Clinical impact of aspirin resistance measured using the Ultegra Rapid Platelet Function Assay-ASA in patients undergoing percutaneous coronary intervention / 대한내과학회지

ABSTRACT

BACKGROUND/AIMS: Aspirin resistance is reported to be associated with myocardial infarction, stroke, and myonecrosis after percutaneous coronary intervention. However, aspirin resistance and its clinical implications in patients undergoing drug-eluting stent (DES) implantation have not been evaluated sufficiently. METHODS: The study enrolled 419 consecutive patients who underwent DES implantation. All of the patients took aspirin 100 mg (228 patients, 54.4%) or 200 mg (191 patients, 45.6%). Aspirin resistance was measured using the Ultegra Rapid Platelet Function Assay-ASA (Accumetrics, San Diego, CA, USA). The results were expressed as aspirin reaction units (ARU). Aspirin resistance was defined as ARU > or =550. We followed all patients for 9 months. RESULTS: Aspirin resistance was found in 33 patients (33/419, 7.9%). The aspirin dose (118.18+/-39.2 vs. 147.93+/-50.0 mg, p= 0.011) was lower in the aspirin-resistant (n=33) versus the aspirin-sensitive (n=386) group. There was no significant difference in the occurrence of myocardial necrosis (15.6% vs. 15.5%, p=0.988). On multivariate analysis, low-dose aspirin (odds ratio (OR) 4.714; 95% confidence interval (CI) 1.865-11.914; p=0.001), age (OR 1.048; 95% CI 1.005-0.092, p=0.029), platelet count (OR 1.007; 95% CI 1.001-1.014, p=0.011), and hypercholesterolemia (OR 2.937; 95% CI 1.310-6.583, p=0.009) were independent predictors of aspirin resistance. Over the 9 months, no stent thrombosis or death occurred; one acute myocardial infarction occurred in the aspirin-sensitive group. CONCLUSIONS: Low-dose aspirin, old age, a higher platelet count, and hypercholesterolemia were associated with a high incidence of aspirin resistance in patients who underwent DES implantation. However, no significant differences in clinical outcome were found between the aspirin-resistant and -sensitive groups during a 9-month follow-up.