Platelet glycoprotein IIb/IIIa blockers for percutaneous coronary intervention and the initial treatment of non-ST segment elevation acute coronary syndromes

  • Review
  • Intervention

Authors


Abstract

Background

During percutaneous coronary intervention (PCI), and in non-ST segment elevation acute coronary syndromes (NSTEACS), the risk of acute vessel occlusion by thrombosis is high. Glycoprotein (GP) IIb/IIIa blockers inhibit platelet aggregation and may prevent mortality and myocardial infarction (MI).

Objectives

To assess the efficacy and safety of GP IIb/IIIa blockers when administered during PCI, and as initial medical treatment in patients with NSTEACS.

Search strategy

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 2 2006), MEDLINE (1966 to June 2006), and EMBASE (1980 to April 2006). Reference list of articles, and relevant conference proceedings were checked. No language restrictions were applied.

Selection criteria

Randomised controlled trials (RCTs) comparing intravenous GP IIb/IIIa blockers with placebo were sought.

Data collection and analysis

2713 publications were screened separately by two reviewers who assessed trial quality and extracted data.

Main results

A total of 38 RCTs with 58,495 patients were included in the review. During PCI, GP IIb/IIIa blockers decreased mortality at 30 days (OR 0.74, 95% CI 0.58 to 0.94) but not at 6 months (OR 0.87, 95% CI 0.73 to 1.03). Death or MI was decreased both at 30 days (OR 0.67, 95% CI 0.61 to 0.74), and at 6 months (OR 0.71, 95% CI 0.62 to 0.82), although severe bleeding was slightly increased (OR 1.38, 95% CI 1.19 to 1.60; absolute risk increase 8.6 per 1000). The results were homogeneous for every endpoint according to the clinical condition of the patients that were studied, but were more marked when a stent was implanted and less marked for patients pre-treated with clopidogrel. As initial medical treatment of NSTEACS, GP IIb/IIIa blockers did not decrease mortality at 30 days (OR 0.92, 95% CI 0.81 to 1.04) or at 6 months (OR 1.01, 95 % CI 0.88 to 1.16). However, death or MI was decreased at 30 days (OR 0.92, 95% CI 0.86 to 0.99) and at 6 months (OR 0.88, 95% CI 0.81 to 0.96), although severe bleeding was slightly increased (OR 1.27, 95% CI 1.12 to 1.44, absolute risk increase 1.2 per 1000).

Authors' conclusions

In patients submitted to PCI, intravenous GP IIb/IIIa blockers reduce the risk of death at 30 days and markedly that of death or MI at 30 days and 6 months at a price of a moderate increase in the risk of severe bleeding. These effects were homogeneous for patients with or without an acute coronary syndrome but seem to decrease when patients are pre-treated with clopidogrel. In contrast, when administered as initial medical treatment in patients with NSTEACS, these agents do not reduce mortality although they slightly reduce the risk of death or MI.

Plain language summary

Platelet glycoprotein IIb/IIIa blockers for percutaneous coronary intervention and the initial treatment of non-ST segment elevation acute coronary syndromes

During the last two decades, doctors have been looking for the best treatment to prevent clots in the coronary arteries of patients with heart disease. This review summarises the results of 38 studies which used a potent new class of antiplatelet drugs - glycoprotein IIb-IIIa blockers. This treatment was tested in two different conditions: in patients undergoing percutaneous coronary intervention (PCI) procedures (coronary angioplasty with or without stenting), and as the initial treatment of patients with acute coronary syndromes (unstable angina and non-ST segment elevation acute myocardial infarction).

Overall, the use of these drugs markedly reduced the risk of death or myocardial infarction at 30 days and 6 months in patients submitted to percutaneous coronary angioplasty or stent implantation. The results were similar for stable and for unstable patients with coronary artery disease, but there was comparatively less benefit for patients previously treated with clopidogrel, a new oral antiplatelet drug. Glycoprotein IIb/IIIa blockers only slightly reduced the risk of death or myocardial infarction when administered as initial medical treatment in patients with unstable angina or non-ST-elevation myocardial infarction. The benefits of glycoprotein IIb/IIIa blockers need to be balance against the slightly increased risk of severe bleeding.