About $30 million taxpayers' money have been spent on finding out if a chemical agent that removes heavy metals from the bloodstream makes any difference in health of heart disease patients, a research that, many experts say, has been a waste of both money and time.

A controversial trial that was presented at the American Heart Association's Scientific Sessions 2012 said that chelation therapy had fewer benefits on people who have cardiovascular diseases.

"We didn't see any effect on the quality of life of chelation therapy patients. Patients weren't any worse, but they weren't any better," said Daniel B. Mark from Duke University Medical Center and Duke Clinical Research Institute in Durham, N.C., in a press release.

The clinical trial, called Trial to Assess Chelation Therapy, or TACT, began about a decade ago and was temporarily suspended in 2008 after it was criticized for being unethical and its disregard for patient safety. Since then, the trial has had a slow rate of enrolment, Forbes reported.

The study assessed patients' ability to perform daily tasks while on chelation therapy or placebo. The scores were based on Duke Activity Status Index. A zero on this scale meant that the person was incapable of performing daily activities like feeding, toileting and dressing themselves whereas a high score of 48 would mean the person is capable of activities that require more energy like sports.

Researchers found that after two years of chelation therapy, participants' score went up from 24.6 to 27.1 while those on placebo saw an increase from 23.5 to 25.1.

"This study has the potential to be extremely dangerous.  Chelation "should not be administered to any patients for the indication of heart disease. ... There are a lot of people, including me, who believe this was a poor use of taxpayer dollars," said cardiologist Steven Nissen of the Cleveland Clinic, to USA Today.

The chelation therapy uses EDTA to remove plaque that has clogged the arteries. According to Quackwatch, the therapy is also used to treat "nonexistent lead poisoning, mercury poisoning, and other alleged toxic states that practitioners diagnose with tests on blood, urine, and/or hair." Mayo Clinic says that that the therapy can be dangerous for people who have a heart disease.

More than 100,000 Americans with heart disease undergo chelation therapy each year, at a cost of about $5,000 per course of treatment, according to New York Times.

The American Heart Association and the Food and Drug Administration haven't approved chelation therapy for heart disease treatment.

Changing diet, reducing weight, quitting smoking and exercising will help reduce risk of heart disease better than undergoing the chelation therapy, writes Art Caplan, head of the division of medical ethics at the NYU Langone Medical Center, on nbcnews.com.