Abstract
Introduction: The NETT noted that baseline exercise tolerance may influence long-term outcomes following lung volume reduction. The association of baseline six minute walk distance (6MWD) to outcomes was examined in a study of endoscopic thermal vapor ablation in patients with heterogeneous emphysema.
Methods: Post hoc subgroup analysis from the Vapor trial, a multicenter single-arm trial of InterVapor (single upper lobe treatment at 10 cal/g) in patients with upper lobe emphysema. Inclusion: FEV1 15%-45% predicted, RV>150%, TLC>100%, 6MWD>140 m, DLCO>20%, prior pulmonary rehabilitation. Outcomes included spirometry, body plethysmography, lobar volume reduction (LoVR) by HRCT, SGRQ, mMRC dyspnea, and 6MWD. Endpoints were dichotomized based on two thresholds for baseline 6MWD.
Results: 44 patients received InterVapor. Demographics: 50% men, age 63 years, FEV1 0.86 L (31% predicted), SGRQ 59 units, 6MWD 300 m. Results at 6 and 12 months (mean change from baseline):
Conclusion: Baseline 6MWD was associated with differences that were most prominent with the subsequent 6MWD and SGRQ at 12 months. Other outcomes showed no consistent pattern of association. A bias such as regression to the mean cannot be ruled out in this analysis.
- © 2012 ERS
