients with severe emphysema. Several randomized controlled trials confirmed the efficacy of this therapeutic approach in COPD patients without significant collateral ventilation. However, patients with clinical relevant hypercapnia were excluded from these trials. <b><i>Aims and Objectives:</i></b> Patients with hypercapnia who underwent endoscopic valve treatment were enrolled in this retrospective analysis. The efficacy of valve treatment and its impact on blood gases were analysed. <b><i>Methods:</i></b> COPD patients with mild to severe hypercapnia (pCO₂ ≥45 mm Hg) who were treated by endoscopic valve placement at the Thoraxklinik, University of Heidelberg, were enrolled in this retrospective trial. Lung function test (vital capacity [VC], forced expiratory volume in 1 s [FEV₁], residual volume [RV]), blood gases (pO₂, pCO₂), and 6-minute-walk test (6-MWT) were assessed prior to intervention and at 3 and 6 months following valve implantation. <b><i>Results:</i></b> 129 patients (mean age 64 ± 7 years) with severe COPD (mean FEV₁ 26 ± 12% of predicted, mean RV 285 ± 22% of predicted) with hypercapnia (pCO₂ ≥45 mm Hg, mean pCO₂ 50 ± 5 mm Hg) underwent endoscopic valve treatment. 3 and 6 months following intervention, statistical significant improvement was observed in VC, FEV₁, RV, and 6-MWT (all <i>p</i> &#x3c; 0.001). Blood gas analysis revealed a significant improvement of mean pCO₂ at 3- and 6-month follow-up (both <i>p</i> &#x3c; 0.001). 40% of the patients had normal pCO₂ values 3 and 6 months following intervention. <b><i>Conclusion:</i></b> COPD patients with hypercapnia should not be excluded from valve treatment, as the hyperinflation reduction improves the respiratory mechanics and thus leading to improvement of hypercapnia.