Carotid Intima Media Thickness as a Surrogate Marker of Atherosclerosis and Cardiovascular Burden in Hypertensive Subjects: Relevance and Implications

Abstract

Background: The availability of surrogate markers of severity of atherosclerosis is essential to monitor and prevent cardiovascular morbidity associated with atherosclerosis. Carotid intima media thickness (c-IMT)) is a marker of atherosclerosis. We aimed to compare the c-IMT of hypertensive subjects with their normotensive counterparts and associated demographic and echocardiographic correlates. Methods: We studied 122 hypertensive and fifty controls. Their demographic and clinical parameters were obtained. All participants had echocardiography. Statistical analysis was done using SPSS 18.0. Results: The hypertensive subjects were well matched in age and gender distribution with their normotensive counterparts. Maximum CIMT was significantly higher among hypertensive subjects than controls right (11.1 ± 5.1 vs. 6.1 ± 1.6, p<0.05), Left coronary artery (11.4 ± 4.7 vs. 6.0 ± 2.2, p<0.05). The mean CIMT was also significantly higher in the RCA of hypertensive subjects (9.01 ± 3.8 vs. 7.6 ± 2.62, p<0.05) although that of the LCA did not achieve statistical significance. CIMT was well correlated to age, blood pressure, left ventricular wall dimensions and mass index. Conclusion: Carotid intima media thickness measurements are mostly significantly higher among hypertensive Nigerian subjects than normotensive counterparts. C-IMT measurements were also well correlated with many cardiovascular risk factors. Left ventricular mass, age and major echocardiographic risk parameters such as ejection fraction, left ventricular wall dimensions and relative wall thickness are the major determinants of the maximum carotid intima media thickness measurements. Therefore c-IMT has a good potential for evaluating cardiovascular burden of hypertensive Nigerian subjects.