An arteriovenous fistula increases exercise capacity in patients with COPD.

BACKGROUND: Supplemental oxygen usually increases exercise capacity in hypoxemic COPD, but some patients are refractory because of venous admixture. An arteriovenous fistula (AVF) with left-to-right shunt increases mixed venous oxygen content and cardiac output; therefore, this might improve arterial oxygen delivery. We hypothesized that creation of an AVF would therefore increase exercise capacity in severe COPD.
METHODS: We created an AVF in 12 patients with severe hypoxemic COPD: mean (SD) age, 66 (6) years; Pao(2), 57.5 (3.0) mm Hg, and FEV(1), 19% (8%) predicted. We measured 6-min walk distance (6MWD) while the subjects were breathing room air and again while they were breathing portable supplemental oxygen at baseline, 6 weeks, and 12 weeks after creation of an AVF in the iliofemoral region.
RESULTS: After surgery, the mean (SEM) 6MWD increased from 217 (63) m at baseline to 272 (18) m and 276 (25) m, 6 weeks and 12 weeks after surgery, respectively. Patients who walked > 54 m further while breathing supplemental oxygen at baseline (n = 5) increased 6MWD while breathing room air by 129 (34) m after 6 weeks (P = .02) and by 124 (29) m after 12 weeks (P = .004). Walking distance did not change in patients who did not have a clinically meaningful response to oxygen at baseline.
CONCLUSIONS: An iliofemoral AVF increased 6MWD patients with severe COPD, matching the improvement seen with supplemental oxygen. An initial response to supplemental oxygen predicted a therapeutic response to the AVF.