ISAR - CABG: Drug-eluting stents
lead to improved outcomes in saphenous vein graft lesions
In the largest randomized, multicenter trial to compare
drug-eluting stents (DES) and bare-metal stents (BMS) placed in saphenous vein
graft lesions, researchers found that DES led to a lower combined rate of death,
heart attack, and repeat revascularization, according to research presented at
the American College of Cardiology's 60th Annual Scientific Session.
While saphenous vein grafts (SVGs) have been used extensively in coronary artery
bypass graft (CABG) surgery, these conduits develop atherosclerotic disease that
results in vessel narrowing or closure in a high percentage of patients. Conducting
a second CABG surgery to fix the graft is a possibility but can result in higher
mortality and morbidity rates than the first operation. Performing angioplasty
with a stent is an alternative to repeat CABG surgery; research is still being
conducted to optimize this procedure.
"DES have proven superior to BMS in all coronary artery lesion subsets
examined, but their performance has been insufficiently evaluated in SVG lesions,"
said Julinda Mehilli, M.D., director of clinical research and data coordinating
in the Intracoronary Stenting and Antithrombosis Research (ISAR) Center at the
German Heart Center Munich, Germany. "The only two very small randomized
trials comparing DES with BMS in SVG lesions provided conflicting results. Thus,
the aim of the ISAR-CABG trial was to investigate this question in a larger population
sufficiently powered to provide information on clinical endpoints."
For the study, German researchers enrolled 610 patients who had previously
undergone CABG surgery. All study patients had subsequently developed at least
one lesion in their saphenous vein graft and were randomized to receive either
a DES (n = 303) or a BMS (n = 307) in the study angioplasty procedure.
The study's primary endpoint was a composite of major adverse cardiac events
[death, heart attack, and target-lesion revascularization (TLR)] at the one-year
follow-up point. The secondary endpoints were the individual rates of death, myocardial
infarction, ARC- definite stent thrombosis (ARC - Academic Research Consortium),
and the need for TLR over one year.
The researchers found that the incidence of major adverse cardiac events was
reduced by 35 percent in the DES cohort compared to the BMS group. Specifically,
16.5 percent of patients in the DES group experienced the primary endpoint compared
with 22.1 percent of patients in the BMS group (hazard ratio [HR] 0.65; 95 percent
confidence interval [CI] 0.45 ? 0.96; p = 0.028). The reduction in the DES group
was primarily due to a significantly lower rate of TLR, which occurred in 7.2
percent of patients in the DES group and in 12.9 percent of patients in the BMS
group (hazard ratio [HR] 0.52; 95 percent confidence interval [CI] 0.30 - 0.90;
p = 0.020).
The research team found no significant differences in the individual rates
of death or heart attack. Additionally, only one patient in the DES cohort experienced
ARC-definite stent thrombosis. None of the patients in the BMS group experienced
this outcome.
"Saphenous vein graft lesions remain a challenging disease subset for
angioplasty. The ISAR-CABG trial, however, demonstrates that DES can safely be
used to reduce adverse events in this high-risk subset of patients," Mehilli
said.
The study was funded by the German Heart Center Munich and by Cordis. Mehilli
had no disclosures to report.
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