When my little sister Bev was booked to have her tonsils removed at age six, our family doctor declared that I must have mine out at the same time – not because there was anything at all wrong with them, but because I was already 12 years old and, for some inexplicable reason, I still had my tonsils intact! (Back then, kids with tonsils were apparently an endangered species. As New York ear/nose/throat specialist Dr. Steven Park described the historical take on tonsils: “In the 50s to 70s, it was a given that if you had tonsils, they were removed.”)
On our designated procedure date, Bev and I were admitted to the pediatric ward at St. Catharines’ Hotel Dieu Hospital together. I remember this experience vividly because the archaic rule at the Hotel Dieu back then was that all pediatric patients had to wear diapers overnight. DIAPERS! As a humiliated almost-teenager, I pleaded with my mother to convince the ward nurses that I most certainly did NOT need to wear diapers at my mature age! But rules were rules, and I somehow managed to survive both an unwarranted surgical procedure and its associated diaper humiliation.
It turns out I wasn’t the only person questioning the wisdom of taking out a perfectly fine pair of tonsils based on flimsy if any medical evidence. Decades later, many researchers – including in this U.K. study published in the journal Archives of Disease in Childhood (1) – blamed not only the physicians who recommended the routine surgical removal of tonsils (and often adenoid glands at the same time) to treat childhood sore throat, but also “parental enthusiasm” as the factors influencing an entire generation of higher-than-necessary rates of surgery.
“Despite the enthusiasm with which tonsillectomy is offered and sought, there is little evidence of efficacy.”
I like this tonsil analogy to illustrate how medical attitudes, no matter how pervasive, can indeed change over time as our physicians rethink the status quo in order to embrace evidence-based medicine.
In other words, just because we’ve been doing this for a long time, is there any evidence that it’s actually what needs to be done?
Cardiology is not immune to the shifting popularity of longheld medical beliefs.
Cardiologist Dr. Michael Rothberg at the Cleveland Clinic warned his colleagues in the journal Circulation(2) that their profession has had a hard time letting go of a significant misconception about coronary artery disease, specifically about what causes heart attacks.
Popular Misconception: Narrowed Arteries are the Problem
As Dr. Rothberg explains, this belief in the clogged pipe theory of heart attack has been popular since the 1970s, when cardiac researchers observed that the degree of coronary artery obstruction (blockage) seemed to be directly linked with a higher risk of having a heart attack.
The culprit at the time was believed to be cholesterol plaques building up within the coronary arteries. Diagnosis was confirmed with tools like the treadmill stress test that looked for supply-demand mismatch; the treatment based on this theory included trying to re-open (revascularize) these blocked arteries through coronary bypass surgery or stents (the small mesh tubes that are used to open blocked arteries and restore blood flow to the heart muscle), much like a plumber re-opens clogged pipes under your kitchen sink.
But as Dr. Rothberg warned:
“Results of such revascularization procedures are visually striking and, in stable disease, may lead to the erroneous conclusion that the plumbing problem has been fixed.
“Doctors should begin by explaining to patients that coronary artery disease is an inflammatory disease in which cholesterol from the blood is deposited in artery walls, causing an inflammatory reaction like a pimple.
“When those pimples pop, they cause the blood in the arteries to clot at the site. If the clot closes off the entire artery, that causes a heart attack, and emergent medical attention is required to remove the clot.”
He further explained that this inflammatory disease model makes it clear that most attempts to revascularize partially blocked arteries are doomed to fail because dangerous vulnerable plaques cannot be identified or stented before rupture.
This reality helps to explain why even a small blockage can sometimes result in a rupture causing a dangerously blocked artery, or why a patient sent home from hospital with “normal” cardiac diagnostic test results on one day can suffer a heart attack on the next. See also: Slow-onset heart attack: the trickster that fools us
Dr. Rothberg is not alone in trying to educate us about the outdated plumber’s pipe theory of heart disease.
Experts at the Harvard Medical School warn that chronic low-grade inflammation is “intimately involved in all stages of atherosclerosis”, and this means that inflammation could be setting the stage for heart attacks, most strokes, peripheral artery disease, and even vascular dementia.
But inflammation doesn’t happen on its own. The Harvard experts explain that inflammation is the body’s perfectly natural response to a host of irritations like smoking, lack of exercise, high-calorie meals and highly processed foods.
Cardiologist Dr. John Mandrola also neatly summarizes the link between heart disease and inflammation like this:
“Heart disease is about inflammation.
“The same mechanisms that cause the throat to swell from an infection, the skin to redden after an insect bite, and a scar to form after a cut are what cause heart problems.”
So instead of trying to convince stable heart patients of the need to open up every potentially blocked coronary artery through invasive procedures, Dr. Rothberg strongly urges the following:
“For patients who have stable coronary disease, it is crucial to take steps to reduce the inflammation, including both evidence-based lifestyle changes (smoking cessation, exercise, stress reduction, and a Mediterranean diet) and taking medications that reduce inflammation and prevent thrombosis (aspirin and statins).
“Doctors should state plainly that for preventing heart attacks, these are the only effective measures.
“If patients have symptoms like angina (chest pain), then they can be told that old plaques, like scarred old pimples, may partially obstruct arteries and cause symptoms and that these symptoms can be relieved with medications.
“Only if symptoms persist despite maximal medication therapy, patients could then be offered revascularization to relieve those symptoms.”
Dr. Rothberg’s 2014 study published in the JAMA Journal of Internal Medicine (2) suggests that even now, few cardiologists discuss the evidence-based reasons for recommending revascularization with patients diagnosed with stable coronary artery disease, with “some physicians implicitly or explicitly overstating the benefits.”
He blames both physicians and researchers who have embraced the plumber’s pipe model of heart disease.Their message, he says, has continued to insist on opening these blockages. Many physicians and researchers, he adds, are “working from an outdated conceptual model, mistakenly focused on improving the technology for keeping open flow-limiting lesions”, while claiming that better stents will eventually yield a mortality benefit in stable heart disease.
Dr. Lisa Rosenbaum, writing in The New Yorker (October 23, 2013), suggests that, for these stable patients with chronic heart disease, the benefit of opening an artery with a stent is far less certain.
“Longstanding coronary artery blockages tend to have hardened exteriors, which can shield the plaque from exposure to the clotting factors in the blood passing by it. Chronic blockages aren’t benign – they can give many patients chest pain. But when it comes to treating chronic disease, medications such as statins, aspirin and beta blockers are often as effective as stents.”
What to do to encourage the medical profession to loosen its grip on the clogged pipe model of heart attacks in the face of current practice guidelines? Dr. Rothberg has this advice:
“Institutions like the American Heart Association should be more proactive in educating doctors about the inflammatory disease model, and how to communicate it to patients.
“Hospitals and doctors should stop using the old plumbing analogy in advertisements, websites, patient educational material, and when obtaining informed consent for any revascularization procedure.
“The current consent process – especially for patients with stable angina – is deeply flawed.
“Most patients do not correctly understand the actual benefits of the cardiac procedure they are about to undergo, and many do not even have angina.”(3)
But Dr. Rothberg is also a realist, and admits that it will be a hard sell to convince his colleagues in cardiology to rethink what’s known as the oculostenotic reflex (a “See it, stent it!” term coined by cardiologist Dr. Eric Topol back in 1988) defined as the “irresistible temptation” to expand narrowed coronary arteries, even when evidence-based guidelines suggest it shouldn’t be done. (4) For example:
“These steps are likely to encounter opposition, partly because it is difficult to admit that in the past we got it wrong and performed what now appear to have been unnecessary procedures, but also because our current payment system continues to reward interventions based on the old model and cardiac procedures are an important source of hospital revenue.
“It is unlikely that hospitals will begin to advertise the power of generic medications and lifestyle changes to combat heart disease.
“Nor will physicians quickly abandon a practice that both supports their income and seems to make sense.”
While you’re waiting for your physicians to embrace this inflammation theory, check out this list of cardiac risk factors that can be reduced, eliminated, or treated to help lower your own risk of heart attack. It’s from Myocardial Infarction: More Complex Than Plumbing(5), written by Harvard’s Drs. Kathryn Melamed and Samuel Goldhaber. The specific culprits that can raise inflammation levels and the subsequent risk of heart attack include:
- cigarette smoking
- alcohol use
- metabolic syndrome – a condition composed of obesity, abnormal lipids (cholesterol), and abnormal glucose metabolism that often leads to diabetes
(1) Lock C et al. Childhood tonsillectomy: who is referred and what treatment choices are made? Baseline findings from the North of England and Scotland Study of Tonsillectomy and Adenotonsillectomy in Children (NESSTAC). Arch Dis Child 2010; 95:203.
(2) Michael B. Rothberg et al. Coronary Artery Disease as Clogged Pipes: A Misconceptual Model. 1941-7705. Circulation: Cardiovascular Quality and Outcomes. 2013. doi: 10.1161/CIRCOUTCOMES.112.967778
(3) Rothberg MB et al. Patients’ and cardiologists’ perceptions of the benefits of percutaneous coronary intervention for stable coronary disease. Ann Intern Med. 2010;153:307–313.
(4) Topol EJ. Coronary angioplasty for acute myocardial infarction. Annals of Internal Medicine. 1988;109:970-980.
(5) Kathryn H. Melamed, MD, Samuel Z. Goldhaber, MD. Myocardial Infarction: More Complex Than Plumbing, Circulation. 2014; 130: e334-e336 doi: 10.1161/CIRCULATIONAHA.114.010614
Q: Is Dr. Rothberg waging a losing battle in urging patients and doctors to abandon the plumber’s pipe theory of heart attack?
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- Squishing, burning and implanting your heart troubles away
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