5-Year Survival after Endobronchial Coil Implantation: Secondary Analysis of the First Randomised Controlled Trial, RESET.

Background: Lung volume reduction surgery is a proven treatment for emphysematous patients with hyperinflation, but the precarious health of candidates has prompted development of less invasive approaches. Bronchoscopic implanted endobronchial coils, shape-memory nitinol filaments, shrink emphysematous lung tissue to restore elastic recoil and to tether airways to maintain patency. Studies have demonstrated an acceptable safety profile and improvements in lung function, exercise capacity, and quality of life out to 3 years. Volume reduction is key. However, data for longer-term survival are limited.

Objective: The aim of this study was to establish the 5-year overall and transplant-free survivals of subjects whose procedure in the first randomized controlled trial, RESET, achieved clinically meaningful reduction in residual volume (RV).

Methods: Patients and their primary care doctors were contacted to confirm vital status and history of additional interventions. Death certificates were acquired via the General Registry Office. Survival time was calculated for responders achieving a reduction of ≥10% in RV compared to non-responders.

Results: 39 patients completed the planned bilateral sequential treatments. Six patients received unilateral implants. At 5 years, 22 patients had died. The overall survivals at 1, 2, 3, 4 and 5 years were 88.9, 88.9, 77.8, 64.4 and 50.6%, respectively. Two patients underwent lung transplantation at 52 and 59 months and were alive at 5 years. The transplant-free (TF) survivals at 1, 2, 3, 4 and 5 years were 88.9, 88.9, 77.8, 64.4 and 46.7%, respectively. Volume reduction responders (n = 18) at 3 months had a 5-year TF survival of 66.7% compared to 36.4% for non-responders (n = 22; p = 0.07). Higher baseline inspiratory capacity (HR 0.13, 95% CI 0.02-0.73; p = 0.02) and partial pressure of oxygen (pO2) (HR 0.57, 95% CI 0.38-0.86; p < 0.01) values were predictive of survival for the entire cohort and were not influenced by age.

Conclusions: Endobronchial coil implantation appears to confer a 5-year survival advantage for those who achieved a 10% reduction in RV at 3 months. Ongoing trials are designed to clarify the mechanisms of action of coils and to refine patient selection.