The new Boston Scientific heart stent is getting a new warning added to their label, according to The U.S. Food & Drug Administration (FDA), who is requiring it. The agency is doing so, even though they are still investigating a rare and serious health issue with Boston Scientific Corp.’s new device, the Promus Element.
The FDA required Boston Scientific to include a section about the problem, longitudinal stent deformation compression on the company’s label, which includes precautions and instructions for using the device. It describes the problem, discusses situations where it occurs most often, provides guidance and suggests techniques to minimize events.
Last month, the FDA approved the heart stent — a tiny tubular device used to prop open diseased arteries — despite reports about a rare event in which the device becomes deformed after implantation.
As of October 31, 2011, there were 136 longitudinal stent deformation events per 829,372 units sold worldwide, according to the company.
Although the problem has also been linked to other stents, it appears to happen most often with Boston Scientific’s device, the FDA said. And, Boston Scientific is the only company, thus far, that has been required to include a precaution on their label.
The reason could be connected to Promus Element’s very thin struts that make the device more flexible and help physicians to implant in narrow or difficult-to-reach vessels. They also make the device more vulnerable to becoming stretched or compressed while being placed in a blood vessel.
“It’s a trade-off,” Ashley Boam, director of the division of Interventional Cardiology Devices Branch at FDA, told Reuters in an interview. “At this time, it still appears this is somewhat of a rare event and …serious complications in particular are rare. “It is still something we are looking at carefully,” she said.
When the stent becomes deformed inside the vessel, it creates a clotting risk that could lead to heart attack.
“Our impression at this point is that design does play a role. But the types of lesions the physician is trying to treat also plays a role,” Boam said.
“Boston Scientific generated the labeling language describing longitudinal stent deformation to provide the user with full information on how to deal with this infrequent phenomenon. The language was then agreed upon with FDA,” Boston Scientific spokeswoman Denise Kaigler said.
The label says, “Although the rate of longitudinal stent deformation is unknown, currently available information suggests that it is a rare adverse event.”
Dr. Andrew Farb, medical officer, division of International Cardiology Devices Branch of FDA, noted that longitudinal compression seems to be associated most often with calcified lesions, tortuous vessels and older lesions, which are often the most challenging to treat. These are also the types of cases for which a flexible stent is the best choice, he added.
Dr. Cindy Grines, a cardiologist at the Detroit Medical Center Cardiovascular Institute and editor of the Journal of Interventional Cardiology, said she was unaware of the note on the label.
“It’s good there’s a warning, but it needs to be advertised to the interventional cardiology community. We’re a high volume center and I haven’t heard about it,” she said, adding that having it buried in a label is not useful. “Nobody reads the labels.”
In conclusion though, I’d like to add this, Dr. Grines may be right in that nobody reads the labels, because they are atrociously long. According to Reuters, the label in question is 20 pages long! Something needs to be done so that people are aware of these dangers, and that a 20 page label doesn’t get left unread!