Anticoagulation management and cardiac surgery in patients with heparin-induced thrombocytopenia.

Unfractionated heparin (UFH) is the gold standard for anticoagulation during cardiopulmonary bypass (CPB). Of patients undergoing CPB operations, 25% to 50% develop heparin-dependent antibodies during the postoperative period, typically between day 5 and 10, if UFH is continued during the postoperative course. In 1% to 3% of all patients undergoing CPB operation with UFH anticoagulation, these antibodies activate platelets causing a prothrombotic disorder, known as heparin-induced thrombocytopenia (HIT), which can lead to life-threatening thromboembolic complications. If urgent cardiac operation with the use of CPB in patients with positive antibody titer is required, different anticoagulatory approaches are available, such as lepirudin, bivalirudin, and danaparoid or UFH in combination with platelet antagonists, such as epoprostenol or tirofiban. In patients with previous HIT but no detectable antibodies, UFH alone can be used only during CPB, but alternative anticoagulation has to be used pre- and postoperatively.