Abstract
Background: The understanding of interactions or associations over the long-term may assist in understanding and predicting changes over time in chronic diseases such as emphysema. The associations among various COPD efficacy endpoints are variable; however, the degree of correlation is often important in examining the consistency of the results across measures not considered redundant.
Objectives: Determine the correlations of improvements in patient-reported outcomes, exercise capacity and BODE score with lung function and lobar volume reduction (LoVR) measured by CT after 1-year post-InterVapor for heterogeneous emphysema.
Methods: Single-arm trial of InterVapor in patients with upper lobe emphysema. Patient criteria: FEV1 15% - 45% predicted, age 40-75 years, RV>150%, TLC>100%, 6 minute walk distance (6MWD)>140 m, DLCO>20%, previous pulmonary rehabilitation. Endpoints included: spirometry, body plethysmography, SGRQ, mMRC dyspnea, 6MWD and LoVR (CT). Pearson correlation coefficients were calculated for associations of changes from baseline to 12 months.
Results: 44 patients received InterVapor. Mean age: 63 years, men 50%, FEV1 0.86 (31% predicted), RV 237% predicted, DLCO 35% predicted, SGRQ 59 units, 6MWD 300 m, mMRC 2.9.
Conclusion: Among lung function tests, FEV1 appeared to correlate the strongest with health outcomes, followed by RV and FRC at one year. The strong correlation of outcomes with LoVR are consistent with the proposed mechanism of action.
- © 2012 ERS
