Background: Thienopyridine use, in particular clopidogrel in acute coronary syndromes, has been associated with an improvement in outcome. However, little information is available regarding their bleeding risk when used in combination with other antithrombotic agents and revascularisation.
Methods: In a large, multinational, prospective registry, the Global Registry of Acute Coronary Events, the major bleeding rate (using GRACE criteria) of 27,358 patients with unstable angina or non-ST-elevation myocardial infarction was recorded during index admission. The interaction of thienopyridines on major bleeding with other antithrombotic agents and with revascularisation was analysed.
Results: The 11,478 patients who received thienopyridines during hospitalisation experienced a significant increase in major bleeding (2.8% with thienopyridines, 2.2% without thienopyridines; p=0.002). No significant interaction with glycoprotein IIb/IIIa inhibitors and thienopyridines was seen with regard to bleeding. Thienopyridines with unfractionated heparin did not alter bleeding risk, but thienopyridines with low molecular weight heparin was associated with a significant excess of bleeding (2.1% with thienopyridines, 1.3% without thienopyridines; p=0.004). There was no significant difference in major bleeding with thienopyridines in patients who did or did not undergo revascularisation.
Conclusions: Major bleeding was increased in patients receiving thienopyridines. No increase in bleeding risk was seen in patients having revascularisation.