Endoscopic Lung Volume Reduction with Valves Improves Cardiovascular Adaptability and 6-MWT Performance in Severely Limited COPD Patients

Background: The 6-minute walk test (6-MWT) assesses exercise capacity in patients with chronic obstructive pulmonary disease. A recent study revealed that selected patients with an advanced emphysema and a baseline walking distance of ≤ 140 m in 6-MWT benefit from endoscopic lung volume reduction with valves (ELVR) with a remarkable improvement in walking distance. However, the reasons for these improvements remain unexplained. Study Design and Methods: We retrospectively analyzed 54 patients with severe emphysema undergoing ELVR at Charité-Universitaetsmedizin Berlin. Patients were stratified into 2 groups by baseline walking distance: those with 6-MWT ≤ 140 m and those with 6-MWT 140– 450 m. Changes in lung function, quality of life, and 6-MWT parameters (peripheral oxygen saturation (SpO 2 ), heart rate (HR), and walking distance) were evaluated using Generalized Estimating Equations (GEE). Results: While lung function and quality of life improved comparably in both groups, patients with 6-MWT ≤ 140 m showed a significantly greater improvement in walking distance versus the 6-MWT 140– 450 m group (105.6 ± 123.2 m versus 12.1 ± 80.8 m, p=0.027). GEE analysis indicated that this improvement was accompanied by a significantly greater reduction in ΔHR from baseline to follow-up compared to the 6-MWT 140– 450 m group (p=0.023), while changes in SpO 2 were similar. Conclusion: Patients with very limited exercise capacity (≤ 140 m) improved their walking distance disproportionately after ELVR. The concomitant decrease in HR suggests an associated cardiovascular benefit in this subgroup. Therefore, a 6-MWT of ≤ 140 m should not be considered an exclusion criterion for ELVR, as these patients can achieve meaningful clinical improvements.