Background: Despite the increasingly prevalent role of platelet glycoprotein (GP) IIb/IIIa receptor inhibitors in acute coronary syndromes and percutaneous coronary interventions, the incidence and clinical relevance of thrombocytopenia occurring with their use remain unclear.
Methods: We identified 8 placebo-controlled, randomized, large trials of GP IIb/IIIa receptor inhibitors reporting the incidence of thrombocytopenia, grouped by severity. The clinical courses of 42 patients with GP IIb/IIIa-related thrombocytopenia in these studies and other case reports were reviewed for bleeding complications.
Results: Abciximab increased mild thrombocytopenia compared with placebo (4.2% vs 2.0%; P <.001; odds ratio 2.14) and increased severe thrombocytopenia compared with placebo (1.0% vs 0.4%; P =.01; odds ratio 2.48). Small-molecule IIb/IIIa inhibitors did not significantly increase mild or severe thrombocytopenia compared with placebo. Mild thrombocytopenia occurred more frequently in acute coronary syndrome trials than in coronary intervention trials, even in patients not receiving any IIb/IIIa inhibitors. No major bleeding sequelae were reported in 23 patients with severe thrombocytopenia or in 19 patients with profound thrombocytopenia.
Conclusions: Abciximab, but not eptifibatide or tirofiban, increases the incidence of thrombocytopenia compared with placebo in patients also treated with heparin. Thrombocytopenia associated with GP IIb/IIIa inhibition does not routinely lead to severe bleeding complications.