Drug-Eluting Stents Outperform Bare Stents in Heart Attack

Anti-clotting drug tirofiban also edges abciximab

CHICAGO, March 30 /PRNewswire/ -- New evidence from a large randomized
study is answering important questions about the best approach to
percutaneous coronary intervention (PCI) in patients with a type of heart
attack known as ST-segment-elevation myocardial infarction (STEMI). In the
study, drug-eluting stents outperformed bare-metal stents, and high-dose
tirofiban, an anti-clotting medication, proved to be equally effective and
have fewer side effects than the catheter lab standard, abciximab.

The study is being reported today in a Late-Breaking Clinical Trials
session at the SCAI Annual Scientific Sessions in Partnership with ACC i2
Summit (SCAI-ACCi2) in Chicago. SCAI-ACCi2 is a scientific meeting for
practicing cardiovascular interventionalists sponsored by the Society for
Cardiovascular Angiography and Interventions (SCAI) in partnership with the
American College of Cardiology (ACC). This study is also being
simultaneously published online in JAMA: Journal of the American Medical
Association.

"These findings may provide a robust scientific rationale for high-dose
tirofiban as an alternative to abciximab in patients with STEMI," said
Marco Valgimigli, MD, PhD, a cardiologist at the Cardiovascular Institute,
Azienda Opedaliera Universitaria di Ferrara, Ferrara, Italy. "In addition,
at mid-term follow-up our study did not confirm some of the safety concerns
over the use of drug-eluting stents in patients with myocardial infarction.
These findings are very reassuring, though we need long-term follow-up to
rule out the possibility of late adverse events."

Drug-eluting stents -- which not only prop open the coronary arteries
but slowly release medication that prevents re-narrowing of the arteries
with scar tissue, or restenosis -- are widely used when PCI is performed
for stable coronary artery disease. But many cardiologists use bare-metal
stents when treating patients with heart attack because studies have
reported conflicting results on the benefits of drug-eluting stents in this
group of patients and have raised concerns over the risk of blood clotting
inside the stent, or stent thrombosis. The new study has certain design
advantages over previous studies, specifically its size and an enrollment
and follow-up protocol that more closely reflects everyday clinical
practice.

As for tirofiban and abciximab, both are in a class of medications
known as glycoprotein 2b/3a inhibitors and prevent blood clotting by
blocking hyperactivation of platelets. Tirofiban is an attractive
alternative for several reasons: It is shorter-acting and is cleared from
the body more readily than abciximab, it is less likely to cause a
dangerous drop in the number of platelets in the blood, and it is far less
expensive. However, previous studies have been too small or have used too
low a dose of tirofiban to reach a definitive conclusion about which
medication is better, Dr. Valgimigli said.

The new study, which involved 16 medical centers, enrolled 745 patients
who were set to undergo PCI for STEMI. Patients were randomly assigned to
an infusion of abciximab or high-dose tirofiban (25 microgram/kg) and, in a
second round of randomization, to treatment with either uncoated or
sirolimus-eluting stents.

To judge the effectiveness of tirofiban and abciximab, researchers
examined electrocardiograms -- 722 of which were interpretable -- to
determine the proportion of patients with at least a 50 percent return of
the elevated "ST-segment" to its normal baseline. The results were
equivalent in the two groups (83.6 percent in the abciximab group vs. 85.3
percent in the tirofiban group). In addition, there was no significant
difference in the rate of major adverse cardiac events (MACE) -- a
combination of death, repeat heart attack, and repeat procedure to open the
treated coronary artery -- in the two groups: 4.8 percent vs. 4.5 percent,
respectively, at 30 days and 12.3 percent vs. 9.9 percent, respectively, at
eight months. The rates of minor and major bleeding did not differ in the
two groups, but a marked drop in the blood platelet count -- a complication
that could cause uncontrolled bleeding -- was more common among patients
treated with abciximab (4.0 percent vs. 0.8 percent, p=0.004).

When comparing the two types of stents, investigators found an
equivalent MACE rate at 30 days (3.9 percent vs. 5.9 percent, p=0.12) with
sirolimus-eluting and bare-metal stents. However, at eight months, the MACE
rate was significantly lower with drug-eluting stents (7.8 percent vs. 14.5
percent, p=0.0039). This difference was mainly driven by a 69 percent
reduction in the need for a repeat procedure to reopen the treated coronary
artery (3.2 percent with sirolimus-eluting stents vs. 10.2 percent with
bare-metal stents, p=0.0004). The rates of death and repeat heart attack
were similar, as was the incidence of stent thrombosis.

"Our study shows that tirofiban is 'noninferior' in its efficacy to
abciximab in this high-risk patient population, and has a better safety
profile," said Dr. Valgimigli. "We have also confirmed that, even in STEMI
patients, drug-eluting stents are highly effective in reducing
reintervention in the target vessel. More important, this came without an
extra price to pay in terms of death, myocardial infarction or stent
thrombosis."

Dr. Valgimigli will present the results of this study on Sunday, March
30 at 9:00 a.m. CDT in the Grand Ballroom, S100. This study will
simultaneously publish in JAMA: Journal of the American Medical
Association.

About SCAI

Headquartered in Washington, DC, the Society for Cardiovascular
Angiography and Interventions is a 4,000-member professional organization
representing invasive and interventional cardiologists in over 60 nations.
SCAI's mission is to promote excellence in invasive and interventional
cardiovascular medicine through physician education and representation, and
advancement of quality standards to enhance patient care. SCAI's annual
meeting has become the leading venue for education, discussion, and debate
about the latest developments in this dynamic medical specialty.

About ACC

The American College of Cardiology is leading the way to optimal
cardiovascular care and disease prevention. The College is a 34,000-member
nonprofit medical society and bestows the credential Fellow of the American
College of Cardiology upon physicians who meet its stringent
qualifications. The College is a leader in the formulation of health
policy, standards and guidelines, and is a staunch supporter of
cardiovascular research. The ACC provides professional education and
operates national registries for the measurement and improvement of quality
care.





See Also

• Non-Invasive Measurement of Heart Muscle Contractility Provide Best Predictor of Survival after Aortic Valve Replacement
• Female Body Building Pictures
• Hardcore Body Building
• Body Building

Via: Healthcare