Stability of improvements in exercise performance and quality of life following bilateral lung volume reduction surgery in severe COPD

Abstract

Study objective: To evaluate the long-term stability of improvements in exercise capacity and quality of life (QOL) after lung volume reduction surgery (LVRS).

Design: Case-series analysis.

Setting: University hospital.

Patients: Twenty-six patients with severe airflow obstruction (mean FEV1 of 0.67+/-0.18 L) and moderate to severe hyperinflation (mean total lung capacity of 7.30+/-1.90 L).

Intervention and measurements: All patients underwent bilateral LVRS via median sternotomy. Serial measurement of lung function, symptom-limited cardiopulmonary exercise tests, 6-min walk distances (6MWD), and sickness impact profile (SIP) scores were done before, and at 3, 6, 12, and 18 months after surgery.

Results: FEV1 (0.93+/-0.29 vs 0.68+/-0.19 L, p<0.001) increased while residual volume (3.47+/-1.2 vs 4.77+/-1.5 L, p<0.001) decreased significantly at 3 months post-LVRS compared to baseline, and these changes were maintained at 12 to 18 months follow-up. Similarly, the increase in 6MWD at 3 months post-LVRS (340+/-84 vs 251+/-114 m, p<0.001) was sustained at all follow-up times. On cardiopulmonary exercise testing, total exercise time (9.0+/-1.8 vs 6.1+/-1.9 min, p<0.001), oxygen uptake at peak exercise (VO2 peak) (14.9+/-4 vs 11.9+/-3 mL/kg/min, p<0.001), maximum oxygen pulse (7.43+/-2.37 vs 5.85+/-1.96 mL/beat, p<0.005), and maximum minute ventilation (VEmax) (30.3+/-10 vs 23.5+/-7.1 L/min, p<0.001) increased significantly at 3 months post-LVRS. On serial study following LVRS, total exercise time remained significantly greater at 6 (8.5+/-1.38 min) and 12 months (8.71+/-2.0 min) post-LVRS compared to baseline (5.81+/-1.9 min, p<0.05). VO2 peak tended to be higher at all follow-up periods (3 months, 16.1+/-4.3; 6 months, 14.5+/-2.6; 12 months, 14.1+/-3.5 mL/kg) compared to baseline (12.6+/-3.9 mL/kg, p=0.08). Similarly, maximum O2 pulse tended to be higher in all follow-up studies (3 months, 8.45+/-2.7; 6 months, 7.6+/-1.7; 12 months, 7.42+/-2.1 mL/beat) compared to baseline (6.39+/-2.5 mL/beat, p=0.06). Higher VEmax continued to be observed at 6 (30+/-10 L/min) and 12 months (28+/-10 L/min) post-LVRS, compared to baseline (23+/-7 L/min, p=0.02). VEmax post-LVRS was significantly higher at 3 and 6 months compared to baseline on post-hoc analysis (p<0.05). Overall SIP scores were lower at 3 months (7 vs 18, p<0.0002) post-LVRS and were sustained in long-term follow-up.

Conclusion: We conclude that bilateral LVRS via median sternotomy in selected patients with severe, diffuse emphysema improves exercise performance and QOL at 3 months following LVRS and these improvements are maintained for at least 12 to 18 months in follow-up.