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 (SpO2), 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 SpO2 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.