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

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.

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 (SpO₂), heart rate (HR), and walking distance) were evaluated using Generalized Estimating Equations (GEE).

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 SpO₂ were similar.

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.