Bivalirudin: Pharmacology and Clinical Applications

One-year clinical outcomes of bivalirudin versus unfractionated heparin in patients with type 2 diabetes undergoing elective percutaneous coronary intervention

BACKGROUND

Patients with diabetes and coronary artery disease have a higher risk of bleeding and thrombotic events. However, data on the safety and efficacy of bivalirudin in these patients undergoing elective percutaneous coronary intervention (PCI) are lacking.

METHODS

1152 patients undergoing elective PCI anticoagulated with bivalirudin and 10,250 patients anticoagulated with unfractionated heparin (UFH) (with or without glycoprotein IIb/IIIa inhibitors [GPI]) were performed propensity-score matching method. The thrombotic endpoint was major adverse cardiovascular and cerebrovascular events (MACCE). The bleeding endpoint was according to the Bleeding Academic Research Consortium (BARC) 2, 3 or 5 bleeding.

RESULTS

Finally, 376 (bivalirudin group) and 878 (UFH group) patients with type 2 diabetes (T2D) were enrolled. After one-year follow-up, there were 130 (10.4%) MACCE and 27 (2.2%) bleeding events occurred. Multivariate COX regression analysis showed no significant difference for MACCE between bivalirudin group and UFH group (P > 0.05). Further analysis showed that there was a reduction in the risk of myocardial infarction (MI) between two groups (Hazard ratio [HR] = 0.199, 95% confidence interval [CI]: 0.047-0.845, P = 0.029), but not in the risk of death, revascularization, stent thrombosis or stroke (all P > 0.05). As for BARC 2, 3 or 5 bleeding, no significant difference was found between two groups (P > 0.05).

CONCLUSIONS

Although diabetes is considered a high-risk factor for poor prognosis, compared with UFH (with or without GPI), bivalirudin did not increase the risk of MACCE and even decreased the risk of MI in patients with T2D undergoing elective PCI, while the risk of bleeding was similar between two groups.

Prolonged infusion of bivalirudin after elective percutaneous coronary intervention protects against procedural myocardial injury (a COBER study)-a randomized trial

Procedural myocardial injury (PMI), which is the most common complication of elective percutaneous coronary intervention (ePCI), is associated with future adverse cardiac events. In this randomized pilot trial, we assessed the effects of prolonged use of the anti-coagulant bivalirudin on PMI after ePCI. Patients undergoing ePCI were randomized into the following two groups: the bivalirudin use during operation group (BUDO, 0.75 mg/kg bolus plus 1.75 mg/kg/h) and the bivalirudin use during and after operation for 4 h (BUDAO, 0.75 mg/kg bolus plus 1.75 mg/kg/h). Blood samples were collected before and 24 h after ePCI (per 8 h). The primary outcome, PMI, was defined as an increase in post-ePCI cardiac troponin I (cTnI) levels of > 1 × 99th% upper reference limit (URL) when the pre-PCI cTnI was normal or a rise in cTnI of > 20% of the baseline value when it was above the 99th percentile URL, but it was stable or falling. Major PMI (MPMI) was defined as a post-ePCI cTnI increase of > 5 × 99th% URL. A total of 330 patients were included (n = 165 per group). The incidences of PMI and MPMI were not significantly higher in the BUDO group than in the BUDAO group (PMI: 115 [69.70%] vs. 102 [61.82%], P = 0.164; MPMI: 81 [49.09%] vs. 70 [42.42%], P = 0.269). However, the absolute change in cTnI levels (calculated as the peak value 24 h post-PCI minus the pre-PCI value) was notably larger in the BUDO group (0.13 [0.03, 1.95]) than in the BUDAO group (0.07 [0.01, 0.61]) (P = 0.045). Moreover, the incidence of bleeding events was similar between the two groups (BUDO: 0 [0.00%]; BUDAO: 2 [1.21%], P = 0.498). Prolonged infusion of bivalirudin for 4 h after ePCI reduces PMI severity without increasing the risk of bleeding.ClinicalTrials.gov.Number: NCT04120961, 09/10/2019.

Heparin Versus Bivalirudin for Anticoagulation in Adult Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis

Extracorporeal membrane oxygenation (ECMO) poses unique thrombotic and hemorrhagic risks, and the optimal anticoagulant choice is unknown. We systematically searched Ovid EBM Reviews, Ovid Embase, Ovid Medline, Scopus, and Web of Science Core Collection for randomized-, crossover-, retrospective cohort-, or parallel-designed clinical studies of adult patients receiving ECMO that compared heparin recipients with bivalirudin recipients. Meta-analysis was performed with random-effects models. The ROBINS-I tool was used to assess the risk of bias. Six retrospective observational studies met the inclusion criteria for the qualitative summary. Five studies were suitable for meta-analysis. Those who received heparin were more likely to experience circuit-related thrombosis (odds ratio [OR] 2.05, 95% confidence interval [CI] 1.25-3.37, p = 0.005, I2 = 0%) and die (OR 1.62, 95% CI 1.19-2.21, p = 0.002, I2 = 0%) compared with those who received bivalirudin. There were no differences in major bleeding events between heparin and bivalirudin recipients (OR 1.83, 95% CI 0.55-6.09, p = 0.33, I2 = 82.7%). In retrospective settings compared with heparin anticoagulation, bivalirudin was associated with less circuit-related thrombotic events and greater survival in adults supported on ECMO, without contributing to more bleeding complications. Prospective controlled studies comparing heparin and bivalirudin in adult ECMO patients are warranted to corroborate these findings.

How to Solve the Conundrum of Heparin-Induced Thrombocytopenia during Cardiopulmonary Bypass

Heparin-induced thrombocytopenia (HIT) is a major issue in cardiac surgery requiring cardiopulmonary bypass (CPB). HIT represents a severe adverse drug reaction after heparin administration. It consists of immune-mediated thrombocytopenia paradoxically leading to thrombotic events. Detection of antibodies against platelets factor 4/heparin (anti-PF4/H) and aggregation of platelets in the presence of heparin in functional in vitro tests confirm the diagnosis. Patients suffering from HIT and requiring cardiac surgery are at high risk of lethal complications and present specific challenges. Four distinct phases are described in the usual HIT timeline, and the anticoagulation strategy chosen for CPB depends on the phase in which the patient is categorized. In this sense, we developed an institutional protocol covering each phase. It consisted of the use of a non-heparin anticoagulant such as bivalirudin, or the association of unfractionated heparin (UFH) with a potent antiplatelet drug such as tirofiban or cangrelor. Temporary reduction of anti-PF4 with intravenous immunoglobulins (IvIg) has recently been described as a complementary strategy. In this article, we briefly described the pathophysiology of HIT and focused on the various strategies that can be applied to safely manage CPB in these patients.

Occurrence and Risk Factors of Adverse Drug Reactions in Patients Receiving Bivalirudin as Anticoagulant During Percutaneous Coronary Intervention: A Prospective, Multi-Center, Intensive Monitoring Study

Background

Bivalirudin is a common anticoagulant during percutaneous coronary intervention (PCI); however, since its application in China, it still lacks comprehensive evaluation of adverse events (AEs) or adverse drug reactions (ADRs) under the real-clinical setting conditions with a large-sample-size population. Therefore, this prospective, multi-center, intensive monitoring study aimed to comprehensively investigate the occurrence and risk factors of AEs and ADRs during PCI with bivalirudin as an anticoagulant.

Methods

A total of 3,049 patients who underwent PCI with bivalirudin as anticoagulant from 27 Chinese medical centers were enrolled. Safety data (AEs/ADRs) were collected from hospital admission to 72 h after bivalirudin administration; then, patients were followed up at the 30th day with the safety data collected as well.

Results

A total of 414 (13.58%) patients occurred AEs, among which 31 (1.02%) cases suffered from severe AEs and 8 (0.26%) cases died due to AEs. Importantly, 118 (3.87%) patients occurred bivalirudin related ADRs, among which 7 (0.23%) cases suffered from severe ADRs while no case (0%) died due to ADRs. Of note, 7 (0.23%) patients showed new ADRs, 34 (1.12%) patients experienced bleeding, and 79 (2.59%) patients had thrombocytopenia. Furthermore, age, renal function impairment, CRUSADE high risk stratification independently correlated with total ADRs risk; CRUSADE high risk stratification, emergency operation, full dose bivalirudin independently associated with bleeding risk; age, renal function impairment independently related to thrombocytopenia risk.

Conclusion

Bivalirudin is well-tolerated as an anticoagulant for PCI procedure; meanwhile, older age, renal function impairment, and CRUSADE high risk stratification serve as independent risk factors of bivalirudin related ADRs.

Impact of Diabetes Mellitus on One-Year Clinical Outcomes in Patients Anticoagulated with Bivalirudin Undergoing Elective Percutaneous Coronary Intervention

Background: Patients with diabetes mellitus (DM) are considered to increase the risk of thrombosis and bleeding. However, whether DM is an independent risk factor for events in patients anticoagulated with bivalirudin during elective percutaneous coronary intervention (PCI) is not clear. Methods: Patients anticoagulated with bivalirudin during elective PCI from January 2017 to August 2018 in 3 centers were enrolled. The primary endpoint of thrombotic events was major adverse cardiac and cerebrovascular events (MACCE, including all-cause death, myocardial infarction, ischemic revascularization, stent thrombosis, and stroke); the primary endpoint of bleeding events was Bleeding Academic Research Consortium (BARC) 2, 3 or 5 bleeding. Results: 1152 patients were finally enrolled. After one-year follow-up, 89 (7.7%) MACCE and 21 (1.8%) BARC 2, 3 or 5 bleeding occurred. Multivariate Cox regression analysis showed DM was not an independent risk factor for MACCE (hazard ratio [HR]: 1.029, 95% confidence interval [CI]: 0.674-1.573, P = .893), but peripheral artery disease (PAD) history (HR: 2.200, 95%CI: 1.290-3.751, P = .004) was an independent risk factor for MACCE. DM was not an independent risk factor for BARC 2, 3 or 5 bleeding (HR: 0.732, 95%CI: 0.293-1.831, P = .505), but PAD history (HR: 3.029, 95%CI: 1.102-8.332, P = .032) and low hemoglobin level (HR = 0.972, 95%CI: 0.947-0.998, P = .036) were independent risk factors for BARC 2, 3 or 5 bleeding. Conclusions: DM was not an independent risk factor for one-year thrombotic and bleeding events in patients anticoagulated with bivalirudin during elective PCI. More attention should be paid to PAD history and hemoglobin level to identify high-risk patients.

Bivalirudin and thrombolytic therapy: a novel successful treatment of severe aortic arch thrombosis in a term neonate

An early-term infant with uncomplicated perinatal history was found to have a large thrombus in the aortic arch after he failed regular newborn critical congenital heart defect screen. He responded well to bivalirudin thrombolytic and tissue-plasminogen activator (tPA) combination therapy, with a significant resolution of the thrombus. The infant tolerated hospital admission well with no significant complications. He was discharged home on daily aspirin at 2 weeks of life. To our knowledge, the combination therapy approach with bivalirudin and tPA is the first one reported in the literature in the neonatal age group.

Age-specific differences in the in vitro anticoagulant effect of Bivalirudin in healthy neonates and children compared to adults

Bivalirudin is a reversible direct thrombin inhibitor that inhibits both bound and free thrombin and binds to the active (catalytic) and fibrinogen-binding sites of thrombin, with high affinity and specificity. Off-label use of bivalirudin in the paediatric population has increased, as an alternative to heparin, particularly in the setting of anticoagulation for patients undergoing coronary bypass surgery (CPB), extracorporeal life support (ECLS) and those on ventricular assist devices (VAD). This study aimed to determine the age-specific in vitro effect of bivalirudin in children compared to adults. Age-specific pools (neonates, ≤2 years, >2 to 5 years, 6 to 10 years, 11 to 17 years and Adults) were prepared using platelet poor plasma samples from 20 individuals per age group. Pooled plasma was spiked with increasing concentrations of Bivalirudin (from 0 g/mL to 10μg/mL), and thrombin inhibition was measured using standard coagulation assays. There was a significantly increased response to bivalirudin across all paediatric age groups as compared to adults. The age-specific difference in response to bivalirudin was specifically evident in neonates, where the potential to generate thrombin was decreased 2-fold compared to adults (p < 0.001). Our findings support the concept of age-specific pharmaco-dynamic responses to Bivalirudin and support the need for further ex vivo studies in hospitalised children to determine accurate clinical dosing recommendations.

Pharmacokinetics of Toxin-Derived Peptide Drugs

Toxins and venoms produced by different organisms contain peptides that have evolved to have highly selective and potent pharmacological effects on specific targets for protection and predation. Several toxin-derived peptides have become drugs and are used for the management of diabetes, hypertension, chronic pain, and other medical conditions. Despite the similarity in their composition (amino acids as the building blocks), toxin-derived peptide drugs have very profound differences in their structure and conformation, in their physicochemical properties (that affect solubility, stability, etc.), and subsequently in their pharmacokinetics (the processes of absorption, distribution, metabolism, and elimination following their administration to patients). This review summarizes and critically analyzes the pharmacokinetic properties of toxin-derived peptide drugs: (1) the relationship between the chemical structure, physicochemical properties, and the pharmacokinetics of the specific drugs, (2) the major pharmacokinetic properties and parameters of these drugs, and (3) the major pharmacokinetic variability factors of the individual drugs. The structural properties of toxin-derived peptides affect their pharmacokinetics and pose some limitations on their clinical use. These properties should be taken into account during the development of new toxin-derived peptide drugs, and for the efficient and safe use of the clinically approved drugs from this group in the individual patients.

Using Drosophila behavioral assays to characterize terebrid venom-peptide bioactivity

The number of newly discovered peptides from the transcriptomes and proteomes of animal venom arsenals is rapidly increasing, resulting in an abundance of uncharacterized peptides. There is a pressing need for a systematic, cost effective, and scalable approach to identify physiological effects of venom peptides. To address this discovery-to-function gap, we developed a sequence driven:activity-based hybrid approach for screening venom peptides that is amenable to large-venom peptide libraries with minimal amounts of peptide. Using this approach, we characterized the physiological and behavioral phenotypes of two peptides from the venom of predatory terebrid marine snails, teretoxins Tv1 from Terebra variegata and Tsu1.1 from Terebra subulata. Our results indicate that Tv1 and Tsu1.1 have distinct bioactivity. Tv1 (100 µM) had an antinociceptive effect in adult Drosophila using a thermal nociception assay to measure heat avoidance. Alternatively, Tsu1.1 (100 µM) increased food intake. These findings describe the first functional bioactivity of terebrid venom peptides in relation to pain and diet and indicate that Tv1 and Tsu1.1 may, respectively, act as antinociceptive and orexigenic agents. Tv1 and Tsu1.1 are distinct from previously identified venom peptides, expanding the toolkit of peptides that can potentially be used to investigate the physiological mechanisms of pain and diet.

Thromboprophylaxis in Extracorporeal Circuits: Current Pharmacological Strategies and Future Directions

The development of extracorporeal devices for organ support has been a part of medical history and progression since the late 1900s. These types of technology are primarily used and developed in the field of critical care medicine. Unfractionated heparin, discovered in 1916, has really been the only consistent form of thromboprophylaxis for attenuating or even preventing the blood-biomaterial reaction that occurs when such technologies are initiated. The advent of regional anticoagulation for procedures such as continuous renal replacement therapy and plasmapheresis have certainly removed the risks of systemic heparinization and heparin effect, but the challenges of the blood-biomaterial reaction and downstream effects remain. In addition, regional anticoagulation cannot realistically be applied in a system such as extracorporeal membrane oxygenation because of the high blood flow rates needed to support the patient. More recently, advances in the technology itself have resulted in smaller, more compact extracorporeal life support (ECLS) systems that can-at certain times and in certain patients-run without any form of anticoagulation. However, the majority of patients on ECLS systems require some type of systemic anticoagulation; therefore, the risks of bleeding and thrombosis persist, the most devastating of which is intracranial hemorrhage. We provide a concise overview of the primary and alternate agents and monitoring used for thromboprophylaxis during use of ECLS. In addition, we explore the potential for further biomaterial and technologic developments and what they could provide when applied in the clinical arena.

Novel method using rotational thromboelastography analysis for intraoperative management of device patient with heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a prothrombotic disease in response to previous heparin exposure. Direct thrombin inhibitors are suitable candidates for the prophylaxis of thrombosis in patients with HIT. Currently activated clotting time and activated partial thromboplastin time are used to guide dosing and monitor anticoagulation. These assays provide a measure of clot initiation and only account for a small fraction of the coagulation pathway. In this case study we performed rotational thromboelastography (ROTEM) analysis on a patient with HIT implanted with a continuous-flow CentriMag device for left ventricular support. ROTEM evaluation confirmed a decline in activated clotting time values and provided further information regarding intrinsic and extrinsic clotting times. Monitoring ROTEM parameters aided in the detection of coagulopathies and the decision to administer platelet or fresh frozen plasma products. Utilizing ROTEM can guide clinical decisions in transfusions, particularly in patients with HIT, where platelet and fibrinogen levels can be safely maintained to prevent thrombosis.

Clot-targeted micellar formulation improves anticoagulation efficacy of bivalirudin

Application of anticoagulants remains the primary strategy for prevention and treatment of thrombosis. However, high rate of bleeding complications limits their use. The peptide anticoagulant bivalirudin has been reported to exhibit a lower rate of bleeding complications than heparin, and it also has the advantage of not causing thrombocytopenia, which is a problem with heparin. Nonetheless, hemorrhage is the most common complication of bivalirudin therapy, and there is no effective antidote. Here we use a thrombus-binding peptide, CR(NMe)EKA, to accomplish selective delivery of the bivalirudin-carrying micellar nanocarrier to sites of thrombosis. Bivalirudin and CR(NMe)EKA, each with a PEG-lipid tail, spontaneously assembled into 30 nm micelles, which almost completely retained the anticoagulant activity of bivalirudin. The micellar formulations exhibited high stability both in vitro and in vivo. In a thromboplastin-induced mouse thrombosis model, the targeted micelles accumulated in lung thrombi 10-fold more than nontargeted micelles. Moreover, the micellar formulation significantly prolonged the half-life and thereby increased the bioavailability of bivalirudin. The micellar bivalirudin had significantly higher anticoagulant activity than free bivalirudin in both the lung thrombosis model and a ferric chloride-induced carotid artery thrombosis model. The specific targeting of thrombi demonstrated here makes it possible to increase the efficacy of bivalirudin as an anticoagulant. Alternatively, the dose could be reduced without loss of efficacy to lower the systemic exposure and improve safety.

Carotid stenting and bivalirudin with and without vascular closure: 3-year analysis of procedural outcomes

OBJECTIVES

The purpose of this study was to examine the outcome of carotid stenting using bivalirudin and the influence of vascular closure devices (VCD) on the incidence and severity of peri-procedural hypotension.

BACKGROUND

Bivalirudin, a short-acting direct thrombin inhibitor, has been shown to be an effective anticoagulant in coronary interventions, with less risk of bleeding compared with heparin. Routine use of VCD has become the standard of care, facilitating patient ambulation after percutaneous carotid and coronary interventions. The combined use of these two therapies (bivalirudin and VCD) may improve outcomes in carotid interventions where prolonged patient immobilization may exacerbate hypotension following stenting.

METHODS

A total of 514 patients underwent 536 carotid stenting procedures in the 3-year period from September 2004 to September 2007. All patients received adjunctive bivalirudin, with and without VCD. This cohort was analyzed for peri-procedural and 30-day clinical outcomes and length of hospitalization.

RESULTS

Thirty-day stroke and death rate was 1.7%. A total of 83 patients (15.4%) experienced intra- or post-procedural hypotension (systolic BP < 80 mm Hg). There were four (0.7%) major bleeding complications requiring transfusion, and length of stay was delayed more than 24 hr in five patients (0.93%), all of whom were in the manual compression group.

CONCLUSIONS

This was a negative study, with no significant difference on prolonged hypotensive events in patients with vascular closure device and bivalirudin, compared with those with manual compression and bivalirudin. Vascular closure devices were safe and effective with a low incidence of complications. In carotid artery stenting, bivalirudin is safe with low incidence of major bleeding and acceptable 30-day adverse event rates (stroke and death).

Dethrombosis of the lower extremity arteries using the power-pulse spray technique in patients with recent onset thrombotic occlusions: results of the DETHROMBOSIS Registry

PURPOSE

To assess the presence of thrombus using intravascular ultrasound (IVUS) and evaluate the feasibility of combined thrombolysis [power-pulse spray (P-PS)] and rheolytic thrombectomy (RT) in patients with recent-onset limb ischemia (<6 months) due to total occlusion of at least 1 infrainguinal vessel.

METHODS

Seventeen patients (12 women; mean age 68.3+/-10.7 years) enrolled in a prospective registry underwent IVUS imaging at baseline, after treatment with P-PS using tissue plasminogen activator and RT (AngioJet), and prior to definitive treatment of the vessel. The primary safety endpoints were major bleeding, distal embolization, vascular access complications, and renal failure. Effectiveness outcomes were (1) procedural success with a residual stenosis <30%, (2) IVUS-documented resolution of the thrombus, and (3) the combined clinical endpoint of procedure-related death, stroke, unplanned amputation, and unplanned urgent revascularization of the treated limb.

RESULTS

At baseline, the majority of patients (16, 94.1%) had a definite thrombus identified by IVUS; in the remaining patient (6.3%), thrombus was likely to be present according to the IVUS scan. By angiography, 2 (11.8%) patients had a definite grade 3 thrombus and 5 (29.4%) patients had a grade 1 thrombus (modified TIMI scale) at baseline. IVUS data were available pre and post P-PS/RT in 16 (94.1%) patients. In 10 (62.5%), the thrombus was partially resolved; in 5 (31.25%), there was no apparent change. The thrombus appeared to have completely resolved in only 1 (6.3%) patient. Embolization occurred in 3 (17.6%) patients with no adverse clinical sequelae. The combined clinical endpoint was met in 1 (5.9%) of 17 patients. After final definitive treatment of the vessel, acute procedural success was 100%, with no angiographic filling defects seen.

CONCLUSION

Thrombus is present in most if not all patients with a recent history of limb ischemia who are found to have an occluded culprit vessel. The application of the P-PS/RT led to partial or complete thrombus resolution in about two thirds of the patients treated. The overall safety outcome was favorable, but large studies are needed to test the effectiveness of the P-PS/RT technique prior to routine use.

Bivalirudin as an anticoagulant for simultaneous integrated coronary artery revascularization - a novel approach to an inherent concern

BACKGROUND

Simultaneous integrated coronary artery revascularization combines coronary artery bypass surgery and percutaneous coronary intervention into a single procedure. This approach provides immediate, complete and optimal myocardial revascularization in a less invasive manner. Because simultaneous integrated coronary revascularization necessitates two distinct anticoagulation protocols for the surgical and percutaneous aspects of the procedure, combining these anticoagulation protocols carries a bleeding risk. Using a single anticoagulant to facilitate the necessities of both aspects of the integrated approach may alleviate this risk.

CASE PRESENTATION

A 45-year-old man with an occluded left anterior descending artery and a moderately stenotic circumflex artery underwent simultaneous integrated coronary revascularization. Bivalirudin was used to achieve anticoagulation for the duration of the procedure. The patient was asymptomatic with excellent patency of both the bypass graft and the stented circumflex artery via angiography at 10 months.

CONCLUSION

Bivalirudin can be used to effectively achieve a unified anticoagulation protocol for simultaneous integrated revascularization.

Impact of bivalirudin on outcomes after percutaneous coronary revascularization with drug-eluting stents

BACKGROUND

The direct thrombin inhibitor bivalirudin has been found to be noninferior to heparin plus planned glycoprotein (GP) IIb/IIIa blockade in the prevention of acute ischemic end points and 1-year mortality after percutaneous coronary intervention (PCI) with bare metal stents. We investigated whether long-term outcomes after bivalirudin use remained comparable to heparin plus GP IIb/IIIa blockade in current clinical practice of drug-eluting stent use.

METHODS

Using the 2004-2005 Cornell Angioplasty Registry, we studied 2504 consecutive patients undergoing urgent or elective PCI with periprocedural use of bivalirudin or heparin plus GP IIb/IIIa platelet inhibitors. Patients presenting with an acute ST-elevation myocardial infarction (MI) < or = 24 hours, thrombolytic therapy < or = 7 days, hemodynamic instability/shock, or renal insufficiency were excluded.

RESULTS

Of the study cohort, 1340 patients (54%) received bivalirudin and 1164 patients (46%) received heparin plus GP IIb/IIIa blockade. The incidence of inhospital mortality (0.3% vs 0.2%, P = .692), MI (6.6% vs 8.1%, P = .191), and combined end point of death, stroke, emergent coronary artery bypass graft/PCI, and MI (6.9% vs 8.3%, P = .199) was similar in the bivalirudin and heparin plus GP IIb/IIIa inhibitor groups. There was a lower incidence of major (0.7% vs 1.9%, P = .012) and minor bleeding (9.6% vs 15.6%, P < .001) in the bivalirudin versus heparin plus GP IIb/IIIa inhibitor group. Mean clinical follow-up was 24.8 +/- 7.7 months. At follow-up, there were 87 (6.5%) deaths in the bivalirudin group versus 42 (3.6%) in the heparin plus GP IIb/IIIa inhibitor group (hazard ratio 1.87, 95% CI 1.30-2.71, P = .001). After a propensity score adjusted multivariate Cox analysis, bivalirudin use was associated with a nonsignificant trend toward increased long-term mortality (hazard ratio 1.45, 95% CI 0.98-2.16, P = .065).

CONCLUSIONS

Compared with heparin plus GP IIb/IIIa inhibition, routine use of bivalirudin as the procedural anticoagulant in contemporary PCI with drug-eluting stents was associated with lower rates of inhospital complications and similar long-term all-cause mortality.

Pilot dose-finding and safety study of bivalirudin in infants <6 months of age with thrombosis

BACKGROUND

Thrombosis is not uncommon in children with serious medical conditions. Unfractionated heparin, the most commonly used anticoagulant in the acute management of thrombosis, has significant pharmacologic limitations, especially in infants. Newer anticoagulants have improved properties relative to heparin, and this may enhance the outcome in children.

OBJECTIVE

To determine dosing, and to assess the safety and efficacy of bivairudin for infants with thrombosis.

METHODS

Infants <6 months old were chosen for this pilot study as they may most benefit from a direct thrombin inhibitor because of their physiologically low antithrombin levels. This was an open label, dose-finding and safety study. Patients received one of three bolus doses and one of two initial infusion doses with subsequent dosing adjusted utilizing the activated partial thromboplastin time. Safety was assessed by specific bleeding endpoints. Efficacy was determined by reassessing the initial imaging study at 48-72 h and by measurement of molecular markers of thrombin generation.

RESULTS

Sixteen patients completed the study. All three bolus doses resulted in therapeutic anticoagulation, as did both initial infusion doses. A dose-response effect was noted for the continuous infusion but not the bolus dosing. Two patients met the study criteria for major bleeding, both with gross hematuria, which resolved with a reduction in the bivalirudin infusion rate. In terms of efficacy, 37.5% of patients had complete or partial resolution of their thrombosis by 48-72 h. There was a significant decrease in all three molecular markers of thrombin generation.

CONCLUSION

This study demonstrates the potential utility of bivalirudin in the pediatric population.