NEW YORK (Reuters Health) – Newer generation everolimus-eluting stents (EES) are significantly less likely to prompt very late stent thrombosis than are the first generation of drug-eluting stents which released sirolimus (SES) or paclitaxel (PES), researchers report in a February 1st on-line paper in Circulation.
The findings are in keeping with those from other studies which suggest benefits from use of EES overall and in specific populations (see Reuters Health reports 2011-10-20 and 2011-08-17).
Dr. Stephan Windecker of Bern University Hospital, Switzerland and colleagues note that although stent thrombosis is rare it may lead to death or myocardial infarction (MI) in up to 90% of cases. Both early drug-eluting and bare metal stents prompt a similar risk for up to 1 year. However, SES and PES continued to present a steady annual risk of 0.5 to 0.6% up to five years.
To investigate the impact of the newer generation stent, the team examined data on 12,339 patients who had undergone unrestricted implantation of SES, PES or EES.
Over 4 years of follow-up, the incidence of definite stent thrombosis was significantly lower in the 4,212 EES patients than it was in the 3,819 given SES and the 4,308 who received PES. After adjustment, the corresponding incidence rates per 100 person-years were 1.4, 2.9 and 4.1.
The results were consistent in stratified analyses across major subgroups including age, gender, diabetes and acute coronary syndromes.
The differences were most pronounced beyond one year with a hazard ratio of 0.33 for EES versus SES and 0.34 for EES versus PES. There was also a reduction in cardiac death or MI with EES compared to PES (hazard ratio, 0.65).
Moreover, the annual incidence rate of very late stent thrombosis was 0.8% for PES, 0.5% for SES and 0.2% for EES.
Thus, the researchers conclude that the reduction in stent thrombosis “overcomes the principal limitation of early generation DES and constitutes an important advance in DES.”
They also note that given these favorable results “it appears unlikely that a prolonged regimen of dual antiplatelet therapy in patients treated with EES can further improve upon stent related outcomes.”
Dr. Windecker did not respond to requests for comments.
Source:
Circulation 2011
