Table 1 Outcomes definition by study included in the meta-analysis

Giri et al. [11]

Persistent systolic BP < 90 mmHg, not responsive to fluid resuscitation, or need for vasopressor agents to maintain a systolic BP > 90 mmHg, with evidence of pulmonary congestion and systemic signs of hypoperfusion.

Not applicable

All patients: aspirin and intravenous heparin. Abciximab was administered in the catheterization laboratory at the discretion of the operator: (0.25 mg/kg bolus followed by a 12-h infusion at 10 ug/min). All patients who received stents were maintained on ticlopidine (250 mg twice daily) or clopidogrel (75 mg once daily) plus aspirin (325 mg once daily) for 21 to 30 days.

Chan et al. [12]

Cardiac index ≤ 2.2 L/min/m² with left ventricular end-diastolic pressure > 18 mmHg or persistent (> 30 min) systolic BP > 80 mmHg associated with elevated neck veins

Not applicable

Not specified

Antoniucci et al. [13]

Systolic BP < 90 mmHg (without inotropic or intra-aortic balloon support) associated with signs of end-organ hypoperfusion. Confirmed by cardiac catheterization by systolic BP < 90 mmHg and left ventricular filling pressure > 20 mmHg.

Not specified

Abciximab was administered immediately before the procedure (0.25 mg/kg bolus followed by a 12-h infusion at 10 ug/min). Aspirin (325 mg/day indefinitely) and ticlopidine (500 mg/day for 1 month).

Tousek et al. [14]

At least one of the following criteria: (1) shock index > 1, i.e., sustained hypotension (systolic BP < 90 mmHg) and HR > 90/min; (2) organ hypoperfusion, cold, wet, sweating skin, and HR > 90/min; (3) the need for catecholamine support to maintain BP > 90/min; or (4) Killip class II–III and systolic BP < 120 mmHg

TIMI criteria as major bleeding (intracranial, overt bleeding with a decrease in hemoglobin > 5 g/l, or decrease in hematocrit > 15%)

All patients received standard antithrombotic and anticoagulant treatment during transport/ at the catheterization laboratory (heparin, aspirin and 300-600 mg of clopidogrel). Patients randomized to receive an intravenous bolus of 0.25 mg/kg abciximab after randomization (upfront administration), followed by the infusion of 0.125 μg/kg/min abciximab (maximum 10 μg/min) for 12 h

Bernat et al. [15]

Systolic BP ≤ 90 mmHg for at least 30 min, HR ≥ 60/min, signs of systemic hypoperfusion, or required inotropes to maintain a systolic BP ≥ 90 mmHg.

Not applicable.

Not specified.

Felice et al. [16]

Systolic BP < 90 mmHg for > 30 min or requiring inotropes to maintain systolic BP > 90 mmHg, evidence of low cardiac output with end organ hypoperfusion and signs of elevated filling pressure (e.g., pulmonary congestion on physical examination or chest X-ray).

Intracranial or clinically significant (drop in hemoglobin > 5 g/dl).

All patients were pre-treated with i.v. aspirin 300–500 mg and 300 or 600 mg clopidogrel. i.v. abciximab: pre-procedural bolus of 0.25 mg/kg followed by continuous infusion of 0.125 μg/kg/min for 12 h (up to a maximum dose of 10 ug/min). Aspirin (100 mg) indefinitely and clopidogrel (75 mg) daily for 6–12 months.

Kanic et al. [17]

Hypotension (systolic BP < 90 mmHg for > 30 min or the need for supportive measures to maintain systolic BP > 90 mmHg) and evidence of end-organ hypoperfusion.

Also included patients after CPR on admission.

According to TIMI bleeding criteria.

Aspirin 300–500 mg orally or 300 mg i.v. and a 300–600 mg clopidogrel were administered until 2011, after which 60 mg prasugrel or 180 mg ticagrelor were mostly used. Upstream administration of P2Y12 was at the discretion of the emergency physician.

GPI (eptifibatide or abciximab) use was at the discretion of the operator (not used upstream).