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TECHNOLOGY: Stent Wars

The NY Times looks at the ongoing battle between J&J’s Cordis and Boston Scientific’s drug-eluting stents. Since Boston Sci has recovered from its recall problems over the summer it has been really cranking out the numbers. It’s Taxus stent sold over $600m last quarter, comfortably besting Cordis’ Cypher and putting it on course to become the best selling medical device of all time–recall that if it gets to a $1 billion quarter, only 3 drugs sell more than that in the US. Cardiologists like Taxus because it’s easier to put in and apparently the problems with early openings are behind it. However, there are some indications that Cypher might actually have better outcomes.The main issue in stents is the restenosis rate, or in English, when you put the stent in, how long does it take for the blood vessel to become blocked again? It’s been a progression as first balloon angioplasty was used, then a bare metal stent and now a drug-eluting stent. But it appears that the restenosis rate for Cypher is better than that of Taxus.

The results of some early studies comparing the two stents were reported last month at a major conference in Washington of cardiologists who perform stent procedures. The studies included one in Korea comparing Taxus and Cypher with a control group that received a bare metal stent that was not coated with any drug. The trial focused on patients with longer blockages, or lesions, in their vessels than the average patient who receives a stent, and had a high proportion of patients with diabetes or other diseases that can lead to complications. While both drug-coated stents achieved far better results than the bare metal control group, various measures showed that Cypher patients had a third to a half as much regrowth of lesions as Taxus patients. And while the number of patients who suffered such extensive reblockage that they needed a second procedure was too small to produce significant results, those data also clearly favored Cypher.

It’s unclear what “far better results than the bare metal control group” means but I’d be very interested in the long term outcomes of this type of study. Recall that last year a Stanford group compared the long term results of those who had bare metal stents with those who had a CABG, and over a 10 year period the CABG group had much better outcomes at a much lower cost. So if the restenois rate for the DES doesn’t stay good in the longer term, they too might be a failure in health services research terms while being a huge market success. As with any technology assessment the attitude of the physicians on the ground is far more important than that of the academic wonks looking at longitudinal data sets. Meanwhile an earlier article in the NY Times questioned whether any of these surgeries–including CABGs–aimed at keeping arteries functioning were a good idea.

Researchers are also finding that plaque, and heart attack risk, can change very quickly — within a month, according to a recent study — by something as simple as intense cholesterol lowering. “The results are now snowballing,” said Dr. Peter Libby of Harvard Medical School. “The disease is more mutable than we had thought.”The changing picture of what works to prevent heart attacks, and why, emerged only after years of research that was initially met with disbelief. In 1999, Dr. Waters of the University of California got a similar reaction to his study of patients who had been referred for angioplasty, although they did not have severe symptoms like chest pain. The patients were randomly assigned to angioplasty followed by a doctor’s usual care, or to aggressive cholesterol-lowering drugs but no angioplasty. The patients whose cholesterol was aggressively lowered had fewer heart attacks and fewer hospitalizations for sudden onset of chest pain.

But really that’s what Dean Ornish has proved for years. With aggressive enough diet exercise and behavior changes, heart disease can be relatively quickly reversed. So does that spell the end for stents and CABGs and a trip to the breadline for cardiologists, cardio-thoracic surgeons and their suppliers? Well probably not. The level of change required to avoid surgery is pretty extreme. I gave a talk to Ornish’s group a while back and had the lunch they provided. I had to break out for a cookie run in the afternoon after the no-fat no-sugar experience was too much for my delicate constitution. In general Americans like this type of intervention over changing their lifestyle.

Their new stents, coated with drugs to prevent scar tissue from growing back in the immediate area, are increasingly popular among cardiologists, and sales are exploding. But there is not yet any evidence that they change the course of heart disease.”It’s really not about preventing heart attacks per se,” said Paul LaViolette, a senior vice president at Boston Scientific, a stent manufacturer. “The obvious purpose of the procedure is palliation and symptom relief. It’s a quality-of-life gain.”

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