See Online Data Supplement 31 for more information on anemia, bleeding, and transfusion. The incidence of thrombocytopenia in patients with ACS var- ies from 1% to 13%. In 1 large prospective registry, one third of patients treated with prolonged heparin therapy developed some degree of thrombocytopenia.728 Independent risk fac- tors for the development of thrombocytopenia include lower baseline platelet count, older age, ACS, cardiac or vascular surgery, intravenous UFH or both UFH and LMWH, duration of heparin therapy, and low body mass index.728 730 The risk of thrombocytopenia is increased in patients treated with abcix- imab and, to a lesser degree, with eptifibatide or tirofiban.731 734 Thrombocytopenia on presentation or related to antithrom- botic therapy is associated with significantly increased risk of thrombotic events, MI, major bleeding, and in-hospital mor- tality in patients with and without ACS.728 731,735 739 The OR for development of these endpoints with thrombocytopenia (com- pared to without thrombocytopenia) is 2 to 8. Data from the CATCH (Complications After Thrombocytopenia Caused by as a threshold, below which there is a linear augmentation in probability of bleeding.740 Results from CATCH highlighted that thrombocytopenia and heparin-induced thrombocytope- nia are often not diagnosed.728 Thrombocytopenia is gener- ally a contraindication for GP IIb/IIIa inhibitor therapy; direct thrombin inhibitors are often considered in preference to UFH or LMWH in patients with thrombocytopenia. See Online Data Supplements 31 and 32 for additional information on anemia, bleeding, and transfusion. 7.10. Cocaine and Methamphetamine Users: Recommendations Class I 1. Patients with NSTE-ACS and a recent history of cocaine or methamphetamine use should be treated Amsterdam et al 2014 AHA/ACC NSTE-ACS Guideline e391 in the same manner as patients without cocaine- or methamphetamine-related NSTE-ACS. 