FDA to investigate stent shrinkage

The FDA is looking at a problem in a newer class of heart stents that causes the devices to shrink--or lengthen--after implantation. The events have been seen most frequently in Boston Scientific's Promus and Ion stents, Reuters quotes the FDA as saying.

"FDA is actively working with (drug-eluting stent) manufacturers, including Boston Scientific, to better understand longitudinal stent deformation with respect to its causes, predisposing underlying anatomic conditions, operator techniques that can reduce the likelihood of its occurrence, and treatment strategies should it occur," the agency told Reuters in an email.

As stents are becoming thinner and more flexible, some are having a hard time withstanding pressure. The medical journal EuroIntervention recently published the first case reports with a number of stents involving this problem, Bloomberg noted earlier this month.

"Stents have a lot of different properties, which vary from one to another," Gregg Stone, director of cardiovascular research at New York Presbyterian Hospital/Columbia University Medical Center, said in a conference call, as quoted by Bloomberg. "Some stents will be more prone to this complication than others. The question is to understand how frequent it is, when does it occur, how to prevent it and how to manage it."

Cardiologist Cindy Grines said she reported the issues to the FDA and Boston Scientific when she first learned of it. "The FDA was very interested and said they got other complaints and would do an extensive analysis," Grines said in a telephone interview with Reuters. "I've never seen anything like this and I've been doing this for 25 years and I do a lot of complex cases."

- get more from Reuters