Yesterday, in its second of 2 days of deliberation, the FDA's Circulatory Systems Devices Advisory Panel on drug-eluting stents (DES) considered what recommendations to make regarding the off-label usage of DES. "Off-label" usage accounts for 60 - 75% of DES implanted, and includes DES in the treatment of acute heart attacks, of restenosis occurring with previous stents, of blockages in bypass grafts, of complex coronary artery lesions, and of small blood vessels.
The panel heard several presentations of data, including new evidence the that the risk of death and heart attack in these more complex patients may be higher with DES than with bare metal stents. In general, the panel agreed that the risk of late thrombosis with DES is higher when these stents are used for off-label indications than when used for on-label indications, and that, at least for patients at highest risk for stent thrombosis, the off-label use of DES should be curtailed to at least some degree.
The panel also appeared to agree that clopidogrel (Plavix) and aspirin should be given to these patients for a full 12 months. While some argued for longer administration of these drugs, and perhaps even for their indefinite use, others pointed out that the antithrombotic therapy itself poses a risk, and that without randomized trials testing their long-term safety and efficacy, it would be inappropriate to formally recommend that these drugs be used for extremely long periods of time. The 12-month recommendation appeared to be a compromise the majority could live with.
The main conclusion of the panel, however, is that insufficient randomized data is available to really make any concrete recommendations about either the appropriateness of off-label use of DES, or the most appropriate length of time to administer Plavix. The kinds of clinical data the panel called for is now being collected, but will not be fully collected and analyzed for several years.
