"Stenting is so accepted that American cardiologists said they were amazed ethics boards agreed to a study with a sham control group.

But in the United Kingdom, said Dr. Davies, getting approval for the study was not so difficult. Neither was it difficult to find patients.

“There are many people who are open to research, and if you tell them you are exploring a question, people agree,” he said. Nonetheless, it took him three and a half years to find the subjects for his study.

Ethics boards at many American hospitals probably would resist, since giving such patients fake procedures “flies in the face of guidelines,” Dr. Boden said."