BACKGROUND: Aspirin hyporesponsiveness increases the risk of ischemic events. Therefore, it is important to investigate the factors influencing aspirin hyporesponsiveness.

MATERIAL AND METHODS: Patients aged 60 years or older who did not take aspirin before enrollment were included, with aspirin 100 mg/day administered after enrollment. The arachidonic acid-induced platelet aggregation rate (Ara) was measured by light transmission assay to evaluate aspirin responsiveness. Patients with Ara in the upper quartile after taking aspirin were assigned to the aspirin hyporesponsive group (Ara-Q4).

RESULTS: A total of 292 elderly patients were included. The median value of Ara after taking aspirin was 5.87% (interquartile range 3.86-10.04%). Compared with the aspirin non-hyporesponsive group (Ara-Q1-3, Ara ≤10.04%, n=220), the level of uric acid (UA) (341.30 µmol/L vs. 299.10 µmol/L, p=0.027) and the ratios of β-blockers (9.72% vs. 2.27%, p=0.015) and diuretics (6.94% vs. 1.36%, p=0.036) were higher in the aspirin hyporesponsive group (Ara-Q4, Ara >10.04%, n=72). After multivariate adjustment, the results demonstrated baseline Ara (odds ratio [OR]: 1.030, 95% confidence interval [CI]: 1.004–1.056, p=0.021), UA level (OR: 1.003, 95% CI: 1.000–1.006, p=0.038), and β-blockers use (OR: 5.487, 95% CI: 1.515–19.870, p=0.010) were independently and positively associated with aspirin hyporesponsiveness.

CONCLUSIONS: This study found that baseline Ara, UA level, and β-blockers use were independently and positively associated with aspirin hyporesponsiveness in elderly Chinese patients, which needs to be validated in large-scale studies.

Keywords: Aspirin, Frail Elderly, Platelet Aggregation Inhibitors, Adrenergic beta-Antagonists, Aged, 80 and over, Asians, Biomarkers, Pharmacological, Odds Ratio, Platelet Aggregation, Platelet Function Tests, Uric Acid