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

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 IIb/IIIa blockers strongly inhibit platelet aggregation and may prevent mortality and myocardial infarction. This is an update of a Cochrane review first published in 2001, and previously updated in 2007 and 2010.

OBJECTIVES

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

SEARCH METHODS

We updated the searches of the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 12, 2012), MEDLINE (OVID, 1946 to January Week 1 2013) and EMBASE (OVID, 1947 to Week 1 2013) on 11 January 2013.

SELECTION CRITERIA

Randomised controlled trials comparing intravenous IIb/IIIa blockers with placebo or usual care.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion, assessed trial quality and extracted data. We collected major bleeding as adverse effect information from the trials. We used odds ratios (OR) and 95% confidence intervals (CI) for effect measures.

MAIN RESULTS

Sixty trials involving 66,689 patients were included. During PCI (48 trials with 33,513 participants) glycoprotein IIb/IIIa blockers decreased all-cause mortality at 30 days (OR 0.79, 95% CI 0.64 to 0.97) but not at six months (OR 0.90, 95% CI 0.77 to 1.05). All-cause death or myocardial infarction was decreased both at 30 days (OR 0.66, 95% CI 0.60 to 0.72) and at six months (OR 0.75, 95% CI 0.64 to 0.86), although severe bleeding was increased (OR 1.39, 95% CI 1.21 to 1.61; absolute risk increase (ARI) 8.0 per 1000). The efficacy results were homogeneous for every endpoint according to the clinical condition of the patients, but were less marked for patients pre-treated with clopidogrel, especially in patients without acute coronary syndromes.As initial medical treatment of NSTEACS (12 trials with 33,176 participants), IIb/IIIa blockers did not decrease mortality at 30 days (OR 0.90, 95% CI 0.79 to 1.02) or at six months (OR 1.00, 95% CI 0.87 to 1.15), but slightly decreased death or myocardial infarction at 30 days (OR 0.91, 95% CI 0.85 to 0.98) and at six months (OR 0.88, 95% CI 0.81 to 0.96), although severe bleeding was increased (OR 1.29, 95% CI 1.14 to 1.45; ARI 1.4 per 1000).

AUTHORS' CONCLUSIONS

When administered during PCI, intravenous glycoprotein IIb/IIIa blockers reduce the risk of all-cause death at 30 days but not at six months, and reduce the risk of death or myocardial infarction at 30 days and at six months, at a price of an increase in the risk of severe bleeding. The efficacy effects are homogeneous but are less marked in patients pre-treated with clopidogrel where they seem to be effective only in patients with acute coronary syndromes. 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 myocardial infarction.

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

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 IIb/IIIa blockers strongly inhibit platelet aggregation and may prevent mortality and myocardial infarction. This is an update of a Cochrane review first published in 2001, and previously updated in 2007 and 2010.

OBJECTIVES

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

SEARCH METHODS

We updated the searches of the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 12, 2012), MEDLINE (OVID, 1946 to January Week 1 2013) and EMBASE (OVID, 1947 to Week 1 2013) on 11 January 2013.

SELECTION CRITERIA

Randomised controlled trials comparing intravenous IIb/IIIa blockers with placebo or usual care.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion, assessed trial quality and extracted data. We collected major bleeding as adverse effect information from the trials. We used odds ratios (OR) and 95% confidence intervals (CI) for effect measures.

MAIN RESULTS

Sixty trials involving 66,689 patients were included. During PCI (48 trials with 33,513 participants) glycoprotein IIb/IIIa blockers decreased all-cause mortality at 30 days (OR 0.79, 95% CI 0.64 to 0.97) but not at six months (OR 0.90, 95% CI 0.77 to 1.05). All-cause death or myocardial infarction was decreased both at 30 days (OR 0.66, 95% CI 0.60 to 0.72) and at six months (OR 0.75, 95% CI 0.64 to 0.86), although severe bleeding was increased (OR 1.39, 95% CI 1.21 to 1.61; absolute risk increase (ARI) 8.0 per 1000). The efficacy results were homogeneous for every endpoint according to the clinical condition of the patients, but were less marked for patients pre-treated with clopidogrel, especially in patients without acute coronary syndromes.As initial medical treatment of NSTEACS (12 trials with 33,176 participants), IIb/IIIa blockers did not decrease mortality at 30 days (OR 0.90, 95% CI 0.79 to 1.02) or at six months (OR 1.00, 95% CI 0.87 to 1.15), but slightly decreased death or myocardial infarction at 30 days (OR 0.91, 95% CI 0.85 to 0.98) and at six months (OR 0.88, 95% CI 0.81 to 0.96), although severe bleeding was increased (OR 1.29, 95% CI 1.14 to 1.45; ARI 1.4 per 1000).

AUTHORS' CONCLUSIONS

When administered during PCI, intravenous glycoprotein IIb/IIIa blockers reduce the risk of all-cause death at 30 days but not at six months, and reduce the risk of death or myocardial infarction at 30 days and at six months, at a price of an increase in the risk of severe bleeding. The efficacy effects are homogeneous but are less marked in patients pre-treated with clopidogrel where they seem to be effective only in patients with acute coronary syndromes. 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 myocardial infarction.

Treatment with tirofiban for acute coronary syndrome (ACS): a systematic review and network analysis

OBJECTIVE

To assess the efficacy of tirofiban in comparison to usual care or other GPIIb/IIIa antagonists (eptifibatide and abciximab). Results were analysed by drug administration with planned percutaneous coronary intervention (PCI) or as medical management without planned PCI, and separately for STEMI or NSTE ACS patients.

RESEARCH DESIGN AND METHODS

A systematic review was performed of randomized controlled trials of tirofiban, abciximab, eptifibatide or usual care given to patients with acute coronary syndrome. Nine databases were searched up to March 2010. Pair-wise meta-analysis was used to combine all available direct comparisons; indirect comparisons and network analysis were performed when this was not possible. The primary outcome was MACE (major adverse cardiac event).

RESULTS

The search yielded 8, 119 records and 50 trials were included (total number of patients = 52,958). Compared to usual care, high and medium-dose tirofiban (25 and 10 µg/kg/min) administered with planned PCI reduced MACE at 30 days for patients with STEMI (RR 0.67, 95% CI 0.45, 0.99; RR 0.28, 95% CI 0.10, 0.80), but was not effective as a medical management. Medium-dose tirofiban (10 µg/kg/min) administered with planned PCI or low dose (0.4 µg/kg/min) as medical management reduced the risk of MACE for patients with NSTE ACS (RR 0.39, 95% CI 0.21, 0.75; RR 0.58, 95% CI 0.41, 0.83) in comparison to usual care, but at the expense of increased thrombocytopenia (RR 3.26, 95% CI 1.31, 8.13). Evidence from RCTs and network analysis indicated tirofiban and abciximab were equally effective and safe. Comparing tirofiban and eptifibatide treatment by indirect and network analysis produced inconclusive results.

CONCLUSIONS

Tirofiban was more effective than usual care for STEMI and NSTE ACS patients receiving planned PCI, and NSTE ACS patients receiving medical management. Tirofiban and abciximab were equally effective. Comparisons of tirofiban and eptifibatide were inconclusive.

Upstream use of small-molecule glycoprotein iib/iiia inhibitors in patients with non-ST-segment elevation acute coronary syndromes: a systematic overview of randomized clinical trials

BACKGROUND

The use of upstream small-molecule glycoprotein (GP) IIb/IIIa inhibitors in non-ST-segment elevation acute coronary syndromes (NSTE ACS) has been studied in multiple randomized clinical trials. We systematically reviewed the effect of upstream GP IIb/IIIa inhibitor use in NSTE ACS as reported in published clinical trials.

METHODS AND RESULTS

Randomized clinical trials of upstream small-molecule GP IIb/IIIa inhibitors in NSTE ACS were identified through a PubMed and EMBASE search and were included if they contained 30-day outcome data. Odds ratios were generated from the published data and pooled by means of random effects modeling. The primary outcome measures were 30-day death and 30-day death or myocardial infarction. Primary safety measures were major bleeding and transfusion during the index hospitalization. Twelve clinical trials were included, evaluating tirofiban, eptifibatide, and lamifiban. Of these, 7 evaluated upstream GP IIb/IIIa inhibitors versus placebo (n=24 031) and 5 evaluated a strategy of upstream GP IIb/IIIa inhibitors versus upstream placebo with later provisional use at the time of percutaneous coronary intervention (n=19 643). Overall, upstream GP IIb/IIIa inhibitor use was associated with an 11% reduction in 30-day death/myocardial infarction (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.83 to 0.95) but no significant mortality effect (OR, 0.93; 95% CI, 0.83 to 1.05). The risk of major bleeding was 23% higher in patients treated with upstream GP IIb/IIIa inhibitors (OR, 1.23; 95% CI, 1.02 to 1.48). Results were similar when only trials comparing upstream GP IIb/IIIa inhibitors versus placebo were considered: 30-day death/myocardial infarction (OR, 0.88; 95% CI, 0.81 to 0.95); 30-day death (OR, 0.89; 95% CI, 0.76 to 1.03); and major bleeding (OR, 1.17; 95% CI, 0.88 to 1.54). Upstream versus selective use at percutaneous coronary intervention trended toward lower 30-day death/myocardial infarction (OR, 0.91; 95% CI, 0.82 to 1.01) but had no effect on mortality (OR, 1.00; 95% CI, 0.81 to 1.23) and increased major bleeding risk by 34% (OR, 1.34; 95% CI, 1.10 to 1.63).

CONCLUSIONS

In NSTE ACS, treatment with upstream small-molecule GP IIb/IIIa inhibitors provides a significant but modest ischemic benefit when compared with initial placebo. Compared with delayed, selective use at percutaneous coronary intervention, early upstream use is associated with a trend toward fewer ischemic events. However, these modest benefits are associated with an increased risk of bleeding.

Meta-analysis of randomized trials of glycoprotein IIb/IIIa inhibitors in high-risk acute coronary syndromes patients undergoing invasive strategy

It is still unknown whether upstream administration of glycoprotein (Gp) IIb/IIIa inhibitors, aiming at cooling the culprit lesion before angioplasty, is superior to its selective downstream administration in high-risk patients with acute coronary syndromes (ACSs) undergoing coronary angioplasty. Therefore, the aim of the present study was to perform a meta-analysis of randomized trials comparing upstream to downstream administration of Gp IIb/IIIa inhibitors in high-risk patients with ACS undergoing early invasive strategy. We obtained results from all randomized trials on this issue. The literature was scanned by formal searches of electronic databases from January 1990 to March 2010. The following key words were used: "randomized trial," "myocardial infarction," "ACS," "coronary angioplasty," "upstream," "downstream," "Gp IIb/IIIa inhibitors," "abciximab," "tirofiban," and "eptifibatide." Primary and secondary clinical end points were mortality and myocardial infarction at 30 days, respectively. Major bleeding complications were assessed as a safety end point. Seven randomized trials were included in the meta-analysis, involving 19,929 patients (9,981 or 50.0% in the upstream Gp IIb/IIIa inhibitors group and 9,948 or 50% in the downstream Gp IIb/IIIa inhibitors group). Upstream Gp IIb/IIIa inhibitors did not decrease 30-day mortality (2.0% vs 2.0%, p = 0.84) or recurrence of myocardial infarction (7.0% vs 7.6%, p = 0.11) but were associated with higher risk of major bleeding complications (1.8% vs 1.3%, p = 0.0002). In conclusion, this meta-analysis shows that in high-risk patients with ACS undergoing an early invasive strategy, upstream administration of Gp IIb/IIIa inhibitors does not improve clinical outcome compared to a downstream selective administration, and it is associated with an increased risk of major bleeding complications. Therefore, a strategy of upstream Gp IIb/IIIa inhibitors cannot be recommended.

[Evaluation of a selective strategy for glycoprotein IIb/IIIa inhibitors administration in non-ST segment elevation acute coronary syndromes]

AIMS

We evaluated the impact of a selective strategy for glycoprotein IIb/IIIa inhibitors administration in non ST-segment elevation acute coronary syndrome.

PATIENTS AND METHOD

Between February 1st, 2007, and February 1st, 2009, 331 consecutive patients were prospectively included in the study. Criteria for upstream glycoprotein IIb/IIIa inhibitors administration were as follows: transient ST elevation greater than 1mm, ST-segment depression greater than 2mm, ischemic recurrence, TIMI risk score greater than 5. Global mortality and cardiovascular outcomes were assessed at Day 7 and Day 30.

RESULTS

The overall use of glycoprotein IIb/IIIa inhibitors was 16%. The procedure was successfully applied in 98%. Compared with non eligible patients (group 1, n = 254), eligible patients (group 2, n = 77) had a higher risk profile, median age: 73 versus 66, p < 0.01, TIMI risk score: 4 versus 3, p < 0.001. Eligible patients (66%) actually received the treatment. Among the 26 eligible but untreated patients, 19% had major bleeding risk, 34% had an unfavourable risk-benefit ratio and 34% were not suitable for an invasive strategy. Cardiovascular events occurred in 5.1% at Day 7 (Group 1, 1.6%), and 6.0% at Day 30 (group 1, 2.4%). Overall mortality at Day 30 was 1.2% (0.4% in Group 1).

CONCLUSION

A strategy for glycoprotein IIb/IIIa inhibitors administration in non ST-segment elevation acute coronary syndrome restricted to 4 very high risk situations may be considered, without evidence for a loss of chance in intermediate risk patients, untreated although eligible for treatment according to the current guidelines.