Cardiologists Are Still Missing COURAGE

DrRich | June 13th, 2011 - 7:21 am

Podcast:

In 2007, when the results were published from the COURAGE trial, all the experts agreed that this study would fundamentally change the way cardiologists managed patients with stable coronary artery disease (CAD).*
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*”Stable” CAD simply means that a patient with CAD is not suffering from one of the acute coronary syndromes – ACS, an acute heart attack or unstable angina. At any given time, the large majority of patients with CAD are in a stable condition.
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But a new study tells us that hasn’t happened. The COURAGE trial has barely budged the way cardiologists treat patients with stable CAD.

Lots of people want to know why. As usual, DrRich is here to help.

The COURAGE trial compared the use of stents vs. drug therapy in patients with stable CAD. Over twenty-two hundred patients were randomized to receive either optimal drug therapy, or optimal drug therapy plus the insertion of stents. Patients were then followed for up to 7 years. Much to the surprise (and consternation) of the world’s cardiologists, there was no significant difference in the incidence of subsequent heart attack or death between the two groups. The addition of stents to optimal drug therapy made no difference in outcomes.

This, decidedly, was a result which was at variance with the Standard Operating Procedure of your average American cardiologist, whose scholarly analysis of the proper treatment of CAD has always distilled down to: “Blockage? Stent!”

But after spending some time trying unsuccessfully to explain away these results, even cardiologists finally had to admit that the COURAGE trial was legitimate, and that it was a game changer. (And to drive the point home, the results of COURAGE have since been reproduced in the BARI-2D trial.) Like it or not, drug therapy ought to be the default treatment for patients with stable CAD, and stents should be used only when drug therapy fails to adequately control symptoms.

When the COURAGE results were initially published they made a huge splash among not only cardiologists, but also the public in general. So cardiologists did not have the luxury of hiding behind (as doctors so often do when a study comes out the “wrong” way) the usual, relative obscurity of most clinical trials. Given the widespread publicity the study generated, it seemed inconceivable that the cardiology community could ignore these results and get away with it.

But a new study, published just last month in JAMA, reveals that ignore COURAGE they have.

In a registry-based survey that covered over 500,000 patients treated in over 1,000 hospitals, the new article reports that there has been little change in the use of drug therapy in patients with stable CAD since the COURAGE study was published. Prior to the publication of COURAGE, only 43.5% of patients who received stents had been tried on optimal drug therapy; two years after publication of COURAGE, that number had “increased” to 44.7%. And while the increase was statistically significant, observers have agreed that it is nonetheless trivial, and that the COURAGE trial apparently has made next to no impact on the practice patterns of cardiologists.

This revelation is proving embarrassing to even the usual spokespersons for the cardiology community, the luminaries who are always trotted out to explain the nuances of their colleagues’ sometimes odd behaviors, and to explain why those behaviors, actually, are not only reasonable but commendable. This time they are at a loss.

The best they can do, according to their commentary on TheHeart.org, is to offer two speculations: a) that, sometimes and for mysterious reasons, it can take several years for the results of important randomized trials to “disseminate” down to practicing physicians, and that apparently even the highly-sophisticated cardiology community is not immune to this phenomenon, and b) the cardiologists are waiting for their professional organizations to issue updated “guidelines” on stable CAD that take the COURAGE results into account. (The last official guidelines were published in 2002.)

Regarding this first explanation, DrRich can assure his readers that the results of the COURAGE trial were not slow to disseminate to American cardiologists. The results (and their implications) were, in fact, known immediately to every one – indeed, the buzz was palpable. It was, perhaps, the biggest news in the cardiology world in several years. If any cardiologists missed this seismic event, they are among that tiny, disconnected minority that is still out making house calls and distributing foxglove leaf, and likely would not know what a stent is, let alone be using them indiscriminately.

Regarding the “guidelines” excuse, DrRich is speechless. Since when are cardiologists guilty of following clinical guidelines to a fault?  If doctors, especially cardiologists, are already sticking strictly, in every particular, to sets of guidelines promulgated by committees of distant experts, even when they know those guidelines are out of date and, frankly, wrong, then (if you are an American patient) all is already lost.

DrRich does not buy either of these explanations. So what, then, is the real reason?

Is it greed? This is likely part of the explanation, and is all of the explanation for some cardiologists. (Self-interest plays as large a role in determining the actions of some practicing physicians as it does in determining the actions of those physicians whose reputations and hoped-for futures as “policy experts” requires them to denigrate the motives of practicing physicians every chance they get.) Indeed, DrRich would not be surprised to learn that some cardiologists of a certain age, realizing that the days of wine and roses are rapidly drawing to a close, are scrambling to insert every stent they can – and any other medical accoutrement they can justify deploying – as rapidly as possible, and then get the hell out.

But DrRich is certain that most cardiologists are genuinely trying to do what is best for their patients, and he believes that the failure to respond to the COURAGE trial is too generalized and too widespread to attribute entirely to greed.

Rather, DrRich believes that the results of the COURAGE trial simply fly in the face of your typical cardiologist’s world view. And while they undoubtedly understand those results intellectually, and even accept the results explicitly, they are simply having trouble incorporating those results into their conceptual framework for CAD. And since CAD is their livelihood, their philosophy, their sun, moon and stars, this amounts to an existential crisis.

When Galileo championed the Copernican view of the universe, and backed it up with sound scientific observations, he felt his views would receive approbation from the highest authority. After all, his old friend, the intellectual cleric Barberini (who had supported the publication of his book), was now Pope Urban VIII. But, while as Barberini his old friend could afford to be intellectually pure, as Pope Uban he could not. For Urban to accept Galileo’s work would formally call all Scripture into question, and seriously undermine the integrity and authority of the organization that had provided structure to western civilization for 1000 years. So Galileo had to suffer.

DrRich thinks that cardiologists find themselves in the position of Pope Urban – having the intellect to understand and accept certain surprising scientific results, but unable to put those results into practice without wrecking an entire way of life, and indeed, an entire way of looking at the world. They can either ignore (with, no doubt, some discomfort) the clear results of COURAGE, or abandon the world view that provides their sustenance and gives their lives meaning. That, DrRich thinks, is the real problem.

Regular readers will know that DrRich is not one to articulate a problem, and then simply walk away, leaving everyone to wonder what to do about it. So, as usual, DrRich has a suggestion.

The cure for the cardiologists’ existential problem is to articulate and accept a new world view, one that incorporates the results of COURAGE (and other clinical trial results that may seem puzzling under the old world view), and which places the proper usage of drugs and stents for CAD into a serviceable framework. While adopting this new world view will not be pain-free, it is one to which cardiologists can adapt – just as the Church eventually adapted to the heliocentric view of the cosmos.

And so, as a public service to his cardiology colleagues (and to their patients), DrRich will articulate a new world view on CAD. DrRich has not himself invented this new world view – most academic cardiologists, he believes, already endorse it, at least implicitly. But an explicit statement of the new world view – and an explicit rejection of the old – may help a few of DrRich’s cardiology friends to begin to accept the new “heliocentric” view of CAD, and thus to cure the existential crisis which (he postulates) is holding them back.

The Old World View

The old world view of CAD goes as follows: CAD produces localized plaques in the coronary arteries, which gradually grow out into the artery’s lumen, causing partial blockage of the artery. These “significant” plaques (generally regarded as plaques that are blocking 75 – 80% of the artery’s lumen) can produce angina (because during exertion not enough blood can get through the partial obstruction), and more importantly, can eventually cause ACS. The ACS occurs because the ballooning plaque can eventually rupture, causing a blood clot to form in the vessel, and producing sudden, high-grade occlusion of the artery.

Therefore, the cardiologist’s job is to identify these significant plaques and to stent them. Doing so will relieve “stable” angina, and will prevent ACS.

In the old world view, CAD is a localized process, that can be adequately treated with localized measures. If the location of the offending plaques can be identified (by cardiac catheterization) they can be treated. Heart attacks and death are thereby prevented.

The New World View

Whether or not CAD is producing a few localized “significant” plaques, the atherosclerosis that causes CAD is a generalized, and not a localized, process. That is, there are usually many plaques within the coronary arteries, most of which are not only “insignificant” (less than 75-80% blockages), but may even be nearly invisible during coronary angiography. Furthermore, it now appears that the majority of heart attacks (and other forms of ACS) occur when one of these “insignificant” plaques ruptures.

This is why it is not particularly unusual for somebody who has a “clean” coronary angiography to have a heart attack soon thereafter. And this is why aggressively treating stable but “significant” blockages with stents does not measurably reduce the incidence of heart attack and death.

CAD is a generalized, progressive disease. The treatment of CAD therefore inherently ought to be a medical (and not a localized, quasi-surgical) process. Ideally, one ought to use drugs that stabilize plaques and reduce the risk of rupture (statins, possibly beta blockers), along with drugs that reduce the propensity of blood to clot within the coronary artery, should a rupture occur (aspirin). And research should be aimed at identifying unstable plaques and finding better ways to stabilize them, and not at tweaking stents to render them marginally better than the prior ones.

A stent is fine to use on a significant blockage that is producing stable angina, but what it is accomplishing, one must realize, is merely to treat the symptom of angina – and not to prevent future heart attacks.

There.*

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* Under the new world view as well as the old, when ACS is actually occurring – when a plaque has ruptured and acute occlusion of an artery is taking place – inserting a stent often appears to be beneficial.
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Now that DrRich has entirely relieved the existential crisis all you cardiologists out there have been experiencing (you’re welcome!), all that remains is for somebody to address those few outliers among you who still haven’t heard about the COURAGE trial, or who are doggedly committed to following approved clinical guidelines under all circumstances, come hell or high water, even when they know them to be wrong, or who are just too consumed by greed to do the right thing.

While DrRich would consider it far from his method of choice for changing physicians’ behavior, and is in fact appalled by it, the Department of Justice’s new policy of conducting, Urban-like, inquisitions against physicians who are slow to adopt the Central Authority’s preferred practice patterns, and then criminally prosecuting those who are slow to comply, should work wonders in this regard.

6 Responses to “Cardiologists Are Still Missing COURAGE”

  1. james gaulte says:

    I wonder what my old mentor, George Burch,chief of Medicine at Tulane (1947-1975),would have to say about catheter treatment of stable CAD in light of clinical trials showing no need for them. Actually, I don’t have to wonder.

  2. pcb says:

    The “stable CAD” thing seems hard to define. Unstable angina can be defined, IIRC, as worsening or new symptoms of cardiac ischemia. If anyone presents to the clinic or ED with more frequent or new symptoms, they are not stable CAD by definition. If you end up stressing those patients or just going right to angiogram, and if you find any narrowings, and if you then stent them, you are “treating” unstable symptoms, not stable ones. Which would put you on the right side of “evidence based medicine”, no? It seems that’s how most stenting is done, and it doesn’t violate COURAGE.

    The only stable angina patients are the ones who ignore going to the doctor when the symptoms arise or change, coming in months/years later and say “doc, every time I mow the lawn, I get this pain, etc.”

    • DrRich says:

      pcb,

      This is an old argument, one I have been hearing for over 30 years – that virtually any CAD symptoms can be construed as being unstable. The COURAGE trial defined stable CAD pretty precisely, and I think you’ll find the definition to be reasonable. However, whether you and/or I agree with the definition as laid out by the COURAGE trial is immaterial. What really ought to matter to cardiologists is the definition which the federal attorneys general will be using, when they criminally prosecute stent implanters for violation of “evidence-based medicine,” as they are doing today with EPs who implant ICDs with imperfect adherence to the guidelines.

      Rich

  3. Gingerr says:

    I listened to your podcast while reading a 2009 issue of Science magazine on the exercise bike at my YMCA this morning. The well-thumbed magazine had a big article about heart attacts, focusing mostly on something about how when oxygen comes back into the cells they proceed to commit suicide. In describing the events stents were what they mentioned as the most common fix for this narrowing. This was two years after your study.

    I think if you went into those exam rooms you’d find that patients are much happier to hear they need a stent because it qualifies as a “fix”, compared to ongoing drug treatment.

    Everybody wants to have the latest and greatest and since Medicare pays why should they settle for some idiot pills when they can have surgery?

  4. Robert A Rosati says:

    I’m not sure there is any evidence that stenting or bypass prevents heart attacks or deaths in patients with unstable angina

    • DrRich says:

      Robert,

      While this is certainly not settled science (like global warming or the need for a universal salt restriction), there is such evidence – specifically, the FRISC II trial, TACTICS-TIMI 18, and RITA 3. The ICTUS trial, on the other hand, showed no mortality improvement.

      Rich

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