Despite the absence of cardiopulmonary bypass, systemic anticoagulation is needed for off-pump coronary artery bypass (OPCAB) surgery. The aim of the current review is to describe the influence of OPCAB surgery on hemostatic activation and to review the literature with regard to perioperative anticoagulation protocols in OPCAB surgery.

Research of the pertinent literature with appropriate terms for anticoagulation in OPCAB surgery.

While during on-pump cardiac surgery a target activated clotting time (ACT) value of 400–480 is generally accepted, to date no standardized target ACT value for OPCAB surgery has been established. However, an ACT value of > 300 seconds is accepted by approximately 80% of US/Canadian surgeons and 60% of European surgeons. Even given the large variation commercially available heparins, the inter-individual variability of the effect of heparins on the ACT, and large differences in coagulation activation and ‘clot detection’ of currently used ACT systems, this target ACT corresponds to a heparin dose of approximately 150–300 IU/kg. New anticoagulant drugs have been proposed, acting through a selective anti-Xa activity (danaparoid) or directly inhibiting thrombin (bivalirudin).

Anticoagulation management is performed without any internationally accepted standard and, due to this and the lack of adequately powered studies, there is scarce information about the effects of OPCAB surgery on hemostatic activation in the immediate perioperative period. Although limited to two modest studies, bivalirudin appears to be an interesting option for the future.