Bivalirudin as an Anticoagulation Agent: Safety and Efficacy in Peripheral Interventions

Bivalirudin versus unfractionated heparin during peripheral vascular interventions: A Propensity-matched Study

OBJECTIVES

This study aimed to compare the association of access site complications and the use of unfractionated heparin versus bivalirudin during subinguinal peripheral vascular intervention.

BACKGROUND

Compared to unfractionated heparin, bivalirudin has been associated with fewer bleeding complications in patients undergoing percutaneous coronary intervention but more ischemic events. The safety and efficacy of direct thrombin inhibitors in peripheral vascular interventions is not well defined.

METHODS

We compared the incidence of in-hospital access site complications and discharge status among patients in the multicenter, prospective Vascular Quality Initiative registry who underwent peripheral vascular intervention between August 2007 and January 2014 using bivalirudin or unfractionated heparin. Propensity score matching was used to obtain a balanced cohort of 1,524 patients in each treatment group.

RESULTS

Patients treated with bivalirudin had a significantly lower incidence of access site hematomas (2.4% vs. 3.9%, P = 0.018), shorter post-procedural hospitalization (1.0 vs. 1.2 days, P < 0.001) and lower rates of discharge to a nursing home or rehabilitation center rather than home (7.61% vs. 9.73%, P = 0.034) when compared with unfractionated heparin-treated patients. The incidence of in-hospital access site occlusion, distal embolization, and mortality did not differ significantly between groups.

CONCLUSIONS

Patients who received bivalirudin had lower rates of access site hematoma, shorter length of stay, and improved discharge status compared with unfractionated heparin during hospitalization for peripheral vascular intervention. Randomized comparisons of these agents are needed to confirm these findings. © 2016 Wiley Periodicals, Inc.

Bivalirudin Is Associated With Improved In-Hospital Outcomes Compared With Heparin in Percutaneous Vascular Interventions

Background—

Peripheral vascular interventions are increasingly preferred for the treatment of patients with symptomatic peripheral arterial disease because they are associated with similar clinical outcomes and lower morbidity than open surgical procedures. The objective of this study was to assess the comparative effectiveness of procedural anticoagulation with bivalirudin compared with unfractionated heparin in patients undergoing peripheral vascular interventions.

Methods and Results—

This was a retrospective, observational study using the Premier Hospital administrative database. We examined 23 934 consecutive patients undergoing lower extremity peripheral vascular interventions between January 2008 and December 2012 who were treated with either bivalirudin or unfractionated heparin. In-hospital end points included death, myocardial infarction, transfusion, stroke, amputation, and the composite end points of major adverse cardiovascular events, and net adverse clinical events. Propensity score matching was performed to control for baseline imbalances and yielded 3649 matched pairs. After propensity score matching, patients treated with bivalirudin had lower in-hospital event rates with significantly lower mortality (odds ratio, 0.40; P =0.017), need for blood product transfusion (odds ratio, 0.74; P =0.009), major adverse cardiovascular events (odds ratio, 0.64; P =0.003), and net adverse clinical events (odds ratio, 0.72; P <0.001). These associations were observed consistently across clinically relevant subgroups.

Conclusions—

In patients undergoing peripheral vascular interventions, procedural anticoagulation with bivalirudin may result in more favorable in-hospital outcomes compared with unfractionated heparin, the current standard of care. These observations will require prospective confirmation in a randomized, controlled trial.

Management of extracranial carotid artery disease

Stroke is the third leading cause of death in developed nations. Up to 88% of strokes are ischemic in nature. Extracranial carotid artery atherosclerotic disease is the third leading cause of ischemic stroke in the general population and the second most common nontraumatic cause among adults younger than 45 years. This article provides comprehensive, evidence-based recommendations for the management of extracranial atherosclerotic disease, including imaging for screening and diagnosis, medical management, and interventional management.

An objective comparison between bivalirudin and heparin during peripheral vascular interventions

ABSTRACT 

Patients undergoing percutaneous peripheral interventions are at increased risk for thrombotic complications hence the routine use of periprocedural anticoagulants. There is currently no American College of Cardiology/American Heart Association guidelines for periprocedural anticoagulants use in percutaneous peripheral interventions. Historically, unfractionated heparin has been the most common periprocedural anticoagulant used during percutaneous peripheral interventions. There may be a role for more predictable periprocedural anticoagulants in percutaneous peripheral interventions as has been demonstrated in percutaneous coronary interventions. Our review focuses on the evidence supporting the use of bivalirudin in percutaneous peripheral interventions.

Safety and efficacy of periprocedural anticoagulation with enoxaparin in patients undergoing peripheral endovascular revascularization

BACKGROUND

Periprocedural anticoagulation is primarily used in endovascular procedures to prevent acute reocclusion of the target vessel, but periprocedural anticoagulation might also have an impact on long-term outcome. Consecutive bleeding events are feared complications. Despite changes in peripheral endovascular revascularizations (EVRs), the periprocedural management has remained unchanged for years. Unfractionated heparin is still the treatment of choice during and immediately after EVR.

MATERIALS AND METHODS

We performed a prospective, single-center, open-label phase III study comparing 2 different regimes of enoxaparin peri-interventional to peripheral EVR stratified into low- and high-risk groups according to the acute and long-term reocclusion risk due to their vessel morphology. In both groups, 0.5 mg/kg of enoxaparin as a bolus was administered intravenously 10 to 15 minutes before the start of the procedure. In the low-risk group, 40 mg of enoxaparin were administered once daily for 7 days; whereas in the high-risk group, 1 mg/kg of enoxaparin was administered subcutaneously (sc) 2 times a day for 48 hours after the procedure and afterward 40 mg of enoxaparin was administered sc once daily for 5 days.

RESULTS

For the analysis of the per protocol population, 44 patients remained in the low-risk group and 140 in the high-risk group. Concerning the primary safety end point, a total of 25 (13.59%) bleeding events occurred until day 30; 5 (11.36%) of them in the low-risk group and 20 (14.29%) in the high-risk group (P = .809 for low vs high risk). None of the bleeding events observed were major according to Thrombolysis In Myocardial Infarction criteria. Concerning our primary efficacy end point, none of the patients showed an acute reocclusion classified as a significant decrease in ankle-brachial index (ABI) or elevated peak systolic velocity ratio confirmed by duplex sonography until day 30. Concerning the second end point of prevention of chronic reobstruction, at day 180 ABI has decreased in the low-risk group from mean 0.94 at day 30 to mean 0.89 and from 1.28 at day 30 to 0.85 after 6 months in the high-risk group. No significant reobstruction was found in the low-risk group, whereas 5 significant reobstruction events were objectified in the high-risk group, all of them in the femoropopliteal arterial segment at day 180.

CONCLUSION

We conclude that low-molecular-weight heparin either in a low-dose or high-dose regime during a peripheral EVR is safe concerning bleeding complications and acute reobstructions. The long-term follow-up showed no significant difference between our high- and low-risk groups concerning reobstruction. The periprocedural anticoagulation seems to have no influence on the long-term patency rate after peripheral EVR.

Successful use of bivalirudin for superior vena cava recanalization and stent placement in a child with heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a potentially life-threatening, adverse effect of heparin therapy. Patients with this complication require an alternative approach to anticoagulation. Bivalirudin is a direct thrombin inhibitor with an efficacy comparable to that of heparin, a short half-life, and reduced bleeding complications in adults. We present the case of a 2-year-old boy with HIT Type II who underwent recanalization of an occluded superior vena cava and stent placement, utilizing bivalirudin as anticoagulant.

Similar Success Rates with Bivalirudin and Unfractionated Heparin in Bare-Metal Stent Implantation

BACKGROUND

Unfractionated heparin (UFH) is the traditional agent utilized during percutaneous peripheral interventions (PPIs) despite its well-known limitations. Bivalirudin, a thrombin-specific anticoagulant, overcomes many of the limitations of UFH and has consistently demonstrated comparable efficacy with significantly fewer bleeding complications. The purpose of this study was to compare procedural success in patients undergoing bare-metal stent implantation for atherosclerotic blockage of the renal, iliac, and femoral arteries and receiving either bivalirudin (0.75 mg/kg bolus/1.75 mg/kg/hr infusion) or UFH (50-70 U/kg/hr bolus) as the primary anticoagulant.

METHODS

This study was an open-label, nonrandomized retrospective registry with the primary endpoint of procedural success. Secondary endpoints included incidence of: death, myocardial infarction (MI), urgent revascularization, amputation, and major and minor bleeding.

RESULTS

One hundred and five consecutive patients were enrolled (bivalirudin = 53; heparin = 52). Baseline demographics were comparable between groups. Patients were pretreated with clopidogrel (approx. 71%) and aspirin (approx. 79%). Procedural success was achieved in 97% and 96% of patients in the bivalirudin- and heparin-treated groups, respectively. Event rates were low and similar between groups.

CONCLUSION

Bivalirudin maintained an equal rate of procedural success in this cohort without sacrificing patient safety. Results of this study add to the growing body of evidence supporting the safety and efficacy of bivalirudin as a possible substitute for UFH in anticoagulation during peripheral vascular bare-metal stent implantation.

Bivalirudin: Pharmacology and Clinical Applications

Bivalirudin (Hirulog, Angiomax) is a specific, reversible and direct thrombin inhibitor with a predictable anticoagulant effect. It is cleared by both proteolytic cleavage and renal mechanisms, predominantly glomerular filtration. Bivalirudin inhibits both circulating thrombin and fibrin bound thrombin directly by binding to thrombin catalytic site and anion-binding exosite I in a concentration-dependent manner. Bivalirudin prolongs activated partial thromboplastin time, prothrombin time, thrombin time and activated clotting time (ACT). ACT levels with bivalirudin do not correlate with its clinical efficacy. Bivalirudin with a provisional GpIIb/IIIa inhibitor is indicated in elective contemporary percutaneous coronary intervention (PCI). In respect to combined ischemic and hemorrhagic endpoints of death, myocardial infarction, unplanned urgent revascularization and major bleeding during PCI (including subgroups of patients with renal impairment and diabetes) bivalirudin is not inferior to unfractioned heparin and planned GpIIb/IIIa inhibitors. In addition, bivalirudin has been consistently shown to have significantly less in-hospital major bleeding than heparin alone or heparin in combination with a GpIIb/IIIa inhibitor. Bivalirudin appears to be also safe and effective during PCI in patients with heparin-induced thrombocytopenia. Finally, data from PCI studies support the safety and efficacy of bivalirudin, although its direct randomized comparison with unfractionated heparin is lacking.

Bivalirudin in Peripheral Interventions

The discovery of heparin and its eventual incorporation into many therapeutic and diagnostic procedures has made this agent ubiquitous in the fields of cardiac and vascular medicine. Heparin however does have a significant complication and side-effect profile that includes both bleeding as well as vessel thrombosis through the development of heparin-induced thrombocytopenia. The recent addition of direct thrombin inhibitors, for example, bivalirudin, to the anticoagulation armaterium has produced favorable outcomes. Most of the experience with bivalirudin has been in coronary interventions and only recently have more interventionalists been turning to this agent as the sole anticoagulant for peripheral interventions even in patients who could tolerate heparin. In this review, we describe our experience with bivalirudin in peripheral interventions emphasizing how we dose and monitor this drug. In addition, this article discusses the findings in existing clinical trials involving bivalirudin.