Boston's Taxus, and J&J's Cypher are the only DES stents FDA approved for sale in the US, but they were approved for limited indications because the studies submitted to support their approval only tested the stents in patients with single, smaller artery blockages, according to the December 8, 2006 Science Daily.
"But doctors quickly started using them," Science reports, "in patients with blockages in multiple vessels and in those with larger blockages or co-existing diseases like diabetes."
Stents are tiny wire-mesh tubes inserted in arteries to keep them open after angioplasty, a procedure in which a balloon is threaded through a vessel in the groin to a blocked artery and then inflated to unclog the artery to restore blood flow to the heart.
The use of stents became popular because the procedure was promoted as being safer and cheaper then heart bypass surgery in which an entire section of a diseased artery is replaced with a vessel taken from elsewhere in the body.
The drug coating on the new expensive stents was a big selling point in convincing doctors to quit using the older bare-metal stents, because the drugs were supposed to reduce the need for repeat procedures by releasing medication to prevent restenosis where scar tissue forms and causes the artery to close up again.
But DES stenting is so profitable that the majority of patients receiving the stents will not benefit at all. At a cost of $10,000 to $38,000, as many as 85% of the procedures are non-emergency and are being performed on people with only partially blocked arteries for the relief of recurrent chest pain, according to March 23, 2007 Associated Press.
The first DES was approved in April 2003, and by December 2006, at a hearing on the "Prospective on Drug eluting Stents: Balancing Risks and Benefits," an FDA advisory panel reported that 3 out of 5 procedures were for unapproved uses and DES patients were developing stent-thrombosis, or blood clots, occurring most often in patients when the devices were used off-label.
While testifying at the hearing, Dr Sanjay Kaul told the panel that bare-metal stents were hardly used anymore. "The current drug eluting stent utilization rate," he said, "is about 80 percent, and we have learned that nearly 60 percent of it is off-label."
"We've also learned from the off-label use," he informed the panel, "that the risk of stent thrombosis is higher, 2 to 3 percent, and in some subsets, like insulin-requiring diabetics, as high as 5 to 6 percent."
As a result of the massive off-label use of DES, by 2005, the device accounted for 43% of total sales for Boston and 52% for J&J, according to Bloomberg on December 4, 2006. By 2006, sales figures show the new stent was a $2 billion seller for Boston.
The stents have been implanted in more than 6 million people worldwide, in what market analysts are calling a modern day record for a new device. In the January/February 2006 issue, Medical Device Link reported that about 1.5 million patients in the US were implanted with stents in 2005.
Yet by end of 2006, Forbes was reporting a study that found that angioplasty and stents did not help patients when used within a few days after a heart attack occurred which "could mean 50,000 such procedures were done unnecessarily every year," Forbes said on December 13, 2006.
And new reports continue show that these unnecessary procedures are extremely costly in more ways than one. On May 14, 2007, Medical News Today reported that 2 studies in the Journal of the American Medical Association found the off-label and untested use of DES is common in US practice, and "ischemic complication rates are higher among patients receiving drug-coated stents for off-label indications."
In one study, 10.9% of patients who got stents for unapproved uses died, had a heart attack, or needed further treatment to clear the artery, compared with 5% of patients who received the devices during on-label procedures. After a year, the study found, the number of complications in off-label patients rose to 17.5% compared to 8.9%.
According to Darshak Sanghavi, a pediatric cardiologist and assistant professor of pediatrics at the University of Massachusetts Medical School, in Slate Magazine on May 8, 2007, "we've wasted a lot of time and money on cardiac angioplasty that does no good."
"Time and time again, he wrote, "studies repeatedly show that opening blocked arteries to prevent heart attacks in people with exercise-induced chest pain or stable blockages is, quite simply, pointless."
"Essentially no clinical trial," he says, "shows that balloon angioplasty or stenting partially blocked coronary arteries prevents heart attacks, saves lives, or reduces the risk of other complications like strokes."
The bottom actually started falling out on the DES stenting for profit industry in late 2005, when reports began to emerge showing patients were developing serious health problems. Unbeknownst to the public, within 6 months of the approval of the first DES, the FDA had already identified 50 cases of allergic reactions associated with new stents.
On January 3, 2006, the Journal of the American College of Cardiology reported a study that found a number of patients had developed serious allergic reactions. A review of the FDA's adverse event database since the first DES was approved through December 2004, initiated by cardiologists at the Health Science Center, identified 17 allergic reactions that were classified as probably or certainly caused by the stent, and 4 resulted in death.
Symptoms included rash, difficulty breathing, hives, itching and fevers and the study concluded that the coating on the stent was the likely cause rather than the drugs released by the device, according to a December 20, 2005 Health Science Center news release.
"The patients in question are not allergic to the stent itself, but to the polymer coating the metal used to hold the drugs for 30-day release," said the report's lead author, Dr Marc Feldman, associate professor of medicine at the Center and associate director of cardiac catheterization laboratories at its teaching University Hospital.
During 2006, reports that patients were developing stent-thrombosis started popping up. On October 11, 2006, the American College of Cardiology posted an editorial on the internet by Dr Sanjay Kaul, director of the cardiology fellowship training program at Cedars-Sinai Medical Center in Los Angeles and a colleague, that warned that blood clots in drug-coated stents may be causing an extra 2,160 deaths in the US alone each year.
On October 23, 2006, Bloomberg reported that 2.9% of DES patients could develop stent-thrombosis within 3 years and because 4 million people had already received the new stents, "clotting related to drug-coated devices may have caused as many as 20,000 heart attacks and 10,000 deaths worldwide."
A November 29, 2006 analysis by the Cleveland Clinic Foundation found that the risk of developing blood-clots was increased as much as 5-fold in patients who receive drug-coated stents compared to patients implanted with the old bare-metal stents.
In December 2006, the FDA panel also sought to determine whether DES patients could forestall the occurrence of stent-thrombosis by taking the anti-clotting drug Plavix and aspirin for a year or more.
With the drug costing about $4 per day, the increased use of DES had already provided a goldmine for Plavix marketers Bristol-Myers Squibb and Sanofi-Aventis because every patient was instructed to take the drug for 3 to 6 months. By 2005, Plavix had become the world's second-best-selling prescription medication.
But the use of Plavix creates problems of its own. At the FDA hearing, Dr Ron Waksman, who presented data from the Contemporary Registries of the Washington Hospital Center, told the panel, "we know that there is a price to prolong Plavix, and this has been given us from three randomized studies in which Plavix was compared to aspirin alone."
He noted that all 3 studies showed there was excessive bleeding with Plavix.
He also told the panel that overall, compliance with taking Plavix at the time the stent thrombosis occurred in patients was actually fairly high. Although 30.4% of patients were off Plavix, he said, 60% of patients were still on Plavix.
Furthermore, Dr Waksman informed the committee, "platelet therapy beyond 6 months is not proven yet to be prohibitive to late stent thrombosis."
Medical experts also say taking Plavix is not recommended unless absolutely necessary because severe bleeding can occur if a patient needs sudden surgery. And stopping Plavix will not help because it takes about a week for platelets to get back to normal with the proper clotting effect which makes any surgery a life-threatening event.
In the end, the FDA panel recommended that the DES should carry warnings that the devices may increase the risk of sudden heart attack or death and said patients may have to take Plavix for the rest of their lives.
So here once again, a new product that supposedly showed few risks in company sponsored trials with a small number of patients, actually causes serious health problems that went undetected until after the device was implanted in millions of people in large part due to the massive off label marketing of the device the minute it was FDA approved.
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The fact is, there is no medical solution to this problem and the millions of patients implanted with the stents who are lucky enough not to experience an adverse event will still have to endure a lifetime of day to day worry and dread.
Also see: Feds Investigate Profits From Off-Label Heart Stent Procedures - Part II