Objective: To elucidate the prognosis of the elderly with neurologically asymptomatic atheromatous plaques of the carotid arteries.
Methods: A total of 228 subjects aged 60 years or older, examined by carotid ultrasonography and platelet aggregation test, were studied. They were divided into 3 groups based on plaque morphology: the no lesion group (n=110), the nodular plaque group (n=47), and the mural plaque group (n=71). Platelet aggregability was assessed as suppressed, normal, or accelerated.
Results: During the 4.0 years of mean follow-up period, 31 subjects died, and 16 of the deaths were due to vascular events such as cerebral infarction or ischemic heart disease. The annual mortality rate due to vascular events was 0.5% in the no lesion group, 1.4% in the nodular plaque group, and 4.1% in the mural plaque group, and Kaplan-Meier survival curve showed poor prognosis of the mural plaque group (logrank statistics: 12.8, Df=2, p=0.0017). According to the Cox proportional hazard model, a high hazard ratio (HR) was seen in the mural plaque group (5.3) and also the accelerated platelet aggregability group (4.0).
Conclusion: These findings suggested that subjects with mural plaques and accelerated platelet aggregability, even when asymptomatic, have a poor prognosis due to vascular events. Antiplatelet therapy and exercise stress test for detecting coronary artery disease should be considered in these subjects.