Bivalirudin as an Alternative to Heparin in Pediatric Cardiac Procedures: Evidence, Challenges, and Future Directions.

Unfractionated heparin remains the standard anticoagulant for pediatric cardiac procedures, but its drawbacks in children are hard to ignore. Because it works through antithrombin, its effect is unpredictable, dosing is difficult to titrate, and it carries the risk of heparin-induced thrombocytopenia (HIT). Bivalirudin, a direct thrombin inhibitor, inhibits thrombin without needing antithrombin. The pediatric evidence, though, is thin. Beyond one cardiac surgery trial and a few catheterization studies, most work comes from ECMO, along with growing use in pediatric ventricular assist device (VAD) support, where direct thrombin inhibitors have replaced heparin and now feature in society guidance. These studies show bivalirudin is feasible and predictable, but not that it consistently beats heparin. For now, its clearest role is in children who cannot tolerate heparin or whose anticoagulation is unstable. The field needs multicenter randomized trials, agreed-upon protocols, and monitoring built for children.