Outcomes of a Canadian Cohort of Subjects Treated With Lung Volume Reduction Coils: Analysis From the Renew Study

Abstract

SESSION TITLE: Late-Breaking Abstracts 1 SESSION TYPE: Late-Breaking Abstract Slide PRESENTED ON: Tuesday, October 31, 2017 at 02:45 PM - 04:15 PM PURPOSE: Bronchoscopic lung volume reduction using nitinol coils (LVRC) is a novel technique to treat severe emphysema. The RENEW study, a multicenter randomized controlled trial comparing LVRC to usual care in 315 subjects with severe emphysema, showed modest improvement in exercise tolerance with LVRC. Our local experience included two subjects treated in an implementation phase, 11 during the randomized phase, and 2 in a crossover phase. We evaluated data from our cohort to compare outcomes to the RENEW study outcomes and described factors possibly accounting for observed differences, if any. METHODS: The Institut universitaire de cardiologie et pneumologie de Québec, a tertiary hospital specializing in chest diseases, was the only Canadian center participating in the RENEW trial. We reviewed baseline, treatment, and follow-up data from coil-treated participants in RENEW as well as post-hoc quantitative CT analyses from baseline and 12-month inspiratory and expiratory HRCT provided by PneumRx. Fifteen subjects (mean age 60 years, 53% male) underwent bilateral LVRC in two separate sessions. One subject opted out of the study after unilateral treatement due to complications. When compared to the cohort of LVRC completed case subjects in the RENEW study (n=128), subjects in our cohort were younger, had higher baseline exercise tolerance, and lower BODE scores. They also had more air trapping per quantitative CT analysis. RESULTS: At 12 months, median improvement in the primary endpoint of 6-minute walking distance (6MWD) was 54 meters (IQR -1, 128m) vs. 9 meters (IQR -33.2, 40m) in the RENEW completed case cohort (p=0.05). A higher proportion of our subjects met the 25m clinically significant response for 6MWD (71% vs 35%, p= 0,01). Other outcomes (FEV1, and St-George’s Respiratory Questionnaire) were similar between the cohorts. Post-hoc quantitative CT analyses revealed significantly greater expiratory lobar volume reduction in our patients compared to RENEW (-440mL vs. -205mL). CONCLUSIONS: Subjects treated with LVRC in Canada demonstrated strong clinical response one year post-treatment. Our patients were largely recruited from the community and were younger, had more hyperinflation and a better baseline exercise tolerance. We observed a significant 6MWT response in our RENEW patients, associated with greater degrees of volume reduction. CLINICAL IMPLICATIONS: Patient selection could play an important role in predicting subsequent response to LVRC therapy in severe emphysema. Lung volume reduction coils for severe emphysema (not yet approved in the US or Canada for this indication)