June 30th, 2014
Registry Study Offers Reassurance About Newer Drug-Eluting Stents
Findings from a large ongoing registry study provide some reassurance about the long-term safety of new-generation drug-eluting stents (DES) in patients with STEMI who undergo primary PCI. The results are published online in the Journal of the American College of Cardiology.
SCAAR (Swedish Coronary Angiography and Angioplasty Registry) investigators analyzed data from 34,000 primary PCI patients who received a bare-metal stent (BMS), an old-generation DES, or a new-generation DES. They found that in the first year after PCI, both new- and old-generation DES patients had a lower risk of stent thrombosis (ST) than did BMS patients. Very late ST up to three years was higher in the old-generation DES group compared to both the new-generation DES and BMS groups, which had similar risks. At one year the ST rate was 1.5% for BMS, 1.1% for the old-generation DES, and 0.9% for the new-generation DES. At three years the rates were 2%, 2.1%, and 1.3%.
ST has been the main source of concern about DES. The new findings lend support to the widespread view that the new-generation DES would reduce the late risk of ST that has been previously observed with old-generation DES.
Precise information about ST has been difficult to obtain from randomized studies, most likely because the studies have been underpowered to detect these sort of differences in the rate of rare but clinically important events.
In an accompanying editorial, Bradley Strauss and Mony Shuvy write that the “results are reassuring and should mitigate concerns about late and very late ST with second-generation DES in STEMI patients.”
Commenting on the papers, L. David Hillis said that “the registry’s size is impressive and it appears that both the authors and the editorialists have discussed the main limitations with these data: (1) the possible selection bias that may enter into any nonrandomized trial and (2) the lack of any information about long-term medical therapy, most importantly dual antiplatelet therapy.”