The Controversial News About Heart Stents

A study published in The Lancet medical journal last week showed that heart stents didn’t help patients with heart disease who were having stable and predictable chest pain.

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The results engendered disbelief from interventional cardiologists — the physicians who place these stents — who offered descriptors like “unbelievable” and “humbling.”

Their sense of bewilderment wasn’t necessarily shared by the rest of the physician community or by the authors of an accompanying expert commentary, whose title questioned whether the study was the “last nail in the coffin” — rather than the first — for this particular application of heart stents.

And the application really matters: if you’re experiencing a heart attack, or actively courting one, a cardiac stent (a “percutaneous coronary intervention” or “PCI”) is probably exactly what you need. It could save your life, and keep your heart from being severely injured.

But if you have “stable angina,” heart disease causing chest pain that comes predictably with activity, then getting a heart stent is way down on the to-do list. There’s strong, convincing evidence that it won’t lower your risk of dying or having a heart attack, and some less strong evidence suggesting it provides only a short-term reduction in angina symptoms when compared to taking anti-angina medications.

What makes the evidence weaker is that in all previous studies, participants (and their cardiologists) were fully aware of who was getting treated with a stent and who wasn’t. That’s important, because it turns out that most of us believe that a procedure beats a pill every time. Invasive treatments and their technical wizardry have been proven to carry a stronger placebo effect: we expect more symptom relief, and so we get more.

Despite the fact that PCI has been around for 40 years, the Lancet study was the first to include a placebo arm: every participant had a coronary angiogram to document a blockage, but only half got a stent. (All procedures were performed through a puncture wound in the upper leg or arm, so patients would not know whether they received a stent or not.) And both groups — the stents, and the no-stents — did about the same.

Here is where the science of health care collides with the group psychology and financing side of health care.

Physicians and health care systems like to do things that help their patients. And the higher the reimbursement from insurance or Medicare, the more we like to do them. This is why lavish joint replacement centers are popping up everywhere and why you don’t see a Mall of Multiple Sclerosis on every interstate cloverleaf.

The PCI procedure pays well, an average of $35,000 to $40,000, and cardiologists do a lot of them. In the U.S. and Europe, half a million patients a year undergo PCI for symptomatic relief of stable angina — ostensibly at the recommendation of the American College of Cardiology (ACC), American Heart Association and European Society of Cardiology, whose guidelines suggest that PCI be used in patients with persistent angina despite those patients being on the best medical therapy.

However, as the Lancet commentary points out, “…only half of all [500,000] PCI procedures for stable coronary artery disease are appropriate according to ACC’s criteria.” So, there’s the guideline and then there’s what actually happens: 250,000 unnecessary PCI cases a year. Now this new study goes even further, suggesting that some portion of the other 250,000 procedures for stable coronary artery disease might also be unnecessary.

It would be wrong to suggest that all physicians or health care systems are disregarding the science or guidelines in favor of the financial bottom line. Doctors sincerely hope that the things we prescribe and the procedures we recommend will improve our patients’ lives.

But physicians, like their patients, are human and similarly capable of being hypnotized by magical thinking, or compelled by the subliminal logic that complicated and costly interventions must be more effective than simple and more affordable ones. Medications do work, despite their yeoman, daily-obligation features.

The truly shocking and unbelievable part of this story is the very real possibility that nothing will change. As an article in The New York Times pointed out, using PCI for stable angina is so “ingrained” that some experts expect “most doctors will continue with stenting, reasoning that the new research is just one study.”

Which it is. Although the Lancet study’s use of a placebo arm earned it “landmark” status, physicians will predictably line up for or against it, interpreting it in the context of their own professional and personal bias.

My bias is that as long as the American health care system remains the most expensive in the world, which it is, by far, we should curb our enthusiasm for expensive interventions whose efficacy isn’t supported by current research.