[Alternatives to heparin and protamine anticoagulation for cardiopulmonary bypass in cardiac surgery]

Heparin anticoagulation followed by protamine reversal is commonly used in cardiopulmonary bypass (CPB) cardiac procedures, but this strategy has some limitations. The primary objective of this study was to determine the reliable alternatives for anticoagulation during CPB for cardiac surgery. For each drug proposed, the secondary objectives were to outline the main advantages and disadvantages, to propose a therapeutic protocol, and to provide a cost-benefit analysis.

A systematic review of the literature was performed between September 2012 and December 2013. It was based on the protocol established by the "Cochrane collaboration Handbook". Twenty articles were analyzed. The Thériaque database from the University Hospital of Grenoble made the economic analysis possible.

Seven alternative anticoagulation strategies were considered: danaparoid sodium, lepirudin, argatroban, bivalirudin, ancrod, idraparinux, and EP217609. Danaparoid sodium has issues with individual variability. Several studies (EVOLUTION-ON, CHOOSE-ON) proposed a reliable therapeutic protocol for bivalirudin. Ancrod resulted in an increase in the transfusion of blood products. Direct thrombin inhibitors offer a promising alternative. EP217609 is a synthetic anticoagulant currently undergoing Phase IIa clinical trials. It is an indirect inhibitor of factor Xa, a direct inhibitor of free and bound thrombin, and can be neutralized by avidin.

The ideal anticoagulation strategy for cardiac surgery with CPB does not exist. Heparin and protamine remain the gold standard for anticoagulation therapy. To date, bivalirudin is the most promising molecule despite its high cost and lack of a readily available antagonist.