Clinical Correlates of Carotid Artery Atherosclerosis in African Americans: Ethnic and Geographic Disparities

Abstract: Objectives: We evaluated whether carotid intima-media thickness (CIMT) and the presence or absence of plaque improved coronary heart disease (CHD) risk prediction when added to traditional risk factors. Background: Traditional cardiovascular disease (CVD) risk prediction schemes need further improvement as the majority of the CVD events occur in the intermediate risk groups. On an ultrasound scan, CIMT and presence of plaque are associated with CVD, and therefore could potentially help improve CHD risk prediction. Methods: Risk prediction models (overall, and in men and women) considered included traditional risk factors (TRF) only, TRF plus CIMT, TRF plus plaque, and TRF plus CIMT plus plaque presence. Predictivity was established by calculating the area under the curve (AUC). Cox proportional hazards models were used to estimate 10-year CHD risk for each risk model. Observed events were compared with expected events, and, the net reclassification index (NRI) was calculated. Results: Overall, the CIMT plus TRF plus plaque model provided the most improvement in AUC in the overall sample. Similarly, the CIMT plus TRF plus plaque model had the best net reclassification index of 9.9% in the overall population. However, comparison of TRF and CIMT and plaque with TRF and CIMT or TRF and plaque only resulted in statistically non-significant changes of the statistical test. Conclusions: Adding plaque and CIMT to TRF improve CHD risk prediction in the Jackson Heart Study (JHS). We hope that our study will shed further light on which patients to identify for further risk factor modification and or medical treatment and further intervention to reduce the burden of cardiovascular disease, and its overall impact in our population.Master of Public Healt