Everolimus-eluting stent shows greater therapeutic benefit over gold
1 Sept 2010
A trial of the newer generation everolimus-eluting stent has
provided preliminary evidence that it gives greater therapeutic benefit
than the previous gold standard, the early generation sirolimus-eluting
The LESSON I trial also provides evidence that the formation of
blood clots (stent thrombosis) — the principal shortcoming of early
generation drug-eluting stents — may be diminished with the newer
generation everolimus-eluting stent. The results were presented at
the European Society of Cardiology (ESC) congress in Stockholm last
Everolimus is an immunosuppressant drug used to prevent
restenosis of drug eluting stents (DES). It is also used in
transplantation medicine, and is a derivative of sirolimus.
"The latter observation," said principal investigator Professor
Stephan Windecker from Bern University Hospital, Switzerland, "may
have important implications for ongoing studies on prolonged
duration of dual antiplatelet therapy after DES implantation, but
will require confirmation in randomised clinical trials."
Drug-eluting stents (DES) are designed to scaffold narrowed
coronary arteries resulting from coronary artery disease. By means
of the radial strength of the cylindrical mesh, DES keep the artery
open, maintain blood flow, and gradually release an
anti-proliferative drug into the surrounding tissue. The role of the
drug is to prevent re-narrowing of the artery within the stented
segment by scar tissue.
The first generation of DES effectively prevented re-narrowing of
the artery but were associated with a small risk of stent thrombosis
late after stent implantation. Newer generation DES have been
developed using modified polymers and thinner metal struts, whose
aim is to further improve upon the results of early generation DES.
The LESSON I (Long-term comparison of everolimus-eluting and
sirolimus-eluting stents for coronary revascularization) study
compared 1601 patients undergoing treatment with everolimus-eluting
stents with 1532 patients having treatment with sirolimus-eluting
stents in a propensity-score matched analysis. The study involved
all patients having percutaneous coronary intervention (PCI) with
either everolimus-eluting or sirolimus-eluting stents at Bern
University Hospital between 2004 and 2009.
The primary endpoint of the study was a composite of death, heart
attacks and repeat interventions. Results showed that up to three
years after the procedure the numbers of deaths, heart attacks and
repeat interventions tended to be lower in patients treated with
everolimus-eluting stents (14.9% of patients in the everolimus-eluting
stent group and 18.0% of patients in the sirolimus-eluting stent
group, a relative risk reduction 17%, P=0.056).
The differences in favour of the everolimus-eluting stent were
found to be most pronounced in reducing heart attacks (3.3% of
patients in the everolimus-eluting stent group versus 5.0% in the
sirolimus-eluting group, a 38% relative risk reduction, P=0.02).
"The lower risk of heart attacks was related at least in part to a
lower risk of stent thrombosis in patients undergoing everolimus-eluting
stent implantation," said Professor Windecker.