Last reviewed by Faculty of Harvard Medical School June 27, 2013
No doubt about it — coronary angioplasty is one of the great advances in cardiology of our times. And the new drug-coated stents are wonderful, greatly reducing the recurrence of narrowings in coronary arteries. If I were to have a heart attack today, I want to get into a cardiac-catheterization laboratory as soon as possible to get my blocked artery opened and held open by a drug-coated stent.
For sudden blockage of a coronary artery, emergency angioplasty with a stent is the best immediate remedy. However, cardiologists are beginning to recognize that they are performing a lot of angioplasties and putting in a lot of stents that may not be absolutely necessary. Besides the costs to the patients and society, these procedures carry a low-but-real rate of complications, such as heart attacks and strokes, so they shouldn't be done unless the benefits outweigh the risks.
Who is at risk of receiving a not-so-useful stent? Here is the most common scenario. Someone who basically feels fine undergoes a screening test for coronary disease, such as an exercise test or an electron beam CT scan. Sometimes a patient may have some chest pain or other symptoms that his or her doctors do not really think is related to the heart, so an exercise test is ordered "just to be safe."
The problems arise when a patient's screening test isn't quite normal. Many, if not most, Americans have some atherosclerosis in their coronary arteries, and we all therefore have a pretty good chance of having some abnormalities on screening tests. The next step is often a coronary angiogram to determine if there is any coronary disease. Because of our high rates of atherosclerosis, coronary angiograms frequently show some narrowings.
At this point, the cardiologist often reaches for a stent, with the grateful support of the patient. The stent is inserted, and the patient goes home the next day, feeling like he or she has been saved.
But have these patients really been helped?
In medicine, physicians are taught to think clearly about what their goals are when doing anything that carries risk for the patient. There are really two possible goals:
- To help the patient live longer
- To make the patient feel better
When patients basically feel fine, as in the case described above, you can't make them feel better. So the goal is to make them live longer. The key question is whether putting stents in people who feel fine will actually help them live longer.
The surprising answer for most patients is "probably not."
How can this be? If you see the enemy, and crush it, that must be good, right? Unfortunately, the narrowings that we stent tend to be just a small part of the atherosclerosis in the arteries of a patient with heart disease. For every big atherosclerotic plaque, there are dozens of smaller ones.
The important insight from research over the last decade has been that these small atherosclerotic plaques are as likely as big ones to rupture and cause a blood clot that kicks off a heart attack. And because small plaques are more common than big ones, most heart attacks actually begin with rupture of a small plaque.
Seeing a big narrowing on a coronary angiogram is important mainly because it tells you that a patient has atherosclerosis. Squashing that plaque against the wall with a stent doesn't make the other plaques go away, or reduce your heart-attack risk.
The good news is that people who have abnormal exercise tests and coronary angiograms can reduce their risk of a heart attack tremendously by controlling their blood pressure, cholesterol, and other risk factors. In short, they can help themselves by going after the widespread problem of atherosclerosis, not focusing on the biggest atherosclerotic plaque.
In fact, a study from Germany showed that patients with mild angina (chest pain) who were randomly assigned to an exercise program actually did better than similar patients who were assigned to angioplasty.
If you have symptoms of angina, squashing that atherosclerotic plaque can make you feel much better as you go through your normal activities. I'm all for angioplasty in that setting. But for most patients with coronary disease who don't have clear angina, angioplasty may seem like it's curing the problem — but that is all too often an illusion.
Thomas H. Lee, M.D. is the chief executive officer for Partners Community HealthCare Inc. He is a professor of medicine at Harvard Medical School. He is an internist and cardiologist at Brigham and Women's Hospital. Dr. Lee is the chairman of the Cardiovascular Measurement Assessment Panel of the National Committee for Quality Assurance.