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:
“CARDIOLOGY CHANGES TODAY!” .
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.
“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.”
Edward Hannan. “Appropriateness of Coronary Revascularization for Patients Without Acute Coronary Syndromes.” Journal of the American College of Cardiology, 2012; 59:1870-1876.
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.
Bowling A. et al. “What do patients really want? Patients’ preferences for treatment for angina.” Health Expectations, Volume 11, Issue2 June 2008; 137-147
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?
-More solid information about the ISCHEMIA trial from Shelley Wood writing in TCTMD
– Dr. Bernard Lown‘s wonderful book, The Lost Art of Healing: Practicing Compassion in Medicine.