Dr. Clyde Yancy, a Northwestern University cardiologist and a former Heart Association president, agreed.
"It's funny business," he said. "I've never seen a study in which one in five people withdrew consent."
The study's leader, Dr. Gervasio Lamas of Mount Sinai Medical Center in Miami, said: "The trial needs to be taken for what it is — a step towards future investigation."
It initially aimed to enroll 2,400 people in the United States and Canada but recruitment lagged and the goal was reset to 1,700.
In 2008, a group of scientists published a long article criticizing the trial, saying participants had not been warned that others had died from chelation. More than half of the doctors running the study make money by selling chelation treatments — a conflict of interest, they complained.
Investigations by the Office for Human Research Protections and the Food and Drug Administration found that several doctors doing the study had been accused of poor practices by state medical boards or involved in insurance fraud, and at least three were convicted felons. That did not prevent them from doing federal research, the government decided, and let the study go on after corrective steps. By that time, 1,500 participants had already been enrolled.
Marilynn Marchione can be followed at http://twitter.com/MMarchioneAP
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