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 wi

Comparison of Ischemic and Bleeding Events Between Short-Duration Versus Long-Duration Tirofiban Regimens in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Percutaneous Coronary Intervention

ABSTRACT

Tirofiban has been used historically as a bridge to platelet inhibition with clopidogrel in ST-segment myocardial infarction (STEMI) during percutaneous coronary intervention (PCI) to prevent stent thrombosis. However, ticagrelor and prasugrel reach similar levels of platelet inhibition at 30 minutes to that of clopidogrel at 6 hours, challenging the need for long-duration tirofiban. This 1-year, retrospective cohort study compared ischemic and bleeding outcomes of short-duration versus long-duration tirofiban regimens in patients with STEMI who received ticagrelor or prasugrel at the time of PCI. The primary outcome was major adverse cardiovascular events (MACEs) including cardiovascular mortality, recurrent myocardial infarction, urgent target vessel revascularization, or stroke. Secondary outcomes included individual MACE, all-cause mortality, bleeding events defined by the International Society on Thrombosis and Hemostasis, thirty-day readmissions for MACE and bleeding, and tirofiban pharmacy cost. A total of 283 charts were reviewed and 177 included (short duration n = 57; long duration n = 120). MACE rates were similar between short-duration and long-duration groups (0 [0%] vs. 5 [4.2%]; P = 0.18), including 4 cardiovascular deaths and 1 recurrent myocardial infarction. Bleeding event rates were also similar in short-duration versus long-duration groups including major bleeds (2 [3.5%] vs. 2 [1.7%]; P = 0.60) and clinically relevant nonmajor bleeds (3 [5.3%] vs. 9 [7.5%]; P = 0.75). Cost analysis indicated lower pharmacy cost with the short-duration group. In this cohort of patients with STEMI receiving a fast-acting P2Y12 inhibitor, the length of tirofiban infusion did not affect ischemic or bleeding outcomes, yet short-duration regimens were lower cost.

Practicability of Bivalirudin plus Glycoprotein IIb/IIIa Inhibitors in Patients Undergoing Percutaneous Coronary Intervention: A Meta-Analysis

A variety of antithrombotic drugs are used during percutaneous coronary interventions (PCIs). We aimed to investigate the practicability of the use of bivalirudin and GPIs in patients receiving PCI. We searched 7 of 629 relevant records from PubMed, the Cochrane Library, EMBASE, and Web of Science for randomised controlled trials. There were no significant differences in the rates of major adverse cardiac events (MACE) between bivalirudin plus GPI and heparin (all P  >  .05). Bivalirudin plus planned GPI was similar to bivalirudin monotherapy in terms of the risk of MACE (risk ratio [RR] = 1.07; 95% confidence interval [CI] = .91 − 1.27; P = .55). Bivalirudin plus provisional GPI was associated with lower bleeding risk (RR = .57; 95% CI = .47 − .69; P < .01) compared to using heparin plus GPI. Compared to bivalirudin alone, bivalirudin plus planned GPI evidently increased bleeding risk (RR = 2.20; 95% CI = 1.73 − 2.79; P < .01). Patients receiving bivalirudin or heparin therapy had semblable efficacy endpoints, but those receiving bivalirudin had a significantly lower bleeding risk. For high-risk bleeding patients, bivalirudin plus provisional GPI can have a better antithrombotic effect than heparin, without increasing the bleeding risk.

Non-inferiority trials using a surrogate marker as the primary endpoint: An increasing phenotype in cardiovascular trials

BACKGROUND/AIMS

Non-inferiority trials are increasing in cardiovascular medicine, with approval of many drugs and devices on the basis of such studies. Surrogate markers as primary endpoints have been also more frequently used for efficient assessment of cardiovascular interventions. However, there is uncertainty about their concordance with clinical outcomes. Non-inferiority design using a surrogate marker as a primary endpoint may pose particular challenges in clinical interpretation. We sought to explore the publication trends, methodology, and reporting features of non-inferiority cardiovascular trials that used a primary surrogate marker as the primary endpoint.

METHODS

We searched six high-impact journals (The New England Journal of Medicine, The Journal of the American Medical Association, The Lancet, The Journal of the American College of Cardiology, Circulation, and European Heart Journal) from 1 January 1990 to 31 December 2018 and identified non-inferiority cardiovascular trials that used a surrogate marker as the primary endpoint. We assessed the non-inferiority margin reported in the manuscript and other publicly available platforms (e.g. protocol, clinicaltrials.gov). We also determined whether the included non-inferiority trials with surrogate markers as primary endpoints were followed by clinical outcome trials.

RESULTS

We screened 15,553 publications and identified 247 cardiovascular trials that used a non-inferiority design. Of these, 37 had a surrogate marker as a primary endpoint (18 drug trials, 13 device trials, 6 others). All of these non-inferiority trials with surrogate outcomes were published after 2000, mostly in cardiology journals (13 in The Journal of the American College of Cardiology, 9 in European Heart Journal, 8 in Circulation, 6 in The Lancet, 1 in The New England Journal of Medicine), and their publication rate increased over time (p < 0.001 for linear trend). The median number of patients in the primary analysis was 300 (interquartile range: 202-465). The study protocol or a methods paper was publicly available for only 13 (35.1%) trials, of which the non-inferiority margin was not reported in 4 trials. In 16 studies (43.2%), the manuscript did not acknowledge the limitations of using a surrogate endpoint or the need for a definitive clinical outcome trial. Thirty-four trials (91.9%) concluded that the tested intervention met non-inferiority criteria. However, only five (13.5%) were followed by clinical outcomes trials the results of which did not always confirm non-inferiority.

CONCLUSION

Non-inferiority trials that use a surrogate marker as the primary endpoint are being increasingly performed. However, these trials pose particular challenges with design, reporting, and interpretation, which are not systematically and consistently addressed or reported.

Individual Patient Data Pooled Analysis of Randomized Trials of Bivalirudin versus Heparin in Acute Myocardial Infarction: Rationale and Methodology

BACKGROUND

 Individual randomized controlled trials (RCTs) of periprocedural anticoagulation with bivalirudin versus heparin during percutaneous coronary intervention (PCI) have reported conflicting results. Study-level meta-analyses lack granularity to adjust for confounders, explore heterogeneity, or identify subgroups that may particularly benefit or be harmed.

OBJECTIVE

 To overcome these limitations, we sought to develop an individual patient-data pooled database of RCTs comparing bivalirudin versus heparin.

METHODS

 We conducted a systematic review to identify RCTs in which ≥1,000 patients with acute myocardial infarction (AMI) undergoing PCI were randomized to bivalirudin versus heparin.

RESULTS

 From 738 identified studies, 8 RCTs met the prespecified criteria. The principal investigators of each study agreed to provide patient-level data. The data were pooled and checked for accuracy against trial publications, with discrepancies addressed by consulting with the trialists. Consensus-based definitions were created to resolve differing antithrombotic, procedural, and outcome definitions. The project required 3.5 years to complete, and the final database includes 27,409 patients (13,346 randomized to bivalirudin and 14,063 randomized to heparin).

CONCLUSION

 We have created a large individual patient database of bivalirudin versus heparin RCTs in patients with AMI undergoing PCI. This endeavor may help identify the optimal periprocedural anticoagulation regimen for patient groups with different relative risks of adverse ischemic versus bleeding events, including those with ST-segment and non-ST-segment elevation MI, radial versus femoral access, use of a prolonged bivalirudin infusion or glycoprotein inhibitors, and others. Adherence to standardized techniques and rigorous validation processes should increase confidence in the accuracy and robustness of the results.

Progress in the development of antiplatelet agents: Focus on the targeted molecular pathway from bench to clinic

Antiplatelet drugs serve as a first-line antithrombotic therapy for the management of acute ischemic events and the prevention of secondary complications in vascular diseases. Numerous antiplatelet therapies have been developed; however, currently available agents are still associated with inadequate efficacy, risk of bleeding, and variability in individual response. Understanding the mechanisms of platelet involvement in thrombosis and the clinical development process of antiplatelet agents is critical for the discovery of novel agents. The functions of platelets in thrombosis are regulated by two major mechanisms: the interaction between surface receptors and their ligands, and the downstream intracellular signaling pathways. Recently, most of the progress made in antiplatelet drug development has been achieved with P2Y receptor antagonists. Additionally, the usage of GP IIb/IIIa receptor antagonists has decreased, because it is associated with a higher risk of bleeding and thrombocytopenia. Agents targeting other platelet surface receptors such as PARs, TP receptor, EP3 receptor, GPIb-IX-V receptor, P-selectin, as well as intracellular signaling factors, such as PI3Kβ, have been evaluated in an attempt to develop the next generation of antiplatelet drugs, reduce or eliminate interpatient variability of drug efficacy and significantly lower the risk of drug-induced bleeding. The aim of this review is to describe the pathways of platelet activation in thrombosis, and summarize the development process of antiplatelet agents, as well as the preclinical and clinical evaluations performed on these agents.

Safety of tirofiban and dual antiplatelet therapy in treating intracranial aneurysms

Background

Endovascular treatment of intracranial aneurysms usually involves stent-assisted coiling (SAC) and flow diverters. Glycoprotein IIb/IIIa inhibitors such as tirofiban and dual antiplatelet therapy (DAPT) are required to prevent thromboembolic complications afterwards. We sought to determine the safety of tirofiban and DAPT in these cases.

Methods

We conducted a retrospective analysis of our database for patients with intracranial aneurysms who underwent SAC or flow diversion. The tirofiban-DAPT protocol used is described. Data regarding duration of infusion, placement of external ventricular devices (EVDs), complications, haemoglobin levels and platelet count before and 24 hours after antiplatelet therapy were collected and analysed.

Results

One-hundred and forty-one patients with 148 aneurysms/procedures were included. 110 aneurysms were treated acutely and 38 electively. Minor and major haemorrhagic events were recognised in 20% (30/148) aneurysms. Only 5 (3.4%) intracerebral haemorrhages were symptomatic: 3 cortical/SAH and 2 EVD-related. The average blood volume in symptomatic haemorrhages was 24.8 cc versus 5.42 cc in asymptomatic haemorrhages (p=0.002). The rate of EVD-related haemorrhages was 15.7% (19/121) and only 2 (1.7%) were symptomatic. Most haemorrhagic events occurred in ruptured aneurysms (90.1%, p=0.01). No significant change in platelet count or haemoglobin levels before and 24 hours after administration of tirofiban and DAPT was documented. Concomitant administration of heparin did not increase haemorrhagic events.

Conclusion

The use of the GP IIb/IIIa inhibitors tirofiban and DAPT in this series was safe. Tirofiban and DAPT did not affect platelet count or haemoglobin levels and did not increase rate of symptomatic haemorrhages or thromboembolic complications.

Comparison of In-Hospital Bleeding and Cardiovascular Events with High-Dose Bolus Tirofiban and Shortened Infusion to Short-Duration Eptifibatide as Adjunctive Therapy for Percutaneous Coronary Intervention

Potent platelet inhibition is one of the most important medical interventions to prevent ischemic complications during and after percutaneous coronary intervention (PCI). Practice has evolved with the introduction of potent oral P2Y₁₂ inhibitors that provide quick, effective platelet inhibition, and the need for routine glycoprotein IIb/IIIa inhibitors (GPIs) has decreased. Additionally, a shorter duration of GPI infusion has been shown to be safe with adequate oral antiplatelet loading, but clinical outcome data are limited to eptifibatide. This single-center, retrospective cohort study analyzed in-hospital outcomes for patients who received adjunctive GPI therapy for PCI before and after an institution-wide switch to high-dose bolus tirofiban with shortened infusion from short-duration eptifibatide. The primary end point was a composite in-hospital outcome of major and minor bleeding and cardiovascular events (death, myocardial infarction, coronary artery bypass grafting, ischemic stroke, and target vessel revascularization). Secondary end points included bleeding and cardiovascular event types. A total of 357 and 446 patients received eptifibatide and tirofiban, respectively, from February 1, 2014 through September 30, 2017. Thirty five eptifibatide and 46 tirofiban patients experienced an in-hospital composite event (9.8% vs 10.3%, p = 0.81). There was no difference found between in-hospital bleeding (6.4% vs 5.4%, p = 0.52) or cardiovascular events (5.6% vs 6.5%, p = 0.60) with the use of eptifibatide or tirofiban, respectively. Multivariable analysis showed that patients with transradial access or an indication of unstable angina were less likely to experience an in-hospital composite event (OR 0.30 and 0.19, respectively, p <0.001 for both). In conclusion, the use of high-dose bolus tirofiban with shortened infusion versus short-duration eptifibatide was not associated with an increase of in-hospital bleeding or cardiovascular events.

Bivalirudin versus heparin in percutaneous coronary intervention-a systematic review and meta-analysis of randomized trials stratified by adjunctive glycoprotein IIb/IIIa strategy

Background

Bivalirudin has been shown to be associated with less major bleeding than heparin in patients undergoing percutaneous coronary intervention (PCI); but the confounding effect of concomitant glycoprotein IIb/IIIa inhibitors (GPI) limits meaningful comparison. We performed a systematic review and meta-analysis to compare bivalirudin to heparin, with and without adjunctive GPI in PCI.

Methods

We searched PubMed, Cochrane, EMBASE, CINAHL and WOS from January 2000 to December 2017 for clinical trials comparing bivalirudin to heparin, with and without adjunctive GPI during PCI. Cochrane's Q statistics were used to determine heterogeneity. Random effects model was used.

Results

Twenty-six comparison groups (22 original studies and 4 subgroup analyses) with 53,364 patients were included. Mean follow-up was 192±303 days. There was no difference between the two groups in all-cause mortality [risk ratio (RR: 0.93; 95% CI: 0.82-1.05, P=0.260), target vessel revascularization (TVR) (RR: 1.17; 95% CI: 0.93-1.46, P=0.174) or stroke (RR: 0.91; 95% CI: 0.71-1.18, P=0.490). Major bleeding was lower in the bivalirudin group with concomitant GPI in one or both arms (RR: 0.64; 95% CI: 0.53-0.77, P<0.001) and without (RR: 0.71; 95% CI: 0.51-0.99, P=0.041) provisional or routine GPIs. Bivalirudin appeared to have a higher risk of stent thrombosis (RR: 1.32; 95% CI: 1.04-1.68, P=0.022) and a trend towards more myocardial infarction (RR: 1.12; 95% CI: 0.98-1.28, P=0.098) though without statistical significance. However, exclusion of studies with GPI showed no difference in stent thrombosis or myocardial infarction with bivalirudin.

Conclusions

Bivalirudin is associated with less major bleeding compared to heparin, regardless of GPI use. The lower anticoagulant effect of bivalirudin is linked with higher stent thrombosis and a trend towards more MI, however a confounding effect of GPI use in the heparin arm cannot be excluded.

An Anti-Coagulation Conundrum: Implantation of Total Artificial Heart in a Patient with Heparin-Induced Thrombocytopenia Type II

BACKGROUND Heparin-induced thrombocytopenia (HIT) is a rare but life-threatening complication of heparin administration. It can present a major clinical dilemma for physicians caring for patients requiring life-saving urgent or emergent cardiac surgery. Studies have been published examining the use of alternative anticoagulants for patients undergoing cardiopulmonary bypass (CPB), however, evidence does not clearly support any particular approach. Presently, there are no large-scale, prospective randomized studies examining the impact of alternative anticoagulants on clinical outcomes for HIT-positive patients requiring cardiac surgery. CASE REPORT We present the case of a patient who underwent SynCardia Total Artificial Heart (TAH) implantation following a recent left ventricular assist device (LVAD) placement. The patient was receiving argatroban for type II HIT with anuric renal failure, and developed a thrombus which occluded the inflow cannula of the LVAD. Based on a published study and after establishing consensus with the surgical, anesthesiology, perfusion, and hematology teams, we decided to use tirofiban as an antiplatelet agent to inhibit the platelet aggregation induced by heparin, and ultimately used heparin as the anticoagulant for cardiopulmonary bypass. CONCLUSIONS When selecting anticoagulation for a HIT-positive patient requiring CPB, so that benefits outweigh risks, it is of paramount importance that the decision be based on a multitude of factors. The team caring for the patient should have a shared mental model and be familiar with the pharmacology, devices used, and local practices. These three elements should be integrated with patient-specific comorbidities along with local monitoring capabilities to ensure safe, efficient patient care.

Clinical approach on challenge and desensitization procedures with aspirin in patients with ischemic heart disease and nonsteroidal anti-inflammatory drug hypersensitivity

BACKGROUND

Hypersensitivity to acetylsalicylic acid (ASA) constitutes a serious problem for subjects with coronary artery disease. In such subjects, physicians have to choose the more appropriate procedure between challenge and desensitization. As the literature on this issue is sparse, this study aimed to establish in these subjects clinical criteria for eligibility for an ASA challenge and/or desensitization.

METHODS

Collection and analysis of data on ASA challenges and desensitizations from 10 allergy centers, as well as consensus among the related physicians and an expert panel.

RESULTS

Altogether, 310 subjects were assessed; 217 had histories of urticaria/angioedema, 50 of anaphylaxis, 26 of nonimmediate cutaneous eruptions, and 17 of bronchospasm related to ASA/nonsteroidal anti-inflammatory drugs (NSAID) intake. Specifically, 119 subjects had index reactions to ASA doses lower than 300 mg. Of the 310 subjects, 138 had an acute coronary syndrome (ACS), 101 of whom underwent desensitizations, whereas 172 suffered from a chronic ischemic heart disease (CIHD), 126 of whom underwent challenges. Overall, 163 subjects underwent challenges and 147 subjects underwent desensitizations; 86 of the latter had index reactions to ASA doses of 300 mg or less. Ten subjects reacted to challenges, seven at doses up to 500 mg, three at a cumulative dose of 110 mg. The desensitization failure rate was 1.4%.

CONCLUSIONS

In patients with stable CIHD and histories of nonsevere hypersensitivity reactions to ASA/NSAIDs, an ASA challenge is advisable. Patients with an ACS and histories of hypersensitivity reactions to ASA, especially following doses lower than 100 mg, should directly undergo desensitization.

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.

Comparison of heparin, bivalirudin, and different glycoprotein IIb/IIIa inhibitor regimens for anticoagulation during percutaneous coronary intervention: A network meta-analysis

BACKGROUND/PURPOSE

Numerous GPIs are available for PCI. Although they were tested in randomized controlled trials, a comparison between the different GPI strategies is lacking. Thus, we performed a Bayesian network meta-analysis to compare different glycoprotein IIb/IIIa inhibitor (GPI) strategies with heparin and bivalirudin for percutaneous coronary intervention (PCI).

METHODS

MEDLINE, Cochrane CENTRAL, and ClinicalTrials.gov were searched by two independent reviewers for randomized controlled trials comparing high-dose bolus tirofiban, abciximab, eptifibatide, heparin with provisional glycoprotein IIb/IIIa inhibitors, and bivalirudin with provisional GPI that reported clinical outcomes. Mixed treatment comparison model generation was performed to directly and indirectly compare between different anticoagulation strategies for all-cause mortality, myocardial infarction, major adverse cardiovascular events, major bleeding, minor bleeding, need for transfusion, and thrombocytopenia.

RESULTS

A total of 41 randomized controlled trials with 38,645 patients were included in the analysis, among which 2654 were randomized to high-dose bolus tirofiban, 6752 to abciximab, 1669 to eptifibatide, 16,500 to heparin, and 11,070 to bivalirudin. Mean age was 64±11years, 75% were male, 91% were treated with stenting, 71% with clopidogrel, and 74% for acute coronary syndrome. High-dose bolus tirofiban was associated with a significant reduction in all-cause mortality compared with heparin (OR 0.57 [credible intervals 0.37, 0.9]) and eptifibatide (OR 0.44 [credible intervals 0.19, 1.0]). GPI regimens had less myocardial infarction and major adverse cardiovascular events but greater bleeding compared with heparin and bivalirudin. There was no difference among the GPI therapies for other outcomes, including myocardial infarction, major adverse cardiovascular events, and major bleeding.

CONCLUSIONS

Our network meta-analysis of 38,645 patients demonstrated that GPI regimens were associated with a reduction in recurrent myocardial infarction or major adverse cardiovascular events for PCI, while bivalirudin was associated with the lowest risk of bleeding.

Bivalirudin Versus Unfractionated Heparin in Acute Coronary Syndromes: An Updated Meta-analysis of Randomized Trials

INTRODUCTION AND OBJECTIVES

Contrasting data have been reported on bivalirudin as an anticoagulation strategy during percutaneous coronary interventions, offering theoretical benefits on bleeding complications but raising concerns on a potential increase in the risk of stent thrombosis. We performed an updated meta-analysis to evaluate the efficacy and safety of bivalirudin compared with unfractionated heparin in patients undergoing percutaneous interventions for acute coronary syndromes.

METHODS

Literature archives and main scientific sessions were scanned. The primary efficacy endpoint was 30-day overall mortality. Secondary endpoints were stent thrombosis and major bleeding. A prespecified analysis was conducted according to clinical presentation.

RESULTS

Twelve randomized trials were included, involving 32 746 patients (52.5% randomized to bivalirudin). Death occurred in 1.8% of the patients, with no differences between bivalirudin and heparin (odds ratio = 0.91; 95% confidence interval, 0.77-1.08; P = .28; P for heterogeneity = .41). Similar results were obtained for patients with non-ST-segment elevation and in ST-segment elevation myocardial infarction. A significantly higher rate of stent thrombosis was observed with bivalirudin (odds ratio = 1.42; 95% confidence interval, 1.09-1.83; P = .008; P for heterogeneity = .09). Bivalirudin was associated with a significant reduction in the rate of major bleeding (odds ratio = 0.60; 95% confidence interval, 0.54-0.75; P < .00001; P for heterogeneity < .0001), which, however, was related to the differential use of glycoprotein IIb/IIIa inhibitors (r = -0.02 [-0.033 to -0.0032]; P = .02) and did not translate into survival benefits.

CONCLUSIONS

In patients undergoing percutaneous coronary interventions, bivalirudin is not associated with a reduction in mortality compared with heparin but does increase stent thrombosis. The reduction in bleeding complications observed with bivalirudin does not translate into survival benefits but is rather influenced by a differential use of glycoprotein IIb/IIIa inhibitors.

Bivalirudin versus unfractionated heparin: a meta-analysis of patients receiving percutaneous coronary intervention for acute coronary syndromes

Objective

Acute coronary syndrome (ACS) encompasses ST segment elevation myocardial infarction (STEMI), with generally high thrombus burden and non-ST segment elevation ACS (NSTE-ACS), with lower thrombus burden. In the setting of percutaneous coronary intervention (PCI) for ACS, bivalirudin appears superior to unfractionated heparin (UFH), driven by reduced major bleeding. Recent trials suggest that the benefit of bivalirudin may be reduced with use of transradial access and evolution in antiplatelet therapy. Moreover, a differential role of bivalirudin in ACS cohorts is unknown.

Methods

A meta-analysis of randomised trials comparing bivalirudin and UFH in patients with ACS receiving PCI, with separate analyses in STEMI and NSTE-ACS groups. Overall estimates of treatment effect were calculated with random-effects model.

Results

In 5 trials of STEMI (10 358 patients), bivalirudin increased the risk of acute stent thrombosis (ST) (OR 3.62; CI 1.95 to 6.74; p<0.0001) compared with UFH. Bivalirudin reduced the risk of major bleeding only when compared with UFH plus planned glycoprotein IIb/IIIa inhibitors (GPI) (OR 0.49; CI 0.36 to 0.67; p<0.00001). In 14 NSTE-ACS trials (25 238 patients), there was no difference between bivalirudin and UFH in death, myocardial infarction or ST. However, bivalirudin reduced the risk of major bleeding compared with UFH plus planned GPI (OR 0.52; CI 0.43 to 0.62; p<0.00001), or UFH plus provisional GPI (OR 0.68; CI 0.46 to 1.01; p=0.05). The reduction in major bleeding with bivalirudin was not related to vascular access site.

Conclusions

Bivalirudin increases the risk of acute ST in STEMI, but may confer an advantage over UFH in NSTE-ACS while undergoing PCI, reducing major bleeding without an increase in ST.

Bivalirudin Anticoagulant Therapy With or Without Platelet Glycoprotein IIb/IIIa Inhibitors During Transcatheter Coronary Interventional Procedures: A Meta-Analysis

The safety and effectiveness of using the direct thrombin inhibitor bivalirudin during transcatheter coronary interventional procedures remains uncertain.This study aimed to systematically assess anticoagulation with bivalirudin alone or bivalirudin plus glycoprotein (GP) IIb/IIIa inhibitors (bivalirudin-based anticoagulant therapy) in patients undergoing percutaneous coronary intervention (PCI) procedures by a meta-analysis of randomized controlled trials (RCTs).Systematical searches of the MEDLINE, EMBASE, and Cochrane databases were conducted. RCTs comparing bivalirudin-based anticoagulant therapy with a comparable heparin therapy in patients undergoing PCI were eligible. Risk ratios (RRs) with 95% confidence intervals (CIs) served as summary statistics.A total of 38,096 patients from 17 RCTs were randomized to the bivalirudin group (n = 18,878) or heparin group (n = 19,218) in the meta-analysis. No significant differences in death, myocardial infarction or reinfarction, ischemia-driven revascularization, or in-stent thrombosis were observed between the 2 groups (all P > 0.05). Notably, bivalirudin-based therapy showed a highly significant 34% decrease in the incidence of major bleeding (RR = 0.66; 95% CI 0.54-0.81; P < 0.001) and a 28% reduction in the need for blood transfusion (RR = 0.72; 95% CI 0.56-0.91; P < 0.01). Meta-regression analyses demonstrated that additional administration of GP IIb/IIIa receptor inhibitors (P = 0.01), especially eptifibatide (P = 0.001) and tirofiban (P = 0.002), was likely to increase the major bleeding risk associated with bivalirudin.Bivalirudin, in comparison to heparin, is associated with a markedly lower risk of major bleeding, and the additional use of GP IIb/IIIa inhibitors may weaken this benefit.

Critical Appraisal of Bivalirudin versus Heparin for Percutaneous Coronary Intervention: A Meta-Analysis of Randomized Trials

Percutaneous coronary intervention with bivalirudin plus bail-out glycoprotein IIb/IIIa inhibitors has been shown to be as effective as unfractionated heparin plus routine glycoprotein IIb/IIIa inhibitors in preventing cardiac ischemic events, but with a lower bleeding risk. It is unknown whether bivalirudin would have the same beneficial effects if compared with heparin when the use of glycoprotein IIb/IIIa inhibitors was similar between treatment arms. We searched the MEDLINE, Web of Science, and Cochrane databases from inception until March 2015 for randomized trials that compared bivalirudin to heparin in patients undergoing percutaneous coronary intervention. We required that the intended use of glycoprotein IIb/IIIa inhibitors was similar between the study groups. Summary estimates were principally constructed by the Peto method. Fifteen trials met our inclusion criteria, which yielded 25,824 patients. Bivalirudin versus heparin was associated with an increased hazard of stent thrombosis (odds ratio [OR] 1.49, 95% confidence interval [CI] 1.15-1.92, P = .002, I² = 16.9%), with a similar hazard of myocardial infarction (OR 1.09, 95% CI 0.98-1.22, P = .11, I² = 35.8%), all-cause mortality (OR 0.88, 95% CI 0.72-1.08, P = .21, I² = 31.5%) and major adverse cardiac events (OR 1.04, 95% CI 0.94-1.14, P = .46, I² = 53.9%). Bivalirudin was associated with a reduced hazard of major bleeding (OR 0.80, 95% CI 0.70-0.92, P = .001, I² = 63.5%). The dose of heparin in the control arm modified this association; when the dose of unfractionated heparin in the control arm was ≥ 100 units/kg, bivalirudin was associated with a reduction in major bleeding (OR 0.55, 95% CI 0.45-0.68, P < .0001), but when the dose of unfractionated heparin was ≤ 75 units/kg, bivalirudin was not associated with reduction in bleeding (OR 1.09, 95% CI 0.91-1.31, P = .36). Among patients undergoing PCI, bivalirudin was associated with an increased hazard of stent thrombosis. Bivalirudin may be associated with a reduced hazard of major bleeding; however, this benefit was no longer apparent when compared with a dose of unfractionated heparin ≤ 75 units/kg.

Bivalirudin as compared to unfractionated heparin in patients undergoing percutaneous coronary revascularization: A meta-analysis of 22 randomized trials

Bivalirudin has gained ground against unfractionated heparin (UFH) in percutaneous coronary interventions (PCI), due to a reported better safety profile. However, whether bivalirudin may provide also advantages in clinical outcome beyond the known benefits in major bleedings, is still a debated matter and was, therefore, the aim of present meta-analysis of randomized trials, evaluating efficacy and safety of bivalirudin as compared with UFH in PCI.

METHODS AND STUDY OUTCOMES

Literature archives (Pubmed, EMBASE, Cochrane) and main scientific sessions were scanned. Primary endpoint was overall mortality. Secondary endpoints were: 1) mortality within 30-days; 2) overall and within 30-days non fatal myocardial infarction; 3) overall and within 30-days stent thrombosis. Safety endpoints were major bleedings (per protocol definition or TIMI classification). A prespecified analysis was conducted according to clinical presentation (Elective, ACS, STEMI).

RESULTS

A total of 22 randomized clinical were finally included, involving 40156 patients randomized to bivalirudin (52.9%) or to UFH (47.1%). Death occurred in 1100 (2.8%) of patients, with no difference between bivalirudin and UFH (2.7% vs 2.8% OR[95%C]=0.94[0.83,-.06], p=0.32, phet=0.48). The results did not change according to clinical presentation. By meta-regression analysis, the effects on mortality were not related to patients risk profile (r=-0.38(-0.89-0.14), p=0.15) or the reduction in bleeding complications (r=-0.008(-0.86-0.85), p=0.98). A significant increase in short-term stent thrombosis was observed with bivalirudin (OR[95%CI]=1.42 [1.10-1.83], p=0.006). However, Bivalirudin significantly reduced bleedings according to both study protocol definition (OR[95%CI]=0.62[0.56-0.69],p<0.00001; phet=0.0003) or TIMI major criteria (OR[95%CI]=0.65[0.53-0.79],p<0.0001, phet=0.95).

CONCLUSIONS

In present meta-analysis, among patients undergoing PCI, bivalirudin, as compared with UFH, is associated with a significant reduction in major bleeding complications that, however, does not translate into mortality benefits. Furthermore, bivalirudin is associated with higher rate of 30-days stent thrombosis and recurrent MI among STEMI patients.

Heparin is Not Inferior to Bivalirudin in Percutaneous Coronary Intervention-Focusing on the Effect of Glycoprotein IIb/IIIa Inhibitor Use: A Meta-Analysis

Our aim was to compare the efficacy and safety of bivalirudin (Biv) versus heparin (Hep) with or without similar usage rate of glycoprotein IIb/IIIa inhibitors (GPIs) during percutaneous coronary intervention (PCI). The PubMed and EMbase were searched. Randomized trials comparing Biv versus Hep were eligible for inclusion. With imbalanced GPI use, Biv had significantly lower major bleeding (pooled risk ratio [RR], 0.67; 95% confidence interval [CI], 0.54-0.83) without difference in mortality (pooled RR, 0.95; 95% CI, 0.80-1.14). With comparable GPI use, no significant difference was observed in major bleeding (pooled RR, 0.95; 95% CI, 0.82-1.10) and mortality (pooled RR, 1.13; 95% CI, 0.85-1.50). With no GPI use, Biv was associated with numerically higher mortality (pooled RR, 1.17; 95% CI, 0.83-1.65) without significant difference in major bleeding (pooled RR, 0.81; 95% CI, 0.64-1.02). In conclusion, when comparing different anticoagulants during PCI, the effect of GPIs should not be underestimated. Heparin as such was found noninferior to Biv.

Bivalirudin versus heparin in patients planned for percutaneous coronary intervention: a meta-analysis of randomised controlled trials

BACKGROUND

Bivalirudin is an alternative to heparin in patients undergoing percutaneous coronary intervention (PCI). We aimed to define the effects of a bivalirudin-based anticoagulation regimen compared with a heparin-based anticoagulation regimen on ischaemic and bleeding outcomes.

METHODS

We searched Medline, the Cochrane Library, and relevant meeting abstracts (search done on April 9, 2014) for randomised trials that assessed bivalirudin versus heparin in patients planned for PCI. The primary efficacy endpoint was the incidence of major adverse cardiac events (MACE) up to 30 days. Secondary efficacy endpoints were death, myocardial infarction, ischaemia-driven revascularisation, and stent thrombosis. The primary safety endpoint was major bleeding up to 30 days. We calculated pooled risk ratios and 95% CIs using random-effects models.

FINDINGS

We included data from 16 trials involving 33 958 patients, of whom 2422 experienced MACE and 1406 had a major bleed. There was an increase in the risk of MACE with bivalirudin-based regimens compared with heparin-based regimens (risk ratio 1·09, 95% CI 1·01-1·17; p=0·0204), which was largely driven by increases in myocardial infarction (1·12, 1·03-1·23) and seemingly also by ischaemia-driven revascularisation (1·16, 0·997-1·34) with bivalirudin compared with heparin, with no effect on mortality (0·99, 0·82-1·18). Bivalirudin increased the risk of stent thrombosis (risk ratio 1·38, 95% CI 1·09-1·74; p=0·0074), which was primarily due to an increase in acute cases in ST-segment elevation myocardial infarction (4·27, 2·28-8·00; p<0·0001). Overall, bivalirudin-based regimens lowered the risk of major bleeding (risk ratio 0·62, 95% CI 0·49-0·78; p<0·0001), but the magnitude of this effect varied greatly (p<0·0001) depending on whether glycoprotein IIb/IIIa inhibitors were used predominantly in the heparin arm only (0·53, 0·47-0·61; p<0·0001), provisionally in both arms (0·78, 0·51-1·19; p=0·25), or planned in both arms (1·07, 0·87-1·31; p=0·53).

INTERPRETATION

Compared with a heparin-based regimen, a bivalirudin-based regimen increases the risk of myocardial infarction and stent thrombosis, but decreases the risk of bleeding, with the magnitude of the reduction depending on concomitant glycoprotein IIb/IIIa inhibitor use. Physicians should weigh the trade-off between ischaemic and bleeding events when choosing between different anticoagulant regimens.

FUNDING

None.

Effect of Early Treatment With Tirofiban on Initial TIMI Grade 3 Flow of Patients With ST Elevation Myocardial Infarction

Background:

Before primary percutaneous coronary intervention (PCI) in patients with ST elevation myocardial infarction (STEMI), it is not clear whether a routine early administration of glycoprotein IIb/IIIa inhibitors in the emergency ward is beneficial or their administration in selected cases in the catheterization laboratory.

Objectives:

The present randomized clinical trial sought to investigate whether an earlier administration of Tirofiban could exert any impact on TIMI grade 3 flows and ST resolution in the electrocardiography of patients with STEMI before primary PCI.

Materials and Methods:

Patients with STEMI within twelve hours of symptom commencement were included if primary PCI was planned to be performed within ninety minutes of admission and excluded if they had contraindications for Tirofiban. Seventy patients were randomized to receive 25 μg/kg of bolus Tirofiban early in the emergency ward (the early Tirofiban group) in three minutes and 70 did not receive Tirofiban (the control group). The primary endpoint of the study was a Thrombolysis in Myocardial Infarction (TIMI) grade 3 flows on the initial angiogram. The study is registered as IRCT201105126463N1 in: www.irct.ir.

Results:

The study population had a mean age of 57.17 ± 10.09 years and included 79.3 % males. TIMI grade 3 flow was seen in 15 (21.4 %) patients of the Tirofiban group and 7 (10 %) of the control group (P = 0.06, odds ratio = 0.407, and 95 % confidence interval = 0.155-1.072). Complete ST resolution was seen in 30 (42.9 %) patients of the Tirofiban group and 34 (48.6 %) of the control group (P = 0.5).

Conclusion:

Although TIMI grade 3 flows trended to be higher in the patients who received early Tirofiban in the emergency ward, the difference did not constitute statistical significance and possible benefits, therefore, require further clarification.

Impact of baseline hemorrhagic risk on the benefit of bivalirudin versus unfractionated heparin in patients treated with coronary angioplasty: a meta-regression analysis of randomized trials

BACKGROUND

Bivalirudin significantly reduces 30-day major and minor bleeding compared with unfractionated heparin (UFH), while resulting in similar or lower rates of ischemic events in both patients with stable and unstable coronary disease undergoing percutaneous coronary intervention. We performed a meta-analysis of randomized trials to evaluate the impact of bivalirudin compared with UFH, with or without glycoprotein IIb/IIIa receptor inhibitors (GPI), on the rates of mortality, myocardial infarction (MI), and major bleeding.

METHODS

We searched electronic databases for randomized controlled trials with >100 patients comparing bivalirudin (±provisional GPI) with UFH with either routine or provisional GPI in patients undergoing percutaneous coronary intervention. The principal efficacy end points were mortality and MI within 30 day, whereas major bleeding was the principal safety end point. We assessed the benefit of bivalirudin for each efficacy end point relative to the baseline bleeding risk, using the control (UFH) major bleeding rate as proxy for that risk.

RESULTS

A total of 12 randomized trials that enrolled 33,261 patients were included. Overall, there was no significant difference in mortality and MI between bivalirudin monotherapy and UFH (±GPI), whereas major bleeding was significantly lower with bivalirudin. Bivalirudin reduced major and minor bleeding across the entire bleeding risk spectrum.

CONCLUSIONS

Bivalirudin significantly reduces major and minor bleeding regardless of the estimated baseline hemorrhagic risk.

Monitoring and Reversal of Anticoagulation and Antiplatelets

Since percutaneous transluminal coronary angioplasty was first described and the breakthrough studies of the role of stents were reported, the evolution in anticoagulation and antiplatelet therapy used during percutaneous coronary intervention (PCI) has reduced periprocedural ischemic events and stent thrombosis. Although greater combinations and doses of anticoagulation with antiplatelets seem to provide the best protection against thrombogenic and embolic events, there is a significant trade-off with a higher risk of major and minor bleeding episodes. This review article expands on each of the commonly used antiplatelet and anticoagulants used at time of PCI, focusing on drug monitoring and reversal.

Role of Parenteral Agents in Percutaneous Coronary Intervention for Stable Patients

Numerous agents are available for anticoagulation during percutaneous coronary intervention (PCI), and various antiplatelet agents are also used. With all of the medications available, an assessment must be made regarding the ischemic risk and risk of bleeding for an individual patient during elective PCI when selecting the optimal medical strategy to support PCI. Whether new antiplatelet medications will enhance or reduce complications when paired with various newer anticoagulant agents requires further investigation. This article summarizes existing data examining the benefits and limitations of the various anticoagulant and antiplatelet medications, and summarizes guidelines for their use.

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.

Optimal use of platelet glycoprotein IIb/IIIa receptor antagonists in patients undergoing percutaneous coronary interventions

Discovery of the central role of platelets in the pathogenesis of acute coronary syndromes (ACS) and ischaemic complications of percutaneous coronary interventions (PCI) has led to the widespread use of oral and parenteral platelet inhibitors to treat these conditions. Glycoprotein (GP) IIb/IIIa (also known as α(IIb)β(3)) receptors on the surface of platelets play an essential role in platelet aggregation and serve as a key mediator in the formation of arterial thrombus. When activated, GP IIb/IIIa receptors bind to fibrinogen, which serves as the 'final common pathway' in platelet aggregation. Of the numerous agents developed for modulating platelet activity, intravenous platelet GP IIb/IIIa receptor antagonists are the most potent. There are four agents in clinical use, including abciximab, eptifibatide, tirofiban and lamifiban, although lamifiban is not approved for use in the US. While all agents block fibrinogen binding to GP IIb/IIIa, they do so by different mechanisms. Abciximab is a humanized form of a murine monoclonal antibody directed against GP IIb/IIIa, eptifibatide is a synthetic, cyclic heptapeptide that contains a lysine-glycine-aspartic acid (KGD) sequence that mimics the arginine-glycine-aspartic acid (RGD) sequence found on GP IIb/IIIa, tirofiban is a non-peptide antagonist derived by optimization of the tyrosine analogue that structurally mimicks the RGD-containing loop of the disintegrin echistatin, and lamifiban is a synthetic, non-cyclic, non-peptide, low-molecular-weight compound. In clinical trials, use of these agents reduces ischaemic adverse cardiovascular events in patients with ACS undergoing PCI, but at a cost of increased bleeding.