Response of right ventricular myocardial function to endoscopic lung volume reduction in patients with advanced emphysema

Introduction: Endoscopic lung volume reduction (ELVR) provides a minimally invasive, effective therapy for patients with severe, progressive lung emphysema. However, its impact on right ventricular (RV) function is unknown. Objectives: The aim of this study was to assess, by use of speckle tracking based RV deformation analysis, the extent of global and regional RV dysfunction in patients undergoing ELVR, and to correlate the results with the clinical outcomes. Methods: We enrolled 25 patients (62±9.8 yrs, 68% male) with severe emphysematous COPD scheduled for bronchoscopic LVR using endobronchial valves (Zephyr®, PulmonX, Inc.). Echocardiography was conducted one day prior to ELVR and at 6-week follow-up visit. Clinical responsiveness was defined by a pre- to post-procedural increase in 6-minute walk test (6MWT) distance of ≥26 m. 15/25 treated patients were clinically responders, with an improvement mean value in 6-MWT distance of 126.3±67.5 m. Results: After ELVR, RV global longitudinal strain improved significantly in the responder group (-17.9±5.4% vs. -21.4±5.2%, p=0.049), whereas there was no significant differences in other parameters of RV function such as RV apical and medial longitudinal strain, TAPSE or mPAP; no significant effect was seen in non-responding patients. These results correlated with the Nt-proBNP-levels showing a statistical trend towards a relevant post-procedural Nt-proBNP decrease in the responder group (239.6±344.6 pg/ml vs. 90.3±69.3 pg/ml, p=0.07). Conclusion: ELVR improved RV function in patients with advanced emphysema. RV global longitudinal strain appears to be the best index to detect RV alterations in these patients.