Summary

Bivalirudin (Angiomax/Angiox) is a synthetic 20-amino-acid peptide direct thrombin inhibitor derived from the structure of hirudin, a natural anticoagulant found in medicinal leech saliva. It reversibly inhibits both free and clot-bound thrombin, offering advantages over heparin including a predictable dose-response, no risk of heparin-induced thrombocytopenia (HIT), and a short ~25-minute half-life. Licensed by the MHRA, EMA, and FDA as an anticoagulant for percutaneous coronary intervention (PCI) — including primary PCI for STEMI — bivalirudin is supported by major Phase 3 RCTs including REPLACE-2 (n=6,010), ACUITY (n=13,819), and HORIZONS-AMI (n=3,602). While it reduces major bleeding compared to heparin + GPIIb/IIIa inhibitors, it has been associated with increased acute stent thrombosis in some trials.

Overview

Bivalirudin is a synthetic 20-amino-acid peptide that functions as a direct thrombin inhibitor. It is a specific and reversible inhibitor of both free and clot-bound thrombin (Factor IIa). Derived from the structure of hirudin — a naturally occurring anticoagulant found in the saliva of the medicinal leech (Hirudo medicinalis) — bivalirudin was designed to retain hirudin's potent thrombin inhibition while improving on its pharmacokinetic profile.

Marketed under the brand name Angiomax (US) / Angiox (UK/EU), bivalirudin is a licensed medicine approved by the MHRA, EMA, and FDA as an anticoagulant in patients undergoing percutaneous coronary intervention (PCI), including those with ST-elevation myocardial infarction (STEMI) undergoing primary PCI.

Bivalirudin is significant in peptide drug design as one of the few direct thrombin inhibitors in clinical use. It offers advantages over unfractionated heparin — including a more predictable dose-response, no requirement for antithrombin III as a cofactor, and direct activity against clot-bound thrombin. Its short half-life (~25 minutes) and reversible binding allow rapid offset of anticoagulation, which is advantageous in procedural settings.

Research Summary

REPLACE-2 Trial — Elective PCI

The REPLACE-2 trial (Lincoff et al., JAMA, 2003) was a randomised, double-blind trial enrolling 6,010 patients undergoing urgent or elective PCI. Patients received bivalirudin plus provisional GPIIb/IIIa inhibitor versus heparin plus routine GPIIb/IIIa inhibitor.

The primary composite endpoint (death, MI, urgent revascularisation, or major bleeding at 30 days) occurred in 9.2% of the bivalirudin group versus 10.0% of the heparin + GPIIb/IIIa group, meeting the pre-specified criterion for non-inferiority (p=0.06). Major bleeding was significantly reduced with bivalirudin (2.4% vs 7.1%, p<0.001).

ACUITY Trial — Non-ST-Elevation ACS

The ACUITY trial (Stone et al., NEJM, 2006) enrolled 13,819 patients with moderate-to-high-risk ACS undergoing an invasive strategy. The trial compared three strategies: heparin + GPIIb/IIIa, bivalirudin + GPIIb/IIIa, and bivalirudin alone (provisional GPIIb/IIIa).

Bivalirudin alone was non-inferior to heparin + GPIIb/IIIa for the primary composite ischaemic endpoint (7.8% vs 7.3%) and significantly reduced major bleeding (3.0% vs 5.7%, p<0.001), leading to a net clinical benefit.

HORIZONS-AMI Trial — Primary PCI for STEMI

The HORIZONS-AMI trial (Stone et al., NEJM, 2008) was a landmark study in 3,602 patients with STEMI undergoing primary PCI. Bivalirudin alone (vs heparin + GPIIb/IIIa) reduced:

  • 30-day major bleeding: 4.9% vs 8.3% (p<0.001)
  • 30-day cardiac mortality: 1.8% vs 2.9% (p=0.03)
  • 30-day all-cause mortality: 2.1% vs 3.1% (p=0.047)

However, there was an early increase in acute stent thrombosis within 24 hours (1.0% vs 0.0%, p<0.001) with bivalirudin, which narrowed over time.

HEAT-PPCI Trial — Controversy

The HEAT-PPCI trial (Shahzad et al., Lancet, 2014) challenged these findings. In this single-centre UK trial of 1,829 STEMI patients, bivalirudin was associated with a higher rate of the primary composite endpoint (8.7% vs 5.7%, p=0.01) compared to heparin alone, driven by increased ischaemic events. This trial highlighted that the benefit of bivalirudin may depend on concomitant antithrombotic strategies and patient selection.

Meta-Analyses

A large meta-analysis (Cavender & Sabatine, 2014) of over 22,000 patients across 4 major trials confirmed that bivalirudin reduces major bleeding compared to heparin + GPIIb/IIIa, but may be associated with increased acute stent thrombosis.

Evidence grade: Strong — supported by multiple large Phase 3 RCTs and meta-analyses. Current ESC guidelines recommend bivalirudin as an alternative to heparin in primary PCI, with a Class IIa recommendation.

Commonly Discussed Protocols

All protocols below are documented from clinical trial literature and prescribing information for research reference only. Bivalirudin is a licensed POM in the UK and must only be administered under medical supervision in a hospital setting.

PCI (Standard Regimen)

  • Bolus: 0.75 mg/kg intravenous bolus
  • Infusion: 1.75 mg/kg/hr continuous IV infusion
  • Duration: For the duration of the PCI procedure; may be continued post-procedure for up to 4 hours at physician's discretion

ACS Managed Medically (NSTEMI)

  • Bolus: 0.1 mg/kg IV bolus
  • Infusion: 0.25 mg/kg/hr continuous IV infusion
  • Duration: Up to 72 hours

Renal Adjustment

  • CrCl 30–59 mL/min: Reduce infusion by 20% (PCI: 1.4 mg/kg/hr; medical: 0.2 mg/kg/hr)
  • CrCl <30 mL/min: Reduce infusion by 60% (PCI: 1.0 mg/kg/hr; medical: 0.1 mg/kg/hr)
  • Dialysis: Reduce infusion by 90% (PCI: 0.25 mg/kg/hr); no bolus adjustment needed as bolus is partially haemodialyzable

Stacking

In clinical practice, bivalirudin is used in combination with:

  • Aspirin: Standard concurrent antiplatelet therapy
  • P2Y12 inhibitors (clopidogrel, prasugrel, ticagrelor): Dual antiplatelet therapy (DAPT)
  • Provisional GPIIb/IIIa inhibitors (abciximab, eptifibatide): For bailout use only — not routinely combined

Bivalirudin is NOT combined with heparin or other anticoagulants (argatroban, fondaparinux) in standard practice. There is no established research literature on combining bivalirudin with non-cardiovascular peptides.

Storage & Reconstitution

  • Formulation: Supplied as lyophilised powder in 250 mg vials
  • Storage: Store at 2–25°C. Do not freeze. Protect from light.
  • Reconstitution: Reconstitute 250 mg vial with 5 mL sterile water for injection → 50 mg/mL concentrate. Dilute further with 0.9% sodium chloride or 5% dextrose to final concentration of 5 mg/mL.
  • Post-reconstitution: Stable for 24 hours at 2–25°C after reconstitution. Do not use if solution is cloudy or contains particulate matter.
  • Note: Bivalirudin is incompatible with dobutamine, dopamine, or other drugs containing benzyl alcohol when co-administered through the same IV line.

Blood Work

In clinical practice, the following are monitored during bivalirudin therapy:

  • Activated clotting time (ACT): Primary monitoring tool during PCI. Target ACT >250 seconds (HemoTec) or >300 seconds (Hemochron). Measured 5 minutes after bolus.
  • Activated partial thromboplastin time (aPTT): Monitored in non-procedural ACS management. Target 1.5–2.5× baseline.
  • Haemoglobin / haematocrit: Monitor for bleeding — bivalirudin reduces major bleeding vs heparin + GPIIb/IIIa but bleeding remains the primary adverse effect.
  • Renal function (creatinine, eGFR): Critical — bivalirudin is partially renally cleared (~20%). Dose adjustment required for CrCl <30 mL/min.
  • Platelet count: Monitor for thrombocytopenia, though significantly less common than with heparin (no risk of HIT — heparin-induced thrombocytopenia — as bivalirudin is not derived from heparin).

UK Legal Status

Bivalirudin is a Prescription-Only Medicine (POM) in the UK, licensed by the MHRA for:

  • Anticoagulation in patients undergoing PCI, including primary PCI for STEMI
  • Anticoagulation in patients with ACS (unstable angina / NSTEMI) managed conservatively

Supplied as Angiox (Medicines Company / Teva). Restricted to hospital use and administered only by specialists in cardiology/critical care. Available on the NHS for licensed indications subject to local formulary approval. Unlicensed supply for human use is illegal. Purchase by research institutions for in vitro or animal studies is legal under research chemical exemptions, but suppliers must not market it for human consumption.

References

References

  1. Lincoff AM, Bittl JA, Harrington RA, et al. REPLACE-2: Bivalirudin and provisional GPIIb/IIIa blockade compared with heparin and planned GPIIb/IIIa blockade during PCI. JAMA. 2003;289(7):853-63. doi:10.1001/jama.289.7.853
  2. Stone GW, McLaurin BT, Cox DA, et al. ACUITY: Bivalirudin for patients with acute coronary syndromes. N Engl J Med. 2006;355(21):2203-16. doi:10.1056/NEJMoa062437
  3. Stone GW, Witzenbichler B, Guagliumi G, et al. HORIZONS-AMI: Bivalirudin during primary PCI in acute myocardial infarction. N Engl J Med. 2008;358(21):2218-30. doi:10.1056/NEJMoa0708191
  4. Shahzad A, Kemp I, Mars C, et al. HEAT-PPCI: Bivalirudin versus heparin in primary PCI. Lancet. 2014;384(9957):1849-58. doi:10.1016/S0140-6736(14)61131-6
  5. Cavender MA, Sabatine MS. Bivalirudin versus heparin in patients planned for percutaneous coronary intervention: a meta-analysis of randomised controlled trials. Lancet. 2014;384(9943):599-606. doi:10.1016/S0140-6736(14)61293-2
  6. Angiox (bivalirudin) Summary of Product Characteristics. The Medicines Company / Teva UK. MHRA. Accessed 2025.