A recent study published in Lancet adds more controversy to the ongoing debate over the safety of TaxusÂ® and CypherÂ® drug-coated stents versus bare-metal stents. Stents are metal devices placed into diseased arteries that act as scaffolding to keep arteries open after angioplasty procedures.
In this article, the researchers reviewed the results of thirty-eight clinical trials comparing the safety and effectiveness of two types of newer stents coated with drugs intended to prevent late-stent thrombosis versus the older bare-metal stent design and concluded that the drug-coated stents (or at least one type of stent) may provide advantages. Last year, there were reports that drug-coated stents were causing a significant number of clots, the exact complication that they were designed to minimize. These reports led to a 40% decline in the sale of drug-coated stents in 2006, with worldwide sales for stents topping $6.5 billion.
More than 18,000 patients in these 38 clinical trials were followed for periods ranging from 6 to 24 months. The researchers concluded that there was no difference in the number of overall deaths or the number of deaths attributed to cardiac causes among patients receiving the three different types of stents. This finding is contrary to data announced last year indicating a higher risk of death associated with drug-coated stents, which prompted a review by the FDA earlier this year.
The most significant finding of the study was in the differences noted between the two types of drug-coated stents. The study compares the TaxusÂ® stent coated with paclitaxel manufactured by Boston Scientific and the CypherÂ® stent coated with sirolimus manufactured by Johnson & Johnson, the only drug-coated stents currently available in the United States currently and the dominant drug-eluting stents used in foreign countries. Currently, nearly 85% of the stents implanted worldwide are drug-coated stents, and Boston Scientific’s TaxusÂ® stent is a leader both in the United States and abroad. The researchers noted a slightly increased risk of blood clots in patients with TaxusÂ® stents over the number of such complications seen in patients with bare-metal and drug-coated CypherÂ® stents. Also, patients with CypherÂ® stents were less likely to require additional cardiac procedures, such as bypass surgery or placement of another stent due to a restenosis of their artery. Not surprisingly, Johnson and Johnson lauded the Lancet study, while Boston Scientific questioned its scientific validity and tried to redirect the focus to other studies that it contends support the safety of drug-coated stents in general and direct comparisons that show no differences between the performance and risks of the TaxusÂ® and CypherÂ® stents.
For more information on this subject, please refer to the section on Drugs, Medical Devices, and Implants.