Chelation therapy didn't change the ability to perform daily tasks or impact the emotional wellbeing of patients who previously suffered a heart attack, according to late-breaking clinical trial research presented at the American Heart Association's Scientific Sessions 2012.
There was no impact on patient's quality of life in this sub-study although the overall Trial to Assess Chelation Therapy (TACT) showed chelation therapy cut the risk of death, second heart attacks, stroke and the need for heart procedures among some patients who already suffered an earlier heart attack.
This quality-of-life study was a planned analysis of 911 randomly chosen patients from the overall trial of chelation therapy, an alternative treatment which uses weekly infusions to remove metals from the bloodstream.
"We didn't see any effect on the quality of life of chelation therapy patients," said Daniel B. Mark, M.D., M.P.H., lead author of the sub-study and professor of medicine, director of outcomes research at Duke University Medical Center and Duke Clinical Research Institute in Durham, N.C. "Patients weren't any worse, but they weren't any better.
One of the tools used to measure quality of life was the Duke Activity Status Index, DASI, to measure patients' ability to complete daily tasks. The lowest score of 0 means the patient couldn't do any chores associated with their own care such as feeding, toileting and dressing themselves. The highest score of 48 would be achieved by a professional athlete, Mark said.
At the beginning of the study, patients taking chelation therapy had a score of 24.6 and after two years it went up to 27.1. Those on placebo, dummy infusions that contained no medicine, had a baseline score of 23.5 that went up to 25.1. The small difference between chelation and placebo wasn't significant enough to show a notable impact on how patients functioned in their daily lives.
The results were similar when researchers used the SF-36, the Short Form Health Survey, which assesses mental wellbeing or stress. After two years of chelation or placebo, patients reported similar scores.
"We thought it might make people feel better, but we didn't see that consistently enough," Mark said.
The main study examined the effectiveness of chelation therapy, which isn't approved by the U.S. Food and Drug Administration to treat heart disease, but has long been used as an alternative treatment. It is approved, however as a prescription treatment for heavy metal poisoning such as mercury and lead poisoning.