Coronary Angioplasty and Drug-Eluting Stents - Applications of Biotechnology in Cardiovascular Therapeutics - page 287

present. There was one in-stent and one in-segment (proximal edge) restenosis in
the metallic stent group. There was no stent thrombosis or aneurysm formation at
follow-up in either group. Another study found that between 2 and 4 years after
implantation of sirolimus-eluting stent, peristent tissue shrank with a concomitant
increase in echogenicity as demonstrated by serial quantitative intravascular ultra-
sound and computer-assisted grayscale value analysis (Aoki et al. 2005 ). These
findings suggest that the neointima does not significantly change from 2 to 4 years
and that the biological phenomenon of a delayed healing response starts to subside.
Although several studies established the superiority of coronary EES over pacli-
taxel-eluting stent system (PES) with respect to angiographic findings, these trials
were not powered for superiority in clinical end points.
XIENCE ™ V is Abbott Vascular's EES using MULTI-LINK VISION ® Coronary
Stent System platform is currently an investigational device in the USA and Japan.
The six studies involving 8,000 patients for evaluating this system for the treatment
of coronary artery disease are:
SPIRIT I - First human study showed positive results through 2 years with no
major adverse cardiac events for patients with previously untreated native coronary
artery lesions.
SPIRIT II - 6 m results of the trial conducted in Europe and Asia-Pacific demon-
strated superiority of the XIENCE V stent system over the TAXUS ® PES with respect
to the study's primary endpoint, which was angiographic in-stent late loss at 6 m.
SPIRIT III - This large-scale randomized pivotal clinical trial in 2006 compared the
XIENCE V system to the TAXUS stent system in the USA and Japan.
SPIRIT IV - This trial evaluated the safety and efficacy of the XIENCE V system
for the treatment of coronary artery disease in a more complex patient population
in the USA; 3,687 patients were randomly assigned at 66 US sites to receive EES
or PES without routine follow-up angiography (Stone et al. 2010 ). The primary end
point was the 1 year composite rate of target-lesion failure (defined as cardiac
death, target-vessel myocardial infarction, or target-lesion revascularization). EES,
as compared with PES, resulted in reduced rates of target-lesion failure at 1 year,
results that were consistent in all patients except those with diabetes, in whom the
results were nonsignificantly different.
SPIRIT V - This study will provide additional clinical experience with the XIENCE V
system throughout Europe, Asia-Pacific, and Canada in real-world patients. One
subset of the study is dedicated to diabetic patients.
SPIRIT WOMEN - The world's first DES trial to study only women will evaluate
the characteristics of women undergoing stent implantation and performance of
XIENCE V in those patients in Europe, Asia-Pacific, Canada, and Latin America.
COSTAR II Clinical Trial
COSTAR ™ (CObalt chromium STent with Antiproliferative for Restenosis)
is developed by Conor Medsystems Inc and is being studied in COSTAR II