Lots of Americans have chest pain because of a lack of blood and oxygen reaching the heart. This is known as angina. For decades, one of the most common ways to treat this was to insert a mesh tube known as a stent into arteries supplying the heart. The stents held the vessels open and increased blood flow to the heart, theoretically fixing the problem.
Cardiologists who inserted these stents found that their patients reported feeling better. They seemed to be healthier. Many believed that these stents prevented heart attacks and maybe even death. Percutaneous coronary intervention, the procedure by which a stent can be placed, became very common.
Then in 2007, a randomized controlled trial was published in The New England Journal of Medicine. The main outcomes of interest were heart attacks and death. Researchers gathered almost 2,300 patients with significant coronary artery disease and proof of reduced blood flow to the heart. They assigned them randomly to a stent with medical therapy or to medical therapy alone.
They followed the patients for years. The result? The stents didn’t make a difference beyond medical treatment in preventing these bad outcomes.
This was hard to believe. So more such studies were conducted.
In 2012, the studies were collected in a meta-analysis in JAMA Internal Medicine. Three studies looked at patients who were stable after a heart attack. Five more examined patients who had stable angina or ischemia but had not yet had a heart attack. The meta-analysis showed that stents delivered no benefit over medical therapy for preventing heart attacks or death for patients with stable coronary artery disease.
Still, many cardiologists argued, stents improved patients’ pain. It improved their quality of life. Even if we didn’t reduce the outcomes that physicians cared about, these so-called patient-centered outcomes mattered, and patients who had stents reported improvements in these domains in studies.
The problem was that it was difficult to know whether the stents were leading to pain relief, or whether it was the placebo effect. The placebo effect is very strong with respect to procedures, after all. What was needed was a trial with a sham control, a procedure that left patients unclear whether they’d had a stent placed.
Many physicians opposed such a study. They argued that the vast experience of cardiologists showed that stents worked, and therefore randomizing some patients not to receive them was unethical. Others argued that exposing patients to a sham procedure was also wrong because it left them subject to potential harm with no benefit. More skeptical observers might note that some doctors and hospitals were also financially rewarded for performing this procedure.
Regardless, such a trial was done, and the results were published this year. (...)
There was no difference in the outcomes of interest between the intervention and placebo groups.
Stents didn’t appear even to relieve pain.
Some caveats: All the patients were treated rigorously with medication before getting their procedures, so many had improved significantly before getting (or not getting) a stent. Some patients in the real world won’t stick to the intensive medical therapies, so there may be a benefit from stents for those patients (we don’t know). The follow-up was only at six weeks, so longer-term outcomes aren’t known. These results also apply only to those with stable angina. There may be more of a place for stents in patients who are sicker, who have disease in more than one blood vessel, or who fail to respond to medical therapy.
But many, if not most patients, probably don’t need them. This is hard for patients and physicians to wrap their heads around because, in their experience, patients who got stents got better. They seemed to receive a benefit from the procedure. But that benefit appears to be because of the placebo effect, not any physical change from improved blood flow. (...)
Even in this study, 2 percent of patients had a major bleeding event. Remember that hundreds of thousands of stents are placed every year. Stents are also expensive. They can add at least $10,000 to the cost of therapy.
Stents still have a place in care, but much less of one than we used to think. Yet many physicians as well as patients will still demand them, pointing out that they lead to improvements in some people, even if that improvement is from a placebo effect.
by Aaron E. Carroll, NY Times | Read more:
Image: Jack Sachs
Cardiologists who inserted these stents found that their patients reported feeling better. They seemed to be healthier. Many believed that these stents prevented heart attacks and maybe even death. Percutaneous coronary intervention, the procedure by which a stent can be placed, became very common.
Then in 2007, a randomized controlled trial was published in The New England Journal of Medicine. The main outcomes of interest were heart attacks and death. Researchers gathered almost 2,300 patients with significant coronary artery disease and proof of reduced blood flow to the heart. They assigned them randomly to a stent with medical therapy or to medical therapy alone.
They followed the patients for years. The result? The stents didn’t make a difference beyond medical treatment in preventing these bad outcomes.
This was hard to believe. So more such studies were conducted.
In 2012, the studies were collected in a meta-analysis in JAMA Internal Medicine. Three studies looked at patients who were stable after a heart attack. Five more examined patients who had stable angina or ischemia but had not yet had a heart attack. The meta-analysis showed that stents delivered no benefit over medical therapy for preventing heart attacks or death for patients with stable coronary artery disease.
Still, many cardiologists argued, stents improved patients’ pain. It improved their quality of life. Even if we didn’t reduce the outcomes that physicians cared about, these so-called patient-centered outcomes mattered, and patients who had stents reported improvements in these domains in studies.
The problem was that it was difficult to know whether the stents were leading to pain relief, or whether it was the placebo effect. The placebo effect is very strong with respect to procedures, after all. What was needed was a trial with a sham control, a procedure that left patients unclear whether they’d had a stent placed.
Many physicians opposed such a study. They argued that the vast experience of cardiologists showed that stents worked, and therefore randomizing some patients not to receive them was unethical. Others argued that exposing patients to a sham procedure was also wrong because it left them subject to potential harm with no benefit. More skeptical observers might note that some doctors and hospitals were also financially rewarded for performing this procedure.
Regardless, such a trial was done, and the results were published this year. (...)
There was no difference in the outcomes of interest between the intervention and placebo groups.
Stents didn’t appear even to relieve pain.
Some caveats: All the patients were treated rigorously with medication before getting their procedures, so many had improved significantly before getting (or not getting) a stent. Some patients in the real world won’t stick to the intensive medical therapies, so there may be a benefit from stents for those patients (we don’t know). The follow-up was only at six weeks, so longer-term outcomes aren’t known. These results also apply only to those with stable angina. There may be more of a place for stents in patients who are sicker, who have disease in more than one blood vessel, or who fail to respond to medical therapy.
But many, if not most patients, probably don’t need them. This is hard for patients and physicians to wrap their heads around because, in their experience, patients who got stents got better. They seemed to receive a benefit from the procedure. But that benefit appears to be because of the placebo effect, not any physical change from improved blood flow. (...)
Even in this study, 2 percent of patients had a major bleeding event. Remember that hundreds of thousands of stents are placed every year. Stents are also expensive. They can add at least $10,000 to the cost of therapy.
Stents still have a place in care, but much less of one than we used to think. Yet many physicians as well as patients will still demand them, pointing out that they lead to improvements in some people, even if that improvement is from a placebo effect.
by Aaron E. Carroll, NY Times | Read more:
Image: Jack Sachs
[ed. See also: Powerless Placebos]
