TACT2 – The second Trial to Assess Chelation Therapy

January 19, 2018 | By More

Since the first report on chelation therapy in 1956, chelation has been a popular alternative treatment for cardiovascular disease. To assess the efficacy of chelation, an international clinical trial was funded in 2002. When the Trial to Assess Chelation Therapy (TACT) results were finally published in 2013, they revealed two important findings: that chelation works, and that it is a historic game-changer for diabetes.

A second trial has been designed to confirm the benefit of this important treatment and better understand how it works. If you are a diabetic, over 50 and have suffered a heart attack, you may be eligible for TACT2.


What is Chelation?

The word chelation comes from ‘chele’, which is Greek for ‘claw’. A molecule that can form strong double bonds with metals is called a chelator. The molecule used in chelation therapy for heart disease is called disodium ethylenediaminetetraacetic acid, or disodium EDTA. It is thought to work by binding and eliminating harmful lead and cadmium from the body.

These two metals are both on the top ten list of hazardous substances ranked by the Agency for Toxic Substances and Disease Registry. Like mercury, arsenic and other metals that have no role in the body, they are called xenobiotic metals. While it is not yet clear exactly how EDTA chelation works, current thinking is that the benefit seen in TACT is related to its ability to bind and eliminate xenobiotic metals from the body. This is supported by evidence that links these metals to heart disease, and might explain its greater effect in diabetes.


Lead & Cadmium

Most people over 50 are exposed to toxic amounts of lead every day, and their bones are the source. An entire life’s lead exposure is stored in the bones, and in the time before it was banned, virtually everyone was exposed to lead in gasoline and paint. Some people are still exposed to lead in water pipes, bullets, soldering or toys. Whatever the source, lead is stored in bones, which releases into the bloodstream again and again as your bones remodel over time.

The harm that is done by this lead has been demonstrated in many studies. Several studies have linked higher blood lead levels to increased risk of cardiovascular mortality and all-cause mortality. In the Normative Aging Study, those with higher bone lead levels were at an 8.37 times increased risk of cardiovascular mortality. This study is important because it measured bone lead levels, which is considered a more accurate measure of total body burden than blood lead, which only reflects recent exposure.

There are several ways in which lead might lead to heart disease. Lead increases blood pressure in animal models, and in vitro studies show that it blocks the production of nitric oxide, a molecule that relaxes arteries, by inhibiting and enzyme called endothelial nitric oxide synthetase (eNOS).  Lead also promotes oxidative stress and inflammation.

The story of cadmium is similar to that of lead. Cadmium is another highly toxic metal that can harm arteries. Cigarette smoke is the most significant source, but everyone is exposed to some cadmium. That is because plants, fruits and grains absorb it from the soil, so there are traces in most of our food. It can damage arteries just like lead can, and it has also been linked to heart disease. At least some of the benefit seen in TACT is likely related to removing cadmium from the body.

Many toxic compounds that damage arteries in diabetes cannot be made without metals.  This includes advanced glycation end-products (AGEs), advanced lipoxygenation endproducts (ALEs) and protein oxidation products. This may explain the increased benefit seen in TACT in those with diabetes.   

It is proposed that EDTA infusions promote cardiovascular health by removing harmful metals that can cause heart disease from the body. This has led some to suggest that these xenobiotic metals are a new modifiable cardiac risk factor.



The potential benefit of chelation in diabetes is significant. In the original TACT trial, 1708 patients were given 55,222 infusions and monitored for an average of 55 months.  Of these, 608 (37%) had diabetes, and among these patients, the chelation group had a 43% lower risk of death from any cause (HR: 0.57 [95% CI: 0.36 to 0.88], p=0.011), and a 52% lower risk of another heart attack (HR: 0.48 [95% CI: 0.26 to 0.88], p=0.015).

What is more intriguing about these results is that the benefit of treatment continued long after the last infusion. The treatment group had their last infusion about 14 months after enrolment, but their risk continued to decline over the entire 5-year period. This not seen in any other current treatment for diabetes. It also supports the hypothesis that removing metals improves vascular health.

The goal of TACT2 is to replicate these findings. 1200 patients will be enrolled to receive 40 weekly infusions and take oral capsules daily. Just like TACT, this trial has a 2×2 design, which means that the infusions will either contain the active TACT infusion or a placebo, and the capsules will contain vitamins and minerals or placebo. Each infusion takes about three hours.

The goal is to see whether diabetic patients receiving chelation therapy have fewer heart attacks, strokes or deaths than those receiving placebo, and whether there are any differences in quality of life.

Information Session

Please join us for a free information session on diabetes, heart disease, and the TACT2 trial:


Dr. Richard Nahas, MD


Tuesday February 13, 2018

Call 613-727-7246, or email trials@seekerscentre.com for more information and to RSVP for this event.

Category: Articles, Health & Natural Therapies

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