Table 2 The STEP-UP trial inclusion criteria

1.

Age ≥ 40 and ≤ 75 years old

2.

Heterogeneous emphysema with upper lobe predominance in both lungs

3.

FEV1 between 20% and 45% predicted

4.

Total lung capacity (TLC) ≥ 100% predicted

5.

Residual volume (RV) > 150% predicted

6.

Post-rehabilitation 6-minute walk test > 140 meters

7.

Marked dyspnea scoring > 2 on the modified Medical Research Council scale (mMRC)

8.

Arterial blood gas levels of: PaCO2 ≤ 50 mm Hg; PaO2 > 50 mm Hg on room air

9.

Non-smoking for 6 months prior to study enrollment

10.

Optimized medical management (treatment consistent with GOLD guidelines)

11.

Evidence of completed pulmonary rehabilitation:

a) ≥ 6 weeks out-patient or ≥ 3 weeks in-patient within 6 months of enrollment; or,

b) Patient has or continues to participate in regular physical activity beyond activities of daily living (i.e. a walking program) for ≥ 6 weeks under the supervision of a health care professional

12.

Mentally and physically able to cooperate with the study procedures and to provide informed consent to participate in the study.