Bivalirudin

Thrombin is the enzyme at the center of clotting: it turns fibrinogen into fibrin strands, activates factor XIII so those strands cross-link, amplifies its own production through factors V and VIII, and switches on platelets. Bivalirudin binds thrombin directly at two places, the catalytic site and a separate docking region called the anion-binding exosite, and it works on thrombin circulating freely as well as thrombin already bound in a clot¹. The binding is reversible because thrombin slowly cuts the bivalirudin molecule, gradually restoring its own activity¹. The drug is broken down by enzymes and cleared through the kidneys. Its half-life is about 25 minutes with normal kidney function and longer when kidney function is reduced, so its effect wears off relatively quickly once it is stopped¹.

Bivalirudin has been compared with heparin in several large randomized trials of coronary procedures. In the original angioplasty trial of 4,098 patients with unstable or post-infarction angina, it matched heparin on ischemic complications and cut bleeding by more than half².

In HORIZONS-AMI (3,602 heart-attack patients having primary PCI), bivalirudin alone lowered 30-day major bleeding and the combined rate of bleeding plus major cardiac events compared with heparin plus a glycoprotein IIb/IIIa inhibitor, but acute stent thrombosis within 24 hours was more common³. Trials run under more modern practice, with wrist access and newer antiplatelet drugs, gave mixed answers. VALIDATE-SWEDEHEART (6,006 patients) found no difference from heparin alone in death, heart attack or major bleeding at 180 days⁴. BRIGHT-4 (6,016 STEMI patients in China) found a lower 30-day rate of death or major bleeding with a bivalirudin regimen that included a post-procedure infusion⁵.

FDA approved bivalirudin as Angiomax in 2000 as an anticoagulant for patients undergoing PCI, including those with heparin-induced thrombocytopenia⁶; generic versions are also approved¹.

Bleeding is the main risk and the most common adverse reaction¹. The label also warns of a higher rate of acute stent thrombosis in STEMI patients undergoing primary PCI, and of clot formation, including fatal cases, during coronary gamma brachytherapy¹. It should not be used during active major bleeding or in people with known hypersensitivity to it¹. Older patients had more bleeding events in studies, and kidney impairment slows its clearance¹.

1. FDA label: Bivalirudin for Injection (Fresenius Kabi; Angiomax generic)FDA label (DailyMed)
2. Bittl et al., N Engl J Med 1995PubMed
3. Stone et al., N Engl J Med 2008PubMed
4. Erlinge et al., N Engl J Med 2017PubMed
5. Li et al., Lancet 2022PubMed
6. Drugs@FDA: Angiomax (NDA 020873)FDA