March 21, 2002
ATLANTA, Georgia (ACC) -- Drug-eluting stents are a hot topic in interventional cardiology
and potentially revolutionary in the treatment of coronary
artery disease, but the ideal stent coating has yet to be
determined.
Investigators testing various coatings discussed their research
at a press conference on Sunday, March 17,
2002. Researchers from France and
Brazil presented positive data from their clinical studies using sirolimus-eluting stents. But a trial from Germany showed
negative results with heparin-coated stents.
The heparin-coated stent trial was described by Michael Haude,
MD, Med Klinik II, University of Essen, Essen, Germany. In the
trial, 600 patients with recurrent small-vessel disease were
randomized to receive PTCA, an uncoated JOSTENT Flex stent, or
the same stent with a heparin coating.
Median lumen diameters at six months were almost identical, at
1.34 mm for PTCA, 1.47 mm for the uncoated stent, and 1.45 mm
for the coated stent. There were no deaths in the PTCA group but
two each in the stent trial arms. And there was one thrombotic
event each in the stent arms versus none in the PTCA arm.
“We conclude that the heparin-coated stent does not provide any
angiographic or clinically-related benefit in small native
coronary arteries,” Dr. Haude said.
More promising data come from two studies using stents coated
with the naturally-occurring antibiotic sirolimus.
Jean Fajadet, MD, Clinique Pasteur, Toulouse, France, reported
on the 210-day followup of the RAVEL study, which found no late
loss and no restenosis in the 120 patients randomized to receive
a sirolimus-eluting Bx Velocity balloon-expandable stent. This
compares very favorably with an average late loss of 0.8 mm and
restenosis rate of 26 percent among the 118 controls who
received the uncoated stent.
Dr. Fajadet said especially impressive was that patients with
diabetes who were treated with the coated stent also had no late
loss or restenosis compared with a late loss of 0.82 mm and
restenosis rate of 42 percent for the controls.
And survival at one year was 94 percent with the sirolimus stent
versus 71 percent for the controls.
“Use of the sirolimus stent is safe and there were no deaths
related to its use,” Dr. Fajadet said.
Results from another sirolimus-coated stent trial were similarly
encouraging. Jose Eduardo Sousa, MD, Institute Dante Pazzanese
of Cardiology, Sao Paulo, Brazil, said the two-year followup of
implantation with the sirolimus-eluting stent showed no
mortality and no restenosis in the stent.
“At two years followup, the sirolimus-eluting stent continues to
be a major breakthrough in the fight against restenosis,” Dr.
Sousa said.
He presented data on 45 patients followed by serial angiography
and ultrasound examination on multiple occasions during the
two-year followup.
The percent of arterial blockage before treatment was 61
percent, Dr. Sousa said. Immediately post procedure it was 4.2
percent, and 1.4 percent at two-year followup.
“These angiographic results were confirmed by intravascular
ultrasound that demonstrated minimal scar-tissue growth in the
stent,” Dr. Sousa said. “The clinical benefits observed after
placement of the sirolimus stent appear durable at late followup.” |