Platelet Responsiveness to Aspirin Loading in Patients with ST Elevation MI Undergoing Primary Percutaneous Intervention Is Associated with Myocardial Reperfusion and Clinical Outcome

• Published in: Blood 2008-11, Vol.112 (11), p.1983-1983
• Main Authors: Varon, Davi d, Matetzky, Shlomi, Fefer, Paul, Shenkman, Boris, Shechter, Michael, Levi, Nitza, Savion, Naphtali, Hod, Hanoch
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.V112.11.1983.1983

Background: In patients with stable coronary artery disease, and patients undergoing elective percutaneous coronary intervention (PCI), laboratory resistance to aspirin is associated with a higher incidence of adverse events. Nevertheless, the responsiveness to aspirin in acute myocardial infarction (AMI) and its implications have not yet been investigated. Methods: The study comprised 76 aspirin naïve patients who underwent primary PCI (PPCI) for ST-elevation MI (STEMI). Platelet reactivity was assessed 30–60 mins after a loading dose of 300mg chewable aspirin, by conventional aggregometry and Impact R, where platelet reactivity to arachidonic acid (AA) was expressed by platelet deposition under flow conditions. Results: Patients were stratified using the median value of AA-induced platelet aggregation (PA) (49%) to good responders to aspirin (n=38), who had a median AA-induced PA of 33% (25–41), and poor responders to aspirin (n=38), who had a median AA-induced PA of 77% (70–84). Similarly, good compared with poor responders had higher surface coverage by Impact R (3.9±2.6 vs. 2.2±1.3, p=0.003). Good versus poor responders were similar regarding baseline demographic, clinical and angiographic characteristics. However, good responders were more likely to demonstrate early ST-segment resolution ≥ 70% after PPCI (84% vs 54%, p