Bivalirudin versus heparin during coronary angioplasty for unstable or postinfarction angina: Final report reanalysis of the Bivalirudin Angioplasty Study

[Heparin-Induced Thrombocytopenia]

The extensive use of therapeutic doses of heparin to prevent thrombosis in critically ill patients with COVID-19 during the pandemic has led to an increased incidence of bleeding and heparin-induced thrombocytopenia (HIT). In addition, the introduction of the AstraZeneca and Johnson&Johnson vaccines against COVID-19 into clinical practice was associated with the development of a rare but very severe, adverse thrombotic complication, vaccine-induced immune thrombotic thrombocytopenia (VITT). Thrombotic complications of VITT turned out to be similar to HIT both clinically and pathophysiologically. HIT is a potentially fatal immune-mediated adverse drug response that results in emergence of antibodies that activate platelets in the presence of heparin. HIT is characterized by a high incidence of venous and arterial thromboses, often with fatal outcomes. Currently, there are clearly defined international guidelines for the diagnosis, treatment and prevention of HIT. In case of thrombotic complications, non-heparin anticoagulants should be used.

Epidemiology of anticoagulation for children supported by extracorporeal membrane oxygenation in the United States: A Pediatric Hospital Information System database study

INTRODUCTION

Due to the risk of thrombosis, nearly all children supported by extracorporeal membrane oxygenation (ECMO) receive systemic anticoagulation. While heparin has traditionally been used, there are reports of increased use of direct thrombin inhibitors. We sought to describe the use of anticoagulation in children supported by ECMO in the United States using a large administrative database.

METHODS

We performed a retrospective cohort study of children supported by ECMO within the Pediatric Health Information System (PHIS) database. Pediatric encounters involving ECMO from 2012 to 2020 were identified. Data regarding demographics, diagnoses, anticoagulation, complications, and outcomes were extracted for eligible encounters.

RESULTS

Eleven thousand five hundred ninety-five encounters that involved ECMO were identified. Fifty-four percent were male with an age range of 0-17 years and a median (IQR) age of 0 (0-2) years. Unfractionated heparin (UFH) only was used in 94% (95% CI: 93.6-94.5%) of encounters and UFH followed by bivalirudin in 5% (95% CI: 4.3-5.1%) of cases. There was a significant difference in the use of bivalirudin from 2012 to 2020 (p < 0.001). Differences in anticoagulation regimens were observed between infants and children (p = 0.004) and between those with and without cardiac indications for ECMO (p < 0.001). Four percent (95% CI: 4.1-4.8%) of encounters were associated with diagnostic coding for thrombosis and differences in occurrence of thrombosis were observed between different anticoagulant regimens (p < 0.001).

CONCLUSIONS

Though the majority of children on ECMO in the United States receive heparin anticoagulation, there is an increase in use of direct thrombin inhibitors. Prospective studies must evaluate the efficacy of different anticoagulants in this patient population.

The Changing Landscape of Anticoagulation in Pediatric Extracorporeal Membrane Oxygenation: Use of the Direct Thrombin Inhibitors

Bleeding and thrombosis frequently occur in pediatric patients with extracorporeal membrane oxygenation (ECMO) therapy. Until now, most patients are anticoagulated with unfractionated heparin (UFH). However, heparin has many disadvantages, such as binding to other plasma proteins and endothelial cells in addition to antithrombin, causing an unpredictable response, challenging monitoring, development of heparin resistance, and risk of heparin-induced thrombocytopenia (HIT). Direct thrombin inhibitors (DTIs), such as bivalirudin and argatroban, might be a good alternative. This review will discuss the use of both UFH and DTIs in pediatric patients with ECMO therapy.

Safety profile of bivalirudin in Chinese female patients undergoing percutaneous coronary intervention: a multi-center study

Background

The present study aimed to comprehensively investigate the occurrence and risk factors of adverse events (AEs) or adverse drug reactions (ADRs) (especially for thrombocytopenia and bleeding) in Chinese female patients receiving bivalirudin during percutaneous coronary intervention (PCI).

Methods

A total of 918 female patients from 27 Chinese medical centers took bivalirudin as anticoagulant for PCI were enrolled in this prospective, multi-center, intensive monitoring study. Safety data (AEs, ADRs, thrombocytopenia and bleeding) were collected from admission to 72 h post bivalirudin administration; then, patients were followed up at the 30^th day with the safety data collected as well.

Results

One hundred and twenty (13.1%) patients occurred AEs, among which 7 (0.8%) cases experienced severe AEs, and 2 (0.2%) cases died. Besides, 40 (4.4%) patients occurred bivalirudin-related ADRs, in which 3 (0.3%) cases experienced severe ADRs, but 0 (0.0%) cases died. It was of note that 27 (2.9%) and 13 (1.4%) patients experienced thrombocytopenia and bleeding, respectively. Subsequent multivariate analyses observed that: clinical presentation of spontaneous coronary artery dissection (SCAD) (odds ratio (OR) = 3.191, P = 0.004), CRUSADE high risk (OR = 2.075, P = 0.031), multiple culprit vessel (OR = 2.328, P = 0.019) independently correlated with higher risk of bivalirudin-related ADRs; clinical presentation of SCAD (OR = 4.388, P = 0.002) and multiple culprit vessel (OR = 2.974, P = 0.010) independently linked with raised thrombocytopenia risk; history of diabetes mellitus (OR = 5.227, P = 0.007) and CRUSADE high risk (OR = 4.475, P = 0.016) were independent factor related to elevated bleeding risk.

Conclusion

Bivalirudin is well tolerated with low ADRs, thrombocytopenia and bleeding incidences in Chinese female patients undergoing PCI.

Therapeutic Potential of Peptides Derived from Animal Venoms: Current Views and Emerging Drugs for Diabetes

The therapeutic potential of venom-derived drugs is evident today. Currently, several significant drugs are FDA approved for human use that descend directly from animal venom products, with others having undergone, or progressing through, clinical trials. In addition, there is growing awareness of the important cosmeceutical application of venom-derived products. The success of venom-derived compounds is linked to their increased bioactivity, specificity and stability when compared to synthetically engineered compounds. This review highlights advancements in venom-derived compounds for the treatment of diabetes and related disorders. Exendin-4, originating from the saliva of Gila monster lizard, represents proof-of-concept for this drug discovery pathway in diabetes. More recent evidence emphasises the potential of venom-derived compounds from bees, cone snails, sea anemones, scorpions, snakes and spiders to effectively manage glycaemic control. Such compounds could represent exciting exploitable scaffolds for future drug discovery in diabetes, as well as providing tools to allow for a better understanding of cell signalling pathways linked to insulin secretion and metabolism.

From Animal Poisons and Venoms to Medicines: Achievements, Challenges and Perspectives in Drug Discovery

Animal poisons and venoms are comprised of different classes of molecules displaying wide-ranging pharmacological activities. This review aims to provide an in-depth view of toxin-based compounds from terrestrial and marine organisms used as diagnostic tools, experimental molecules to validate postulated therapeutic targets, drug libraries, prototypes for the design of drugs, cosmeceuticals, and therapeutic agents. However, making these molecules applicable requires extensive preclinical trials, with some applications also demanding clinical trials, in order to validate their molecular target, mechanism of action, effective dose, potential adverse effects, as well as other fundamental parameters. Here we go through the pitfalls for a toxin-based potential therapeutic drug to become eligible for clinical trials and marketing. The manuscript also presents an overview of the current picture for several molecules from different animal venoms and poisons (such as those from amphibians, cone snails, hymenopterans, scorpions, sea anemones, snakes, spiders, tetraodontiformes, bats, and shrews) that have been used in clinical trials. Advances and perspectives on the therapeutic potential of molecules from other underexploited animals, such as caterpillars and ticks, are also reported. The challenges faced during the lengthy and costly preclinical and clinical studies and how to overcome these hindrances are also discussed for that drug candidates going to the bedside. It covers most of the drugs developed using toxins, the molecules that have failed and those that are currently in clinical trials. The article presents a detailed overview of toxins that have been used as therapeutic agents, including their discovery, formulation, dosage, indications, main adverse effects, and pregnancy and breastfeeding prescription warnings. Toxins in diagnosis, as well as cosmeceuticals and atypical therapies (bee venom and leech therapies) are also reported. The level of cumulative and detailed information provided in this review may help pharmacists, physicians, biotechnologists, pharmacologists, and scientists interested in toxinology, drug discovery, and development of toxin-based products.

Direct Thrombin Inhibitors as an Alternative to Heparin During Catheter Ablation: A Multicenter Experience

OBJECTIVES

The goal of this study was to report a multicenter series of left-sided catheter ablations performed by using intravenous direct thrombin inhibitors (DTIs) as an alternative to heparin.

BACKGROUND

Amidst a looming worldwide shortage of heparin, there are insufficient data to guide nonheparin-based peri-procedural anticoagulation in patients undergoing catheter ablation.

METHODS

This study reviewed all catheter ablations at 6 institutions between 2006 and 2019 to assess the safety and efficacy of DTIs for left-sided radiofrequency catheter ablation of atrial fibrillation and ventricular tachycardia.

RESULTS

In total, 53 patients (age 63.0 ± 9.3 years, 68% male, CHA₂DS₂-VASc [congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke/transient ischemic attack, vascular disease, age 65 to 74 years, sex category] score 2.8 ± 1.6, left ventricular ejection fraction 46 ± 15%) underwent ablation with DTIs (75% bivalirudin, 25% argatroban) due to heparin contraindication(s) (72% heparin-induced thrombocytopenia, 21% heparin allergy, 4% protamine reaction, and 4% religious reasons). The patient's usual oral anticoagulant was continued without interruption in 69%. Procedures were performed for atrial fibrillation (64%) or ventricular tachycardia/premature ventricular contractions (36%). Transseptal puncture was undertaken in 81%, and a contact force-sensing catheter was used in 70%. Vascular ultrasound was used in 71%, and femoral arterial access was gained in 36%. A bolus followed by infusion was used in all but 4 cases, and activated clotting time was monitored peri-procedurally in 72%, with 32% receiving additional boluses. Procedure duration was 216 ± 116 min, and ablation time was 51 ± 22 min. No major bleeding or embolic complications were observed. Four patients had minor self-limiting bleeding complications, including a small pericardial effusion (<1 cm), a small groin hematoma, and hematuria.

CONCLUSIONS

In this multicenter series, intravenous DTIs were safely used as an alternative to heparin for left-sided catheter ablation.

Efficacy and safety of bivalirudin vs heparin in patients with coronary heart disease undergoing percutaneous coronary intervention: A meta-analysis of randomized controlled trials

BACKGROUND

This meta-analysis is to evaluate the efficacy and safety of bivalirudin in patients with ST-elevation myocardial infarction (STEMI).

METHODS

PubMed, Cochrane Library, Embase, CNKI, CBMdisc, and VIP database were searched. Randomized controlled trial (RCT) was selected and the meta-analysis was conducted by RevMan 5.1. The primary efficacy endpoint was the incidence of major adverse cardiovascular events (MACE) and the primary safety endpoint was the incidence of major bleeding. Secondary efficacy endpoints were myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis (ST), stock, mortality, and thrombocytopenia. The pooled risk ratios (RRs) with the corresponding 95% confidence intervals (CI) were used to assess the efficacy and safety of bivalirudin vs heparin.

RESULTS

Seven RCTs met the inclusion criteria, and 16,640 patients were included. We found that bivalirudin associated with lower risk of mortality (RR = 1.05; 95% CI = 0.74-1.49; P = .03; I = 2%), major bleeding (RR = 0.64; 95% CI = 0.54-0.75; P < .00001; I = 70%) and thrombocytopenia (RR = 0.39; 95% CI = 0.25-0.61; P < .0001; I = 0) compared with heparin. However, the use of bivalirudin increase the risk of MI(RR = 1.37; 95% CI = 1.10-1.71; P = .004; I = 25%) and ST(RR = 1.61; 95% CI = 1.05-2.47; P = .03; I = 70%) and has similar risk of MACE (RR = 1.00; 95% CI = 0.90-1.11; P = .97; I = 16%), TVR (RR = 1.43; 95% CI = 0.92-2.22; P = .11; I = 46%) and stock (RR = 1.43; 95% CI = 0.92-2.22; P = .11; I = 46%) compared with heparin used in STEMI patients.

CONCLUSION

Bivalirudin associated with lower risk of mortality, major bleeding and thrombocytopenia compared with heparin. However, the use of bivalirudin increase the risk of MI and ST and has similar risk of MACE, TVR and stock compared with heparin used in STEMI patients.

Exploration of Bivalirudin Use during Percutaneous Coronary Intervention for High Bleeding Risk Patients with Chronic Total Occlusion

The safety and efficacy of bivalirudin during percutaneous coronary intervention (PCI) in high bleeding risk patients with chronic total occlusion lesions (CTO) has not been studied till date. The use of bivalirudin may increase the thrombotic events during CTO-PCI.Between May 2013 and April 2014, a total of 117 high bleeding risk patients with CTOs underwent PCI. Bivalirudin was used in 89 cases with different strategies, including standard usage, combination of heparin, and additional bolus of bivalirudin on the basis of standard usage. The clinical characteristics, procedural details and antithrombotic strategies were assessed, and the bleeding and ischemic events were evaluated. The first 7 of 9 patients with standard application of bivalirudin exhibited acute thrombogenesis in the procedure. Heparin was then added in decreasing amounts in the next 8 patients wherein no thrombosis occurred; however, 2 patients had bleeding complications. The subsequent 72 patients were randomly assigned to the heparin bolus or additional bivalirudin bolus groups before the percutaneous transluminal coronary angioplasty (PTCA) was performed. The baseline clinical characteristics and procedure information were identical in both the groups. There were no ischemic and bleeding events in both the groups during the 6-month follow-up.Monotherapy with bivalirudin in CTO-PCI should be treated with caution, as the potential risk of thrombogenesis may be due to the long procedure time, the frequent change of equipment and temporary blood flow convection. Combination of heparin or an additional bolus of bivalirudin before PTCA was observed to be likely to decrease the incidence of thrombogenesis.

Impact of anticoagulation strategy with bivalirudin or heparin on nonaccess site bleeding in percutaneous coronary interventions: A meta-analysis of randomized trials

BACKGROUND

Transradial approach has significantly decreased the rate of access site bleeding in patients undergoing percutaneous coronary interventions (PCI), therefore potentially mitigating the benefits offered by bivalirudin in lowering major bleeding complications as compared to heparin. However, nonaccess site bleeding, that represent the majority of hemorrhagic complications, still carry negative prognostic consequences for these patients and no study has so far defined the exact impact of bivalirudin on nonaccess site bleeding, that was therefore the aim of present meta-analysis.

METHODS AND STUDY OUTCOMES

Literature archives (Pubmed, EMBASE, Cochrane) and main scientific sessions were scanned comparing bivalirudin vs. heparin in patients undergoing PCI. Primary endpoint was the occurrence of nonaccess site bleeding within 30 days. Secondary endpoints were 30 days mortality and the occurrence of access-site bleeding.

RESULTS

A total of nine randomized clinical trials were finally included, involving 32,587 patients, 55.8% randomized to bivalirudin. Bivalirudin significantly reduced the rate of nonaccess site bleeding (2.6 vs. 3.8%, OR [95% CI] = 0.68 [0.60-0.77], P < 0.00001, P_het  = 0.10). However, the reduction of hemorrhagic events was more pronounced when bivalirudin was compared to heparin plus glycoprotein IIbIIIa inhibitors than when it was compared to heparin alone (r = -0.01 (-0.02; -0.001), P = 0.02). Similar results were observed for access-site bleeding (OR [95% CI] = 0.67 [0.57-0.79], P < 0.000001, P_het  = 0.10), with a significant role of glycoprotein IIbIIIa inhibitors use (r = -0.02 (-0.04; -0.004), P = 0.017). Moreover, the observed benefits in hemorrhagic complications did not translate into mortality benefits (OR [95% CI] = 0.89 [0.76-1.05], P = 0.18; P_het  = 0.12; r = 0.21 (-1.12; 1.53), P = 0.76).

CONCLUSIONS

The present meta-analysis shows that bivalirudin can provide a significant reduction of both access and nonaccess site bleeding in patients undergoing PCI. However, these hemorrhagic benefits did not impact on survival, and moreover, were significantly conditioned by the association of heparin with potent antithrombotic strategies, such as glycoprotein IIbIIIa inhibitors, rather than by heparin or bivalirudin alone. Therefore, we could not provide any clinical evidence for the routine use of bivalirudin as preferred anticoagulation strategy for PCI. © 2017 Wiley Periodicals, Inc.

Cardiac Catheter Laboratory Based Computer Generated Bivalirudin/Glycoprotein IIb/IIIa Flow Sheet

Bivalirudin and glycoprotein IIb/IIIa antagonists are commonly used during percutaneous coronary interventions (PCI). The Pharmacy Department of Charlton Memorial Hospital implemented a dosing flow sheet that is operated by the Cardiac Catheter Lab nursing staff. The computer-oriented program utilizes the Microsoft Excel spreadsheet program. The computer spreadsheet calculates an estimated creatinine clearance (CrCl) rate and inserts proper renal adjusted dosages of both bivalirudin and glycoprotein IIb/IIIa antagonists into a printed flow sheet. The computer program is encoded to follow specific medication regimens for patients whether or not they are on dialysis. Institutions can develop medication dosing flow-sheet forms utilizing the spreadsheet concept.

Efficacy and safety of bivalirudin versus heparin in patients with diabetes mellitus undergoing percutaneous coronary intervention: A meta-analysis of randomized controlled trials

BACKGROUND

The efficacy and safety of bivalirudin (Biva) versus heparin in patients with diabetes mellitus (DM) who undergo percutaneous coronary intervention (PCI) remain controversial. Our meta-analysis was undertaken to evaluate the efficacy and safety of Biva compared with those of heparin in patients with diabetes undergoing PCI.

METHODS

We searched PubMed, EMBASE, Cochrane Library, and Clinical Trials.gov databases for randomized controlled trials (RCTs). The primary efficacy endpoint was the incidence of major adverse cardiovascular events (MACE), and the primary safety endpoint was the incidence of major bleeding. Secondary efficacy endpoints were incidence of net adverse clinical events (NACE), myocardial infarction (MI), and death. The pooled risk ratio (RR) with the corresponding 95% confidence intervals (CIs) were used to assess the efficacy and safety of Biva versus heparin.

RESULTS

Eleven RCTs met the inclusion criteria, and 8428 patients were included. No significant difference was observed in the subgroup and overall risk of MACE (RR 0.87; 95% CI 0.74-1.02; P = .08; I = 39%) and NACE (RR 0.81; 95% CI 0.61-1.07; P = .14; I = 71%). Biva had an effect similar to that of heparin on the endpoint of death (RR 0.75; 95% CI 0.56-1.02; P = .07; I = 0) and MI (RR 0.92; 95% CI 0.67-1.26; P = .59; I = 0) but decreased the risk of major bleeding (RR 0.63; 95% CI 0.52-0.75; P < .00001; I = 0%).

CONCLUSION

The use of Biva and heparin is associated with a similar risk of MACE, NACE, death, and MI. Biva decreases the risk of major bleeding more significantly than heparin.

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.

Heparin Versus Bivalirudin in Acute Myocardial Infarction: Unfractionated Heparin Monotherapy Elevated to Primary Treatment in Contemporary Percutaneous Coronary Intervention

Bivalirudin, a direct thrombin inhibitor, was developed as an antithrombin agent for patients undergoing percutaneous coronary interventions (PCI) with the hypothesis that it would reduce bleeding complications without compromising the rate of ischemic events compared to heparin plus GP IIb/IIIa inhibitors. Although the cumulative evidence makes a strong argument for the use of bivalirudin rather than heparin plus systematic GP IIb/IIIa inhibitors for the great majority of patients with acute myocardial infarction (AMI) undergoing PCI, the benefit observed with bivalirudin was achieved because of the major bleeding complications with the use of heparin plus GP IIb/IIIa inhibitors. When bivalirudin was compared with unfractionated heparin alone there was no benefit in ischemic complications with a decrease in major bleeding. However, in a recent large randomized controlled trial comparing bivalirudin with unfractionated heparin alone in AMI patients undergoing primary PCI, bivalirudin did not reduce bleeding complications and was associated with higher rates of stent thrombosis, myocardial reinfarction, and repeat revascularization compared with heparin. Moreover, a very recent meta-analysis shed more insights on the utilization of bivalirudin versus heparin regimens during PCI. Findings from this meta-analysis suggest that routine use of bivalirudin offers little advantage over heparin among PCI patients. In a detailed analysis of some randomized trials and observational studies with bivalirudin in AMI patients done by myself and published almost five years ago in this journal, I rendered some reflections on the future widespread use of bivalirudin. “In the setting of PCI in AMI patients, and in the absence of GP IIb/IIIa inhibitors, bivalirudin did not offer any beneficial effect in the incidence of the composite end points when compared with heparin alone. For now, in real world practice, one would probably choose a well known cheaper drug that has already passed the test of time, heparin. There may be reinforcement in the sole utilization of heparin confining GP IIb/IIIa inhibitors and other intravenous antithrombotics to bailout therapy for periprocedural PCI complications in AMI patients”. Therefore, instead of being the beginning of a new era with bivalirudin, it sure is a welcome back to an old friend, heparin. Indeed, after more than two decades, it is always good to welcome back an old friend, unfractionated heparin, as monotherapy and preferred anticoagulant regimen for contemporary PCI in AMI patients.

Bivalirudin vs Heparin in Percutaneous Coronary Intervention: A Pooled Analysis

Objective: This study evaluates outcomes with bivalirudin vs heparin in various patient subgroups and the overall population during percutaneous coronary interventions (PCI). Background: Recent data suggest that bivalirudin, a reversible direct thrombin inhibitor, provides ischemic protection superior to heparin and comparable to heparin plus glycoprotein (GP) IIb/IIIa inhibitors but with significantly fewer bleeding complications. Whether this advantage persists in different subgroups has not been fully defined. To our knowledge, this is the largest pooled analysis of bivalirudin to date.

Methods: Four randomized controlled trials were identified that compared bivalirudin to heparin (with or without GP IIb/IIIa inhibitors) in PCI. The incidence of death, myocardial infarction (MI), revascularization, and major bleeding at 48 hours was compared between these two agents overall and in patients with and without diabetes mellitus, hypertension, renal insufficiency, and advanced age.

Results: The trials consisted of 11,638 patients (bivalirudin, 5,861; heparin, 5,777). There were no significant differences in patient characteristics between the two groups. At 48 hours, the incidence of death, MI, revascularization, and major bleeding was significantly reduced in the bivalirudin group (7.8% vs 1.08%, P < .001); individual ischemic end points were significantly reduced for death (0.01% vs 0.02%, P = .049) and revascularization (2.0% vs 2.7%, P = .02), with similar reductions for major bleeding (2.7% vs 5.8%, P < .001). Subgroup analysis was generally consistent with the overall findings.

Conclusion: This analysis further supports the superiority of bivalirudin compared with heparin. Bivalirudin provides excellent ischemic protection with a significant reduction of bleeding complications, even in high-risk subgroups.

Efficacy and Safety of Bivalirudin Versus Heparins in Reduction of Cardiac Outcomes in Acute Coronary Syndrome and Percutaneous Coronary Interventions

Recent data suggest that bivalirudin, a reversible direct thrombin inhibitor, may be noninferior to heparins (unfractionated heparin/low molecular weight heparin) in providing protection against cardiovascular events, with significantly fewer bleeding complications. Whether this advantage is consistent has not been fully defined. We evaluated cardiac outcomes with bivalirudin vs the heparins in management of acute coronary syndromes (ACS), including patients undergoing percutaneous coronary interventions (PCI). Formal computer-aided searches of electronic databases (MEDLINE, PubMed, Cochrane Controlled Trials Registry) were performed by scrutiny of the reference lists of trials and review articles, abstracts, meeting proceedings, and the manufacturers of direct thrombin inhibitors. Five randomized controlled trials (BAT, 1995; CACHET, 2002; REPLACE-2, 2003; REPLACE-1, 2004; and ACUITY, 2006) comparing bivalirudin to the heparins in patients with ACS, including patients undergoing PCI, were identified. The meta-analysis consisted of 25 457 patients (bivalirudin, 15 077; heparins, 10 380). The primary safety end point was major bleeding, defined as intracranial, intraocular, or retroperitoneal hemorrhage; clinically overt blood loss leading to a hemoglobin drop exceeding 3 g/dL (or 10% of hematocrit) and transfusion of 2 or more units of whole blood or packed red blood cells. The combined relative risks (RR) across all of the studies and the 95% confidence intervals of death, myocardial infarction (MI), and revascularization (bivalirudin vs heparins) were computed using the Mantel-Haenszel fixed-effect model, whereas the random-effect model was used for major bleeding. A 2-sided α error < .05 was considered to be significant. There were no significant differences in patient characteristics between the 2 groups. Compared to the heparins, the risk of death, MI, revascularization, and composite ischemic end points were similar with bivalirudin monotherapy. However, the risk of major bleeding was significantly lower with bivalirudin use (RR = 0.553; 95% CI = 0.402-0.761; P = .001). The present meta-analysis suggests that bivalirudin may be noninferior to the heparins in reducing the composite of ischemic end points. Additionally, compared to the heparins, bivalirudin monotherapy may lower the rate of major bleeding.

Trends in use of anti-thrombotic agents and outcomes in patients with non-ST-segment elevation myocardial infarction (NSTEMI) managed with an invasive strategy

Objective

To analyze trends in utilization of anti-thrombotic agents (ATA) and in-hospital clinical outcomes in non-ST-elevation myocardial infarction (NSTEMI) patients managed with an invasive strategy from 2007 to 2010.

Methods & results

Using ACTION Registry^®-GWTG™ data, we analyzed trends in use of ATA and in-hospital clinical outcomes among 64,199 NSTEMI patients managed invasively between 2007 and 2010. ATA included unfractionated heparin (UFH), low molecular weight heparin (LMWH), glycoprotein IIb/IIIa inhibitors (GPI) and bivalirudin. Although the proportion of NSTEMI patients treated with PCI within 48 h of hospital arrival was similar in 2007 and 2010, percentage use of bivalirudin (13.4–27.3%; p < 0.01) and UFH increased (60.0–67.5%, p < 0.01), and that of GPI (62.3–41.0%; p < 0.01) and LMWH (41.5–36.8%; p < 0.01) declined. Excess dosing of UFH (75.9–59.3%, p < 0.01), LMWH (9.6–5.2%; p < 0.01) and GPI (8.9–5.9%, p < 0.01) was also significantly lower in 2010 compared with 2007. Though in-hospital mortality rates were similar in 2007 and 2010 (2.3–1.9%, p = 0.08), the rates of in-hospital major bleeding (8.7–6.6%, p < 0.01) and non-CABG related RBC transfusion (6.3–4.6%, p < 0.01) were significantly lower in 2010 compared with 2007.

Conclusion

Compared with 2007, patients with NSTEMI, who were managed invasively in 2010 received GPI and LMWH less often and bivalirudin and UFH more frequently. There were sizeable reductions in the rates of excess dosing of UFH (though still occurred in 67% of patients), GPI and LMWH. In-hospital major bleeding complications and post-procedural RBC transfusion were lower in 2010 compared with 2007.

Investigational new drugs for the treatment of acute coronary syndrome

INTRODUCTION

Ischemic heart disease is the most common cause of death worldwide. Despite improvements in interventional and pharmacological therapy for acute coronary syndrome (ACS), the risk of recurrent myocardial ischemia and mortality early after ACS remains high. Our improved understanding of the increasing role of inflammation in the pathogenesis of ACS and its relationship to atherosclerotic plaque rupture and thrombosis has led to the development of more potent anti-thrombotic and novel anti-inflammatory therapies for the treatment of ACS.

AREAS COVERED

In this review, the authors explore: the developing pharmacotherapy in the field of cardiology for ACS; antiplatelet agents (both further development of classical modalities together with pioneering agents); evolving use of anticoagulation in its treatment, and exploration in the use of novel anti-inflammatories and biological agents.

EXPERT OPINION

Data from trials involving the use of immunological and cellular-based treatments show promising results and herald further possible reduction in infarct burden in ACS alongside the possibility of recovery in cardiac function following infarction.

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.

Heparin Versus Bivalirudin in Contemporary Percutaneous Coronary Intervention: A Welcome Back to an Old Friend Unfractionated Heparin

The results of randomized trials and observational studies make a strong argument for the use of bivalirudin rather than heparin plus systematic glycoprotein (GP) IIb/IIIa inhibitors for the great majority of patients undergoing percutaneous coronary interventions (PCI). However, there is no doubt that the benefit observed with bivalirudin was achieved because of the major bleeding complications with heparin plus GP IIb/IIIa inhibitors. Therefore, if we diminish bleeding complications by eliminating the systematic utilization of GP IIb/IIIa inhibitors, there would be a lesser benefit with the use of bivalirudin. When this latter drug was compared with unfractionated heparin alone there was no benefit in ischemic complications but a decrease in major bleeding complications with bivalirudin. However, a very recent meta-analysis shed more insights on the utilization of bivalirudin versus heparin regimens during PCI. Findings from this meta-analysis suggest that routine use of bivalirudin offers little advantage over heparin among PCI patients. In a detailed analysis of some randomized trials and observational studies with bivalirudin in non-ST-segment elevation acute coronary syndrome patients done by myself and published almost 4 years ago in this journal, I rendered some reflections on the future widespread use of bivalirudin. "In the setting of PCI and in the absence of GP IIb/IIIa inhibitors, bivalirudin did not offer any beneficial effect in the incidence of the composite end points when compared with heparin. For now, in real world practice, one would probably choose a well-known cheaper drug that has already passed the test of time, heparin. There may be reinforcement in the sole utilization of heparin confining GP IIb/IIIa inhibitors and other intravenous antithrombotics to bailout therapy for periprocedural PCI complications in acute coronary syndrome patients." Therefore, is it the beginning of a new era with bivalirudin or is it a welcome back to an old friend, heparin? Indeed, after more than two decades, it is always good to welcome back an old friend, unfractionated heparin.

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.

Adaptive control of bivalirudin in the cardiac intensive care unit

Bivalirudin is a direct thrombin inhibitor used in the cardiac intensive care unit when heparin is contraindicated due to heparin-induced thrombocytopenia. Since it is not a commonly used drug, clinical experience with its dosing is sparse. In earlier work [1], we developed a dynamic system model that accurately predicts the effect of bivalirudin given dosage over time and patient physiological characteristics. This paper develops adaptive dosage controllers that regulate its effect to desired levels. To that end, and in the case that bivalirudin model parameters are available, we develop a Model Reference Control law. In the case that model parameters are unknown, an indirect Model Reference Adaptive Control scheme is applied to estimate model parameters first and then adapt the controller. Alternatively, direct Model Reference Adaptive Control is applied to adapt the controller directly without estimating model parameters first. Our algorithms are validated using actual patient data from a large hospital in the Boston area.

Bivalirudin is superior to heparins alone with bailout GP IIb/IIIa inhibitors in patients with ST-segment elevation myocardial infarction transported emergently for primary percutaneous coronary intervention: a pre-specified analysis from the EUROMAX trial

Aims

In the HORIZONS trial, in-hospital treatment with bivalirudin reduced bleeding and mortality in primary percutaneous coronary intervention (PCI) compared with heparin and routine glycoprotein IIb/IIIa inhibitors (GPI). It is unknown whether this advantage of bivalirudin is observed in comparison with heparins only with GPI used as bailout.

Methods and results

In the EUROMAX study, 2198 patients with ST-segment elevation myocardial infarction (STEMI) were randomized during transport for primary PCI to bivalirudin or to heparins with optional GPI. Primary and principal outcome was the composites of death or non-CABG-related major bleeding at 30 days. This pre-specified analysis compared patients receiving bivalirudin (n = 1089) with those receiving heparins with routine upstream GPI (n = 649) and those receiving heparins only with GPI use restricted to bailout (n = 460). The primary outcome death and major bleeding occurred in 5.1% with bivalirudin, 7.6% with heparin plus routine GPI (HR 0.67 and 95% CI 0.46–0.97, P = 0.034), and 9.8% with heparins plus bailout GPI (HR 0.52 and 95% CI 0.35–0.75, P = 0.006). Following adjustment by logistic regression, bivalirudin was still associated with significantly lower rates of the primary outcome (odds ratio 0.53, 95% CI 0.33–0.87) and major bleeding (odds ratio 0.44, 95% CI 0.24–0.82) compared with heparins alone with bailout GPI. Rates of stent thrombosis were higher with bivalirudin (1.6 vs. 0.6 vs. 0.4%, P = 0.09 and 0.09).

Conclusion

Bivalirudin, started during transport for primary PCI, reduces major bleeding compared with both patients treated with heparin only plus bailout GPI and patients treated with heparin and routine GPI, but increased stent thrombosis.

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.

Bivalirudin: an anticoagulant option for percutaneous coronary intervention

Coronary artery thrombosis is usually triggered by platelet-rich thrombus superimposed on a spontaneously or mechanically disrupted atherosclerotic plaque. Thrombin and platelets both play a role in this process. Unfractionated heparin and aspirin have served as cornerstones in the prevention and treatment of intracoronary thrombus, but unfractionated heparin has several limitations that necessitate the use of adjunctive therapies, such as glycoprotein IIb/IIIa receptor inhibitors and clopidogrel, in order to reduce the risk of ischemic events. These combination therapies, however, typically increase the risk for bleeding complications, as well as the cost and complexity of treatment. Bivalirudin (Angiomax, The Medicines Company), a thrombin-specific anticoagulant, does not share heparin's limitations. Bivalirudin appears to provide clinical advantages over unfractionated heparin therapy in acute coronary syndrome patients and those undergoing percutaneous coronary intervention, without increasing cost or complexity of treatment for most patients.