In the mid-90s the first stent was approved. A stent is a metal mesh tube that gets placed into the artery to keep it open. This looked like the solution to re-clotting, and sure enough, short term studies showed it worked in most people. But the metal stent was recognized as a foreign substance by the body. This provoked the body to make cells to attack the stent, and eventually re-clot it. Longer term studies showed a disappointing failure of many stents.
A decade later came the invention of drug-coated stents; this was supposed to keep them from clotting up again. The short term studies were spectacular, so that very soon drug-coated stents accounted for 80% of all stents put in at the time of angioplasty. Finally a study was done to look at how the patients did when followed a year after getting their stents. It was found that drug coated stents were much more likely to close up again compared to the bare metal stents!
How could this be? It turns out that the majority of patients who got the drug coated stents did not have the particular artery blockages that the FDA said these stents were supposed to be used for. Did the doctors who placed these stents tell the patients that the FDA only approved these stents to a select group of patients? The approved use of the stents were for long lengths of disease (about 3 cm) in arteries that were within a specific width (2.5 to 3.5 mm).
However, instead of clamping down on inappropriate use of these specialized stents, the FDA only required that the label on the stent needed to warn that, “Until more data are available, the DES [drug coated stent] labels should state that when DES [drug coated stents] are used off-label, patient outcomes may not be the same as the results observed in the clinical trials conducted to support marketing approval.” Is any patient reading the label on the stent packaging? Is any doctor translating it for you by telling you that the stent he’s putting in your body may not work and hasn’t been approved by the FDA for your condition?
The doctors found something else to blame for their poor results with drug-coated stents. They decided that all that was needed was to tell the unlucky drug-coated stent patients that they had to keep taking their clot-preventing drugs for a longer time period. So now anyone with a drug coated stent needs to stay on clopidrogel (Plavix®) for at least a year. The fact is no one knows when it is really safe to come off the drug. People with bare metal stents don’t necessarily have to stay on Plavix. In any case, it makes you wonder what is keeping the artery open, the stent or the medication.
How could all this bad news about angioplasties and stents just be coming out now, when angioplasties are one of the top medical procedures in the world? One of the leaders of a stent study wondered why earlier studies had not reported the same problems with stents that so many other researchers are now finding. His team inspected all 132 scientific papers on drug coated stents since they came out in 2003. 20% of the reports didn’t give any information about how many patients went on to have heart attacks, heart failure, death or stroke. Less than 2/3 of the studies even reported how long they followed the patients. Of those that reported, only 4% followed the patients for longer than a year. In other words, most studies were reporting very short term results. Less than a quarter of the papers reported about any accidents that happened during the angioplasty procedure. Remember, lack of reporting doesn’t mean these things didn’t happen.
What about the anti clotting drugs like Plavix? In patients who get a drug coated stent, there is a higher chance of needing a repeat angioplasty within the first year compared to patients who just get the bare stents. To handle this problem the patients who get a drug coated stent are now required to stay on Plavix for at least a year.
Many of these stent patients are also on drugs to lower stomach acid. This is because they have reflux problems, or the doctor simply feels the need for stomach protection while the patient is on Plavix or similar drugs. But now we know that anyone on a stomach acid reducing drug has a 50% greater chance of the stent re-clotting. This may be because the stomach medication prevents the anti-clotting drug from being absorbed.
Do people who get angioplasty have a better quality of life? A recent study showed that there were no big differences in the quality of life of people who got angioplasties compared to the people treated with medication only. The angioplasties were much more expensive, though.
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Notice: The information provided here is an interpretation of information that is made generally available to the physician. This is not intended to be a comprehensive nor exhaustive review of everything known in any quarter about the topic. It is provided as supplement to patient/doctor discussions in order to facilitate informed consent. ©2009 Medical Accountability Network
Last updated 7-28-09
The stent maker never proved that their stents would work for patients with other less severe blockages. So what was happening is that people with all kinds of artery blockages were getting the drug coated stents. In other words, the doctors were using the drug coated stents “off label”. It is doubtful that most patients were informed ahead of time that they were getting a stent that was not FDA approved for their condition. Suddenly the results did not look so good anymore.
DO THE ANTI-CLOTTING DRUGS WORK?
So what are your chances of getting an angioplasty or bypass or medications alone? A study showed that the more heart tests that are done, the more likely a person is to get an angioplasty. In other words, there is no “threshold” – it seems that tests are done until they find one test result that gives a good excuse for angioplasty. The study authors concluded that patients who live in areas of the country where lots of tests are being done are getting too many angioplasties that they don’t want or need.
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