The role of carotid plaque echogenicity in baroreflex sensitivity

The baroreflex sensitivity is impaired in patients with carotid atherosclerosis. The purpose of our study was to assess the impact of carotid plaque echogenicity on the baroreflex function in patients with significant carotid atherosclerosis, who have not undergone carotid surgery.

Spontaneous baroreflex sensitivity (sBRS) was estimated in 45 patients with at least a severe carotid stenosis (70%-99%). sBRS calculation was performed noninvasively, with the spontaneous sequence method, based on indirectly estimated central blood pressures from radial recordings. This method failed in three patients due to poor-quality recordings, and eventually 42 patients were evaluated. After carotid duplex examination, carotid plaque echogenicity was graded from 1 to 4 according to Gray-Weale classification and the patients were divided into two groups: the echolucent group (grades 1 and 2) and the echogenic group (grades 3 and 4).

Sixteen patients (38%) and 26 patients (62%) were included in the echolucent and echogenic group, respectively. Diabetes mellitus was observed more frequently among echolucent plaques (χ(2) = 8.0; P < .004), while those plaques were also more commonly symptomatic compared with echogenic atheromas (χ(2) = 8.5; P < .003). Systolic arterial pressure, diastolic arterial pressure, and heart rate were similar in the two groups. Nevertheless, the mean value of baroreflex sensitivity was found to be significantly lower in the echogenic group (2.96 ms/mm Hg) compared with the echolucent one (5.0 ms/mm Hg), (F [1, 42] = 10.1; P < .003).

These findings suggest that echogenic plaques are associated with reduced baroreflex function compared with echolucent ones. Further investigation is warranted to define whether such an sBRS impairment could be responsible for cardiovascular morbidity associated with echogenic plaques.