Aspirin failure, defined as occurrence of an acute coronary syndrome despite aspirin use, has been associated with a higher cardiovascular risk profile and worse prognosis. Whether this phenomenon is a manifestation of patient characteristics or failure of adequate platelet inhibition by aspirin has never been studied. We evaluated 174 consecutive patients with acute myocardial infarction. Of them, 118 (68%) were aspirin naive and 56 (32%) were regarded as having aspirin failure. Platelet function was analyzed after <72 hours of aspirin therapy in all patients. Platelet reactivity was studied by light-transmitted aggregometry and under flow conditions. Six-month incidence of major adverse coronary events (death, recurrent acute coronary syndrome, and/or stroke) was determined. Those with aspirin failure were older (p = 0.002), more hypertensive (p <0.001), more hyperlipidemic (p <0.001), and more likely to have had a previous cardiovascular event and/or procedure (p <0.001). Cumulative 6-month major adverse coronary events were higher in the aspirin-failure group (14.3% vs 2.5% p <0.01). Patients with aspirin failure had lower arachidonic acidinduced platelet aggregation (32 ± 24 vs 45 ± 30, p = 0.003) after aspirin therapy compared to their aspirin-naive counterparts. However, this was not significant after adjusting for differences in baseline characteristics (p = 0.82). Similarly, there were no significant differences in adenosine diphosphateinduced platelet aggregation and platelet deposition under flow conditions. In conclusion, our results suggest that aspirin failure is merely a marker of higher-risk patient profiles and not a manifestation of inadequate platelet response to aspirin therapy. © 2011 Elsevier Inc. All rights reserved.
Beigel, R., Hod, H., Fefer, P., Asher, E., Novikov, I., Shenkman, B., … Matetzky, S. (2011). Relation of aspirin failure to clinical outcome and to platelet response to aspirin in patients with acute myocardial infarction. American Journal of Cardiology, 107(3), 339–342. https://doi.org/10.1016/j.amjcard.2010.09.025