Most of the study on chelation therapy is clinical study, not so call double blind control study. Besides that, unfortunately the result published in Integrative Medical Journal, Journal of Science, Journal of Advancement in Medicine and Alternative Medical Journal which is not read by many doctors.
In the year 1998 senate USA approved USD30 million for research on chelation therapy, small money indeed but at least somewhere to start with. Unfortunately, the research was designed by non-chelationist physicians. In 2002, discussion among chelationist physician noted that the study design seems meant to fail and they expect it to fail. This is because, we noted that the research was design in such a way that it will fail. The truth is, and not a surprise that the research was abandoned for various reasons they know best.