Intima – Media Thickness of Left Anterior Descending Coronary Artery in a Black Kenyan Population: Correlation with Morphological Features

Abstract

Background: Intima-Media thickness is an acknowledged surrogate marker for predicting and profiling of atherosclerotic cardiovascular disease. It displays geographical and ethnic variation but is seldom reported among black populations of Africa. The left anterior descending coronary artery is one of the most frequently afflicted arteries by atherosclerosis. This study, therefore, aimed at correlating its intima-media thickness with morphological features of left coronary artery in a black Kenyan population. Materials and methods: Materials for this study were 126 hearts obtained during autopsy at the Department of Human Anatomy, University of Nairobi Kenya from black adult Kenyans [72 males, 54 females] who died of noncardiovascular causes. The left coronary artery was identified, its termination pattern recorded and its length and bifurcation angle measured. Specimens for light microscopy were taken from the proximal segment of the left anterior descending artery and processed for paraffin embedding and sectioning. Five micron sections were stained with Masson's trichrome and examined at magnification x35. The results were analyzed using SPSS version 17.0. Student t-test was performed at 95% confidence interval where p ≤ 0.05 was taken to be statistically significant. They are presented in micrographs and tables. Results: The mean intima-media thickness was 0.332 mm. It was higher in males (0.357 ± 0.06 mm) than in females (0.25 ± 0.03 mm), increased with number of branches of left coronary artery, from 0.336 ± 0.014 mm in bifurcation to 0.506 ± 0.01 mm in pentafurcation; and was also higher in left coronary arteries that were shorter than 5 mm and those with bifurcation angles >800. Conclusion: The intima-media thickness of left anterior descending artery is influenced by length, bifurcation angle and terminal branching pattern of left coronary artery, and is higher in males than in females. This suggests that these morphological features of left coronary artery constitute anatomical risk factors for atherosclerosis. Individuals with these features should be screened for atherosclerosis, to inform early intervention.