Endobronchial valve helps improve lung function in severe emphysema
Adding endobronchial valve (EBV) treatment to standard of care (SoC) in hyperinflated patients with severe heterogenous emphysema without collateral ventilation improves lung function, exercise tolerance, dyspnoea, and quality of life compared with SoC alone, according to the TRANSFORM* study.
“Whilst lung volume reduction surgery [LVRS] has proven effective in selected populations, the technique is relatively under-utilized owing to concerns about the invasiveness of the procedure,” according to the researchers led by Dr Samuel Kemp of Royal Brompton Hospital in London, UK. “Bronchoscopic lung volume reduction with Zephyr EBVs aims to provide the benefits seen with LVRS but with a reduction in morbidity.”
The EBVs are one-way valves inserted into the emphysematous airways by a minimally invasive bronchoscopy to prevent air from entering while allowing air and secretions out of the diseased regions, thereby reducing hyperinflation.
After 3 months, more patients in the EBV arm had ≥12 percent improvement in FEV1** from baseline, the study’s primary endpoint, compared with SoC (55.4 percent vs 6.5 percent; p<0.001). The improvements were maintained up to 6 months (56.3 percent vs 3.2 percent; p<0.001), with an almost 30 percent difference in the mean FEV1 changes between the two groups (20.7 percent vs -8.6 percent). [Am J Respir Crit Care Med 2017; in press]
Improvements in secondary outcomes with EBV were also significant at 6 months, including residual volume (p<0.002) and exercise tolerance measured on 6MWD# (p<0.001). Other outcomes such as quality of life based on SGRQ## (p=0.031) and multidimensional disease outcomes assessed with the BODE index### (p<0.001), which also predicts mortality risk, were significantly improved in the EBV vs the SoC groups.
“For each outcome measure, a significantly greater number of subjects in the EBV group met or exceeded the minimal clinically important difference,” the researchers noted.
Over 6 months, more respiratory-related serious adverse events (SAEs) occurred in the EBV vs the SoC groups (47.7 percent vs 9.4 percent; p<0.001), with most events occurring within 1 month of the procedure. Among EBV-treated patients, pneumothorax was the most common while other SAEs included dyspnoea, COPD exacerbation, and pneumonia.
The multicentre prospective study randomized 97 exsmokers (aged ≥40 years) with severe heterogenous emphysema without collateral ventilation in a 2:1 ratio to receive EBV+SoC or SoC alone.
“The success of the treatment requires accurate patient selection … Absence of collateral ventilation and achieving complete lobar occlusion [are] necessary elements for successful lung volume reduction with EBVs,” said Kemp and co-authors, who also pointed out the importance of managing procedural complications.
Of note, a majority of the patients in the SoC arm (94 percent) chose to receive EBV treatment after 6 months. Patients in the EBV arm will continue to be followed up to 2 years, according to the authors.
“EBV treatment has the added benefits of being suitable for both upper and lower lobe disease, as well as homogeneous disease [as shown in previous study], and is a reversible procedure … [making it] a viable treatment option in those who remain symptomatic on maximal medical therapy,” said Kemp and co-authors. [Am J Respir Crit Care Med 2016;194:1073-1082]