Thrombocytopenia Caused by Abciximab or Tirofiban and Its Association with Clinical Outcome in Patients Undergoing Coronary Stenting

Background-Thrombocytopenia is a possible complication of treatment with glycoprotein (GP) IIb/IIIa antagonists during percutaneous coronary interventions, but it is not clear whether different GP IIb/IIIa inhibitors carry a different risk of thrombocytopenia, and its relation to clinical outcome is unknown. Methods and Results-We analyzed data from the Do Tirofiban and Reopro Give Similar Efficacy Outcomes (TARGET) study, which compared the safety and efficacy of abciximab and tirofiban in patients undergoing coronary stenting. Platelets were measured at baseline and 6 and 24 hours after the beginning of treatment. Thrombocytopenia (nadir platelet count <100×10⁹ cells/L) developed in 2.4% of patients treated with abciximab and 0.5% of those treated with tirofiban (P<0.001). The variables independently associated with thrombocytopenia were treatment with abciximab within the previous 6 months (OR, 4.4; 95% CI, 1.7 to 11.2), baseline creatinine levels of ≥0.8 mg/dL (OR, 3.8; 95% CI, 1.7 to 8.8), previous transient ischemic attack (OR, 3.2; 95% CI, 1.4 to 7.6), female gender (OR, 1. 9; 95% CI, 1.2 to 3.1), and history of peripheral vascular disease (OR, 1.78; 95% CI, 1.0 to 3.1). Severe bleeding occurred more frequently in patients with thrombocytopenia (5.1% versus 0.7%, P=0.001), who also more frequently received blood transfusions (6.1% versus 1.4%, P=0.001). At the 30-day follow-up, 2.0% of patients with thrombocytopenia and 0.4% of those without (P=0.022) had died; myocardial infarction occurred in 9.13% versus 6.11% (P=NS); and target vessel revascularization occurred in 6.07% versus 0.60% (P<0.001). Conclusions-During coronary stenting, abciximab and other risk factor are independently associated with thrombocytopenia. Regardless of the cause, thrombocytopenia is associated. with more ischemic events, bleedings, and transfusions.