Heart Stents Fail to Ease Chest Pain

I guess the patients knew they were taking part in an experiment, and got paid for it.

"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."

I had the same thought! However, the article mentions at some point that the drugs were the "optimal treatment"... implying that the exact value/necessity of stenting is... a little... unclear? Maybe I misunderstand, but perhaps a stent is like the cherry on top of the aspirin/statin/blood pressure regimen.

> One day when I was a junior medical student, a very important Boston surgeon visited the school and delivered a great treatise on a large number of patients who had undergone successful operations for vascular reconstruction. At the end of the lecture, a young student at the back of the room timidly asked, "Do you have any controls?" Well, the great surgeon drew himself up to his full height, hit the desk, and said, "Do you mean did I not operate on half the patients?" The hall grew very quiet then. The voice at the back of the room very hesitantly replied, "Yes, that's what I had in mind." Then the visitor's fist really came down as he thundered, "Of course not. That would have doomed half of them to their death." God, it was quiet then, and one could scarcely hear the small voice ask, "Which half?"

–Dr. E. E. Peacock, Jr., University of Arizona College of Medicine; Medical World News (September 1, 1972), p. 45, as quoted in Tufte's Data Analysis for Politics and Policy

Disclaimer: Haven't had a chance to read the original paper yet. IIRC, there was already pretty good evidence that angioplasty (without stenting) does not lower risk of death from heart disease unless there is actually an acute myocardial infarction (heart attack) in progress. In other words, if done in people having chest pain due to intermittently insufficient blood flow (angina), but not actually having a heart attack, there was no difference in death / disability, but there was less pain afterwards. Both angioplasty and stenting definitely help (reduced risk of death / disability) in people having acute heart attacks.

There are also complications associated with stents. I certainly don't think it was unethical, but I agree with your question for this reason - many studies that may be ethical, but may lead to reduced sales of very expensive items somehow are deemed 'unethical'. I assume the way they did it was that everyone got a diagnostic angiogram, but only the experimental group got the stent. That way there was still benefit to all the patients (assuming diagnostic angiography is useful...), whether or not they got the stent.

Hints in the full text:

"...it might be unethical to expose patients to an invasive placebo procedure. However, no evidence of harm to placebo groups was found in a systematic review of placebo-controlled surgical trials... After the follow-up assessments, study participation was complete, and patients and physicians were then unblinded to the treatment group allocation. Patients who had the placebo procedure had the opportunity to choose to undergo PCI after consultation with their physician."

But yes, it must have taken a lot of persuasion to get through ethical approval.

I'm a little confused by this. Patients can get stents in multiple arteries during one cath lab session. Generally it's a diagnostic cath at first, finding all blockages, and deciding which vessels should be ballooned/stented. I've been in multiple procedures (shadowing, not performing) where they did 2+ vessels.

Well, for starters, it's hard to get 200 people who might be eligible for life-preserving surgery to volunteer to possibly get a sham procedure for the exclusive benefit of othewars; not to mention build a team of surgeons, hospitals, etc. willing to do the trial; and someone to pay for millions of dollars in treatment and administrative costs. Clinical trials involving surgery, especially with sham procedures as a proper control, are exceedingly rare in the US for these reasons. (this is discussed in the OP itself.)

Not to mention the difficult of finding patients for surgical trials, especially of relatively pre-existing procedures, the cost per procedure could be (conservatively) $10k making this still a $2M study.

I once read a study that the half life of truth in medicine is 20 years. Namely in 20 years roughly half of the things we identified as truth are overturned. Examples? Fat clogs arteries. Cholesterol clogs arteries. LDL causes heart disease. High blood pressure causes atherosclerosis. All of these "truths" have been debunked in the last 30 years or so. Apparently there are many more. Stents save lives? There's 50% chance you'll be proven wrong in ~20 years! Maybe much sooner.