Staying on Plavix Cuts Stent Risk
Big Drug-Coated Stent Questions Loom on Eve of FDA Panel Meeting
Urgent Need for More Data
The Swiss study's data come from a reanalysis of a 746-patient clinical trial.
That trial was designed to compare drug-coated stents with bare-metal ones -- not to look at late-occurring side effects like clogged arteries. So Pfisterer warns the data can't be considered definitive.
"There is a lack of data -- and we need that data," Pfisterer says. "We need to look at all these issues in more detail."
Major questions remain:
- Which patients need extended Plavix/aspirin treatment?
- What dose of Plavix is best?
- How long should Plavix/aspirin treatment continue?
- What, exactly, are the risks and benefits of extended Plavix/aspirin treatment?
- Are there patients who should not receive drug-coated stents?
Currently, the FDA has approved drug-coated stents only for relatively uncomplicated procedures. But heart doctors readily admit they have been using them for all kinds of patients.
"About two-thirds of our patients were really treated with off-label use of drug-eluting stents," Pfisterer says.
"The FDA label says these are only for stable patients with limited disease. But, in fact, most doctors who use drug-eluting stents use them in unstable patients and in more complex disease," says Pfisterer.
In an editorial accompanying the Pfisterer study, Califf and colleague Robert A. Harrington, MD, argue that clinical research on drug-eluting stents is not keeping up with clinical realities.
"As is frequently seen with new cardiac devices, rapid increase in clinical adoption [of drug-eluting stents] quickly outstripped what is known about the device from limited clinical trials," Harrington and Califf note.
The Swiss study and other recent data, the Duke researchers conclude, "have led us to the conclusion that patients with drug-eluting stents should remain on [Plavix] and aspirin if at all possible until adequate studies are completed."
This week, the FDA is convening an expert panel to discuss the safety issues swirling around drug-coated stents.
Heated debate is expected.