Airway Bypass Stents for Emphysema, Algorithm to Exclude Precapillary Pulmonary Hypertension, and Sildenafil for Pulmonary Hypertension in Heart Failure with Preserved Ejection Fraction

In selected patients with emphysema, lung volume reduction surgery has been shown to improve exercise capacity, quality of life, and survival (2). Because of restrictive inclusion criteria and risk of surgery, there has been interest in bronchoscopic lung volume reduction as an alternative to lung volume reduction surgery. Creating airway bypass tracts (ABTs) attempts to bypass collapsed small airways, allowing air to escape on expiration. The Exhale Airway Stents for Emphysema (EASE) trial was the first randomized, double-blind, sham-controlled study of ABTs (1). Patients were included if they had homogeneous emphysema with an FEV1 less than 50% predicted and an RV/TLC greater than 0.65. Of the 1,522 patients assessed for eligibility, 208 were randomized to ABT and 107 to sham bronchoscopy. All patients had bronchoscopy under general anesthesia; the intervention group had passages created in the airway and paclitaxel stents placed to maintain patency. Bayesian analysis did not show any superiority of ABT for the coprimary efficacy end point, which was met if the FVC increased by at least 12% and modified Medical Research Council (mMRC) score fell by 1 point from baseline at 6 months of follow-up. Mean FVC increased on Day 1 in the ABT group, but this returned to baseline by 3 months. Mean mMRC scores were significantly lower only at the 6-month time point in the intervention group. This trial used a robust randomized, sham-controlled study design that included patients most likely to benefit from the treatment. There was no benefit in the coprimary end point, likely due to stent expectoration and low rates of stent patency (66% onDay 1 and 21% at 6mo). Although there were no differences in composite safety end points or 6-month mortality between the groups, the risk of chronic obstructive pulmonary disease exacerbation or infection was almost twofold higher in the treatment group. This highlights the importance of noting individual safety end points that may be masked by reporting a composite end point alone. The EASE trial demonstrates that airway bypass tract formation with paclitaxel stents does not improve outcomes in patients with severe homogeneous emphysema. This is an interesting example of how theoretical benefit was attained through an intervention but was not sustained because of technical aspects of the procedure.