Association of carotid wall layers with atherosclerotic plaques and cardiac hypertrophy in hypertensive subjects.

Abstract

Carotid intima-media thickness (cIMT) is considered a marker of subclinical atherosclerosis and is related to target-organ damage in hypertensive patients. However, increased cIMT may be due to increases in the thickness of intima (cIT) and media (cMT) layers. This study evaluated whether cIMT layers (cIT and cMT) had a greater association with carotid atherosclerotic plaques and left ventricular hypertrophy (LVH) than cIMT in hypertensive subjects. We cross-sectionally evaluated clinical, carotid, and echocardiography characteristics of 186 hypertensive patients followed at an outpatient clinic. High-resolution images of common carotid arteries were obtained by ultrasonography equipped with 10-MHz transducers, and cIT, cMT, and cIMT were manually measured using an image-processing software. Among all participants (n = 186; age = 60.8 ± 10.9 years, 43% males), there were 58% with carotid plaques and 58% with LVH. Mean cIT, cMT, and cIMT values were 0.267 ± 0.060, 0.475 ± 0.107, and 0.742 ± 0.142 mm, respectively. In logistic regression analysis adjusted for relevant covariates, carotid plaques showed stronger association with cIT than with cMT and cIMT. Furthermore, cIT showed greater area under the ROC curve (0.92; 95% CI 0.87-0.96) than cIMT (0.79; 95% CI 0.72-0.85) and cMT (0.64; 95% CI 0.56-0.72) to identify plaques. Conversely, cIT, cMT, and cIMT had modest association and accuracy to identify LVH (area under the ROC curve = 0.61, 0.57, and 0.60, respectively). In conclusion, cIT is a more accurate marker of atherosclerosis than cMT or cIMT, while cIT and cMT provide no incremental value in identifying LVH when compared with cIMT among hypertensive subjects.