IP213. Ethnic Minorities With Critical Limb Ischemia Derive Equal Amputation Risk Reduction From Autologous Cell Therapy Compared to Caucasians

Abstract

Ethnic minorities with critical limb ischemia (CLI) have historically done worse compared to Caucasians in regards to amputation risk reduction and amputation-free survival (AFS) after peripheral vascular interventions. This analysis was performed to determine whether this CLI precedent also extended to injections of concentrated bone marrow aspirate (cBMA) to the affected limb of patients without a revascularization option. The treatment arm of the randomized, double-blind, multicenter MOBILE trial was stratified by ethnicity and evaluated for demographics, comorbidities, and outcomes. Primary end point was 1-year AFS (above-ankle or greater). Noninferiority analysis was performed with the margin set at a hazard ratio of 1.297. There were 37 non-Caucasian patients (9 placebo, 28 cBMA) with “no surgical option” CLI randomized to placebo or cBMA at a 1:3 ratio during the MOBILE trial. There was no difference in outcomes between the ethnic minority (African Americans, Hispanics, others) and the Caucasian population (Fig). At the 1-year follow-up mark for the treatment group, overall AFS was 84%. Of the 28 minorities randomized to cBMA intervention, 25 (89%) survived amputation free compared to a rate of 82% in Caucasians, and 22 of 24 (92%) African Americans survived amputation free at 1-year follow-up. Noninferiority testing confirmed no difference in cBMA-treated patients by ethnicity when looking at amputation risk reduction; however, the null hypothesis could not be rejected when looking at AFS. No significant differences were noted when comparing cBMA treated patients by ethnicity in terms of quality of life, pain, ankle-brachial index, toe-brachial index, transcutaneous pressure of oxygen, and 6-minute walk testing. The MOBILE trial demonstrates noninferiority of cBMA intervention in minorities with “no option” CLI for amputation risk prevention. cBMA, therefore, represents a novel treatment option and should be aggressively explored for minorities who face impending amputation secondary to progressive, end-stage CLI.