Direct thrombin inhibitors

Direct thrombin inhibitors (DTIs) are a new class of therapeutics possessing theoretic advantages over unfractionated heparin (UFH). In contrast to UFH, DTIs do not activate platelets, have no circulating inhibitors, and bind to both free and clot-bound thrombin. These theoretical advantages have spurred clinical trials investigating DTIs in a variety of cardiovascular indications. Currently, the major role for DTIs in cardiology is as an adjunct during percutaneous coronary intervention (PCI). Such a role stems from the results of the Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events (REPLACE)-2 randomized trial, in which bivalirudin with provisional abciximab was demonstrated to be equivalent to UFH plus planned abciximab with respect to ischemic endpoints, while being associated with less bleeding. Ongoing clinical trials will define the role of bivalirudin as an adjunct to primary PCI for ST-segment elevation myocardial infarction and in non-ST segment elevation acute coronary syndrome as an adjunct to an early invasive strategy.     

Bivalirudin in Percutaneous Coronary Intervention,is it the Anticoagulant of Choice?

For decades, unfractionated heparin (UFH) has been widely used in catheterization laboratories for anticoagulation for percutaneous coronary intervention (PCI). The direct thrombin inhibitors, bivalirudin, has emerged as an alternative to UFH for PCI procedures, due to its lower bleeding risk. More recently, randomized trials and meta‐analyses questioned the efficacy of bivalirudin, and demonstrated that bivalirudin might be associated with a higher incidence of ischemic events and in particular stent thrombosis. In this review, we discuss the pharmacology of bivalirudin along with the clinical evidence comparing bivalirudin versus UFH in patients undergoing PCI for various indications.     

Bivalent direct thrombin inhibitors: hirudin and bivalirudin

Hirudin derivatives (e.g. lepirudin, desirudin) and hirudin analogues (e.g. bivalirudin) are bivalent direct thrombin inhibitors; that is, they bind to two distinct sites on thrombin-its active (catalytic) site and its fibrinogen-binding site (exosite 1). These bivalent binding properties contribute to their high affinity and high specificity for thrombin. This review compares the pharmacological properties of these agents, and describes studies of their efficacy and safety in diverse clinical settings such as immune heparin-induced thrombocytopenia, postoperative antithrombotic prophylaxis, and treatment of acute coronary syndrome. Certain disadvantages of hirudin, such as its predominant renal excretion and immunogenicity, have been overcome through development of the hirudin analogue, bivalirudin. Compared with hirudin derivatives, bivalirudin exhibits a shorter half-life (25 vs 80 minutes), predominant non-renal (enzymic) metabolism, and low immunogenicity. Further work is required to define the scope of clinical thrombosis problems that could benefit from these novel agents.     

Bivalirudin versus unfractionated heparin in patients undergoing percutaneous coronary intervention after acute myocardial infarction.

BACKGROUND: Bivalirudin is replacing heparin as the anticoagulant agent of choice for elective percutaneous coronary intervention (PCI). This study aimed to assess the safety and clinical outcomes of bivalirudin versus unfractionated heparin (UFH) in patients undergoing PCI for acute myocardial infarction (AMI). METHODS: A cohort of 672 consecutive patients presenting with AMI without prior thrombolytic therapy were treated with either bivalirudin (216 patients) or UFH (456 patients). Platelet glycoprotein IIb/IIIa inhibitors were administered at the operator's discretion. The in-hospital, 30-day, and 6-month outcomes of the two groups were compared. RESULTS: Baseline clinical and angiographic characteristics were similar between the groups. In-hospital complications were similar, although there was a trend of a less major hematocrit drop in the bivalirudin group (0.9% vs. 3.1%, P=.09). All clinical outcomes were similar between the groups at 30-day and 6-month follow-ups. There was no statistical significance for acute thrombosis and subacute thrombosis between the groups, and there was no late thrombosis from either group. The event-free survival rate was similar between the groups (P=.41). CONCLUSION: The use of bivalirudin in patients undergoing PCI after AMI is safe and feasible. Bivalirudin should be considered as an alternative anticoagulant agent during PCI to treat patients presenting with AMI.     

Bivalirudin Inhibits Periprocedural Platelet Function and Tissue Factor Expression of Human Smooth Muscle Cells

Aim: A major concern of stent implantation after percutaneous coronary intervention (PCI) is acute stent thrombosis. Effective inhibition of periprocedural platelet function in patients with coronary artery disease (CAD) leads to an improved outcome. In this study, we examined the periprocedural platelet reactivity after administrating bivalirudin during PCI compared to unfractionated heparin (UFH) administration. Further, the effect of bivalirudin on induced tissue factor (TF) expression in smooth muscle cells (SMC) was determined. Methods: Patients with CAD (n = 58) and double antithrombotic medication were treated intraprocedural with UFH (n = 30) or bivalirudin (n = 28). Platelet activation markers were flow cytometrically measured before and after stenting. The expression of TF in SMC was determined by real‐time PCR and Western blotting. The thrombogenicity of platelet‐derived microparticles and SMC was assessed via a TF activity assay. Results: Bivalirudin significantly diminished the agonist‐induced platelet reactivity post‐PCI. Compared to UFH treatment, the adenosine diphosphate (ADP) and thrombin receptor‐activating peptide (TRAP)‐induced thrombospondin expression post‐PCI was reduced when bivalirudin was administrated during intervention. In contrast to UFH, bivalirudin reduced the P‐selectin expression of unstimulated and ADP‐induced platelets post‐PCI. Moreover, bivalirudin inhibited the thrombin‐, but not FVIIa‐ or FVIIa/FX‐induced TF expression and pro‐coagulant TF activity of SMC. Moreover, bivalirudin reduced the TF activity of platelet‐derived microparticles postinduction with TRAP or ADP. Conclusions: Bivalirudin is better than UFH in reducing periprocedural platelet activation. Moreover, thrombin‐induced TF expression is inhibited by bivalirudin. Thus, bivalirudin seems to be a better anticoagulant during PCI than UFH.     

Intracoronary macrothrombus formation during percutaneous coronary intervention despite optimal activated clotting time using bivalirudin--a case report

The occurrence of intracoronary thrombus during percutaneous coronary intervention (PCI) is a well-known complication. It has been estimated that it complicates approximately 6% of all coronary procedures. Patients at highest risk for this complication include those with acute ischemic syndromes or with angiographically apparent thrombus. Since the development of PCI, intravenous unfractionated heparin (UFH) has remained the primary antithrombotic therapy for the prevention of periprocedural ischemic complications. The availability of a rapid "point of care' test for dose individualization (the activated clotting time [ACT]) has facilitated this process. Other forms of antithrombotic therapies such as direct thrombin inhibitors or low-molecular-weight heparin have been proposed as more effective anticoagulants during PCI. Bivalirudin is a direct thrombin inhibitor proven to decrease post-PCI ischemic complication rate compared with UFH and have a lower vascular complication rate compared with glycoprotein IIb/IIIa receptor antagonists. We herein report a case of acute macrothrombus formation during PCI despite adequate ACT achieved with bivalirudin.     

Comparison of platelet function and morphology in patients undergoing percutaneous coronary intervention receiving bivalirudin versus unfractionated heparin versus clopidogrel pretreatment and bivalirudin

We hypothesized that direct thrombin inhibition could attenuate platelet activation and release of soluble CD40 ligand (sCD40L), a marker of inflammation, during percutaneous coronary intervention (PCI). To assess platelet function under flow conditions with bivalirudin versus unfractionated heparin (UFH), we employed the cone and plate(let) analyzer (CPA) assay in drug-spiked blood samples from volunteers (n = 3) in vitro, and then in PCI patients who received bivalirudin alone (n = 20), UFH alone (n = 15), and clopidogrel pretreatment plus bivalirudin (n = 15). Scanning electron microscopy was employed to image bivalirudin or UFH-treated platelets to determine whether platelet function observations had a morphologic explanation. Enzyme immunoassay was used to measure sCD40L levels in PCI patients. In vitro, bivalirudin decreased platelet surface coverage; UFH increased platelet surface coverage. In PCI patients, bivalirudin alone decreased platelet surface coverage, UFH alone increased platelet surface coverage, and clopidogrel pretreatment plus bivalirudin additively reduced platelet surface coverage. Unlike UFH, bivalirudin did not activate platelets in SEM studies. Bivalirudin alone or coupled with clopidogrel significantly reduced plasma sCD40L in PCI patients. In conclusion, our findings suggest that under flow conditions, bivalirudin alone or coupled with clopidogrel may have an antiplatelet effect versus UFH alone during PCI. These data suggest that bivalirudin and UFH may confer an anti-inflammatory effect by reducing sCD40L during PCI.     

Bivalirudin: a new approach to anticoagulation

Bivalirudin is one of the first of a new class of anticoagulants known as direct thrombin inhibitors. These drugs are able to overcome many of the shortcomings of traditional heparin anticoagulation by virtue of this unique mechanism of action. Bivalirudin is a semisynthetic derivative of hirudin, a modified component of leech saliva. Hirudin has been plagued by bleeding complications, likely due to its high affinity for thrombin. Bivalirudin has lower thrombin affinity than hirudin and therefore is believed to be a much safer compound. Bivalirudin has been shown to be a very effective anticoagulant in laboratory models, though its clinical efficacy remains to be fully proven. Bivalirudin has been studied in the setting of coronary angioplasty, unstable angina, and acute myocardial infarction and has shown some promise in many of these settings, particularly in preventing complications of percutaneous coronary interventions. Bivalirudin has consistently shown less major bleeding compared with standard heparin, although limitations in study methodologies somewhat hinder an accurate interpretation of this finding. Larger-scale studies are indicated and are currently being performed, the results of which will more definitively define the role of bivalirudin for the treatment of cardiovascular disease.     

Comparison of safety and efficacy of bivalirudin versus unfractionated heparin in high-risk patients undergoing percutaneous coronary intervention (from the Anti-Thrombotic Strategy for Reduction of Myocardial Damage During Angioplasty-Bivalirudin vs Heparin study)

Bivalirudin, a direct thrombin inhibitor, is as effective as unfractionated heparin (UFH), with decreased bleeding in patients with acute coronary syndromes who undergo percutaneous coronary intervention (PCI). The aim of this study was to evaluate the effectiveness of bivalirudin versus UFH in selected PCI patients at high bleeding risk. Four hundred one consecutive patients who underwent PCI fulfilling ≥ 1 enrollment criterion (age >75 years, chronic renal failure, and diabetes mellitus) were randomized to bivalirudin (bolus 0.75 mg/kg followed by infusion during the procedure; n = 198) or UFH (75 IU/kg; n = 203). In the overall population, 39% were aged >75 years, 22% had renal failure, 63% had diabetes, and 29% had acute coronary syndromes. The primary efficacy end point was the 30-day incidence of major adverse cardiac events (cardiac death, myocardial infarction, stent thrombosis, or target vessel revascularization). The primary safety end point was the occurrence of any bleeding or entry-site complications after PCI. All patients were preloaded with clopidogrel 600 mg. Glycoprotein IIb/IIIa inhibitors were used at the operators' discretion. Thirty-day major adverse cardiac event rates were 11.1% in the bivalirudin group and 8.9% in the UFH group (p = 0.56); the primary efficacy end point was reached mainly because of periprocedural myocardial infarction; 1 patient in the bivalirudin group had stent thrombosis. Occurrence of the primary safety end point was 1.5% in the bivalirudin group and 9.9% in the UFH group (p = 0.0001); this benefit was essentially driven by the prevention of entry-site hematomas >10 cm (0.5% vs 6.9%, p = 0.002). In conclusion, Anti-Thrombotic Strategy for Reduction of Myocardial Damage During Angioplasty-Bivalirudin vs Heparin (ARMYDA-7 BIVALVE) indicates that bivalirudin, compared with UFH, causes significantly lower bleeding and has a similar incidence of major adverse cardiac events in patients with older age, diabetes mellitus, or chronic renal failure who undergo PCI.     

Direct antithrombins: new perspectives in cardiovascular medicine

Thrombin converts fibrinogen to fibrin and is the most powerful activator of platelets thus playing a crucial role in arterial and venous thrombosis. The limitations of heparin, largely used in the therapy of arterial and venous thromboembolism, has prompted the development of new antithrombotic drugs, able to directly inhibit thrombin. They comprise hirudin, bivalirudin and argatroban, which are antithrombins for parenteral use, and the orally active ximelagatran which, once absorbed, is converted to the active compound melagatran. Hirudin is a polypeptide able to irreversibly block both the active site and the fibrin(ogen) binding site of thrombin; bivalirudin, a synthetic hirudin derivative, has the same binding sites of hirudin to thrombin but has a shorter pharmacological action and is safer for clinical use. Several clinical trials which tested these drugs in acute coronary syndromes, coronary angioplasty and venous thromboembolism. demonstrate that hirudin and bivalirudin are superior to heparin in significantly reducing cardiac major events. The advantage of hirudin and bivalirudin over heparin was also confirmed in adjuncts to thrombolytic therapy as well as in percutaneous angioplasty relating to thrombotic events but not to restenosis. Hirudin was also significantly better than both unfractionated heparin and low molecular weight heparin (LMWH) in the prophylaxis of venous thromboembolism in patients undergoing elective arthroplasty. Major bleeding associated to hirudin was not different from that observed with heparin. Preliminary data also indicate that melagatran/ximelagatran may be used in the prophylaxis of venous thromboembolism and in the prevention of arterial embolism in patients with non-valvular atrial fibrillation.     

Bivalirudin in Percutaneous Coronary Interventions and Acute Coronary Syndromes: New Concepts, New Directions

Inhibition of thrombin and platelets during percutaneous coronary intervention (PCI), using a combination of unfractionated heparin and aspirin, is designed primarily to minimize the rare but devastating potential acute thrombotic complications of the procedure. Direct thrombin inhibitors, such as bivalirudin (formerly Hirulog, The Medicines Company, Cambridge, MA), offer specific theoretic advantages over unfractionated heparin as antithrombin therapy. This review focuses on the pharmacologic promise and the clinical performance of bivalirudin in PCI, and in the pharmacologic management of acute coronary syndromes. Clinical experience with bivalirudin in PCI preceded recent dramatic advances in mechanical interventional techniques and the emergence of novel potent platelet inhibitors. The role of bivalirudin and other direct thrombin inhibitors in the modern era of coronary intervention therefore requires further elucidation.     

Novel Approaches for Preventing or Limiting Events (Naples) III Trial: Randomized Comparison of Bivalirudin Versus Unfractionated Heparin in Patients at Increased Risk of Bleeding Undergoing Transfemoral Elective Coronary Stenting

ObjectivesThis study sought to assess the safety and the efficacy of bivalirudin compared with unfractionated heparin (UFH) alone in the subset of patients at increased risk of bleeding undergoing transfemoral elective percutaneous coronary intervention (PCI).BackgroundBivalirudin, a synthetic direct thrombin inhibitor, determines a significant decrease of in-hospital bleeding following PCI.MethodsThis is a single-center, investigator-initiated, randomized, double-blind, controlled trial. Consecutive biomarker-negative patients at increased bleeding risk undergoing PCI through the femoral approach were randomized to UFH (UFH group; n = 419) or bivalirudin (bivalirudin group; n = 418). The primary endpoint was the rate of in-hospital major bleeding.ResultsThe primary endpoint occurred in 11 patients (2.6%) in the UFH group versus 14 patients (3.3%) in the bivalirudin group (odds ratio: 0.78; 95% confidence interval: 0.35 to 1.72; p = 0.54). Distribution of access-site and non–access-site bleeding was 18% and 82% in the UFH group versus 50% and 50% in the bivalirudin group (p = 0.10).ConclusionsThe results of this randomized study, carried out at a single institution, suggest that there is no difference in major bleeding rate between bivalirudin and UFH in increased-risk patients undergoing transfemoral PCI. (Novel Approaches in Preventing and Limiting Events III Trial: Bivalirudin in High-Risk Bleeding Patients [NAPLES III]; NCT01465503)     

Bivalirudin in PCI: an overview of the REPLACE-2 trial

The Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events (REPLACE)-2 trial is one of the largest acute randomized controlled trials evaluating the efficacy of two anticoagulant strategies during contemporary urgent or elective percutaneous coronary intervention (PCI). The direct thrombin inhibitor, bivalirudin, with provisional use of glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitor was compared to low-dose unfractionated heparin (UFH) plus planned GP IIb/IIIa inhibitor. At 30-day follow-up, the primary quadruple composite endpoint (death, myocardial infarction (MI), urgent repeat revascularization, or in-hospital major bleeding) occurred in 9.2% of patients in the bivalirudin group versus 10.0% of patients in the UFH plus GP IIb/IIIa inhibitor group. The secondary triple composite endpoint (death, MI, urgent repeat revascularization) occurred in 7.6% of patients in the bivalirudin group compared with 7.1% of patients in the UFH plus GP IIb/IIIa inhibitor group. Both endpoints met formal statistical criteria for noninferiority to UFH plus GP IIb/IIIa inhibitor. By imputed comparison from historic GP IIb/IIIa trials between bivalirudin versus UFH alone, REPLACE-2 demonstrated that bivalirudin was superior to UFH alone with respect to the quadruple and triple composite endpoints. Furthermore, bivalirudin plus provisional GP IIb/IIIa blockade was associated with a significant reduction in in-hospital bleeding (2.4% vs. 4.1%; p < 0.001). At 6 months' follow-up, there was no significant difference in rates of death, MI, or revascularization between the two groups. Furthermore, there was no evidence that the early, nonsignificant 0.5% excess non-Q-wave MI in the bivalirudin group translated into later mortality. There was a trend toward decreased mortality at 6 months in the bivalirudin arm (0.95% vs. 1.35%; p = 0.148). The relative efficacy of bivalirudin versus UFH plus GP IIb/IIIa inhibitor was similar in several high-risk subgroups, including patients with diabetes mellitus or prior MI, women, the elderly (age > 65 years), and patients undergoing PCI of bypass grafts. Bivalirudin represents an exciting alternative to UFH plus GP IIb/IIIa inhibitor in patients undergoing urgent and elective PCI with similar suppression of ischemic events, fewer bleeding complications, and the potential for greater cost savings and ease of administration.     

Bivalirudin, blood loss, and graft patency in coronary artery bypass surgery

A safe and effective alternative is needed for patients in whom unfractionated heparin (UFH) or protamine is contraindicated (e.g., those with heparin-induced thrombocytopenia or allergy to protamine). Furthermore, choice of anticoagulant may influence graft patency in coronary surgery and may therefore be important even when there is no contraindication to UFH. Direct thrombin inhibitors have several potential advantages over UFH, demonstrated in acute coronary syndromes. However, there are also potential difficulties with their use related to lack of reversal agents and paucity of clinical experience in monitoring their anticoagulant activity at the levels required for cardiac surgery with cardiopulmonary bypass (CPB). In the first prospective randomized trial of an alternative to heparin in cardiac surgery, we compared bivalirudin (a short-acting direct thrombin inhibitor) with UFH in 100 patients undergoing off-pump coronary artery bypass (OPCAB) surgery. Blood loss for the 12 hours following study drug initiation in the bivalirudin group was not significantly greater than in the heparin group. Median graft flow was significantly higher in the bivalirudin group. We concluded that anticoagulation for OPCAB surgery with bivalirudin was feasible without a clinically important increase in perioperative blood loss. A larger study is needed to investigate the impact of improved graft patency on other clinical outcomes after cardiac surgery.     

Antithrombotic efficacy of bivalirudin compared to unfractionated heparin during percutaneous coronary intervention for acute coronary syndrome

Bivalirudin is associated with an increased risk of acute stent thrombosis (AST) compared to unfractionated heparin (UFH) in acute coronary syndrome patients (ACS) during short-duration percutaneous coronary intervention (PCI). The mechanisms involved are unknown. We aimed to investigate the antithrombotic efficacy of bivalirudin compared to UFH during PCI. In a monocenter study, we prospectively enrolled 30 patients undergoing PCI for a non–ST elevation ACS. They were randomly assigned to a single intravenous (IV) bolus of UFH (70 IU/kg) or an IV bolus of bivalirudin 0.75 mg/kg followed by a 1.75 mg/kg/h infusion during PCI. All patients received a loading dose (LD) of 180 mg of ticagrelor at the time of PCI. The VASP index and activated partial thromboplastin time (aPTT) were used to assess the course of platelet reactivity (PR) and antithrombotic activity. The two groups were similar regarding baseline, angiographic, and interventional characteristics. There was no difference between the two groups in the course of PR following ticagrelor LD. An optimal PR inhibition was obtained 4 h after the LD of ticagrelor. The level of antithrombotic activity was significantly lower in the bivalirudin group compared to the UFH group (p < 0.001) during PCI but similar at 2 and 4 h post-PCI. We observed that, in ACS undergoing PCI, the antithrombotic efficacy of an IV bolus of bivalirudin is significantly lower than that of a 70-IU/kg UFH bolus. This could contribute to the excess in thrombotic acute events observed during short-duration PCI.     

国产比伐卢定在急诊介入治疗中对血小板功能的影响

目的：探讨国产比伐卢定在急诊经皮冠状动脉介入治疗（PCI）中对血小板功能的影响。方法：100例急性ST段抬高性心肌梗死接受急诊PCI的患者随机分为肝素组（53例）和比伐卢定组（47例）。检测两组 PCI术前后二磷酸腺苷（ADP）诱导的血小板聚集率,并进行统计学比较。结果：急诊PCI术前,两组 ADP诱导的血小板凝聚率差异无统计学意义（ P＝0.99）。急诊 PCI术后,比伐卢定组 ADP 诱导的血小板凝聚率显著低于肝素组[（16.46±10.23）％比（25.21±15.91）％, P＜0.01]。结论：PCI术中,与常规肝素抗凝相比,作为抗凝剂的比伐卢定可以更明显抑制血小板凝聚,具有抗血小板的功能。     

Meta-analysis comparing bivalirudin versus heparin monotherapy on ischemic and bleeding outcomes after percutaneous coronary intervention

With femoral access, bivalirudin decreases risks of major bleeding after percutaneous coronary intervention (PCI) and provides better net clinical benefit compared to unfractionated heparin (UFH) plus planned glycoprotein IIb/IIIa inhibitors. Whether this benefit exists compared to UFH monotherapy is less clear. We performed a systematic review and meta-analysis to compare outcomes in patients undergoing transfemoral PCI with UFH or bivalirudin. Randomized trials (n = 3) and observational studies (n = 13) comparing bivalirudin to UFH monotherapy were reviewed. Primary outcomes were 30-day rates of major adverse cardiovascular events (MACEs) including death, myocardial infarction (MI), urgent revascularization, as well as all-cause mortality, MI, major bleeding, and blood transfusion. We collected data from 16 studies involving 32,492 patients undergoing PCI. Most observational studies were performed in the United States, whereas all randomized trials were done in Europe. Compared to UFH monotherapy, bivalirudin was associated with similar risk of MACEs (odds ratios [OR] 0.92, 95% confidence interval [CI] 0.75 to 1.12), a substantial 45% relative decrease in major bleeding (OR 0.55, 95% CI 0.43 to 0.72), and a trend in the decrease of transfusion (OR 0.87, 95% CI 0.70 to 1.08). A decrease in mortality was seen in observational studies (OR 0.62, 95% CI 0.45 to 0.85) but remained inconclusive in randomized trials (OR 0.63, 95% CI 0.20 to 2.01). MI rate was similar with the 2 anticoagulants. In conclusion, in patients undergoing transfemoral PCI, the benefit of bivalirudin over UFH monotherapy is driven by a significant decrease in major bleeding with similar rates of MACE. As PCI practice moves toward other bleeding-avoidance strategies such as the radial approach, future studies should focus on the interaction between anticoagulant strategy and access-site choice.     

Bleeding risk and outcomes of Bivalirudin versus Glycoprotein IIb/IIIa inhibitors with targeted low-dose unfractionated Heparin in patients having percutaneous coronary intervention for either stable or unstable angina pectoris

For patients undergoing elective percutaneous coronary intervention (PCI), procedural anticoagulation with bivalirudin was previously shown to significantly reduce bleeding complications at the cost of a modest increase in ischemic events compared with unfractionated heparin (UFH) and glycoprotein IIb/IIIa inhibitors (GPIs). However, the excess bleeding in patients treated with UFH and GPIs may have been caused by excessively high UFH doses and increased activated clotting times. This study sought to determine the bleeding risk of targeted low-dose UFH with GPIs compared with bivalirudin in patients undergoing elective PCI. Of 1,205 patients undergoing elective PCI, 602 underwent PCI with adjunctive UFH and GPIs with the UFH dose targeted to an activated clotting time of approximately 250 seconds, and 603 patients matched for baseline characteristics underwent PCI with bivalirudin. Outcomes were analyzed for major bleeding (hematocrit decrease >15%, gastrointestinal bleed, or major hematoma) and 6-month major adverse cardiac events (death, myocardial infarction, and target-lesion revascularization). The maximum activated clotting time achieved was 261.7 +/- 61.6 seconds in the UFH/GPI group and 355.4 +/- 66.6 in the bivalirudin group (p <0.001). In-hospital major bleeding rates were similar between groups (1.8% UFH/GPI vs 1.7% bivalirudin; p = 0.83), as were transfusion requirements (1.2% UFH/GPI vs 0.5% bivalirudin; p = 0.61). The 6-month major adverse cardiac event rate was also similar between groups (9.5% UFH/GPI vs 9.0% bivalirudin; p = 0.81). In conclusion, there were no significant differences in major bleeding and 6-month major adverse cardiac events for patients undergoing elective PCI treated with targeted low-dose UFH and GPIs compared with those treated with bivalirudin.     

Adjunctive pharmacologic therapy in percutaneous coronary intervention: part II anticoagulant therapy

Pharmacological adjuvant therapies to protect against procedure-related thrombotic complication are indispensable during percutaneous coronary intervention. In addition to antiplatelet therapy, use of anticoagulants to prevent acute thrombotic complication during percutaneous coronary intervention is essential. Besides unfractionated heparin (UFH), new anticoagulants have been developed and compared with UFH. Low-molecular weight heparins, direct thrombin inhibitors (e.g. bivalirudin), and recently developed agents such as fondaparinux (a factor Xa inhibitor) provide new alternatives to conventional UFH.     

Safety and Efficacy of Bivalirudin for Percutaneous Coronary Intervention with Rotational Atherectomy

Background: Although bivalirudin use in percutaneous coronary intervention (PCI) results in less bleeding compared to unfractionated heparin (UFH) use, its safety in patients undergoing rotational atherectomy (RA) is unknown. Methods: A cohort of 503 patients who underwent PCI with RA from 2000 to 2009 was studied. Patients receiving bivalirudin (n = 322) were compared to those (n = 181) treated with UFH ± glycoprotein IIb/IIIa inhibitor (GPI) as PCI anticoagulation. Safety was assessed by the frequency of major bleeding (hematocrit drop ≥15%, intracerebral or gastro‐intestinal bleeding) and need for transfusion. Efficacy was assessed by a composite end‐point of in‐hospital death, Q wave myocardial infarction (MI) or urgent coronary artery bypass graft (CABG). Results: Those in the bivalirudin group were older, more hypertensive, and had greater body mass index. The UFH group was more likely to have prior MI, prior CABG, and an acute coronary syndrome at baseline. GPI was used in 93 patients (52%) of the UFH group. No difference was found between groups for the composite of death/Q wave MI/urgent CABG (1.9% vs. 1.7%, respectively, in bivalirudin vs. UFH group; P = 0.2). The frequency of major bleeding (2.2% vs. 1.7%; P = 0.8) or transfusion (5.6% vs. 8.7%; P = 0.9) was also similar between groups. After adjustment, bivalirudin use was not associated with a reduction in death/Q wave MI/urgent CABG, major bleeding, or transfusion compared to UFH. Conclusion: Bivalirudin use seems to be as safe and effective as UFH in patients undergoing RA. (J Interven Cardiol 2010;23:223–229)