Context: Glycoprotein IIb/IIIa (Gp IIb/IIIa) inhibitors improve myocard ial rep erfusion and clinical outcomes of patients undergoing primary percutaneous coron ary intervention (PCI), but optimal timing of administration remains unclear. No systematic reviews have comprehensively examined the effects of early vs delaye d administration of these agents. Objective: To perform a meta-analysis of ra nd omized trials of early (prior to transfer to the catheterization laboratory) vs late (at the time of PCI) intravenous administration of Gp IIb/IIIa inhibitors i n acute ST-segment elevation myocardial infarction (STEMI). Data Sources: MEDLI NE 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 man ufacturers; and text and journal article bibliographies. Study Selection and Dat a Extraction: We examined trials of randomized comparisons between early adminis tration at the point of initial contact (emergency department or ambulance) and late administration (catheterization laboratory) of Gp IIb/IIIa inhibitors in ST EMI. Outcome data had to be available on both culprit artery patency evaluated b y Thrombolysis in Myocardial Infarction (TIMI) flow grades on admission and mort ality. Two authors independently reviewed abstracts or complete articles. Six st udies met inclusion criteria. Independent data extraction was performed by 2 rev iewers and confirmed by consensus. Data Synthesis: The 6 trials enrolled 931 STEMI patients treated with abciximab (3 trials) or tirofiban (3 trials) in combination with primary P CI. TIMI grade 2 or 3 flow (41.7%<<194/465 vs 29.8%<<139/466>>) as well as TIMI g rade 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 <>, 1.69; 95%con fidence interval <>, 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 ass ociated with a 28%reduction of mortality from 4.7%to 3.4%, which was not sign ificant but consistent with similar trends for reinfarction and the composite is chemic end point. Conclusions: 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 supporti ve of a strategy of facilitated PCI. Further evaluations in adequately powered l arge trials are awaited to confirm the clinical benefit of this strategy. Context: Glycoprotein IIb / IIIa (Gp IIb / IIIa) inhibitors improve myocard ial rep erfusion 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 delaye d administration of these agents. Objective: To perform a meta-analysis of ra nd omized 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 infarction (STEMI). Data Sources: MEDLI NE 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 man ufacturers; and text and journal article bibliographies. Study Selection and Dat a Extraction: We examined trials o f randomized comparisons between early adminisration at the point of initial contact (emergency department or ambulance) and late administration (catheterization laboratory) of Gp IIb / IIIa inhibitors in ST EMI. 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 contributors reviewed abstracts or complete articles. Six st udies met inclusion criteria. Independent data extraction was performed by 2 rev iewers and confirmed by consensus. Data Synthesis: The 6 trials enrolled 931 STEMI patients treated with abciximab (3 trials) or tirofiban (3 trials) in combination with primary P CI. TIMI grade 2 or 3 flow (41.7% << 194/465 vs 29.8% << 139/466 >>) as well as TIMI g rade 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% con fidence interval << CI >>, 1.28-2.22; P <.00The early administration of Gp IIb / IIIa inhibitors was associated with a 28% reduction of mortality from 4.7% to 3.4%, which is equivalent to 28% reduction in mortality from 1%; and OR, 1.85; 95% CI, 1.26-2.71; was not sign ificant but consistent with similar trends for reinfarction and the composite is chemic end point. Conclusions: In a meta-analysis of 6 randomized trials, early administration of Gp IIb / IIIa inhibitors in STEMI to improve coronary patency with favorable trends for clinical evaluations These findings are supportive of a strategy of facilitated PCI. Further evaluations in adequately powered energized trials are awaited to confirm the clinical benefit of this strategy.