Two weeks after my husband had a couple of stents installed in his coronary arteries, he awoke to this headline in the New York Times: “‘Unbelievable’: Heart Stents Fail to Ease Chest Pain.” He was incredulous. For weeks before his surgery, he had felt stabbing pains in his chest any time he exerted himself. Now he felt fantastic and was back to playing his beloved Ultimate Frisbee.
The headline reflected the results of a British study, published online last November in the Lancet, that used what is probably the best methodology for assessing a surgical procedure: sham surgery. In this case, 200 patients with a blocked artery were randomly assigned to get either a real stent operation or a fake one. In the real version, a surgeon snaked a balloon-tipped catheter through an artery in the groin or arm up to the blockage, widened the vessel by inflating the balloon, and then kept it open with a tubelike stent made of wire mesh. In the sham procedure, a catheter was directed to the blockage, but the surgeon only pretended to do the rest. The astonishing finding: there was no difference in how the patients felt six weeks after surgery. Both groups reported less pain, and both performed better on treadmill tests.
Stent operations, or angioplasties, are wildly popular. At least half a million are done annually around the world. There is little question they are great for people in the throes of a heart attack but serious debate over their merits for other patients. Multiple studies have shown that they do not lower the risk of heart attacks or death. The main justification has been to relieve symptoms such as chest pain, known as stable angina, and shortness of breath. The British study has now undercut that idea. Giving drugs to control cardiovascular disease, as was done for all 200 patients in the study, along with lifestyle changes, appears to be the way to go for most people.
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How did an operation that now seems to have a rather limited application become such a blockbuster? You might ask the same question about many other procedures. Take arthroscopic knee surgery, the number-one most common orthopedic operation. More than two million are done annually to tidy up ragged cartilage in people with arthritis and degenerative wear and tear in their knees, including a torn meniscus. Yet sham surgery studies and other research have shown it offers no advantages for the vast majority of such patients. They would do just as well with physical therapy, weight loss and exercise.
Consider this: before a new drug is approved for marketing, researchers must show that it is more effective than a sugar pill. Not so for a new operation. And yet surgeries have a much bigger placebo effect than drugs. To quantify the difference, a 2013 meta-analysis looked at placebo effects in 79 studies of migraine prevention: sugar pills reduced headache frequency for 22 percent of patients, fake acupuncture helped 38 percent, and sham surgery was a hit for a remarkable 58 percent. “There's a big placebo effect with any procedure,” says cardiologist Rita Redberg of the University of California, San Francisco.
And yet sham surgery studies are rarely done, especially in the U.S., where ethics boards resist subjecting patients to incisions, anesthesia and other risks without delivering an actual treatment. Redberg, who has written about the value of these studies, takes the opposite view: “I think it's unethical not to do them.” Otherwise you may be exposing millions of people to the risks and the financial costs of surgery for a placebo effect that will not likely last.
Sham-controlled studies have spared us some useless operations. Vertebroplasty—injecting bone cement to mend a fractured vertebra—was gaining credence in the early 2000s until a 2009 sham study showed it was no better than a placebo. Since then, its popularity has dropped by about 50 percent, according to David S. Jevsevar, chair of orthopedics at the Geisel School of Medicine at Dartmouth. His research also shows a 28 percent decline in people with arthritis getting arthroscopic meniscus surgery.
But changing doctors' behavior is tough. They tend to think that “‘this is what we've been trained to do and we get good results, so we should keep on doing it,’” Jevsevar observes.
Stent surgery will most likely remain unreasonably popular for a long while. My advice if someone close to you is about to get it is to ask questions, lots of questions, beginning with: Wouldn't drugs, diet and exercise do the trick?
