Occurrence and clinical significance of thrombocytopenia in a population undergoing high-risk percutaneous coronary revascularization

Objectives. This study sought to determine the frequency of thrombocytopenia and its relation with clinical outcomes in high risk patients undergoing percutaneous coronary revascularization who received either the platelet glycoprotein (GP) IIb/IIIa receptor antagonist abciximab (ReoPro, c7E3 Fab) or conventional therapy. Background. The development of thrombocytopenia on exposure to GPIIb/IIIa antagonists threatens the utility and economic viability of this drug class for patients with vascular disease. Methods. We analyzed data from the Evaluation of c7E3 for the Prevention of Ischemic Complications trial (EPIC), a 2,099-patient, randomized trial of placebo, abciximab bolus or abciximab bolus plus a 12-h infusion during high risk coronary revascularization. Results. Thrombocytopenia (nadir platelet count <100 x 10(9)/liter) developed in 81 patients (3.9%) during their hospital stay, with 19 (0.9%) developing severe (<50 x 10(9)/liter) thrombocytopenia. Both thrombocytopenia and severe thrombocytopenia were more frequent in the bolus plus infusion arm (5.2% and 1.6%, respectively) than in the bolus-onty and placebo arms combined (p = 0.020 and p = 0.025, respectively). Acute profound thrombocytopenia developed in two patients in the bolus plus-infusion arm. Patients with thrombocytopenia experienced more unfavourable clinical outcomes than those who did not develop thrombocytopenia, regardless of treatment assignment, but those with thrombocytopenia who received abciximab had fewer worse out comes at 30 days. Multivariable logistic modeling revealed a lower baseline platelet count, alder age and lighter weight to be important predictors of thrombocytopenia. In a logistic regression model, bolus-plus-infusion treatment was a significant predictor of thrombocytopenia (p = 0.016) and remained so after adjustment for procedures and baseline risk factors (p = 0.0077). Conclusions. Thrombocytopenia was associated with adverse clinical outcomes and excessive bleeding, but patients receiving abciximab fared better than those receiving placebo.