Purified antithrombin concentrates or human recombinant antithrombin have been proposed for treating heparin resistance in cardiac operations with cardiopulmonary bypass, and exert a beneficial effect in terms of haemostatic system activation control. However, little information is available with respect to antithrombin supplementation and clinical outcome in selected categories of patients. The aim of this study is to evaluate clinical outcome data in patients intraoperatively treated with purified antithrombin compared to a control population.

89 patients forming the AT-treated group received purified antithrombin to correct preoperatively low values of antithrombin activity or to treat heparin resistance. The Control group was retrospectively created with a propensity score analysis. After verifying the homogeneity of the two groups, various outcome variables were compared between groups.

Patients in the AT-treated group had a shorter Intensive Care Unit (2.6 ± 3 vs. 3 ± 2.7 days) and Hospital (7.5 ± 3.5 vs. 8.6 ± 4.5 days) stay, and a lower rate (relative risk 0.1, 95% confidence interval 0.01–0.81) of severe postoperative morbid events. Conversely, they demonstrated a significant, albeit clinically irrelevant, more pronounced postoperative bleeding tendency.

AT supplementation in patients at risk for inadequate thrombin suppression during the operation reduces postoperative complications and shortens the recovery time. However, a careful monitoring of the heparin requirements is recommended in order to avoid an undesired excessive postoperative bleeding.

The main aim of this review is to summarize the literature with respect to the impact of anticoagulation monitoring strategies and therapeutic strategies to manage heparin resistance and optimize anticoagulation with cardiac surgery.

This review was generated using peer-reviewed manuscripts pertinent to this topic that were identified using a computer-based Medline search.

There are a small number of well-controlled prospective, randomized studies, some of which suggest that bleeding and transfusion can be attenuated by refining heparin monitoring techniques by sustaining better anticoagulation during cardiopulmonary bypass especially when applied to operative cases that involve complex procedures that require long intervals on cardiopulmonary bypass. Recent studies indicate that antithrombin III concentrates can be used to treat heparin resistance and thereby enhance preservation of the hemostatic system during CPB. A few recent retrospective analyses suggest that low ATIII concentration is associated with negative outcomes.

The literature indicates that enhanced anticoagulation via more sophisticated heparin monitoring schemes can reduce bleeding and transfusion and that antithrombin III concentrates can be used to effectively manage heparin resistance during cardiac surgery. Well-controlled, randomized studies are needed to better define the relative importance of AT IIII supplementation with respect to either the management of heparin resistance or with respect to optimization of anticoagulation during CPB and specifically if these interventions are able to decrease the incidence of bleeding and/or thrombotic complications.