SVS endobronchial valve improves QoL in patients with emphysema
In the 24-month follow-up results of the EMPROVE trial, treatment with the Spiration Valve System (SVS) endobronchial valve provided a sustained clinically significant benefit in disease-specific health-related quality of life (QoL) in patients with severe heterogeneous emphysema.
“Up to 15 percent of patients with chronic obstructive pulmonary disease (COPD) have emphysema,” said Dr Gerard Criner from Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania, US, at ERS 2022. “Patients with emphysema typically have significant impairments in daily activities and a reduced QoL.”
“Current COPD treatments are effective for patients with predominant airway disease that alleviate the hyperinflation that patients face. However, among those with predominant emphysematous phenotype, it is challenging for those drugs to give effective relief,” said Criner.
Evidence shows that minimally invasive bronchoscopic placement of endobronchial valves led to improvements in FEV1 and disease-specific QoL and reductions in hyperinflation and breathlessness. [Eur Respir Rev 2019;28:180121]
Thus, Criner and colleagues sought to further evaluate the potential of the SVS endobronchial valve to provide benefit in this patient setting. “Even if [a procedure] is considered less invasive … we need to know the ramifications and treatment benefits over a longer period of time,” he pointed out.
In this multicentre trial, 174 patients with advanced emphysema were randomized 2:1 to either the SVS treatment or optimal medical management (usual care). Participants were followed for up to 2 years (80 percent of the cohort who presented at the 1-year follow-up). The 20-percent attrition rate was attributable to death, patients moving on to lung transplantation, missed visits, or withdrawal.
At 24 months, compared with patients who received usual care, those in the SVS treatment arm had clinically meaningful improvements in the severe dyspnoea scale, as reflected by the mean change from baseline mMRC* (–0.6 points; p<0.01), as well as in SGRQ** total score (mean change from baseline, –6.5 points; p=0.05) and CAT*** score (mean change from baseline, –2.6 points; p<0.05).
There was no significant difference in SF-36# despite similar levelling-off patterns of the curves in both arms. Quality of Well-Being scores between arms were neither clinically different nor statistically significant.
Month 24 saw a 90-mL difference in FEV1 between the SVS treatment and the usual care arms, favouring the former over the latter (p<0.05). The intergroup difference at 12 months was 100 mL. “Both FEV1 declines had similar slopes over time, suggesting disease progression and not a change in the trajectory of change with SVS vs control,” said Criner.
There were no between-group differences in terms of all serious adverse events, deaths, COPD exacerbation, pneumonia, and pneumothorax between months 12 and 24.
Mechanism of action
During the procedure, endobronchial valves are delivered to the target lobe to occlude and collapse hyperinflated lobes. To achieve complete lobal occlusion, it might be necessary to place multiple valves. The valves redirect air to the healthier lobe during inhalation and allow trapped air and secretions to escape from the hyperinflated lobe upon exhalation. “By allowing air to leave but not enter diseased areas of the lung, it is possible to reduce hyperinflation in the targeted lobe,” noted Criner.
“[Taken together, our study showed that] SVS treatment resulted in statistically significant and clinically meaningful improvements in lung function and dyspnoea along with a good safety profile, which indicates durability of its treatment benefits,” said Criner.