Heavy metal ions and bivalent cations have tendency to settle and form deposits inside a tissue or a in a given systems. Ethlenediamine tetra acetic acid EDTA, and its di and tetra sodium salts have ability to bind such ions and make them soluble in water at a basic side on PH scale. That is why Ethylenediamine tetra acetic acid EDTA has gained important place in analytical chemistry in pharmaceuticals.
Its property of chelating heavy metals bi, tri and tetra valent cataions and making them soluble after chelating has gained application in medical treatments of some diseases.
Chelation therapy was so far used for removing toxic metal like mercury and lead from body in event of accidental intake or poisoning. It is also used to treat patients suffering with thalassemia who receive frequent blood transfusions, frequent blood transfusions cause deposition of high level of iron in bone and muscular tissue , which may become fetal, in such condition iron is removed from body by giving chelating therapy by infusing EDTA .
Recently National institute of health has conducted a clinical trial to investigate efficacy and safety of chelating therapy with EDAT in patients suffering from coronary heart diseases, the treatment is used by doctors along with other drug treatments to lower cholesterol and to reduce blood pressure ,(statin, aspirin, beta blockers) but its efficacy was not yet established through any clinical trial.
The idea behind using chelating therapy was to remove higher concentration of deposited calcium from coronary artery , this calcium deposit in the tissue is one of major factor which render artery hard and facilitate formation of plaque.
Clinical trial was conducted over about 1700 patients , of which a group was given chelating therapy along with regular medicine and vitamin C. Other group was given placebo.
It was found that there was the chelating therapy when given in stringent control and supervision has beneficial effect, when efficacy evaluated after comparison the both groups is very little and the all questions remains still unanswered with the present out come.