Dear Doctor: I've been having chest pain, and my doctor said that although I shouldn't panic, I should consider a stent. Now I read they're useless. What are my options?
Dear Reader: What you're describing is angina -- chest pain caused by decreased blood flow to the heart via the coronary arteries. Stable angina occurs with exertion, not rest, because the exertion makes your heart work harder. Unstable angina is irregular, can occur even at rest and is a harbinger of an imminent heart attack.
In 1977, doctors began to treat angina with angioplasty, which uses a balloon to open the partially clogged coronary arteries. In the 1990s, they started using stents to keep the arteries open and make them less likely to collapse. In this procedure, a metal stent is placed over a balloon so that when the balloon expands, the stent presses outward to buttress open the artery. Because these metal stents can increase the risk of blood clots, they're often now coated with a drug that prevents clots. Angioplasty has been found to reduce the risk of heart attacks and strokes in people with unstable angina.
For stable angina, the picture recently became murkier. The study to which you're referring assessed outcomes in stable angina patients with one or more coronary arteries at least 70 percent narrowed. People were excluded from the study if they'd had a previous heart attack, bypass surgery or another vessel blocked more than 50 percent but not causing symptoms. In the first six weeks of the study, participants received standard medical therapy, including blood thinners, cholesterol-lowering medication, blood pressure medications and long-acting nitrates.
After that, study subjects were randomized into a group that received a stent or a control group that didn't receive a stent. In fact, in the second group, the patients didn't even know if they'd received a stent or not. After another six weeks, all the patients underwent a cardiac stress test and an assessment of symptoms.
No difference in symptoms was found. Even an evaluation of the ability to walk on a treadmill showed no difference between the two groups. However, when given a medication to stress the heart, the stent group showed an improvement in contraction of the heart muscle as seen on ultrasound.
Similarly, a 2007 study showed no difference in death rate or heart attack rate among people with stable angina treated with angioplasty compared to those who received medical therapy. The group that received an angioplasty did report an improvement in symptoms 2 1/2 to seven years after the treatment, but it's possible the placebo effect played a role. That's because, unlike the more recent group, the 2007 study participants knew whether they'd had angioplasty.
That said, stents are not useless. They do prevent heart attacks and death in people with unstable angina, and they may benefit people with stable angina who have symptoms even on medication or who are intolerant to medication. But it seems to me that the robust benefit of stents in people with stable angina is not evident. I'd recommend talking with your doctor further; you do have a choice.
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