Critical Limb IschemiaPhase 3TACT3aNCT03982693
Trial to Assess Chelation Therapy in Critical Limb Ischemia
A Phase 3 study testing Edetate Disodium in people with Critical Limb Ischemia and Diabetes, run by Mt. Sinai Medical Center, Miami at 1 site in United States.
Trial summary
TACT3a is a double blind, placebo-controlled, randomized trial to test a novel therapy, edetate disodium-based chelation of environmentally acquired toxic metals, to reduce cardiovascular events including amputation in high-risk diabetic patients. Read more about this study
- Who is it for?
- Ages 50 years and older
- Conditions the study is for
- Critical Limb Ischemia, Diabetes
- What is being tested?
- Edetate Disodium
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 50 participants
- Where
- 1 siteUnited States
- Study dates
- 19 Mar 2019to Jul 2027
- Phase
- Phase 3
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 50 years
- History of diabetes, defined as medical record evidence or patient report of currently using insulin or oral hypoglycemic agents, or with a history of fasting blood glucose measurement of 126 mg/dL or higher, or a history of HbA1c of 6.5% or higher.
- Significant stenosis (≥ 75%) of two or more infra-popliteal arteries in the affected limb as verified by at least one imaging technique (angiography, magnetic resonance angiogram, coronary computed tomography angiogram, or doppler examination) within 6 months prior to enrollment;
- History of CLI defined as moderate or high-risk infra-popliteal chronic critical limb ischemia (Rutherford Clinical Severity Score 4 or 5) defined as:
- The presence of rest pain or non-healing ulceration or gangrene for at least 2 weeks plus documentation of severely compromised tissue perfusion:
- If there is tissue loss, a resting ankle systolic pressure of ≤ 60 mmHg in the affected limb; or a resting toe systolic pressure of ≤ 40 mmHg or a tissue perfusion pressure (TPP) <40 mmHg.
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- If there is no tissue loss, a resting ankle pressure of ≤ 50 mmHg or resting toe systolic pressure of ≤ 30 mmHg or a tissue perfusion pressure (TPP) < 30 mmHg.
- Not a candidate or a failed candidate for surgical or transcatheter revascularization;
- Able to give informed consent.
Who cannot join
- <7 days following lower extremity (infra-popliteal), carotid, or coronary revascularization.
- Arterial insufficiency in the lower extremity as the result of a non-atherosclerotic disorder.
- Subjects with evidence of active infection (e.g., cellulitis, osteomyelitis) or deep ulceration exposing bone or tendon or extensive heel ulceration
- Subjects with extensive gangrene extending above the MT joint
- Subjects in whom there is severe pain at rest uncontrollable with pain medications
- Prior intravenous chelation therapy consisting of > 1 infusion within 5 years; if only 1 infusion took place, patient cannot be enrolled for at least 12 months after said infusion.
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- Oral chelation with an FDA-approved chelating agent within 2 years
- Allergy to any components of the study drug
- Planned leg revascularization within 1 month of enrollment
- Symptomatic or clinically evident acute heart failure
- Heart failure hospitalization within 3 months
- Blood pressure >160/100
- No venous access
- eGFR < 30 mL/min per 1.73 m2 or lower (CKD stages 1-3) calculated with MDRD
- Known or suspected acute kidney injury using prevalent KDIGO criteria45
- Platelet count <100,000/mm3
- Cigarette smoking within the last 3 months
- Liver disease or Alanine aminotransferase (ALT), aspartate aminotransferase (AST) > 2.0 times the upper limit of normal (this will require clearance by the Study PI)
- Diseases of copper, iron, or calcium metabolism (other than osteopenia or osteoporosis, or simple iron deficiency). These require evaluation by the Study PI
- Inability to tolerate the study-required fluid load
- Other medical condition likely to affect patient survival within 3 years
- Women of child-bearing potential
- Any factor that suggests that the potential participant will not be able to adhere to the protocol.
Trial locations and contacts
1 site in 1 country.
United States1 site
Mount Sinai Medical Center
Miami Beach, Florida, 33140
About this study
TACT3a is a double blind, placebo-controlled, randomized trial to test a novel therapy, edetate disodium-based chelation of environmentally acquired toxic metals, to reduce cardiovascular events including amputation in high-risk diabetic patients.
Read the detailed description
TACT3a is a double blind, placebo-controlled, randomized trial to test a novel therapy, edetate disodium-based chelation of environmentally acquired toxic metals, to reduce cardiovascular events including amputation in high-risk diabetic patients.
The study plans to enroll 50 patients with diabetes and critical limb ischemia (CLI) to prevent the major cardiovascular endpoints of major amputation, coronary revascularization, stroke, Myocardial Infarction (MI), or death (all-cause) during an average 1.25 years of follow-up. Patients will be randomly assigned to chelation or placebo with a 3:2 (30 active, 20 placebo) allocation ratio. Treatment will consist of 40 active or placebo infusions over 30 weeks. Active therapy will be the same edetate disodium-based infusion used safely and successfully in a previous published study, Trial to Assess Chelation Therapy (TACT). Baseline and post infusion urine metals will be collected. Following the final infusion, patients will be contacted quarterly until the end of the study.
- Conditions
- Critical Limb Ischemia, Diabetes
- Being tested
- Edetate Disodium, Placebo
- Keywords
- Chelation, Critical Limb Ischemia, Diabetes
- Medical subject headings
- Chronic Limb-Threatening Ischemia, Diabetes Mellitus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Edetate DisodiumDrug
Also called TACT EDTA infusion
The solution contains up to 3 g of edetate disodium adjusted based on creatinine clearance, 2 g of magnesium chloride, 100 mg of procaine hydrochloride, 2500 U of heparin, 7 g of ascorbate, 2 milliequivalent (mEq) potassium chloride (KCl), 840 mg sodium bicarbonate, 250 mg pantothenic acid, 100 mg of thiamine, 100 mg of pyridoxine, and sterile water to complete 500 mL.
PlaceboOther
Placebo infusions consist of 500 ml normal saline.
| Study group | Role | What they receive |
|---|---|---|
| Active | Active comparator | edetate disodium (EDTA)dff active infusion Receives: Drug: Edetate Disodium |
| Placebo | Placebo comparator | Placebo infusion Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Prevention of major cardiovascular endpoints
Major cardiovascular endpoints include: coronary revascularization, stroke, MI, death (all-cause), or major amputation
Measured: 3 years (average follow-up 1.25 years)
Secondary outcomes (9)
Amputations
- Major amputations due to vascular disease. Major amputations are defined as any procedure that results in amputation at the level above the ankle. 49, 50
- Total amputations due to vascular disease
Measured: 3 years (average follow-up 1.25 years)
Heart failure
- Heart failure hospitalizations or prolonged (>12 hours) ER stay for heart failure
Measured: 3 years (average follow-up 1.25 years)
Changes in Pain severity
- Any changes in pain will be recorded at baseline, infusions 10, 20, 40 (or final), and end of study recorded using the Patient-Reported Outcomes Measurement Information System (PROMIS) Pain Interference- Short Form 8a. The scale range is 1 to 5, with 1 being the best outcome (no pain interference) and 5 the worse (very much interference)
Measured: 3 years (average follow-up 1.25 years)
Urine Metals
- Changes in urine metal levels measured at the Metals Core Lab and measured at baseline and infusion 40 (or final).
Measured: 1 year
Changes in Quality of Life
- Health-related quality of life (QOL) changes recorded at baseline, 10, 20, 40 (or final), and end of study using the 36-Item Short Form Health Survey (SF-36 v2). The 36 questions assess eight health-related concepts: physical functioning, role limitations due to physical health problems (role physical), bodily pain, general health, energy levels/fatigue (vitality), social functioning, role limitations due to emotional problems (role emotional), and psychological distress (mental health). The scales vary depending on the question asked.The survey will be used to detect change (better or worse) in participants' health state over the course of the study.
Measured: 3 years (average follow-up 1.25 years)
Wound Severity
Wound severity (quantified and imaged with HIPAA-compliant photography) photographed at baseline 10, 20, 40 (or final), and end of study
Measured: 3 years (average follow-up 1.25 years)
Changes in skin perfusion pressure in the ankle
- Changes in skin perfusion pressure will be measured at 10, 20, 40 (or final), and end of study, using the ankle-brachial index (mmHg)
Measured: 3 years (average follow-up 1.25 years)
Changes in skin perfusion pressure in the toe
- Changes in skin perfusion pressure will be measured at 10, 20, 40 (or final), and end of study, using the toe-brachial index (mmHg).
Measured: 3 years (average follow-up 1.25 years)
Changes in PAD Quality of Life
- PAD related quality of life (QOL) changes recorded at baseline, 10, 20, 40 (or final), and end of study using the Peripheral Artery Questionnaire (PAQ), which is a 20-item questionnaire measuring physical limitations, symptoms, symptom stability, treatment satisfaction, quality of life, and social function. The scales vary depending on the question asked. The survey will be used to detect change (better or worse) in participants responses over the course of the study.
Measured: 3 years (average follow-up 1.25 years)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Jun 2019
- Study start19 Mar 2019
- Primary completionDec 2026 (estimated)
- Study completionJul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Critical Limb IschemiaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Mt. Sinai Medical Center, Miami
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Gervasio Lamas, MD, Mt. Sinai Medical Center, Miami
- Investigators
- Gervasio Lamas, MD, Principal investigator, Icahn School of Medicine at Mount Sinai
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03982693
- Sponsor's protocol ID
- 19-05-H-01
- Acronym
- TACT3a
- Status last verified
- Jun 2026
- First submitted
- 27 May 2019
- Last updated
- 1 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Publications
Arenas IA, Navas-Acien A, Ergui I, Lamas GA. Enhanced vasculotoxic metal excretion in post-myocardial infarction patients following a single edetate disodium-based infusion. Environ Res. 2017 Oct;158:443-449. doi: 10.1016/j.envres.2017.06.039. Epub 2017 Jul 6.
PubMed 28689036Lamas GA, Goertz C, Boineau R, Mark DB, Rozema T, Nahin RL, Drisko JA, Lee KL. Design of the Trial to Assess Chelation Therapy (TACT). Am Heart J. 2012 Jan;163(1):7-12. doi: 10.1016/j.ahj.2011.10.002.
PubMed 22172430Escolar E, Lamas GA, Mark DB, Boineau R, Goertz C, Rosenberg Y, Nahin RL, Ouyang P, Rozema T, Magaziner A, Nahas R, Lewis EF, Lindblad L, Lee KL. The effect of an EDTA-based chelation regimen on patients with diabetes mellitus and prior myocardial infarction in the Trial to Assess Chelation Therapy (TACT). Circ Cardiovasc Qual Outcomes. 2014 Jan;7(1):15-24. doi: 10.1161/CIRCOUTCOMES.113.000663. Epub 2013 Nov 19.
PubMed 24254885Ujueta F, Arenas IA, Diaz D, Yates T, Beasley R, Navas-Acien A, Lamas GA. Cadmium level and severity of peripheral artery disease in patients with coronary artery disease. Eur J Prev Cardiol. 2019 Sep;26(13):1456-1458. doi: 10.1177/2047487318796585. Epub 2018 Aug 28. No abstract available.
PubMed 30152247Ujueta F, Arenas IA, Escolar E, Diaz D, Boineau R, Mark DB, Golden P, Lindblad L, Kim H, Lee KL, Lamas GA. The effect of EDTA-based chelation on patients with diabetes and peripheral artery disease in the Trial to Assess Chelation Therapy (TACT). J Diabetes Complications. 2019 Jul;33(7):490-494. doi: 10.1016/j.jdiacomp.2019.04.005. Epub 2019 Apr 14.
PubMed 31101487