Hundreds of thousands, maybe millions, of Americans owe their lives to a miniscule piece of mesh called a coronary stent used to prop open a clogged artery. For heart attack patients, stents provide the greatest chance of recovery of any medical device.
Since 1994, when the Food and Drug Administration first approved implanting them as a voluntary procedure, the use of stents in America has become big business. An estimated 700,000 Americans will have a stent implanted this year in one of their arteries to prevent either a heart attack or stroke from recurring, or simply to relieve chest pain. There’s no doubt these tiny devices are a medical breakthrough. But whether doctors are implanting too many and whether as a society we’re paying too much for too little are questions that still remain.
Over the past decade, hospitals opened cardiac catheterization labs in record numbers and interventional cardiologists made huge sums for a relatively easy procedure. By 2005, the stent market had reached nearly $4 billion. Yet there was a cost in both dollars and possible side effects.
Coronary stents represent an easier fix for a clogged artery than bypass surgery, which has a longer recovery period. While a bare metal stent can cost less than $1,000, the cost of the procedure and the hospital stay can be anywhere from $30,000 to more than $100,000. Compared to bypass surgery, stents cost less. As a result, the worldwide stent market, especially in the United States, boomed in the mid-1990s, then surged a decade later with drug-eluting stents — meant to prevent arteries from reclogging by slowly emitting drugs embedded in the device.
The COURAGE Trial
Last year in the Recovery Act the Obama administration gave $1 billion in additional funding for comparative effectiveness research. The increase may prove a drop in the bucket compared to the onslaught of industry-funded research aimed at advancing the latest technologies and beating the competition.
Industry research largely compares the latest technology with the even newer one, omitting whether the latest technology is better than something older. In the case of coronary stents, Abbot Laboratories recently published a series of studies comparing its drug-eluting Xience stent to the drug-eluting Taxus stent by Boston Scientific, the market leader at the time. The studies helped make Abbot the current market leader.
In contrast, researchers who challenge a multibillion-dollar industry face intense pressures. A paper that cardiologist William Boden co-authored on the COURAGE trial (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) and published in the New England Journal of Medicine in 2007 sparked widespread controversy. Both were randomized controlled studies that concluded that in patients with chronic stable chest pain, stents did not lower the risk for heart attack and death compared to medical therapy alone. Stents simply relieved their chest pain, Boden said.
"[In response to COURAGE,] the industry unleashed a media blitz designed to denigrate and discredit the study," said Boden from his office in Hartford, Conn. "It was orchestrated. As it turns out, in data we obtained from the American College of Cardiology national cath lab data registry, a large registry of participating hospitals with 2.5 million patients over the past three years, the percentage of patients [receiving a stent] with elective stable coronary disease or stable angina was 52 percent."
Boden said he’s proud that COURAGE helped give doctors the confidence to practice medical therapy, such as exercise and healthy eating, as opposed to expensive interventions which can be avoided. But the industry was about to take a billion-dollar hit and doctors were looking for answers to serious red flags raised a year earlier about drug-eluting stents. "It was a perfect storm," Boden said.
Drug-eluting stents are meant to prevent restenosis, which requires another stent procedure. This was happening in 5 to 30 percent of patients with bare-metal stents. Some researchers say doctors can now effectively limit the probability to around 5 percent. So drug-eluting stents have become the fallback, representing more than half of all stents implanted by interventional cardiologists in the U.S., France and elsewhere.
But many experts now say bare-metal stents are just as good, especially in heart attack patients. They pose fewer deadly risks, such as sudden blood clots. Today, around 1 percent of drug-eluting stents might cause a blood clot that could lead to heart attack, stroke or death.
Researchers estimate 50 to 60 percent of stents implanted in the U.S. and some European countries today are drug eluting. This suggests that not only are doctors likely placing too many coronary stents, they’re likely placing too many of the drug-eluting kind.
Dr. Steven Bailey, professor and cardiologist at University of Texas Health Science in San Antonio and president of the Society for Cardiovascular Angiography and Interventions, said doctors are responsive to good science, but he largely dismissed the COURAGE trial.
Bailey said doctors have to keep adapting to the latest research with a critical eye. "The most difficult populations we see are more likely to benefit from bare-metal stents," he said. "There are situations where we choose to do angioplasty and use drug-eluting stents. There are patients that do just as well with a bare-metal stent." Bailey denied that profits influence medical treatment decisions.
In 2004, nine cardiologists were suspended from their Tampa Bay-area hospital for performing inappropriate angioplasties and stents. A peer review reported by the St. Petersburg Times found that, in some cases, doctors had "performed angioplasty on arteries that were not sufficiently clogged with plaque, propped open clogged arteries with stents of the wrong size or type, and used incorrect or inadequate medicines to treat coronary artery disease."
The doctors said the hospital was retaliating against them for choosing stents over what they said were the more expensive and profitable bypass surgeries. Last June, two of those doctors started performing angioplasties at an affiliated hospital in Florida.
Mattias Neyt, an economist at Belgium’s Healthcare Knowledge Center, co-authored a paper in the journal Health Policy last year that said drug-eluting stents were not a cost-effective choice even in patients with a greater likelihood of artery reclogging. The paper analyzed the costs of bare-metal stents versus drug-eluting ones relative to repeat procedures and the gain in expected life years.
"The extra cost [of drug-eluting stents] was not in balance with the extra benefit," Neyt said. "There are other interventions with better cost-effectiveness ratio to invest money in as a policymaker."
Freelance writer David Rosenfeld first published this piece on Miller-McCune.com