New England Journal of Medicine stent studies released

By Harvey Kirk
Posted February 13, 2007

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A series of articles in next months New England Journal of Medicine involve the study of drug eluting stents.  These devices have been the subject of concern recently following reports that they increase the risk of blood clots, heart attacks and death for patients who have the small wire tubes implanted in their arteries.

>>INFORMATION: Drug coated stent problems

Drug eluting stents were approved in the United States four years ago, and they grew to account for nearly 90% of all stents implanted by 2006.  Over 6 million people worldwide have had a drug coated stent placed in their artery to keep a previously clogged artery open following angioplasty. 

Recently concerns regarding the long-term risks associated with the small mesh tubes has been the focus of FDA advisory panels and cardiologists.  Studies have indicated that the medicated stents carry a statistically significant risk of potentially fatal blood clots which can occur months or even years after stent placement as a result of the drug coating.

NEW ENGLAND JOURNAL OF MEDICINE STENT STUDY

The March 2007 issue of the New England Journal of Medicine contains information and studies regarding drug eluting stent safety.  Five stent articles and two commentaries were released this week on the internet.

The New England Journal of Medicine stent studies indicate somewhat conflicting results:

• A March 2006 study performed by Swedish researchers followed the results of 20,000 patients who received stents in Sweden during 2003 and 2004.  These patients did not participate in the stent manufacturers’ clinical trials.  The study found that patients receiving drug eluding stents suffered five to 10 more heart attacks or deaths per 1,000 patients each year, when compared with patients receiving older, bare metal stents.
• A new study to be published in NEJM reviewed data supplied by the manufacturers, following 5,000 patients who were included in the clinical trials. This study indicates that the patients in the clinical trials experienced an increased rate of stent blood clots, but had no statistically significant difference in deaths or heart attacks.

Critics have pointed out that the New England Journal of Medicine stent study which evaluates the clinical trial data supplied by the manufacturers ignores the results of a large number of patients who have had drug-eluting stents implanted “off-label”, or for uses not approved by the FDA.  Previous estimates indicate that between 60% and 80% of all stents implanted are for “off-label” uses which were not studied in the clinical trials or determined to be safe according to the FDA.  Patients who are sicker or who have more complex blockages were not followed in the clinical trials, but these “off-label” uses were included in the Swedish study. 

The Swedish stent study provides more of a real world analysis of the drug eluding stent problems, since it includes both on-label and off-label uses.  The results of this data show a clear increase in the risk of death, finding that patients receiving drug eluting stents were 18% more likely to die within three years, than patients who received bare metal stents.

There has been speculation that the drug coated stent fatality rate may even be higher than that reported in the Swedish study, since patients were not assigned randomly to controlled groups.  The study reached conclusions by examining medical records of patients after the stents were implanted.  A more controlled stent study, where patients are randomly assigned to receive either a drug coated stent or bare metal stent, could show an even higher rate of death since the patients in Sweden who received the drug eluting stents were found to be healthier to start out than those who received bare metal stents.

RELATED STUDY: Drug coated stents and diabetes

ADDITIONAL STENT STUDY IS NEEDED

There remains no clear consensus on the extent of the drug coated stent blood clot risk or how long the danger lasts.  Experts are recommending patients who receive the medicated stents take an anticlotting medication, such as Plavix, for at least a year or longer.  Additional studies are needed to review concerns about the extent of the risk, as well as Plavix side effects associated with long term use of the drug and whether taking the drug longer than one year will reduce the risk of the stent blood clots.

Controlled clinical trials comparing patients receiving medicated stents with those who receive bare metal stents would provide a more reliable and accurate basis for physicians and heart patients to weigh the risks and benefits of drug coated stents.  Controlled studies usually only occur if the manufacturers are interested in the data and willing to fund the study.   

The makers of drug eluding stents failed to fully study drug eluting stents prior to allowing the devices to be implanted into patients.  They have a clear financial interest in the continued use of drug eluting stents, since the new devices cost around $2,000 a piece, compared with approximately $800 for bare metal stents.  This may be another example of a corporation placing profits before the safety of the consumer.

DRUG ELUTING STENT LAWYERS

The stent lawyers at Saiontz & Kirk, P.A. represent hundreds of patients nationwide who have suffered blood clots, heart attacks, death or a reclogging of the artery after a drug eluting stent was implanted.  Stent lawsuits are being reviewed for any patients who received the Johnson and Johnson Cypher stent or Boston Scientific Taxus stent.  If you, a friend or family member had a stent implanted and suffered blood clots, heart attack, death or underwent a proceedure to unclog the artery after the stent placement, request a free claim evaluation.