March 23, 2002
ATLANTA, Georgia (ACC) -- Innovations
in stenting were highlighted during Sunday’s
(March 17, 2002) Late-Breaking Clinical Trials session.
In the ISAR-STEREO-2 trial in Germany, use of a thin-strutted
stent was associated with a 43 percent reduction in the
restenosis rate at six months compared with a thick-stented
strut. And researchers in the TRENDS study report that direct
stenting without pre-dilatation is both feasible and safe.
“Device characteristics of coronary stents appear to have a
significant impact on restenosis development and long-term
outcome,” said Dr. Helmut Schuhlen, of the German Heart Center,
Munich, who described the ISAR-STEREO-2 (Intracoronary Stenting
and Angiographic Results-Strut Thickness Effect on Restenosis
In the trial, 611 PTCA patients were randomized to the
first-generation Multilink stent with 50-micrometer struts, or
to the BX Velocity stent that is similar in design but has
Median stented length for the group of 309 patients receiving
the Multilink was 22.0 mm and 20.7 for the 302 patients
receiving the BX Velocity.
At six months, the rate of angiographic stenosis of 50 percent
or greater was 17.9 percent for the thin strut compared with
31.4 percent for the thick strut, a 43 percent reduction, Dr.
Schuhlen said. Median lumen diameter at six months was 1.96 mm
with the thin-strut stent versus 1.70 mm with the thicker-strut
model, a striking difference between the two, he said.
Survival free of myocardial infarction was approximately the
same, 95.1 percent at one year for the thin strut and 93.7
percent for the thick strut.
Procedural success was also approximately the same, 99.4 percent
for thin stents and 99.0 percent for thick stents. But device
success was different: 87.1 percent for the thin-strut Multilink
versus 99.0 percent for the BX Velocity, an outcome that Dr.
Schuhlen attributed to the fact that the Multilink is a
first-generation device, while the BX Velocity is a
“This trial demonstrates that there may be significant
differences in restenosis based on stent design,” said session
co-moderator William W. O’Neill, MD, Royal Oak, MI. “In the
past, all of us concluded that lesion characteristics,
implantation technique, and other nuances impacted most. But
stent thickness may also impact enormously.”
Dr. O’Neill said because they will be comparing stents of
different strut thickness, future trials of drug-eluting stents
should take this information into account.
Direct Stenting Feasible
Stenting can be done with or without balloon predilatation
and each approach has its advantages and disadvantages. But
early results from the TRENDS (Tetra Randomized EuropeaN Direct
Stenting) study show that the rate of major adverse cardiac
events is approximately the same for both techniques.
“The strategy of direct stenting is contentious and in Europe
there is a wide variety of opinions as to whether this is the
best approach,” said Dr. Keith D. Dawkins, Wessex Cardiac Unit,
That debate may now be answered by the TRENDS study. The direct-stenting
strategy failed in 31 of 541 stents—that is, only 5.8 percent of
stents deployed directly failed to reach the lesion and had to
be crossed over to the predilatation arm.
There were two deaths at 30 days among the 501 patients
randomized to direct stenting, he said, versus one death among
the 499 predilatation-arm patients.
Dr. Hawkins noted that the two trial arms were well balanced and
that both included large subsets of patients with complex
lesions that reflected a real-life patient population.
Approximately 97 percent of all patients had a history of