FDA Investigating Problems with Newer Stents

The U.S. Food & Drug Administration (FDA) is investigating a new class of heart stents and dangerous changes that can occur in the stents after implantation.

The problems are rare, but considered quite serious in the newer heart stent class. Reuters explained that the tiny mesh, tubular heart devices can shrink or lengthen and specifically involve the Promus and Ion devices, both are manufactured by Boston Scientific Corp. The Promus Element is sold outside of the U.S.; Boston Scientific recently submitted a pre-market application with the FDA, added Reuters.

Some 600,000 angioplasties with and without stents are performed in the U.S. annually, costing over $12 billion; angioplasty, which usually involves the use of heart stents to widen blocked blood vessels, can result in clotting, which can increase heart attack and stroke risks in people with no heart symptoms. Meanwhile, the FDA said it considers the Ion stent, approved this spring, as safe when used for its authorized indications, said Reuters. “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,” said the agency in an emailed response to Reuters.

Stent deformation has been discussed in two journals and was a topic at the very recent Transcatheter Cardiovascular Therapeutics meeting in San Francisco, said Reuters. Drug-eluting stents, such as the Promus and Ion, prop open unhealthy arteries, sending medication to help ensure vessels do not reclog. When longitudinal deformation occurs, the stents deform within the vessel, which can create an increased risk for clotting and lead to a heart attack, Reuters explained. There are some factors that increase a patient’s disposition to the problem, such as coronary artery calcification, when an implant occurs in a twisted blood vessel, and if the stent is improperly positioned, said the FDA, according to Reuters.

Reuters pointed out that heart stents have come under scrutiny after research indicated that conventional medication and exercise might be better for some patients versus implantation with the devices. For instance, we wrote that in 2008, a study published in the New England Journal of Medicine called COURAGE—Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation—found that stents weren’t any better than drugs in treating patients suffering from chronic but stable chest pain.

Last December, we reported that Baltimore surgeon Mark Midei came under scrutiny for implanting allegedly unnecessary cardiac stents in hundreds of patients at St. Joseph’s Medical Center in Towson, Maryland. According to a Senate Finance Committee report, Abbott Laboratories, another stent manufacturer, provided Midei with many perks, such as pig roast to mark an occasion in which the surgeon may have broken an Abbott record by implanting 30 stents in one day.

In another case, 141 patients underwent unneeded angioplasties at Westmoreland Hospital in Western Pennsylvania in 2010. The questionable stents were implanted by Drs. Ehab Morcos and George Bousamra, who voluntarily resigned their privileges at Westmoreland in January.

Stent giant, Boston Scientific has had issues in the wake of a number of stent recalls as far back as 2004, as well as issues over its problematic 2006 acquisition of stent and pacemaker manufacturer, Guidant Corp., Reuters explained. This year, Johnson & Johnson announced it would no longer be making drug-eluting stents; the devices are still manufactured by Medtronic Inc. and Abbott Laboratories Inc.