A multicenter study of the tolerability of tirofiban versus placebo in patients undergoing planned intracoronary stent placement

A randomized trial assessing the impact of three different glycoprotein IIb/IIIa antagonists on glycoprotein IIb/IIIa platelet receptor inhibition and clinical endpoints in patients with acute coronary syndromes

AIMS

To compare three glycoprotein IIb/IIIa receptor antagonists (GPIs) in terms of platelet inhibition and major adverse cardiac events (MACEs), and assess the rate of bleeding and MACEs between GPIs and coadministered P2Y12 agents.

METHODS

Eighty-three acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) with planned GPI use were randomized to receive high-dose bolus tirofiban, double-bolus eptifibatide, or abciximab followed by a 12-hour infusion. Glycoprotein IIb/IIIa platelet receptor inhibition was measured at baseline and at 10 minutes, 1 hour, and 24 hours postbolus dose. Major adverse cardiac events and bleeding complications at 30 days were documented. The incidence of MACEs and bleeding in patients receiving ticagrelor or prasugrel were compared to those given clopidogrel.

RESULTS

There were no statistically significant differences in platelet inhibition between GPIs at 10 minutes (P=.085) and 1 hour (P=.337). At 24 hours, abciximab achieved statistically significantly higher median [interquartile range] platelet inhibition (75 [65-88]%) compared to tirofiban (28 [3-56]%; P<.0001) and eptifibatide (44 [31-63]%; P=.007). There were no differences in bleeding or MACEs depending on GPI or P2Y12 inhibitor administered.

CONCLUSIONS

Glycoprotein receptor inhibitors achieve similar levels of platelet inhibition at 10 minutes and 1 hour; however, abciximab maintains this benefit 24 hours after bolus dose. We did not witness an increased rate of bleeding in patients given new potent P2Y12 inhibitors and a GPI in the modern era.

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.

Would tirofiban have been shown non-inferior to abciximab had the TENACITY trial not been terminated for financial reasons?

OBJECTIVES

To investigate whether tirofiban would have been non-inferior to abciximab had the trial completed enrollment and place the termination of this trial in a broader research ethics context.

BACKGROUND

TENACITY was terminated by the sponsor for financial reasons. At the time, event rates for the 2 treatment arms were unknown.

METHODS

TENACITY was designed to compare tirofiban with abciximab in approximately 8,000 patients; however, enrollment was terminated after 383 (4.8%) patients. The primary end-point was a composite of 30-day death, myocardial infarction, and urgent target vessel revascularization. Non-inferiority was defined as the likelihood that tirofiban would preserve at least 50% of the ability of abciximab to reduce the primary end-point at 30 days, based on abciximab's demonstrated ability to reduce such events by 43% (relative risk, 0.573; 95% confidence interval [CI], 0.507-0.648; P < 0.001). To determine the probability of non-inferiority given the patients already enrolled, a Bayesian approach was used.

RESULTS

The primary composite end-point occurred in 8.8% of patients randomized to abciximab versus 6.9% receiving high-bolus-dose tirofiban (odds ratio, 0.77; 95% CI, 0.37-1.64). The estimated conditional power for the test that tirofiban would be non-inferior to abciximab if all patients been enrolled is 93.7%. Using the estimated predictive power method, the likelihood was 84.8%.

CONCLUSIONS

TENACITY was well powered to identify non-inferiority with tirofiban versus abciximab, and the patients enrolled strengthened the probability that this would have been the outcome had the trial been completed. When a clinical trial is terminated solely for financial reasons, it is incumbent upon the sponsor to provide proper patient follow-up and publication of the findings.

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.

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

OBJECTIVES

To assess the effects and safety of 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 3, 2009), MEDLINE (1966 to October 2009), and EMBASE (1980 to October 2009).

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. Odds ratios (OR) and 95% confidence intervals (CI) were used for effect measures.

MAIN RESULTS

Forty-eight trials involving 62,417 patients were included. During PCI, IIb/IIIa blockers decreased mortality at 30 days (OR 0.76, 95% CI 0.62 to 0.95) and at six months (OR 0.84, 95% CI 0.71 to 1.00). Death or MI was decreased both at 30 days (OR 0.65, 95% CI 0.60 to 0.72), and at 6 months (OR 0.70, 95% CI 0.61 to 0.81), although severe bleeding was increased (OR 1.38, 95% CI 1.20 to 1.59; 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 ACS.As initial medical treatment of NSTEACS, IIb/IIIa blockers did not decrease mortality at 30 days (OR 0.91, 95% CI 0.80 to 1.03) or at six months (OR 1.00, 95% CI 0.87 to 1.15), but slightly decreased death or MI at 30 days (OR 0.92, 95% CI 0.86 to 0.99) and at six months (OR 0.88, 95% CI 0.81 to 0.96), although severe bleeding was increased (OR 1.27, 95% CI 1.12 to 1.43; ARI 1.4 per 1000).

AUTHORS' CONCLUSIONS

When administered during PCI, intravenous IIb/IIIa blockers reduce the risk of death and of death or MI 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 ACS. 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.

Meta-analysis of clinical efficacy and bleeding risk with intravenous glycoprotein IIb/IIIa antagonists for percutaneous coronary intervention

OBJECTIVE

Percutaneous coronary intervention (PCI) has become the most common mode of coronary revascularization. Inhibition of platelet aggregation via glycoprotein (GP) IIb/IIIa receptor blockade significantly reduces the acute ischemic complications associated with PCI, but the risk of bleeding may also be increased with these agents. The purpose of the present study was to provide an up-to-date meta-analysis on the clinical efficacy and safety of intravenous GP IIb/IIIa antagonists in patients undergoing PCI.

METHODS

A comprehensive search was undertaken to identify all randomized trials of GP IIb/IIIa antagonists versus control in patients intended to undergo PCI. Medline, Embase, Biosis, HealthStar and hand searches were performed. The primary outcome was all-cause mortality. Secondary outcomes included myocardial infarction (MI), repeat revascularization, thrombocytopenia and bleeding. OR and their 95% CI were calculated using the random effects model.

RESULTS

Twenty-one randomized trials were identified, which together included 23,941 patients. The mortality rate at seven days was 0.33% in the GP IIb/IIa group compared with 0.50% in the control group (OR 0.70, 95% CI 0.29 to 1.68); at 30 days, the mortality rate was 0.83% versus 1.21%, respectively (OR 0.72, 95% CI 0.56 to 0.94); at six months, the mortality rate was 1.92% versus 2.33%, respectively (OR 0.85, 95% CI 0.68 to 1.07); and at one year, the mortality rate was 2.61% versus 3.32%, respectively (OR 0.80, 95% CI 0.64 to 1.00). The number needed to treat at 30 days to save one life was 296. The mortality benefit appeared to dissipate by six months and was of borderline significance at one year. The incidence of MI in the treatment group compared with the control group was reduced at seven days (4.31% versus 6.97%, respectively; OR 0.59, 95% CI 0.46 to 0.75), at 30 days (4.54% versus 6.46% respectively; OR 0.63, 95% CI 0.54 to 0.74) and at six months (5.73% versus 8.29%; OR 0.65, 95% CI 0.55 to 0.77). Repeat revascularization procedures were also significantly lower in the GP IIb/IIIa group compared with the control group at seven days (2.47% versus 4.44%, respectively; OR 0.43, 95% CI 0.29 to 0.84), at 30 days (3.44% versus 5.19%, respectively; OR 0.66, 95% CI 0.56 to 0.77) and at six months (15.21% versus 17.40%, respectively; OR 0.86, 95% CI 0.78 to 0.94). Overall, the composite of death, MI and repeat revascularization was reduced at all time points. An assessment of risk revealed that the incidence of thrombocytopenia (OR 1.41, 95% CI 1.10 to 1.81) and minor bleeding (OR 1.80, 95% CI 1.47 to 2.21), but not major bleeding (OR 1.29, 95 CI 0.98 to 1.68), was significantly increased in the GP IIb/IIIa group versus the control group.

CONCLUSIONS

Treatment with GP IIb/IIIa inhibitors in the setting of PCI significantly reduces the rates of 30-day mortality, MI and repeat revascularization procedures. These beneficial effects are achieved at an increased risk of thrombocytopenia and minor bleeding, but not major bleeding.

Comparison of abciximab with “high-dose” tirofiban in patients undergoing percutaneous coronary intervention

BACKGROUND

The TARGET study has been criticised for sub-optimal platelet inhibition with tirofiban. We aimed to compare a high-dose bolus regimen of tirofiban (hd-tirofiban) to standard dose of abciximab for patients undergoing percutaneous coronary intervention (PCI).

METHODS

We assessed consecutive patients who received either hd-tirofiban (25 mcg/kg bolus followed by 0.15 mcg/kg/min infusion for 18 h) or standard dose abciximab. In-hospital and 6-month outcomes were obtained in all cases.

RESULTS

Over an 18-month period, 109 patients who received hd-tirofiban were compared with 110 patients who received abciximab. Both hd-tirofiban and abciximab groups had acute coronary syndromes in 86% and 80% and diabetes in 10% and 13% respectively. Most patients had coronary stent implantation (96% vs. 98%). Thrombocytopenia (platelet count< 100,000) developed in 0.9% of patients receiving hd-tirofiban and 2% of patients receiving abciximab (p = 0.566). Bleeding requiring transfusion occurred in 7.3% and 3% of patients respectively (p = 0.118). Peri-procedural troponin rise was 0.9% in patients receiving hd-tirofiban and 5.5% in patients receiving abciximab (p = 0.07). MACE (Myocardial infarction, Stroke, Revascularisation and Death) at 6 months was 23% in the hd-tirofiban group and 20% in the abciximab group (p = 0.711). The pharmaceutical costs were AUD 322 for hd-tirofiban (one ampoule) and AUD 1,350 for abciximab (3 ampoules).

CONCLUSION

There was a small increase in bleeding requiring transfusion and a lower rate of peri-procedural troponin rise in the hd-tirofiban group however, the overall 6-month MACE rates were similar in both groups. There was a considerable cost-saving with the use of hd-tirofiban. A prospective randomised trial of hd-tirofiban vs. abciximab is warranted.

Single high-dose bolus tirofiban with high-loading-dose clopidogrel in primary coronary angioplasty

Glycoprotein IIb/IIIa inhibitor therapy during primary percutaneous coronary intervention (PCI) decreases the incidence of major adverse cardiac events. These effects directly result from the level of platelet inhibition. It was shown that standard dosing of tirofiban is insufficient for optimal platelet inhibition. We sought to determine the efficacy and safety of single high-dose bolus (HDB) tirofiban with high-dose clopidogrel loading in primary PCI in acute ST elevation myocardial infarction. A total of 100 patients (mean age 55.2 +/- 9.9 years, male/female = 86/14) undergoing primary PCI, pretreated with clopidogrel (450 mg) and aspirin (325 mg), were consecutively randomized into two groups. Group I (n = 50) received a standard dose bolus of tirofiban (10 microg/kg/3 min) with 24-h infusion at a rate of 0.15 microg/kg/min. Group II received single HDB tirofiban (25 microg/kg/3 min). The assessed angiographic, clinical, and echocardiographic endpoints were: initial and final Thrombolysis in Myocardial Infarction (TIMI) grade flow (TGF), corrected TIMI frame count (CTFC), ST-segment resolution (STR) at 90 min, in-hospital bleeding complications, echocardiographic left ventricular ejection fraction (LVEF), death, reinfarction, and repeat target vessel revascularization at 1 month. Platelet function inhibition was measured using PFA-100 (Behring-Dade, Liederbach, Germany) with a test cartridge unit containing a membrane coated with 2 microg of equine Type I collagen and 50 microg adenosine diphosphate before, and 10 min, 2, 4, 6, 12, and 24 h after the bolus of the tirofiban in the first 10 cases of each group. There were no significant differences in baseline characteristics between groups. Initial TGF III was more frequent (24% vs 8%, P = 0.029) and the value of CTFC was lower (75 +/- 34 vs 89 +/- 25, P = 0.03) in group II. Postprocedural TGF, CTFC, STR, bleeding complications, and LVEF at 1 month were not different between the two groups. There was a higher rate of reinfarction in group II (8%) compared with group I (2%), but this difference was not statistically significant (P > 0.05). The results of platelet function analyses showed that group II patients had significantly prolonged platelet function assay closure times (299 +/- 6 s) compared with group patients (236 +/- 97 s) at 10 min after the bolus dose (P = 0.04). However, after the first dose between 2 and 24 h, PFA closure times were significantly prolonged in patients with tirofiban infusion. High-dose bolus of tirofiban seems to be safe and more effective than conventional dose at the periprocedural time, whereas continuous infusion of tirofiban may be necessary in the first 24 h before stable and safe antiplatelet status is reached with clopidogrel. However, safety and efficacy of HDB tirofiban and high-loading-dose clopidogrel together with tirofiban infusion requires further studies with a larger population.

Comparison in patients having primary coronary angioplasty of abciximab versus tirofiban on recovery of left ventricular function

In patients treated with primary coronary angioplasty, the use of abciximab improves microvascular perfusion and enhances the recovery of contractile function. This study compared the effects of the new dose regimen of tirofiban (25-microg/kg bolus followed by an 18-hour infusion at 0.15 microg/kg/min) on left ventricular function with those of abciximab in patients who underwent direct angioplasty. One hundred patients who underwent primary coronary angioplasty were randomized to receive a standard dose of abciximab or a large-dose bolus of tirofiban. The primary end point of the study was change in the infarct-zone wall motion score index between the initial and 30-day follow-up echocardiographic studies. The secondary end points were procedural evaluations before and after Thrombolysis In Myocardial Infarction (TIMI) grade flow, TIMI grade myocardial perfusion, and corrected TIMI frame count. Baseline global and regional ventricular functions were similar in the 2 treatment groups. After the procedure, a TIMI grade 3 flow was obtained in 86% of patients treated with abciximab and 88% of those receiving tirofiban (p = 1.0), whereas TIMI grade 3 myocardial perfusion was present in 70% and 76%, respectively (p = 0.65); corrected TIMI frame count was 22.5 +/- 1.9 and 22.1 +/- 2.5 (p = 0.37). After 30 days, we obtained 87 paired echocardiographic studies. The infarct-zone wall motion score index decreased from 2.20 +/- 0.3 to 1.99 +/- 0.2 in the abciximab group and from 2.18 +/- 0.3 to 1.95 +/- 0.3 in the tirofiban group (p = 0.67). Thus, in patients who had primary coronary angioplasty, abciximab, and the large-dose bolus of tirofiban showed similar effects on the initial angiographic results and 30-day recovery of left ventricular function.

Safety of a high bolus dose of tirofiban in patients undergoing coronary stent placement

To overcome the suboptimal platelet inhibition induced by tirofiban in the first hour after a percutaneous coronary intervention, a new regimen of 25 microg/kg bolus followed by an 18-hr infusion of 0.15 microg/kg/min has been proposed. The aim of this study was to compare the effects of this high bolus dose of tirofiban with those of abciximab on bleeding risk and 30-day clinical outcome in patients undergoing coronary stenting. We compared two cohorts of patients who underwent coronary stent placement between January 2000 and December 2002. In the first cohort, the only available IIb/IIIa receptor inhibitor was abciximab, which was given to 280 (34.9%) out of 802 stented patients; in the second cohort, tirofiban was administered to 274 (38.3%) out of 716 treated patients. The primary endpoints were the proportion of patients with major bleeding and the rate of site access complications; the 30-day incidence of major adverse cardiac events (MACE) was also assessed. After the procedure, the patients were given ticlopidine for 4 weeks and aspirin indefinitely. Major bleeding episodes were observed in four patients receiving abciximab and in none receiving tirofiban (1.4% vs. 0%; P = 0.12); the rates of site access complications were similar (3.6% vs. 3.3%; P = 0.96). The 30-day incidence of MACE was 7.1% in the abciximab group and 5.8% in the tirofiban group (P = 0.65). In patients undergoing coronary stenting, the high bolus dose of tirofiban is safe and not associated with an increased risk of major bleeding or site access complications in comparison with abciximab.

Platelet glycoprotein IIb/IIIa blockers for percutaneous coronary revascularization, and unstable angina and non-ST-segment elevation myocardial infarction

BACKGROUND

During percutaneous coronary revascularisation (i.e. coronary angioplasty (PTCA) with or without stent implantation), and in unstable angina/non-ST-segment elevation myocardial infarction, the risk of acute vessel occlusion by thrombosis is high in spite of treatment with aspirin and heparin. GP IIb/IIIa antagonists inhibit platelet aggregation and may prevent mortality and myocardial infarction.

OBJECTIVES

To assess the efficacy and safety of GP IIb/IIIa blockers during percutaneous coronary revascularisation, and in patients with unstable angina/non-ST-segment elevation myocardial infarction.

SEARCH STRATEGY

We searched the Cochrane Library (issue 1, 2000), MEDLINE (1966 to June 2001), EMBASE (1980 to Nov 1999), reference list of articles, medical websites and handsearch among abstracts from cardiology congresses.

SELECTION CRITERIA

Randomized controlled trials comparing intravenous GP IIb/IIIa blockers with standard medical treatment during percutaneous coronary revascularisation, and in patients with unstable angina/non-ST-segment elevation myocardial infarction.

DATA COLLECTION AND ANALYSIS

A list of titles and abstracts was screened separately by two reviewers who assessed trial quality and extracted data.

MAIN RESULTS

Percutaneous coronary revascularisation: Fourteen trials involving 17,788 patients were included. GP IIb/IIIa blockers were associated with decreased mortality at 30 days (OR 0.71 (95% CI 0.52, 0.97)) but not at 6 months (OR 0.85 (0.66, 1.11)). Mortality or infarction was decreased both at 30 days (OR 0.62 (0.55, 0.70); ARR: 31 per 1,000), and at 6 months (OR 0.65 (0.58, 0.73); ARR: 38 per 1,000)), but severe bleeding was increased (10 per 1,000; OR 1.38 (1.04, 1.85)). Unstable angina/non-ST-segment elevation myocardial infarction: Eight trials involving 30,006 patients were included. GP IIb/IIIa blockers were not associated with decreased mortality at 30 days (OR 0.90 (0.80, 1.02)) or at 6 months (OR: 1.01 (0.88, 1.16)). Mortality or infarction was decreased at 30 days (OR 0.91 (0.85, 0.98); ARR: 13 per 1,000)) and at 6 months (OR 0,88 (0.81, 0.95); ARR: 13 per 1,000)), although severe bleeding was increased (1 per 1,000; OR 1.27 (1.12, 1.44)).

REVIEWER'S CONCLUSIONS

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 in patients submitted to percutaneous coronary revascularisation at a price of a moderate increased risk of severe bleeding. In contrast, in patients with unstable angina/non-ST-segment elevation myocardial infarction, these agents do not reduce mortality, only slightly reduce the risk of death or MI, and slightly increase the risk for severe bleeding.