Intralesional versus intracoronary administration of glycoprotein IIb/IIIa inhibitors during percutaneous coronary intervention in patients with acute coronary syndromes: A meta-analysis of randomized controlled trials.

BACKGROUND: Glycoprotein IIb/IIIa inhibitors (GPIs) have been regarded as an adjuvant regimen to deal with no-reflow. However, whether intralesional (IL) administration of GPIs improves myocardial reperfusion without increasing bleeding in patients with acute coronary syndrome (ACS) compared with intracoronary (IC) administration has not been well addressed. Our meta-analysis aimed to evaluate the efficacy and safety of IL versus IC administration of GPIs for patients with ACS during percutaneous coronary intervention. METHODS: We systematically searched Medline, Embase, the Cochrane Central Register of Controlled Trials, and Cambridge Scientific Abstracts from January 2007 to May 2017. Thrombolysis in Myocardial Infarction (TIMI) 3 flow, corrected TIMI frame count (CTFC), and complete ST-segment resolution (>70%) were selected as the primary outcomes. Major adverse cardiac events (MACEs) were the secondary outcome, and major bleeding complications were the safety outcome. Data analysis was conducted using the Review Manager 5.3 software. RESULTS: Six randomized controlled trials were included in our meta-analysis. Compared with IC, IL obtained better results in terms of TIMI grade 3 flow [odds ratio (OR) 2.29; 95% confidence intervals (CIs) 1.31-4.01; P = .004], CTFC [weighted mean difference (WMD) -4.63; 95% CI -8.82 to -0.43; P = .03], and complete ST-segment resolution (OR 1.55; 95% CI 1.12-2.14; P = .008). There was a trend toward decreased MACE in the IL administration groups, which was not of statistical significance (OR 0.63; 95% CI 0.30-1.31; P = .22). No significant difference was found between the two groups in terms of in-hospital major bleeding events (OR 2.52; 95% CI .66 to 9.62; P = .18). CONCLUSION: IL administration yielded favorable outcomes in terms of myocardial tissue reperfusion as evidenced by the improved TIMI flow grade, CTFC, complete ST-segment resolution, and decreased MACE without increasing in-hospital major bleeding events. The IL administration of GPIs can be recommended as the preferred regimen to guard against no-reflow.

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.

Glycoprotein IIb/IIIa inhibitors: The resurgence of tirofiban.

Glycoprotein (GP) IIb/IIIa inhibitors block platelet aggregation, reducing thrombotic events in acute coronary syndrome. They are most often utilized in patients who likely have an intracoronary thrombus. Tirofiban, eptifibatide, and abciximab are the three GP IIb/IIIa inhibitors approved for use in the United States. Each agent has unique pharmacological properties. They all have a rapid onset and are most often utilized in conjunction with heparin. Tirofiban, in particular, fell out of favor due to inferior dosing with its original Food and Drug Administration (FDA) approved indication, but has re-emerged in the market with a high-dose bolus regimen that is considered equally as effective as the FDA approved dosing regimens of other GP IIb/IIIa inhibitors. This review looks at pharmacological properties of all three agents, significant clinical trials associated with their use, and their place in current guidelines.

Mechanism of action of antiplatelet drugs on decompression sickness in rats: a protective effect of anti-GPIIbIIIa therapy.

Literature highlights the involvement of disseminated thrombosis in the pathophysiology of decompression sickness (DCS). We examined the effect of several antithrombotic treatments targeting various pathways on DCS outcome: acetyl salicylate, prasugrel, abciximab, and enoxaparin. Rats were randomly assigned to six groups. Groups 1 and 2 were a control nondiving group (C; n = 10) and a control diving group (CD; n = 30). Animals in Groups 3 to 6 were treated before hyperbaric exposure (HBE) with either prasugrel (n = 10), acetyl salicylate (n = 10), enoxaparin (n = 10), or abciximab (n = 10). Blood samples were taken for platelet factor 4 (PF4), thiobarbituric acid reactive substances (TBARS), and von Willebrand factor analysis. Onset of DCS symptoms and death were recorded during a 60-min observation period after HBE. Although we observed fewer outcomes of DCS in all treated groups compared with the CD, statistical significance was reached in abciximab only (20% vs. 73%, respectively, P = 0.007). We also observed significantly higher levels of plasmatic PF4 in abciximab (8.14 ± 1.40 ng/ml; P = 0.004) and enoxaparin groups (8.01 ± 0.80 ng/ml; P = 0.021) compared with the C group (6.45 ± 1.90 ng/ml) but not CD group (8.14 ± 1.40 ng/ml). Plasmatic levels of TBARS were significantly higher in the CD group than the C group (49.04 ± 11.20 µM vs. 34.44 ± 5.70 µM, P = 0.002). This effect was prevented by all treatments. Our results suggest that abciximab pretreatment, a powerful glycoprotein IIb/IIIa receptor antagonist, has a strong protective effect on decompression risk by significantly improving DCS outcome. Besides its powerful inhibitory action on platelet aggregation, we suggest that abciximab could also act through its effects on vascular function, oxidative stress, and/or inflammation.

Three-year follow-up of the MULTIcentre evaluation of Single high-dose Bolus TiRofiban versus Abciximab with Sirolimus-eluting STEnt or Bare-Metal Stent in Acute Myocardial Infarction StudY (MULTISTRATEGY).

BACKGROUND: The Multicentre Evaluation of Single high-dose Bolus TiRofiban versus Abciximab with Sirolimus-eluting Stent or Bare Metal Stent in Acute Myocardial Infarction Study [MULTISTRATEGY]) randomised 745 patients with ST-elevation myocardial infarction to receive high-dose bolus (HDB) tirofiban or abciximab infusion and sirolimus-eluting (SES) or uncoated-stent (BMS) implantation. Tirofiban was non-inferior to abciximab in terms of ST-segment resolution after intervention, whereas 8 month-major adverse cardiac events occurred in 14.5% in the BMS and 7.8% in the SES groups (P = 0.0039), reflecting a reduction of reintervention rates (10.2% vs. 3.2%). A three-year follow-up was performed to extend previous short- to mid-term findings. METHODS AND RESULTS: Complete data at 3 years was available for 736 patients (99%). All-cause mortality was 6.7% in the tirofiban and 7.8% in the abciximab (P = 0.56) and 7.5% in the BMS vs 7.0 in the SES groups, P = 0.79. The composite of all-cause death or MI was identical at 12.9% in tirofiban and abciximab groups, P = 0.99 and it occurred in 13.2% in the BMS vs. 12.6% in the SES groups (P = 0.83). The need for reintervention remained more than twice as common with BMS (13.7%; versus 6.2%, P = 0.0006). The cumulative rate of stent thrombosis (ST) did not differ. This is inspite of a higher very late definite, probable or possible ST thrombosis rate in the SES group. CONCLUSIONS: The 3-year follow-up of MULTISTRATEGY demonstrated comparable outcomes with HDB Tirofiban or abciximab and a sustained efficacy of SES to reduce reintervention with no difference in death, repeat MI or ST.

Sex-specific benefits of sirolimus-eluting stent on long-term outcomes in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention: insights from the Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study trial.

OBJECTIVES: We assessed the relation between female sex and sirolimus-eluting stent (SES) use on long-term outcomes in acute myocardial infarction. BACKGROUND: There are no data on sex-specific differences in long-term benefit of SES use compared with bare-metal stent (BMS) use among patients undergoing primary percutaneous coronary interventions. METHODS: We performed a post hoc analysis of the MULTISTRATEGY trial. Hazard ratios (HRs) of events with 95% CI for sex and stent type were computed using Cox proportional regression with adjustment for confounders. RESULTS: A total of 744 patients, 64 years old (55-73 years old), 179 (24.1%) women, were enrolled. After a follow-up of 1,080 days, SES use was associated with a significant reduction of major adverse cardiovascular events, that is, the composite of all-cause death, reinfarction, or clinically driven target vessel revascularization (TVR) (13.9% vs 23.6%, adjusted HR 0.62, 95% CI 0.41-0.94, P = .026) and of TVR (6.1% vs 15.1%, adjusted HR 0.35, 95% CI 0.19-0.63, P < .001) in men. Conversely, SES use was not associated to a better outcome among women (major adverse cardiovascular events 21.9% in SES vs 18.2% in the BMS group, adjusted HR 1.27, 95% CI 0.53-3.02, P = .59; TVR 6.6% vs 9.1%, adjusted HR 0.62, 95% CI 0.17-2.21, P = .46). CONCLUSIONS: In this analysis, the clinical benefit of SES use, over BMS, at 3-year follow-up was restricted to men and was not observed among women.

Safety and efficacy of tirofiban as adjunctive therapy for patients with ST-elevation myocardial infarction: a comparison versus placebo and abciximab.

Tirofiban is a nonpeptide tyrosine derivative that together with eptifibatide (both small molecules) and abciximam belongs to the group of glycoprotein IIb/IIIa inhibitors. Though similar to abciximab in that it has a high affinity for the GP IIbIIIa inhibitor receptor, tirofiban dissociates from it much faster tan abciximab, what makes its action reversible in a few hours. Initially used upstream for treatment of patients with non ST-elevation acute coronary síndromes, recent evidence has shown its role as adjuntive therapy in patients with ST-elevation acute myocardial infarction treated with primary angioplasty when used at a higher dose. In this article, we performed a thorough and systematic review of randomized trials comparing tirofiban versus pacebo and tirofiban versus abciximab when used in this subset of patients. All these studies showed tirofiban to be a well tolerated and effective IIbIIIa inhibitor. When compared with placebo, tirofiban was associated with a significant reduction in mortality and myocardial infarction at one month, with a higher risk of minor bleeding in the follow-up. When compared with abciximab, tirofiban showed no difference in mortality and a tendency to higher rate of the composite of death and myocardial infarction in the short term follow-up that disappeared when only studies with high-dose tirofiban were considered. On the basis of the high-dose regimen, tirofiban may be considered useful in the management of patients with ST-elevation myocardial infarction who undergo primary angioplasty.

A randomized two-by-two comparison of high-dose bolus tirofiban versus abciximab and unfractionated heparin versus bivalirudin during percutaneous coronary revascularization and stent placement: the tirofiban evaluation of novel dosing versus abciximab with clopidogrel and inhibition of thrombin (TENACITY) study trial.

BACKGROUND: In the absence of high-dose thienopyridines, placebo-controlled trials have demonstrated a reduction in ischemic events with intravenous glycoprotein IIb/IIIa antagonists during percutaneous coronary intervention (PCI). One head-to-head trial comparing abciximab and tirofiban among PCI patients found tirofiban to be inferior, and laboratory evidence confirmed that the bolus dose of tirofiban tested in that trial to be less effective than abciximab. Whether a higher bolus dose of tirofiban would be as efficacious as abciximab during PCI is uncertain. METHODS AND RESULTS: Patients undergoing PCI were randomized equally to abciximab or to tirofiban, given as high-dose bolus (25 µg/kg) plus 12-hr infusion (0.15 µg/kg/min). All patients received aspirin and clopidogrel and were additionally randomized to unfractionated heparin or bivalirudin. Approximately 8,000 patients were to be studied, but after 383 were enrolled, the study sponsor discontinued the trial for financial reasons. The primary endpoint of 30-day death, myocardial infarction, or urgent target vessel revascularization occurred in 8.8% of patients randomized to abciximab and 6.9% of those randomized to tirofiban. The respective rates of major bleeding were 1.5 and 1.6%. Additionally, the primary endpoint occurred in 8.1% of patients randomized to unfractionated heparin and 7.6% of those randomized to bivalirudin. The respective rates of major bleeding were 2.5% and 0.5%. CONCLUSION: With limited assessment, this direct comparison of high-dose bolus tirofiban versus abciximab produced encouraging results and suggests that further study of this tirofiban dose regimen is warranted. The limited assessments comparing heparin and bivalirudin are consistent with prior observations.

Profound delayed thrombocytopenia presenting 16 days after Abciximab (Reopro®) administration.

Abciximab occasionally causes severe thrombocytopenia. This is variable in severity and usually occurs within hours of administration but has been reported to present up to 8 days later. This report describes a case of life-threatening thrombocytopenia 16 days following Abciximab administration. The patient required supportive transfusions and ultimately improved following dexamethasone and intravenous immunoglobulin. The case represents the longest delay between Abciximab administration and thrombocytopenia published to date.

Persistent coronary no flow after wire insertion is an early and readily available mortality risk factor despite successful mechanical intervention in acute myocardial infarction: a pooled analysis from the STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) trials.

OBJECTIVES: These studies sought to investigate the impact on mortality of coronary flow after passage of the wire through the culprit vessel in patients with ST-segment elevation myocardial infarction (STEMI) undergoing mechanical reperfusion. BACKGROUND: Reduced spontaneous coronary flow before percutaneous coronary intervention influences mortality in patients with STEMI. Response to vessel wiring in patients with an occluded coronary artery before intervention might further discriminate outcomes irrespective of pre- and post-intervention coronary flow. METHODS: Data from the STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) trials were pooled: of 919 index procedures, 902 films (98%) were technically adequate for core laboratory TIMI (Thrombolysis In Myocardial Infarction) flow determination. RESULTS: TIMI flow grade 0 was present before percutaneous coronary intervention in 59% of infarct vessels, TIMI flow grade 1 to 2 was found in 21%, whereas the remainder of infarct arteries presented with TIMI flow grade 3. In 49% of patients who showed persistent TIMI flow grade 0 after wire insertion (AWI), mortality was higher at 30 days (5.3%) and 1 year (9.4%) compared with patients in whom TIMI flow grade before percutaneous coronary intervention was either >0 (0.8%; p < 0.003 and 3.6%, p < 0.008) or improved from 0 AWI (1.5%, p < 0.04 and 3.6%, p < 0.02). After correcting for multiple imbalances, including baseline and final flow, persistent TIMI flow grade 0 AWI remained associated at 30 days to 2-fold (risk ratio [RR]: 2.1, 95% confidence interval [CI]: 1.08 to 5.00; p = 0.038) and at 1 year to almost 3-fold increases of mortality (RR: 2.7, 95% CI: 1.3 to 5.6; p = 0.008). CONCLUSIONS: STEMI patients displaying persistent no-flow AWI have a lower survival rate despite an apparently successful mechanical intervention. As an early marker for high residual mortality risk, persistent no-flow AWI may qualify STEMI patients for dedicated pharmacomechanical treatment strategies.

Prediction of 1-year clinical outcomes using the SYNTAX score in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: a substudy of the STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) trials.

OBJECTIVES: This study sought to evaluate the impact of SYNTAX score (SXscore), and compare its performance in isolation and combination with the PAMI (The Primary Angioplasty in Myocardial Infarction Study) score, for the prediction of 1-year clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention. BACKGROUND: Patients with STEMI were excluded from the original SYNTAX score (SXscore) algorithm. Therefore, the utility of using the SXscore in this patient group remains undefined. METHODS: SXscore was calculated retrospectively in 807 patients with STEMI enrolled in the randomized STRATEGY (Single High-Dose Bolus Tirofiban and Sirolimus-Eluting Stent Versus Abciximab and Bare-Metal Stent in Acute Myocardial Infarction) and MULTISTRATEGY (Multicenter Evaluation of Single High-Dose Bolus Tirofiban Versus Abciximab With Sirolimus-Eluting Stent or Bare-Metal Stent in Acute Myocardial Infarction Study) clinical trials. Clinical outcomes of all-cause death, reinfarction, and clinically driven target vessel revascularization were subsequently stratified according to SXscore tertiles: SX(LOW) ≤ 9 (n = 311), 9 < SX(MID) ≤ 16 (n = 234), SX(HIGH) >16 (n = 262). RESULTS: At 1-year follow-up, all clinical outcomes including mortality, mortality/reinfarction, major adverse cardiac events (MACE) (a composite of all-cause death, reinfarction and target vessel revascularization), and definite, definite/probable, and any stent thrombosis were all significantly higher in patients in the highest SXscore tertile. SXscore was identified as an independent predictor of mortality, MACE, and stent thrombosis out to 1-year follow-up. The combination SYNTAX-PAMI score led to a net reclassification improvement of 15.7% and 4.6% for mortality and MACE, respectively. The C-statistics for the SXscore, PAMI score, and the combined SYNTAX-PAMI score were 0.65, 0.81, and 0.73 for 1-year mortality, and 0.68, 0.64, and 0.69 for 1-year MACE, respectively. CONCLUSIONS: SXscore does have a role in the risk stratification of patients with STEMI having primary percutaneous coronary intervention; however, this ability can be improved through a combination with clinical variables. (Multicentre 2×2 Factorial Randomised Study Comparing Tirofiban Versus Abciximab and SES Versus BMS in AMI; NCT00229515).

Tirofiban as adjunctive therapy for acute coronary syndromes and percutaneous coronary intervention: a meta-analysis of randomized trials.

AIMS: To perform a thorough and updated systematic review of randomized clinical trials comparing tirofiban vs. placebo or vs. abciximab. METHODS AND RESULTS: We searched for randomized trials comparing tirofiban vs. placebo or any active control. Odds ratios (OR) were computed from individual studies and pooled with random-effect methods. Thirty-one studies were identified involving 20,006 patients (12 874 comparing tirofiban vs. heparin plus placebo or bivalirudin alone, and 7132 vs. abciximab). When compared with placebo, tirofiban was associated at 30 days with a significant reduction in mortality [OR = 0.68 (0.54-0.86); P = 0.001] and death or myocardial infarction (MI) [OR = 0.69 (0.58-0.81); P < 0.001]. The treatment benefit persisted at follow-up but came at an increased risk of minor bleedings [OR = 1.42 (1.13, 1.79), P = 0.002] or thrombocytopenia. When compared with abciximab, mortality at 30 days did not differ [OR = 0.90 (0.53, 1.54); P = 0.70], but in the overall group tirofiban trended to increase the composite of death or MI [OR = 1.18 (0.96, 1.45); P = 0.11]. No such trend persisted at medium-term follow-up or when appraising studies testing tirofiban at 25 microg/kg bolus regimen. CONCLUSION: Tirofiban administration reduces mortality, the composite of death or MI and increases minor bleedings when compared with placebo. An early ischaemic hazard disfavouring tirofiban was noted when compared with abciximab in studies based on 10 but not 25 microg/kg tirofiban bolus regimen.

Benefits from small molecule administration as compared with abciximab among patients with ST-segment elevation myocardial infarction treated with primary angioplasty: a meta-analysis.

OBJECTIVES: The aim of the study was to perform a meta-analysis of randomized trials (RTs) comparing abciximab versus small molecules (eptifibatide and tirofiban) in primary angioplasty (PPCI) for ST-segment elevation myocardial infarction (STEMI). BACKGROUND: Abciximab has been shown to provide significant benefits in PPCI for STEMI. However, small molecules represent an attractive strategy due to the reversibility of the inhibition of platelet aggregation and the lower costs. METHODS: We obtained results from RTs comparing abciximab versus small molecules in PPCI. The literature was scanned by searches of electronic databases (MEDLINE and CENTRAL) up to October 2008. The following key words were used: RT, myocardial infarction, reperfusion, primary angioplasty, glycoprotein IIb/IIIa inhibitors, abciximab, tirofiban, and eptifibatide. Concerning tirofiban, we only included trials or groups of patients with high-dose bolus and infusion. The primary end point was 30-day mortality. Secondary end points were 30-day reinfarction, post-procedural Thrombolysis In Myocardial Infarction (TIMI) flow grade 3, and ST-segment resolution. RESULTS: A total of 6 RTs were included in the meta-analysis, involving 2,197 patients (1,082 randomized to abciximab and 1,115 to small molecules [high-dose tirofiban in 5 trials and eptifibatide in 1 trial]). Abciximab did not improve post-procedural TIMI flow grade 3 (89.8% vs. 89.1%, p = 0.72) or ST-segment resolution (67.8% vs. 68.2%, p = 0.66). Abciximab did not reduce 30-day mortality (2.2% vs. 2.0%, p = 0.66) or reinfarction (1.2% vs. 1.2%, p = 0.88), nor was there any difference in major bleeding complications (1.3% vs. 1.9%, p = 0.27). CONCLUSIONS: This meta-analysis shows among STEMI patients undergoing PPCI similar results between abciximab and small molecules in terms of angiographic, electrocardiographic, and clinical outcome.

Left ventricular function after ST-elevation myocardial infarction in patients treated with primary percutaneous coronary intervention and abciximab or tirofiban (from the Facilitated Angioplasty with Tirofiban or Abciximab [FATA] Trial).

Abciximab therapy during primary percutaneous coronary intervention (PCI) has shown to ameliorate left ventricular (LV) function recovery in patients with ST elevated myocardial infarction. High-dose bolus tirofiban has similar effect on platelet inhibition. Whether this is associated with comparable efficacy on LV function recovery remains unclear. We sought to evaluate the impact on LV function of high-dose bolus tirofiban or abciximab in patients undergoing primary PCI with the predictors of favorable (> or = 50%) LV ejection fraction (EF) and LV function recovery at 30 days. We studied 314 patients (abciximab n = 154; tirofiban n = 160) undergoing primary PCI in the randomized Facilitated Angioplasty with Tirofiban or Abciximab (FATA) Trial. LVEF was assessed within 48 hours and at 30 days after primary PCI. In patients with systolic dysfunction at baseline, LV function recovery was defined by either increase of LVEF > or = 10% compared with baseline or LVEF > or = 50%. Similar LVEF was observed in the 2 groups postprocedure (abciximab 49.7 +/- 10.1% vs tirofiban 49.3 +/- 10.1%, p = 0.9) and at 30 days (abciximab 53.1 +/- 9.8% vs tirofiban 52.5 +/- 10.2%, p = 0.6). Independent predictors of 30-day LVEF > or = 50% were preprocedure Thrombolysis In Myocardial Infarction flow class >0 (odds ratio = 2.4, 95% confidence interval 1.32 to 4.34), anterior location (odds ratio = 0.25, 95% confidence interval 0.15 to 0.42), and age (odds ratio = 0.97, 95% confidence interval 0.95 to 0.99). Preprocedure Thrombolysis In Myocardial Infarction flow grade >0 was the only predictor of LV function recovery (odds ratio = 6.73, 95% confidence interval 2.69 to 16.88). In conclusion, this study showed no difference in LV function recovery in patients undergoing primary PCI treated either with abciximab or high-dose bolus tirofiban. Preprocedure Thrombolysis In Myocardial Infarction flow grade >0 seems to be the most important predictor of favorable LVEF and LV function recovery at 30 days.

Defining the role of platelet glycoprotein receptor inhibitors in STEMI: focus on tirofiban.

Tirofiban is a small molecule, nonpeptide tyrosine derivative. Although similar to abciximab in that it has a high specificity and affinity for the glycoprotein (GP) IIb/IIIa receptor, tirofiban dissociates from the GP IIb/IIIa receptor more rapidly than abciximab. Additionally, the action of tirofiban is reversed within hours after completion of the infusion, whereas abciximab binds irreversibly resulting in a considerably longer effect. The efficacy of tirofiban in ST-segment elevation myocardial infarction (STEMI) has been demonstrated when administered in patients being managed with primary percutaneous coronary intervention (PCI). These trials primarily studied tirofiban utilizing the high-dose bolus regimen (25 microg/kg bolus followed by a maintenance infusion of 0.15 microg/kg/min for 18-24 hours). The On-TIME (Ongoing Tirofiban in Myocardial Infarction Evaluation) 2 trial assessed early administration of the high-dose bolus regimen of tirofiban either at the referral centre or in the ambulance, in patients being transferred to a primary PCI centre. Early use of tirofiban resulted in both a significant increase in the rate of complete resolution of ST-segment deviation pre- and post-PCI, and improvement in clinical outcomes at 30 days. Moreover, the multi-factorial MULTISTRATEGY (Multicentre Evaluation of Single High-Dose Bolus Tirofiban vs Abciximab With Sirolimus-Eluting Stent or Bare Metal Stent in Acute Myocardial Infarction) trial, which compared the high-dose bolus regimen of tirofiban with standard dose administration of abciximab administered immediately prior to PCI, revealed similar effects on myocardial perfusion, ST-segment elevation recovery and clinical outcomes between the two agents, and confirmed the safety of tirofiban when used in combination with drug-eluting stents in patients with STEMI undergoing primary PCI. These studies showed tirofiban to be a well tolerated and effective GP IIb/IIIa inhibitor. On the basis of the demonstrated benefits of the high-dose bolus regimen, tirofiban may be considered useful in the management of patients with STEMI.

Randomized comparison between tirofiban and abciximab to promote complete ST-resolution in primary angioplasty: results of the facilitated angioplasty with tirofiban or abciximab (FATA) in ST-elevation myocardial infarction trial.

AIMS: To test the equivalence of high-dose bolus (HDB) tirofiban vs. abciximab during primary percutaneous coronary intervention (PPCI) in terms of ST-segment resolution (STR). METHODS AND RESULTS: The FATA trial (Facilitated Angioplasty with Tirofiban or Abciximab) was a prospective, multicentre, open-label trial that enrolled 692 patients with ST-segment elevation myocardial infarction (STEMI) undergoing PPCI. Patients were randomized 1:1 to receive abciximab (n = 341) or HDB tirofiban (n = 351). Primary endpoint was the rate of complete (> or =70%) STR 90 min after first balloon inflation. Thirty-day incidence of major bleedings, death, re-infarction and new revascularizations was also evaluated. Baseline characteristics of the two groups were well-balanced, with the exception of previous MI rates (tirofiban 6% vs. abciximab 2.6%, P = 0.03). The procedure was successful in 96.7% of the abciximab and in 96.6% of the tirofiban cohort (P = 0.94). Complete STR was obtained in 67.05% of the tirofiban and 70.45% of the abciximab group (Delta -3.4%, 95% confidence interval -10.35 to +3.56), which falls beyond the predefined Delta +/- 10% equivalence boundaries. Rates of secondary endpoints were similar between the two groups. CONCLUSION: This study failed to show the equivalence of HBD of tirofiban and abciximab as adjunctive therapy to PPCI.

Comparison of angioplasty with infusion of tirofiban or abciximab and with implantation of sirolimus-eluting or uncoated stents for acute myocardial infarction: the MULTISTRATEGY randomized trial.

CONTEXT: Abciximab infusion and uncoated-stent implantation is a complementary treatment strategy to reduce major adverse cardiac events in patients undergoing angioplasty for ST-segment elevation myocardial infarction (STEMI). It is uncertain whether there may be similar benefits in replacing abciximab with high-dose bolus tirofiban. Similarly, the use of drug-eluting stents in this patient population is currently discouraged because of conflicting results on efficacy reported in randomized trials and safety concerns reported by registries. OBJECTIVE: To evaluate the effect of high-dose bolus tirofiban and of sirolimus-eluting stents as compared with abciximab infusion and uncoated-stent implantation in patients with STEMI undergoing percutaneous coronary intervention. DESIGN, SETTING, AND PATIENTS: An open-label, 2 x 2 factorial trial of 745 patients presenting with STEMI or new left bundle-branch block at 16 referral centers in Italy, Spain, and Argentina between October 2004 and April 2007. INTERVENTIONS: High-dose bolus tirofiban vs abciximab infusion and sirolimus-eluting stent vs uncoated stent implantation. MAIN OUTCOME MEASURES: For drug comparison, at least 50% ST-segment elevation resolution at 90 minutes postintervention with a prespecified noninferiority margin of 9% difference (relative risk, 0.89); for stent comparison, the rate of major adverse cardiac events, defined as the composite of death from any cause, reinfarction, and clinically driven target-vessel revascularization within 8 months. RESULTS: ST-segment resolution occurred in 302 of 361 patients (83.6%) who had received abciximab infusion and 308 of 361 (85.3%) who had received tirofiban infusion (relative risk, 1.020; 97.5% confidence interval, 0.958-1.086; P < .001 for noninferiority). Ischemic and hemorrhagic outcomes were similar in the tirofiban and abciximab groups. At 8 months, major adverse cardiac events occurred in 54 patients (14.5%) with uncoated stents and 29 (7.8%) with sirolimus stents (P = .004), predominantly reflecting a reduction of revascularization rates (10.2% vs 3.2%). The incidence of stent thrombosis was similar in the 2 stent groups. CONCLUSIONS: In patients with STEMI undergoing percutaneous coronary intervention, compared with abciximab, tirofiban therapy was associated with noninferior resolution of ST-segment elevation at 90 minutes following coronary intervention, whereas sirolimus-eluting stent implantation was associated with a significantly lower risk of major adverse cardiac events than uncoated stents within 8 months after intervention. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00229515.

Real-time monitoring of adhesion and aggregation of platelets using thickness shear mode (TSM) sensor.

Hemostasis is required to maintain vascular system integrity, but thrombosis, formation of a clot in a blood vessel, is one of the largest causes of morbidity and mortality in the industrialized world. Novel clinical and research tools for characterizing the hemostatic system are of continued interest, and the object of this research is to test the hypothesis that clinically relevant platelet function can be monitored using an electromechanical sensor. A piezoelectric thickness shear mode (TSM) biosensor coated with collagen-I fibers to promote platelet activation and adhesion was developed and tested for sensitivity to detect these primary events. Magnitude and frequency response of the sensor were monitored under static conditions at 37 degrees C, using platelet-rich plasma (PRP), and PRP with adenosine diphosphate (ADP), a clinical aggregation inhibitor (abciximab), or a collagen binding inhibitor. Sensors loaded with PRP exhibited a 3-stage response; no significant change in response for the first 20 min (Stage-1), followed by a larger drop in response (Stage-2) and subsequently, response gradually increased (Stage-3). Exogenous ADP stimulated an immediate Stage-2 response, while abciximab delayed and reduced the magnitude change of Stage-2. In the presence of collagen inhibitor, Stage-2 response was similar to that of control but was delayed by an additional 20 min. The obtained results, supported by epifluorescence and complementary SEM studies, demonstrated the selective sensitivity of TSM electromechanical biosensors to monitor platelet function and inhibition, particularly aggregation.

A novel anti-ischemic nitric oxide donor (LA419) reduces thrombogenesis in healthy human subjects.

BACKGROUND: Platelet and endothelial production of nitric oxide (NO) is known to be impaired in coronary artery disease patients. Compounds that release NO (e.g. nitrates) have antiplatelet effects, but at supratherapeutic doses with hypotensive side effects. OBJECTIVES: To investigate the antithrombotic effect on human blood of a novel NO donor (LA419) with known anti-ischemic properties but without hypotensive side effects and to compare with abciximab. PATIENTS/METHODS: Healthy subjects (n = 8; 32 +/- 3 years) received daily aspirin starting three days prior to the study day. Treatments (LA419 10 and 20 microm, and abciximab 4 microm) were added ex vivo to non-anticoagulated blood, and the antithrombotic properties were assessed by measuring changes in thrombus size from pretreatment baseline in the Badimon perfusion chamber at low and high shear rates. Platelet surface adhesion using a Cone and Platelet Analyzer (CPA) and platelet fibrinogen-receptor activation with flow cytometry were also evaluated. RESULTS: At low shear rates, LA419 displayed a reduction in thrombus area of 43% +/- 8% (10 microm) and 56% +/- 6% (20 microm), whereas at high shear rates the reductions were 44% +/- 3% (10 microm) and 62% +/- 6% (20 microm). Platelet surface adhesion with the CPA was also reduced. Abciximab exhibited a strong inhibitory effect on thrombus formation, platelet surface adhesion and fibrinogen receptor activation. CONCLUSIONS: The novel NO donor, LA419, shows a strong antithrombotic effect in human blood, which is comparable to abciximab, especially under high shear rate conditions. Our observations suggest that the availability of an NO donor could prove beneficial in the prevention of thrombotic complications of cardiovascular disease. Further clinical studies are warranted.