Lung volume reduction coils improve dyspnea, FEV1 in COPD (RCT)
ATLANTA -- In a small, open-label pilot study, bronchoscopically-placed metal coils that retract emphysematous lung, creating lung volume reduction without surgery, produced functional and airflow improvements in a majority of patients with severe COPD, the lead researcher reported at CHEST 2012.
Investigators randomized 47 patients with severe emphysema type COPD to undergo either bronchoscopic implantation of the coils, made by PneumRx, or standard supportive COPD treatment. The 10-15 cm coils, called "RePneu," are made of metallic Nitinol, and are flexible with a "memory" for their coiled shape, tugging lung tissue as they coil and effectively reducing dead-space nonfunctional lung volumes.
Zaid Zoumot of the Royal Brompton and Harefield Hospital Trust in London, reported his team's results at 90 days of followup:
After adjusting for differences in baseline variables, the coil group had mean St George's Respiratory Questionnaire scores after treatment 8.35 points higher than the control group, with 4 points being considered clinically significant.
More than half the coil group had an 8-point improvement in SGRQ, compared to 13% of controls.
Six-minute walk distance improved by at least 26 meters in 74% of the coil group, compared to 17% of controls.
Significant lung volume reduction was achieved in 57% of the coil group, who had a 0.35 L reduction in residual volume on spirometry, compared to 22% of controls.
61% of the coil group had a 12% increase in FEV1, compared to 26% of controls.
PneumRx paid for the study.
The coils appeared to cause pneumothoraces in three patients in the coil group, and one had a pneumonia, neither of which occurred in the control group. Two patients receiving coils and one in the control group had COPD exacerbations. After the first month, no adverse effects besides COPD exacerbations were noted in either group.
Since there was no sham bronchoscopic procedure in the control arm, subjective improvement due to a placebo effect is hard to rule out.
Lung volume reduction surgery is known to improve outcomes in a majority of people with severe COPD, but because of its small but definite operative mortality risk, lung volume reduction surgery has only been performed on a handful of patients. Numerous non-surgical techniques have been tried before to reduce lung volumes (such as implanting one-way Exhale airway stents in bronchi to the upper lobes); several showed initial promise but in larger trials, did not demonstrate a benefit.
Zoumot, PneumRx and team are planning a larger trial of the lung volume reduction coils, enrolling 330 patients, to begin next month, they reported.
Zaid Zoumot et al. Randomized Controlled Trial of RePneu Endobronchial Coils for the Treatment of Severe Emphysema With Hyperinflation (RESET). CHEST Conference 2012 Update, CHEST.2012;142(4_MeetingAbstracts):1024A-1024A. doi:10.1378/chest.1457157