Abstract TP110: Clinical Risk Factors For Stroke And Associations With Microembolic Signals On Transcranial Doppler

Abstract

Introduction: Transcranial Doppler (TCD) has been used to identify microembolic signals (MES) in individuals with carotid atherosclerosis. MES are hypothesized to originate from unstable carotid plaque and have been identified in both symptomatic and asymptomatic individuals with cerebrovascular disease. The purpose of this study was to examine the relationship of clinical risk factors (CRF) for stroke and the presence of MES to further understand how clinical risk factors are associated with MES. Method: Participants (n=89) scheduled for clinically indicated CEA (>60% stenosis NASCET and ACAS Criteria) were evaluated preoperatively for CRF for stroke and the presence MES with TCD. TCD was performed for 60 minutes examining both the right and left middle cerebral arteries. Kendall’s tau correlation coefficients were used to examine the relationship between MES and continuous CRFs. Pearson χ2 test was used to examine the relationship between MES and categorical CRFs. Logistic regression analysis with backward selection was used to examine the relationship between MES presence and CRFs (symptomatic status, age, sex, BMI, heart rate, blood pressure, hypertension, hyperlipidemia, diabetes, peripheral vascular disease, previous stroke, tobacco use, cardiac risk for MES, cancer, and taking aspirin). Results: Participants had a median (interquartile range [IQR]) age of 71(13) years, 30(33.7%) female, and 53(59.6%) were symptomatic. MES were detected in 32 (36%) participants. There was significant evidence of association between MES with older age (p =0.026) and male sex (p =0.007). No other clinical variables showed significant association with MES (all p-values>0.05). Logistic regression (with p output 0.10) demonstrated that a model including age(p=0.018), sex(p=0.013) and hyperlipidemia(p=0.083) was significantly associated with the presence of MES(p=0.001). Conclusion: MES were associated with age and sex in a cohort with advanced carotid atherosclerosis. Symptomatic status was not a predictor for MES in this cohort, suggesting that plaques in both symptomatic and asymptomatic individuals have the ability to release microemboli, highlighting the need for further work to be done to identify unstable plaques.