Optical platelet aggregometry does not appear useful as a means of assessing the risk of recurrent vascular events in aspirin-treated patients.

ABSTRACT

OBJECTIVES: To investigate whether the results of optical platelet aggregometry indicate the risk of recurrent ischemic events. MATERIALS AND METHODS: Cerebro- and cardiovascular patients taking aspirin for at least 30 days were studied retrospectively. Ischemic vascular events occurring prior to testing and the presence of vascular risk factors were recorded. RESULTS: 241 subjects were included. Among the 78 patients (32.4%) who displayed recurrent vascular episodes, the age (62.5 +/- 10.6 vs. 58.4 +/- 11.6, P = 0.009) and the proportion of hypertensives (80.8% vs. 68.1%, P = 0.040) were significantly higher when compared with the participants who exhibited single events. The degree of platelet aggregation did not differ significantly between the patients with and those without recurrent episodes. Logistic regression analysis identified only age (OR 1.033, 95% CI 1.008-1.058, P = 0.010), and not aggregation values, as a risk condition for recurrent vascular episodes. CONCLUSIONS: Results of optical platelet aggregometry were not indicative of the risk of recurrent vascular events. The role of conventional risk factors appeared to be more important.