The Use of Bivalirudin in Pediatric Cardiac Surgery and in the Interventional Cardiology Suite

Abstract

Anticoagulation is an essential component for patients undergoing cardiopulmonary bypass or extracorporeal membrane oxygenation and for those with ventricular assist devices. However, thrombosis and bleeding are common complications. Heparin continues to be the agent of choice for most patients, likely owing to practitioners' comfort and experience and the ease with which the drug's effects can be reversed. However, especially in pediatric cardiac surgery, there is increasing interest in using bivalirudin as the primary anticoagulant. This drug circumvents certain problems with heparin administration, such as heparin resistance and heparin-induced thrombocytopenia, but it comes with additional challenges. In this manuscript, the authors review the literature on the emerging role of bivalirudin in pediatric cardiac surgery, including its use with cardiopulmonary bypass surgery, extracorporeal membrane oxygenation, ventricular assist devices, and interventional cardiology. Moreover, they provide an overview of bivalirudin's pharmacodynamics and monitoring methods.

Keywords: ECMO; anticoagulation; bivalirudin; cardiopulmonary bypass; pediatric cardiac surgery.

Figure 1.. Bivalirudin’s mechanism of action.

(A) Indirect inhibition of thrombin by antithrombin, which is activated via unfractionated or low molecular weight heparin. (B) Direct inhibition of thrombin by argatroban and bivalirudin. Bivalirudin is cleaved by thrombin via proteolysis. This represents the major elimination mechanism of bivalirudin. Used with permission from Veale et al.(42)

Figure 2.. Anticoagulation cascade of bivalirudin and heparin.

Coagulation cascade (excluding actions of factors XI, XII, and XIII) and points of inhibition by anticoagulants. Generation of thrombin is key to continued clot formation, as the formation of thrombin results in a positive feedback loop, activating factor V and factor VIII, which results in additional thrombin. Thrombin then activates fibrinogen to form fibrin. AT, antithrombin; DTI, direct thrombin inhibitor; F, factor; TF, tissue factor; UFH, unfractionated heparin.