Abstract 9793: Walking Performance, Quality of Life, and Hemodynamic Characteristics in Patients with Peripheral Artery Disease and End-Stage Kidney Disease (PAD-ESKD)

Abstract

Background: Patients with peripheral artery disease and end-stage kidney disease (PAD-ESKD) have poor outcomes that may be related to the presence of medial arterial calcification. These patients have been excluded from prior studies of medical interventions; thus, there is a need to better understand baseline functional capacity to aid design of interventional studies. Methods: Patients receiving hemodialysis (HD) who met the following inclusion criteria: age ≥55 OR ≥45 with diabetes, PAD as defined by ankle-brachial index (ABI) <0.90 and/or toe-brachial index (TBI) <0.70, and described symptoms with walking were enrolled at 7 US sites in a cross-sectional study of functional status. Patients with chronic limb-threatening ischemia, recent revascularization, or a non-PAD condition limiting walking were excluded. We measured walking with the 6-minute walk distance (6MWD), repeated after a 1-week interval, and the Walking Impairment Questionnaire (WIQ). We assessed claudication symptoms with the San Diego Claudication Questionnaire (SDCQ). Results: Of 67 patients who were screened, 36 (54%) met eligibility criteria, and 30 have completed the ongoing study: 43% women, mean (SD) age 69 (8) years, and mean (range) time since initiation of HD 53 (1-219) months. All patients had abnormal TBI with mean 0.46 (0.15). Consistent with the presence of medial arterial calcification, 10 patients (33%) had ABI ≥1.2 in one or both legs. Ten patients (33%) had intermittent claudication (IC). Overall mean (SD) 6MWD was 357 (261) meters (range 60-975). Test-retest reliability of 6MWD was good with an intraclass correlation of 0.97. The 6MWD was <350 meters in 19 patients (63%). Mean (SD) WIQ overall score was 32 (26), range 0-92, out of a possible 100 max. Patients who reported IC, as well as those who did not, had walking impairment as assessed by 6MWD and WIQ. Conclusion: We demonstrate the high prevalence of impaired walking ability in patients with PAD-ESKD, a previously poorly characterized population. The PAD-ESKD population has high clinical need, supporting a planned randomized, placebo-controlled trial to evaluate the effects of SNF472, a novel investigational inhibitor of vascular calcification.