Figure 2.

Comparison of frequency of improvement in functional outcomes after randomization to lung volume reduction surgery (LVRS, solid bars) versus optimal medical treatment (OMT, gray bars) for patients with upper lobe–predominant emphysema and low exercise capacity at baseline. Outcomes were consistently better with LVRS through Year 3 (column A1). On further classification by upper zone perfusion, those with low (column A2) rather than high upper zone perfusion (column A3) derived greater benefit from LVRS. These improvements were durable to Year 3 in patients with low but not high upper zone perfusion. SGRQ = St. George's Respiratory Questionnaire; SORQ = University of California at San Diego Shortness of Breath Questionnaire. *Improvement in exercise capacity by at least 10 W; ^†improvement in FEV₁ by at least 100 ml; ^‡improvement in total SGRQ score by at least 8 points; ^§improvement in SOBQ score by at least 5 points from baseline.