March 21, 2002
ATLANTA, Georgia (ACC) -- In patients
undergoing stent procedures, glycoprotein IIb/IIIa inhibitors
have been shown to reduce the risk of immediate complications
and improve patient outcomes. However, not yet established is
the relative safety and efficacy of different IIb/IIIa agents
and whether the acuity of the presenting clinical syndrome,
which may affect the degree of platelet inhibition required or
achieved, influences the response to different anti-platelet
The Do Tirofiban and ReoPro Give Similar Efficacy Trial, or
TARGET, may shed some light on this issue. In the trial,
patients who needed stenting as a result of an acute coronary
syndrome (ACS) were significantly less likely to experience a
heart attack within 30 days and six months if they were treated
initially with abciximab vs. tirofiban.
The trial randomized 4,809 patients undergoing PCI with stenting
to either abciximab or tirofiban. Of these, 3,025 had ACS and
1,784 were non-ACS patients. In particular, said TARGET lead
researcher Gregg W. Stone, MD, of the Lenox Hill Heart and
Vascular Institute, New York, abciximab proved to be more
effective than tirofiban in reducing the combined endpoint of
death, myocardial infarction (MI), and urgent target vessel
revascularization (TVR) 30 days after stenting. The 30-day
composite incidence of death, MI, or urgent TVR in ACS patients
occurred in 6.3 percent of patients given abciximab vs. 9.3
percent given tirofiban. Those percentages were 5.6 and 4.5
percent, respectively, in non-ACS patients. Dr. Stone presented
his findings at a press conference Sunday.
By six months, 15.1 percent of ACS patients on abciximab vs.
17.6 percent of ACS patients on tirofiban experienced death, MI,
or any TVR. For non-ACS patients, the percentages were 13
percent and 10.2 percent, respectively. The TARGET trial,
published last November in The New England Journal of Medicine,
showed no apparent difference in mortality with either inhibitor
at 30 days, six months, or one year.
In terms of specific events, ACS patients treated with abciximab
undergoing stent implantation had lower 30-day (5.8 percent vs.
8.5 percent, respectively) and six-month (7.1 percent vs. 9.6
percent, respectively) rates of MI than ACS patients with
tirofiban. However, survival was identical, said Dr. Stone. For
ACS patients, 0.5 percent on abciximab and 1.1 percent on
tirofiban experienced urgent TVR vs. 0.9 percent and 0.5 percent
of non-ACS patients, respectively.
For Dr. Stone, the potency of these IIb/IIIa inhibitors have
far-reaching implications. “These data raise important issues
regarding the relative pharmacocdynamic potency of IIb/IIIa
inhibition required in varying clinical scenarios,” he said, “as
well as having important implications for cost-effective
utilization of IIb/IIIa inhibitors.”