Chelation Therapy in Diabetic Patients With Critical Limb Ischemia

The purpose of this research study is to evaluate the effect of ethylenediaminetetraacetic acid (EDTA) based chelation therapy plus vitamins in diabetic patients with severe peripheral artery disease presenting with impending amputation and determine if there is an improvement in outcomes and a delay or reduction of amputations. The investigators propose to enroll 10 patients in an open-label study of TACT-formula, EDTA-based chelation therapy + commercially available TACT oral multi vitamins, delivering 40-50 infusions over 1 year. Clinical assessment, and noninvasive blood flow assessments will be performed at baseline, and at completion of 20 and 40 infusions. HIPAA-compliant photographs of the affected lower limbs will be taken at each infusion visit. The specific aims of this open-label pilot study are to: 1. Assess the effect of EDTA-based chelation therapy plus vitamins in diabetic patients with below-the-knee peripheral artery disease presenting with impending amputation and determine if there is an improvement in vascular flow parameters, such that the scheduled amputation can be averted or reduced in extent. 2. Co-primary severity endpoint: Changes in pain scores, quality of life, wound severity, segmental lower extremity pressures and endothelial function. 3. Assess safety of EDTA-based chelation therapy in this patient population, defined as deterioration of renal function, symptomatic hypocalcemia or hypoglycemia within 8 hours of each infusion, or Class 4 heart failure within 24 hours of an infusion.