Heart Stents Fail to Ease Chest Pain(nytimes.com)
nytimes.com
Heart Stents Fail to Ease Chest Pain
https://www.nytimes.com/2017/11/02/health/heart-disease-stents.html?_r=0
24 comments
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.
"...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 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."
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."
In a practical sense, I wonder how they'd successfully do it in the US.
Stents cost on the order of $11k-$44k per the article. Wouldn't you just know from looking at your bill afterward whether you got the stent or not?
Stents cost on the order of $11k-$44k per the article. Wouldn't you just know from looking at your bill afterward whether you got the stent or not?
A simple way around that would be to pay for them so that no patient was billed for one.
Is there not a problem that in the US it would encourage people who otherwise couldn't afford the operation to opt for the "riskier" trial, even if they'd really prefer not to. Whereas in the UK, they would have received the operation free in or out of the trial, therefore the patients financial situation wouldn't factor in to their decision to join. Which feels significantly more ethical to me.
In theory you either have insurance that should cover this (more than 90% of Americans are covered), or else you'd be too poor to really even be able to afford such an operation or medical care. The system sucks, but I don't think the way the system is set up would cause a significant number of people to use free research for medical alternatives.
Even if you have insurance you get a statement from your insurance provider detailing how much everything cost and how much of it insurance paid for.
People in a clinical trial typically don't pay for the treatment (or placebo).
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
–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.
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.
Stents are an incredible piece of engineering, but probably are over-used (particularly in the USA). There are a few issues at play:
-Chest pain
-Artery narrowing
-Heart attack risk
They aren't the same, although there is correlation between each. The original idea behind stents was to stabilise vessels in the process of a heart attack. They are increasingly used in a preventative way - but the problem is there aren't very many or good tools to tell how at risk an individual is to a heart attack.
Another major problem (as the article mentions) is that stents improve the situation in one artery, but most patients that need a stent have atherosclerosis in multiple vessels. This likely explains why the chest pain remains.
-Chest pain
-Artery narrowing
-Heart attack risk
They aren't the same, although there is correlation between each. The original idea behind stents was to stabilise vessels in the process of a heart attack. They are increasingly used in a preventative way - but the problem is there aren't very many or good tools to tell how at risk an individual is to a heart attack.
Another major problem (as the article mentions) is that stents improve the situation in one artery, but most patients that need a stent have atherosclerosis in multiple vessels. This likely explains why the chest pain remains.
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.
Agreed that multiple stents and multiple vessels can be stented in one cath session. My point was more that there isn't very strong evidence or criteria for what constitutes a vessel that should be stented versus which should not. Worse, plaques are dynamic – what looks benign today could rupture and cause a complete/near occlusion. Rupture and subsequent thrombosis is more dangerous than stenosis itself.
Previous research showed that stents increase lifespan only in patients who have already had a heart attack.
They only assessed the patients after 6 weeks. It would be interesting what a longer follow up of the patients would reveal.
A 6-week study of 200 people.
Why is this news?
Why is this news?
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.)
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.
When I was at med school 7 years ago we were told for years. I thought it was just a way of saying that medical knowledge increases so quickly, but then whilst I was there we had:
- Total change in how we manage chest pain/heart attacks (moving from previous full/partial thickness infarction to STEMI/NSTEMI and totally revising treatment algorithms
- Introduction of ipilumimab for melanoma (changed metastatic melanoma from a condition with 6 month average survival to 5 years/chronic disease
- Introduction of cure for help c (previously followed the rule of 20 and it was a chronic disease)
- Total revision of food pyramid
- Multitude others
I believe 4-6 years. So much changes, without CPD/CME you are useless.
- Total change in how we manage chest pain/heart attacks (moving from previous full/partial thickness infarction to STEMI/NSTEMI and totally revising treatment algorithms
- Introduction of ipilumimab for melanoma (changed metastatic melanoma from a condition with 6 month average survival to 5 years/chronic disease
- Introduction of cure for help c (previously followed the rule of 20 and it was a chronic disease)
- Total revision of food pyramid
- Multitude others
I believe 4-6 years. So much changes, without CPD/CME you are useless.
>I once read a study that the half life of truth in medicine is 20 years.
i heard that as a joke - Medical school dean to his graduates : "A half of the things we taught you will be proven wrong in 5 years. We just don't know which half."
i heard that as a joke - Medical school dean to his graduates : "A half of the things we taught you will be proven wrong in 5 years. We just don't know which half."
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.
"All were treated for six weeks with drugs to reduce the risk of a heart attack, like aspirin, a statin and a blood pressure drug, as well as medications that relieve chest pain by slowing the heart or opening blood vessels.
"Then the subjects had a procedure: a real or fake insertion of a stent. This is one of the few studies in cardiology in which a sham procedure was given to controls who were then compared to patients receiving the actual treatment.
"In both groups, doctors threaded a catheter through the groin or wrist of the patient and, with X-ray guidance, up to the blocked artery. Once the catheter reached the blockage, the doctor inserted a stent or, if the patient was getting the sham procedure, simply pulled the catheter out."
I would really like to know how they got that study past the assorted ethics committees.