ISCHEMIA study: that blockage isn’t a time bomb in your chest

by Carolyn Thomas     @HeartSisters  

If you’re a heart patient living with stable angina, the ISCHEMIA clinical trial presented at the 2019 American Heart Association Scientific Sessions is all about you. Cardiologist Dr. John Mandrola described the impact of this study in his Medscape column like this:


But realistically, does one study have the power to actually change the practice of cardiology?      .

Many of us learned about the results of this long-anticipated study via news headlines like this one:

Stents and Bypass Surgery are No More Effective Than Drugs” – Washington Post

But before we take such a dramatic headline as gospel, I have both questions and concerns:

My first concern: of the 5,000+ participants enrolled in this $100 million study (down from the 8,000 that researchers tried to recruit), over 3/4 were men.

My question: how could anyone accurately extrapolate how the study’s conclusions apply to female heart patients when women made up only 23 per cent of the participants being studied?

Consider, for example, how the accuracy of that headline from the Post could be clarified by simply including the required word “MEN” . For example:

“Stents and Bypass Surgery are No More Effective Than Drugs FOR MEN!”

My question:  why was half of the world’s population inadequately represented in this study?

The ISCHEMIA trial focused on whether cardiologists should recommend what is called OMT  (Optimal Medical Therapy that included lifestyle modifications and medications) vs. OMT plus invasive interventions (stents or coronary bypass surgery) in people with moderate-to-severe stable angina – defined basically as chest pain that comes on with exertion, and goes away with rest.

That definition is important. Invasive cardiac interventions can and do save lives – but that is largely true only for those having or at high risk for having a heart attack, not in those with stable angina or no angina symptoms at all.(1)  The ISCHEMIA trial, however, specifically excluded high-risk patients (e.g. those with ‘unacceptable’ levels of angina). Some critics (not all of whom are interventional cardiologists or cardiac surgeons as you might expect) have described ISCHEMIA as a “miserable failure” with “problems galore”, while pointing out that 35% of enrolled patients in this study had no angina the prior four weeks, and only 20% had daily or weekly angina. Again, should the flashy headlines have been further amended to read “…for LOW-RISK men”And 20% of patients in the conservative OMT group did end up getting an invasive procedure within five years.

Basically, what previous studies have suggested is that invasive cardiac procedures to help re-establish blood flow to the heart muscle do not “fix” the problem that caused a blockage in the first place. Usually, it’s only the ‘culprit lesions’, as cardiologists call the most significant blockages, that get treated.

But the true cause of each blockage – the systemic issue that likely started decades earlier – is not “fixed” at all. What invasive interventions can do is manage significant cardiac symptoms (although the ISCHEMIA results found that, astonishingly, only about half of the patients in the invasive intervention group were symptom-free after one year).
By comparison, OMT (the treatment option recommended for stable angina in the ISCHEMIA study) can positively affect every cell in the body.
My question:  Didn’t we know that already?
Dr. Judith Hochman, one of the lead authors on ISCHEMIA, predicted this: if interventional cardiologists (coincidentally, the ones who earn a living implanting stents) adopted the findings of this study, it could mean saving over $500 million dollars every year in U.S. health care spending alone.
My concern:  when people with the letters M.D. after their names tell us that one or more of our coronary arteries feeding the heart muscle has some type of blockage inside, it can be a short hop/skip/jump/freakin’ leap to the frantic fear that something catastrophic is happening to us RIGHT NOW, and that this blocked artery needs to be unblocked.
This is because heart patients tend to have an intuitive affection for action over inaction when something seems wrong. Physicians, by the way, can demonstrate this preference as well, in what researchers call intervention bias”.  Studies (like this one, for example) suggest that “a majority of physicians will choose aggressive patient management options even when more conservative management is considered medically acceptable.” (2)
So while some patients may be open to non-invasive options like OMT, researchers report that heart patients seem to have a distinct preference for invasive procedural interventions (80 per cent) over medications (16 per cent). In fact, about 1/3 of patients studied believed that “medications do not really solve the problem.” (3)
This suggests that OMT alone may be a tough sell unless doctors clearly explain the benefits and risks of each potential treatment option to help patients decide. That’s called shared decision-makingSee also:  Informed Consent: More Than Just a Patient’s Signature
Research also supports this reality: a study published in the journal Annals of Internal Medicine, for example, found that over 80% of heart patients who did have a stent implanted mistakenly believed that the procedure would cut their odds of having a future heart attack.  But about the same proportion of the cardiologists who had treated these patients claimed that they had told the patients that stents would do nothing more than relieve chest pain.(4)
My question: where are patients getting this mistaken belief in stents as lifesavers?  Many of my Heart Sisters blog readers have similarly told me during the past decade that the cardiologist who performed their intervention (even in the absence of a heart attack) had “saved my life.”

Dr. John Mandrola opened his Medscape column about ISCHEMIA with a direct ‘thank you’ to pioneer cardiologist Dr. Bernard Lown, whom I wrote about here.

As Dr. Lown had quietly explained in 2012, long before the ISCHEMIA trial supported his conclusion:

“Doctors counsel heart patients to undergo invasive interventions because they are true believers of what they communicate.
“Often, though, they think like plumbers rather than like scientists: a blocked pipe has to be unblocked.  In the case of the heart, the sooner the better.
“But such medical opinions, though seemingly propelled by common sense, are not supported by clinical evidence.”

Even before that 2012 statement, Dr. Lown and his colleagues had published an anti-plumber paper in the New England Journal of Medicine back in 1981 (yes, 40 years ago) suggesting that, among his study group of 212 men – only men were studied back in those days – “medical management is highly successful and associated with a low mortality.”

Dr. Mandrola considers the new ISCHEMIA study “influential”  because it confirms that OMT treats the systemic disease  – not just a specific blockage. Despite the study’s limitations, he adds:

That blockage is not a time bomb in your chest. The clear results of ISCHEMIA, combined with the prior evidence, show that the clogged pipe frame of treating (stable) coronary artery disease was wrong. Clinicians must help change the public perception.

“The results do not mean that stents and surgery have no role. It means the initial approach is to treat the underlying disease.”

  1. Edward Hannan. “Appropriateness of Coronary Revascularization for Patients Without Acute Coronary Syndromes.” Journal of the American College of Cardiology, 2012; 59:1870-1876.
  2. Foy, A. J.  & Filippone, E. J.  “The case for intervention bias in the practice of medicine.” The Yale Journal of Biology and Medicine, 86(2), 2013; 271–280. 
  3. Bowling A. et al. “What do patients really want? Patients’ preferences for treatment for angina.”  Health Expectations, Volume 11, Issue2 June 2008; 137-147
  4. Rothberg MB, Sivalingam SK, Ashraf J, et al. “Patients’ and Cardiologists’ Perceptions of the Benefits of Percutaneous Coronary Intervention for Stable Coronary Disease.” Ann Intern Med. 2010; 153:307–313.

NOTE FROM CAROLYN: I wrote more about both invasive and non-invasive cardiac treatments in my book, “A Woman’s Guide to Living with Heart Disease” . You can ask for it at your favourite bookshop, or order it online (paperback, hardcover or e-book) at Amazon, or order it directly from my publisher, Johns Hopkins University Press (use the JHUP code HTWN to save 20% off the list price).

Q: Will this big study change the way cardiology is practiced?

.See also:

-More solid information about the ISCHEMIA trial from Shelley Wood writing in TCTMD

 Dr. Bernard Lowns wonderful book, The Lost Art of Healing: Practicing Compassion in Medicine.

Did you really need that coronary stent?

Squishing, burning and implanting your heart troubles away

Women’s heart health: why it’s NOT a zero sum game

Cardiac gender bias: we need less TALK and more WALK


9 thoughts on “ISCHEMIA study: that blockage isn’t a time bomb in your chest

  1. I have a bias in favor of mechanical solutions, partly because I understand them, having done that work, but mainly because I don’t like to take any medication that is not absolutely necessary, and plenty of evidence backs me up on that. I have apical hypertrophic cardiomyopathy, and betablockers are standard Rx, but I can’t take them – my resting heart rate already is very, very low.

    For over 16 years, I have reported chest pains, inappropriate fatigue and shortness of breath. Last week I had an angiogram, and had chest pain while waiting on the gurney just outside the OR. “Well,” I thought, “I guess they’re going to find out what’s going on.”

    It seems that the blood flow through my major arteries really is just fine. I also had an endothelial function test, in which I felt those very familiar chest pains. I do indeed have coronary spasms, and now take slow acting nightly nitroglycerin, on top of the fast-acting taken as needed. Mom says her own father, who had what then was called “a bad heart,” carried a little bottle of nitroglycerin in his pocket.

    Liked by 1 person

    1. Hello Kathleen – my first thought on reading about this most recent experience was “Good! She’s having her symptoms right there while waiting for the test!!” I’m curious about whether your slow-acting nitro seems to be working on the symptoms you’ve been having all these years? I sure hope so.

      Your grandfather’s nitro experience reminds me of the old “nitro is your friend” adage in cardiology. I met a woman at Mayo Clinic once who was a tournament tennis player with ‘refractory angina’ (that’s chest pain that cannot be eased with standard medications). She would take a dose of her nitro before starting each tennis match, then stop halfway through, sit down, take another dose, wait 5 minutes, and then get up and finish the game. She’d been doing this for years…

      Take care, stay safe. . . ♥


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  3. Hi Carolyn…
    I am up to four stents now, and two of them were probably necessary because they were unstable angina (something the first cardiologist, who just sent me home till he got back from vacation, missed)….

    After the last stent, my ejection fraction went up about 10%, so it seemed to make a real difference to get that major arterial highway cleared…

    It is remarkable to me that 3/4 of the people in the study were male. Apparently the medical world is not too much different than the patriarchal collective we inhabit.

    I would also note that OMT, while it includes lifestyle changes, doesn’t really seem to deliberately name psychological support — and lifestyle changes are exactly what psychologists work with, not to mention the depression, anxiety, and sometimes PTSD that accompany heart events that psychologists are used to working with.

    I have heard that medical practice is essentially thirty years behind medical knowledge…. Most of us don’t have thirty years to wait….

    Is there another planet we can go to for treatment?

    Liked by 1 person

    1. Hello Dr. Steve

      I’m glad you weighed in here with that very important (missing) piece in OMT (Optimal Medical Therapy). The typical list of elements in OMT varies depending on the cardiac study from drugs only (e.g. ranging from “aspirin, a P2Y12 inhibitor, a lipid-lowering agent (usually a statin), a β-blocker and possibly an ACE inhibitor”) to “medication and lifestyle changes” as the ISCHEMIA study calls them.

      But it’s hardly surprising that there appears to be no mention of ANY psychosocial support as part of those lifestyle changes. There is still – even in some supervised cardiac rehabilitation programs – little value placed on how heart-related depression/anxiety/PTSD can predictably sabotage heart patients’ ability to start/maintain meds as prescribed, healthy eating, smoking cessation, exercise or any of the nice lifestyle improvement recommendations from their physicians.

      In my response to Jill (below), I mention the book Ending Medical Reversal: Improving Outcomes, Saving Lives which is focused precisely on what you mention (medical practice not keeping up with medical knowledge).

      But DO NOT READ this book, Dr. Steve – you may find it too depressing!


  4. I feel that no single study should necessarily radically change any practice but should serve to inform clinical decisions that above all address each patient as an individual.

    I am glad my cardiologist is up to date on these studies. He is even head of a committee to examine the frequency of invasive procedures and how they measure up to new research. HOWEVER, when it came to making a clinical decision in my individual case, he coupled this new information, with my cardiac history and family history and his intuition and recommended a stent. I will never know if it prevented a heart attack.

    But that’s Okay with me.

    RE: The Plumber approach.

    You know plumbers use a chemical and life style approach to the plumbing in our homes but when you need the pipes reemed out, you need them reemed out.

    I know Heart Disease is not that simple…It will always require a modicum of caution and an individualized approach that does not exclude lifestyle, medication or invasive intervention.

    Liked by 1 person

    1. Hello Jill – I too hope that, overall, the ISCHEMIA study will come down to an individualized approach that’s based on good data.

      It’s an uphill battle, though, as Dr. Vinay Prasad (co-author with Dr. Adam Cifu of the book, Ending Medical Reversal: Improving Outcomes, Saving Lives”) has said: “Medicine is quick to adopt practices based on shaky evidence, but slow to drop them once they’ve been blown up by solid proof.”


      1. Like the evidence concerning coffee, salt and eggs. The back and forth is enough to make you dizzy! I read somewhere quite a while ago that all the research on salt and heart failure had been done on the current, chemically stripped NaCl that we bought in the grocery store. They proposed that using small amounts of pure sea salt might present a totally different picture….. hmmm Food for thought, though I admit I have not done current research. I switched to sea salt years ago in my own cooking and I seem to “blow up” with fluid retention only when I indulge in processed foods. So much to know about each of our own bodies…

        I still require 100mg of spironolactone per day to normalize sodium retention in my kidneys that is a reaction to my diastolic heart failure or Heart Failure with preserved ejection fraction.

        Liked by 1 person

        1. Hi again Jill – your example of sea salt vs “table salt” is an example of a well-researched topic that has essentially remained credible for decades since iodine was first added to table salt in 1924 to improve thyroid function and prevent gout (at one time, a significant problem as high as 30% of some populations) associated with iodine deficiency.

          According to Mayo Clinic, “sea salt and table salt have the same basic nutritional value, despite the fact that sea salt is often promoted as being healthier.” That’s an example of an assessment of fact from a very credible resource that can still “feel” counter-intuitive to us because we often make choices based on what “feels” best.

          Your own conclusions, based on simple and reproducible before-and-after observations (like “blowing up” after eating processed food) is in fact supported by research that suggests between 75% and 90% of sodium in the average American’s diet comes from prepared or processed food – NOT the salt shaker.


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