Lung function improves with endobronchial valve in COPD, alpha-1 antitrypsin deficiency
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Key takeaways:
- Studies assessing bronchoscopic lung volume reduction often leave out patients with alpha-1 antitrypsin deficiency.
- In addition to FEV1, residual volume and total lung capacity significantly improved.
SAN DIEGO — After bronchoscopic lung volume reduction, or BLVR, patients with COPD and alpha-1 antitrypsin deficiency had better lung function, according to a poster at the American Thoracic Society International Conference.
“BLVR is an effective therapy for appropriately selected patients with alpha-1 antitrypsin deficiency and COPD,” Michael Nicholson, DO, second-year pulmonary and critical care fellow at Temple University Hospital, told Healio.
“Significant improvement in lung function can be achieved regardless of the affected lobe,” he continued. “This improvement can be expected to sustain into the intermediate term and perhaps beyond.”
In a retrospective, single-center chart review, Nicholson and Gerard J. Criner, MD, FACP, FACCP, chair and professor of thoracic medicine and surgery at Lewis Katz School of Medicine at Temple University and director of the Temple Lung Center, assessed 14 patients (mean age, 61.5 years; 79% men) with alpha-1 antitrypsin deficiency (AATD) and COPD who had BLVR with Zephyr (Pulmonx) endobronchial valves between August 2018 and December 2022 to find out how the procedure impacts lung function in this patient population after a median of 7 months.
As Healio previously reported, patients with severe emphysema who received a Zephyr endobronchial valve had sustained improvements in lung function and quality of life out to at least 24 months.
Nicholson told Healio this review was carried out because trials assessing BLVR typically leave out patients with AATD.
“Consequently, BLVR may be underutilized as a treatment option for AATD patients,” he said. “The distinct pathophysiology of AATD poses challenges in extrapolating findings from trials involving COPD patients without AATD. Variations in affected lung lobes and disease progression are major differences between the AATD and non-AATD populations.”
Between baseline and the median 7-month follow-up, FEV1 went up by more than 15% for half (n = 7) of the cohort.
According to researchers, post-bronchodilator FEV1 increased by a median of 0.11 L (13.9% change).
“The sustained improvements up to 7 months post-BLVR are encouraging as some clinicians are concerned the ongoing destruction of lung tissue in AATD could cause initial BLVR improvements to regress,” Nicholson said.
In addition to lung function, researchers observed significant improvements (P < .05) in several outcomes at 7 months from baseline:
- BODE index (median, –1 point; interquartile range [IQR], –3 to 0);
- FEV1 percent predicted (median, 3.5% predicted; IQR, 2-8.3);
- residual volume (median, –1.11 L; IQR, –1.7 to –0.6);
- total lung capacity (median, –0.67 L; IQR, –1.3 to –0.5); and
- residual volume/total lung capacity ratio (median, –15.9%; IQR, –22.1% to –9.2%).
Notably, eight of the 14 patients had left lower lobe disease, but this did not impact lung function improvement.
“The sustained improvements seen at 7 months post-BLVR in patients with lower lobe disease were unexpected and promising,” Nicholson said. “In contrast to the National Emphysema Treatment Trial, which found lung volume reduction surgery ineffective for lower lobe disease, our study revealed significant improvements in lower lobe disease following BLVR. This is an important finding, as the majority of AATD patients are affected by lower lobe disease.”
Looking ahead, Nicholson hopes future studies include patients with AATD.
“The gold standard for investigating any medical intervention is a randomized controlled trial,” he said. “Prospective examination of BLVR vs. the current standard of care in AATD patients would provide invaluable data.”
Nicholson noted that several more patients with AATD have been added to this analysis, and the researchers will continue to track patients’ lung function as time progresses from the BLVR procedure.