Echogenic Carotid Plaques Are Associated With Aortic Arterial Stiffness in Subjects With Subclinical Carotid Atherosclerosis

A better understanding of the interrelationships between the structure and function of the large arteries would lead to optimize cardiovascular disease prevention strategies. In this study, we investigated the relationships of aortic arterial stiffness assessed by carotid-femoral pulse-wave velocity (PWV), with carotid plaque echogenicity assessed by B-mode ultrasound. We analyzed 561 subjects (without coronary heart disease or stroke) who were volunteers for free health examinations (age, 58.3+/-10.8 years; 32.6% women). Extracranial carotid plaque echogenicity was graded from 1 (plaque appearing black or almost black) to 4 (plaque appearing white or almost white) according to the Gray-Weale classification. Plaques of grades 1 and 2 were defined as echolucent plaques, and plaques of grades 3 and 4 were defined as echogenic plaques. Fifty-one subjects (9.1%) had echolucent carotid plaques, 109 (19.4%) had echogenic plaques, and 401 (71.5%) had no plaques. Subjects with echogenic plaques had higher PWV mean (12.9+/-2.8 m/s) compared with those without plaques (11.1+/-2.3 m/s, P<0.001) and compared with those with echolucent plaques (11.3+/-2.3 m/s, P<0.01). The PWV means in subjects without plaques and those with echolucent plaques were similar and not statistically different (P=0.55). When multivariate adjustment for major known cardiovascular risk factors was performed, these results were not markedly modified. Similar patterns of results were also observed in many subgroups according to age, gender, and hypertensive status. This study provides the first evidence that echogenic but not echolucent carotid plaques are associated with aortic arterial stiffness. This association applies to individuals with normal blood pressure and those with elevated blood pressure. Assessment of the joint and interaction effects of plaque morphology and arterial stiffness on the occurrence of cardiovascular events would permit a better identification of high-risk subjects.