Blog #9

Shuchman. “Trading Restenosis for Thrombosis? New Questions about Drug-Eluting Stents”. The New England Journal of Medicine. 355. November 9 (2006): 1949-1952. Print

http://nejm.highwire.org/cgi/content/extract/355/19/1949

Up to this point, drug-eluting stents have had a golden reputation. They had proven to be able to reduce both emergency cardiac surgery and additional angioplasty. They are also associated with substantially lower restenosis rates than bare metal stents as proven by prior papers. At the time of this paper (2006), more than 90% of angioplasty procedures used drug-eluting stents rather than bare metal stents and more than 6 million patients have drug eluting stents in their arteries

However, in this editorial Shuchman reviews the growing concerns with drug-eluting stents: late thrombosis. “Late stent thrombosis (LST)” is defined as occuring 3 to 6 months after the surgery, while “very late stenosis thrombosis (VLST)” is greater than 6 months. After tracking patients from early clinical trials researchers have discovered that thrombosis is a major concern. For example, four years of data on nearly 3500 patients randomly assigned to receive a drug eluting stent (Taxus) or a bare metal stent has shown the risk of thrombosis formation 6 months after Taxus stent placement. The difference in risk increased by .2% per year, so 3 years after stent placement there is a .5% higher risk in Taxus over the bare metal stent. These reviewers suggested that there might be an increased risk of myocardial infarction and death associated with stent thrombosis.

What does this mean for the public? Well at the time of this article the FDA claimed that there is a “small additional risk of late stent thrombosis after a year”. Is this risk worth it? The newer drug eluting stents do confer better protection against restenosis but do have this small thrombosis risk. Therefore, many physicians now concluded that an extended or lifetime prescription of aspirin and plavix (clodigrel) are necessary when a patient receives a drug eluting stent. The initial recommendation of 6 months was extended to “12 months or indefinitely”, unless a patient has a high risk of bleeding. These stents are thus still beneficial and useful but second and third generation drug eluting stents should look into creating better polymers to solve this thrombosis problem.