Glycoprotein IIb/IIIa (Gp IIb/IIIa) inhibitors improve myocardial reperfusion
and clinical outcomes of patients undergoing primary percutaneous coronary
intervention (PCI), but optimal timing of administration remains unclear.
No systematic reviews have comprehensively examined the effects of early vs
delayed administration of these agents.
To perform a meta-analysis of randomized trials of early (prior to transfer
to the catheterization laboratory) vs late (at the time of PCI) intravenous
administration of Gp IIb/IIIa inhibitors in acute ST-segment elevation myocardial
MEDLINE and the Cochrane Controlled Trials Register search of the literature
over the past 10 years; papers presented at major cardiac conferences; consultation
with national and international colleagues as well as Gp IIb/IIIa inhibitor
drug manufacturers; and text and journal article bibliographies.
Study Selection and Data Extraction
We examined trials of randomized comparisons between early administration
at the point of initial contact (emergency department or ambulance) and late
administration (catheterization laboratory) of Gp IIb/IIIa inhibitors in STEMI.
Outcome data had to be available on both culprit artery patency evaluated
by Thrombolysis in Myocardial Infarction (TIMI) flow grades on admission and
mortality. Two authors independently reviewed abstracts or complete articles.
Six studies met inclusion criteria. Independent data extraction was performed
by 2 reviewers and confirmed by consensus.
The 6 trials enrolled 931 STEMI patients treated with abciximab (3 trials)
or tirofiban (3 trials) in combination with primary PCI. TIMI grade 2 or 3
flow (41.7% [194/465 vs 29.8% [139/466]) as well as TIMI grade 3 flow (20.3%
[84/413] vs 12.2% [51/418]) were significantly more frequent in the early
group compared with the late group (odds ratio [OR], 1.69; 95% confidence
interval [CI], 1.28-2.22; P<.001; and OR, 1.85;
95% CI, 1.26-2.71; P<.001, respectively). The
early administration of Gp IIb/IIIa inhibitors was associated with a 28% reduction
of mortality from 4.7% to 3.4%, which was not significant but consistent with
similar trends for reinfarction and the composite ischemic end point.
In a meta-analysis of 6 randomized trials, early administration of Gp
IIb/IIIa inhibitors in STEMI appeared to improve coronary patency with favorable
trends for clinical outcomes. These findings are supportive of a strategy
of facilitated PCI. Further evaluations in adequately powered large trials
are awaited to confirm the clinical benefit of this strategy.