Bivalirudin versus heparin as an antithrombotic agent in patients treated with a sirolimus-eluting stent

Quantitation of bivalirudin, a novel anticoagulant peptide, in human plasma by LC-MS/MS: Method development, validation and application to pharmacokinetics

A rapid and sensitive method based on liquid chromatography–tandem mass spectrometry (LC–MS/MS) for the determination of a novel anticoagulant peptide bivalirudin in human plasma has been developed and validated. Plasma samples were precipitated protein with acetonitrile and re-extracted with dichloromethane, after which the analyte and triptorelin as an internal standard (IS) were separated on a 300SB-C18 column (150 mm×4.6 mm i.d., 5 μm particle size) using 0.1% formic acid:methanol (45:55, v/v) as mobile phase. The triple-quadrupole mass spectrometer, equipped with electrospray ionization (ESI) interface, was operated in the positive ion mode, and the multiple-reaction monitoring (MRM) transitions of bivalirudin and IS were at m/z 1091.0→650.4 and m/z 656.5→249.3, respectively. The lower limit of quantification (LLOQ) was 1 ng/mL for 100 μL plasma sample and the assay was linear over the concentration range 1–1000 ng/mL. The accuracy was within a range from −0.4% to 0.5% in terms of relative error (RE) and the intra- and inter-day precisions in terms of relative standard deviation (RSD) were ≤2.92 and ≤3.36, respectively. The method was successfully applied to a pharmacokinetic study involving intravenous administration of bivalirudin (0.5 mg/kg) to Chinese volunteers.

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.

Darwin and the survival of the fittest in modern interventional cardiology

The diabetic patient requires a full armamentarium of proven and developing treatments in order to minimise periprocedural risk as well as improve long term outcome.

Bivalirudin: a direct thrombin inhibitor used during percutaneous coronary intervention

Complications during percutaneous coronary intervention remain of great concern and in particular, intracoronary thrombus formation is an unwanted complication associated with mortality and morbidity. This has been prevented with the use of intense anticoagulant treatment, but often at the price of minor and major bleeding complications. Traditionally, unfractionated heparin has been used to prevent intracoronary thrombosis during balloon angioplasty and coronary stent implantation. However, there are several problems with the use of unfractionated heparin and recent data suggest that alternative anticoagulants, such as low-molecular-weight unfractionated heparin, or a direct thrombin inhibitor, may provide protection against ischemic events. The purpose of this article is to review the evidence for the use of bivalirudin, a direct thrombin inhibitor, during percutaneous coronary intervention.

Bivalirudin: a review

Bivalirudin (Angiomax) is a thrombin-inhibiting oligopeptide that was developed via rational drug design as a hirudin analogue ('hirulog'). Similar to hirudin, it is a bivalent thrombin inhibitor, as its 20-amino acid structure combines a carboxy-terminal region that recognises thrombin's fibrin(ogen)-binding site, and an amino-terminal tetrapeptide that inhibits the active site of thrombin, connected by a tetraglycine spacer. It has certain pharmacological advantages over hirudin, including enzymic metabolism (less dependence on renal clearance) and low immunogenicity (reduced potential for anaphylaxis). Bivalirudin is approved for use in percutaneous transluminal coronary angioplasty (PTCA), and is undergoing active investigation for anticoagulation during cardiac surgery, both 'off-pump' and with cardiopulmonary bypass ('on-pump'). Anecdotal 'off-label' experience for the treatment of heparin-induced thrombocytopenia shows promise.

Bivalirudin

Bivalirudin (Angiox, Angiomax) is a synthetic 20-amino acid peptide analogue of hirudin. It is a direct thrombin inhibitor that binds specifically and reversibly to both fibrin-bound and unbound thrombin. Intravenous bivalirudin is approved in Europe for use as an anticoagulant in patients undergoing percutaneous coronary intervention (PCI). In the US, bivalirudin is approved in patients with unstable angina pectoris undergoing percutaneous transluminal coronary angioplasty (PTCA) and has recently been approved for use with provisional glycoprotein (GP) IIb/IIIa inhibition in patients undergoing PCI. Bivalirudin plus provisional GP IIb/IIIa inhibition is effective in patients undergoing PCI. The large, well controlled REPLACE-2 (Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events) study showed that bivalirudin plus provisional GP IIb/IIIa inhibition was noninferior to heparin plus planned GP IIb/IIIa inhibition and that bivalirudin was associated with a reduced risk of bleeding complications. In patients with heparin-induced thrombocytopenia (HIT), bivalirudin was effective against ischaemic events and there was a low incidence of bleeding complications. Bivalirudin should be considered as an alternative to heparin plus planned GP IIb/IIIa inhibition in any patient undergoing urgent or elective PCI, especially in any patient with a high risk of bleeding complications.