Polak Joseph F, Post Wendy S, Carr J Jeffrey, Szklo Moyses, O'Leary Daniel H
Department of Radiology, Tufts Medical Center, Boston, Massachusetts.
Johns Hopkins University, Baltimore, Maryland.
J Am Soc Echocardiogr. 2014 Sep;27(9):991-7. doi: 10.1016/j.echo.2014.04.019. Epub 2014 Jun 15.
Common carotid artery (CCA) intima-media thickness (IMT) can be measured using ultrasound near to or below the carotid bulb. This might affect associations of IMT with coronary heart disease (CHD) risk factors and events.
IMT measurements were performed near and below the divergence of the CCA bulb in 279 white individuals aged 45 to 54 years free of CHD at baseline and a subset of the Multi-Ethnic Study of Atherosclerosis, a cohort composed of whites, blacks, Chinese, and Hispanic subjects. Participants were followed for an average of 8.2 years. Far wall mean of the maximum IMT (MMaxIMT) and mean of the mean IMT of the right and left CCAs were averaged. Framingham risk factors were used in multivariate linear regression models. Parsimonious Cox proportional regression models included first-time CHD as outcome.
Mean of the mean IMT below the bulb was smaller than near the bulb (0.51 ± 0.078 vs 0.56 ± 0.088 mm, P < .001) and had similar associations with risk factors (model R(2) = 0.215 vs 0.186). MMaxIMT below the bulb was associated with risk factors (model R(2) = 0.211), but MMaxIMT near to the bulb was not (R(2) = 0.025). Mean of the mean IMT and MMaxIMT below the bulb were associated with CHD events (hazard ratios, 1.67 [P = .047] and 1.72 [P = .037], respectively) but not when measured near the bulb.
CCA IMT measurements made below the bulb are smaller but have more consistent associations with CHD risk factors and outcomes compared with IMT measured near the bulb.
可使用超声在颈总动脉（CCA）球部附近或其下方测量颈总动脉内膜中层厚度（IMT）。这可能会影响IMT与冠心病（CHD）危险因素及事件之间的关联。
在动脉粥样硬化多族裔研究中，对279名年龄在45至54岁、基线时无冠心病的白人个体以及由白人、黑人、中国人和西班牙裔受试者组成的队列中的一个子集，在CCA球部分叉处附近及其下方进行IMT测量。参与者平均随访8.2年。将右侧和左侧CCA的最大IMT（MMaxIMT）远壁平均值以及平均IMT平均值进行平均。在多变量线性回归模型中使用弗雷明汉危险因素。简约Cox比例回归模型将首次发生冠心病作为结局。
球部下方的平均IMT平均值小于球部附近（0.51±0.078 vs 0.56±0.088 mm，P <.001），并且与危险因素具有相似的关联（模型R(2)=0.215 vs 0.186）。球部下方的MMaxIMT与危险因素相关（模型R(2)=0.211），但球部附近的MMaxIMT则不然（R(2)=0.025）。球部下方的平均IMT平均值和MMaxIMT与冠心病事件相关（风险比分别为1.67 [P =.047]和1.72 [P =.037]），但在球部附近测量时则不然。
与在球部附近测量的IMT相比，在球部下方进行的CCA IMT测量值较小，但与冠心病危险因素及结局的关联更一致。
