12th November 2017
Another slight detour I am afraid. This is due to the recent publication of the ORBITA study. Reported in the British Medical Journal (BMJ), thus:
‘Percutaneous coronary intervention (PCI) is not significantly better than a placebo procedure in improving exercise capacity or symptoms even in patients with severe coronary stenosis, research has found.1
The ORBITA study, published in the Lancet, is the first double blind randomised controlled trial to directly compare stenting with placebo in patients with stable angina who are receiving high quality drug treatment.’ Compared to the sham-controlled group:
- PCI did not significantly improve exercise time. The numerical incremental increase in average exercise time was 16 seconds (P=0.20).
- PCI did not significantly improve measures on well-validated patient-centered angina questionnaires.
- PCI did not significantly improve the Duke treadmill score or peak oxygen uptake.
- PCI did significantly improve the dobutamine stress echo wall-motion index, indicating that stenting reduced ischemic burden.
In short, PCI did nothing at all. I can hear cardiologists across the US putting plans for new swimming pools on hold. 2
As many people know, the purpose of a stent is to open up obstructed coronary arteries, and then keep them open, using a metal framework ‘stent’, that sits within the artery. This procedure has been done on thousands, millions, of people. In an acute myocardial infarction (MI or heart attack to you) it provides benefits. However, in non-acute blockage it does nothing, apart from enrich interventional cardiologists.
Frankly, I was surprised that these researchers got ethical approval for this study. Carrying out a sham operation is a pretty major thing to do to a patient. I am further surprised they managed to get any volunteers, but they did. I very much take my hat off to these researchers. Bold, very bold, indeed. They must have been pretty damned certain they were going to see no benefit from stents.
Anyway, this study only proves what many people had suspected for some time. Stents, in the non-acute situation, do not work. Of course, this study has already been attacked and dismissed. Here is one review from SouthWestern medical centre, entitled ‘Stents do work: A closer look at the ORBITA study data.’:
‘ORBITA was small – too small, in fact, considered definitive evidence that cardiologists should change the role of stents in clinical practice.
I participate in a number of cardiology care guidelines committees and even wrote a piece about the ORBITA trial for the American College of Cardiology. In order for regulating bodies to change clinical practices, research studies must present data from a much larger pool, such as the 2007 COURAGE PCI study, which enlisted more than 2,000 participants. In general, larger trials present data that are more statistically significant and more appropriate to apply to specific patient segments.’ 3
Too small? Wrong patient type, no doubt the wrong atmospheric pressure as well. Unlike the studies that were used when cardiologists first started doing stents, where the study size was precisely zero. In fact, if you read the entire article from the Southwestern medical centre, it is gibberish. But it will have the desired effect. The ORBITA study will have no impact stenting revenue. Like many other ideas in medicine, it is too seductive, and far too lucrative. The artery is blocked, it must be opened. End of.
Many years ago, Bernard Lown had precisely the same issue with Coronary Artery Bypass Grafting (CABG). Another massively lucrative intervention which rapidly became the operation – based on no evidence whatsoever. It was such an obviously brilliant idea that to question it was to defy ‘common sense.’ You have a blockage in an artery, bypass it with a graft.’
One thing that you find about good science is that it is usually very far removed from ‘pure common sense.’ It is counterintuitive. It is counterintuitive because it challenges established thinking a.k.a. prejudices. As Einstein had to say. ‘Common sense is nothing more than a deposit of prejudices laid down in the mind before age eighteen.’ He also said that ‘It is harder to crack prejudice than an atom.’
If you want a really good read, I recommend Bernard Lown [he is my hero]. He was the first to challenge the orthodoxy that CABG was an unquestioned good. For which he was of course, roundly attacked. His essay on this can be read here4. I include a particularly poignant section by Bernard Lown discussing CABG:
‘One might wonder why patients acquiesced to undergoing a painful and life-threatening procedure without the certainty of improving their life expectancy. I have long puzzled at such acquiescence. Surprisingly, patients not only agreed to the recommended intervention but commonly urged expediting it. Such conduct is compelled by ignorance as well as fear. Patients are readily overwhelmed by the mumbo-jumbo of medical jargon. Hearing something to the effect of “Your left anterior descending coronary artery is 75 percent occluded and the ejection fraction is 50 percent” is paralyzing. To the ordinary patient such findings threaten a heart attack or, worse, augur sudden cardiac death.
Cardiologists and cardiac surgeons frequently resort to frightening verbiage in summarizing angiographic findings. This no doubt compels unquestioning acceptance of the recommended procedure. Over the years I have heard several hundred expressions, such as: “You have a time bomb in your chest” and its variant “You are a walking time bomb.” Or, “This narrowed coronary is a widow maker.” And if patients wish to delay an intervention, a series of fear-mongering expressions hasten their resolve to proceed: “We must not lose any time by playing Hamlet.” Or, “You are living on borrowed time.” Or, “You are in luck — a slot is available on the operating schedule.” Maiming words can infantilize patients, so they regard doctors as parental figures to guide them to some safe harbour.’
The man is a genius and he can write far better than wot I can. I should hate him.
Some forty years later, or so, we find that CABG has been replaced by PCI/stenting. Exactly the same knuckle headed stupidity has driven stenting. The noise of sheep bleating ‘Narrow artery bad, open artery good,’ fills the air. My goodness, I think they’ve got it. Who could possibly argue with that? Kerching!
Those who have read my endless blog on the causes of on CVD will know I have long been highly sceptical of stenting as the answer to anything very much. Other than the removal of large sums of money from person A, to hospital B, and interventional cardiologist C.
Why does it not work? How can it possibly not work?
Because the heart is not simply a pump, arteries are not simply pipes, and humans are not inanimate objects whereby our function, or lack thereof, is purely dependant on some form of medical or surgical intervention. Thus endeth the lesson on stenting.