Is carotid intima-media thickness useful in cardiovascular disease risk assessment? The Rotterdam study

Background and Purpose-We determined the contribution of common carotid int ima-media thickness (TMT) in the prediction of future coronary heart diseas e and cerebrovascular disease when added to established risk factors. Methods We used data from a nested case-control study comprising 374 subjec ts with either an incident stroke or a myocardial infarction and 1496 contr ols. All subjects were aged 55 years and older-and participated in the Rott erdam Study. Mean follow-up was 4.2 years.(range, 0.1 to 6.5 years). We eva luated which correlates of coronary heart disease and cerebrovascular: dise ase contribute to the prediction of either a new incident myocardial infarc tion or a stroke. Logistic regression modeling and the area under the recei ver operating characteristic curve (ROC area) were used to quantify the pre dictive value of the established risk factors and the added value of IMT, Results-The ROC area of a model with age and sex only was 0.65 (95% CI, 0.6 2 to 0.69), Independent risk factors were previous myocardial infarction an d stroke. diabetes mellitus, smoking, systolic blood pressure, diastolic bl ood pressure, and total and HDL cholesterol levels,:These risk factors incr eased the ROC area from 0.65 to 0.72 (95% CI, 0.69 to 0.75). This model cor rectly predicted 17% of all subjects with coronary heart disease and cerebr ovascular disease. When common carotid IMT was added to the previous model, the ROC area increased to 0.75 (95% CI, 0.72 to 0.78). When only the IMT m easurement was used, the ROC area was 0.71 (95% CI, 0.68 to 0.74), and 14% of all Subjects were correctly predicted. There was no difference in ROC ar ea when different measurement sites were used. Conclusions-Adding IMT to a risk function for coronary heart disease and ce rebrovascular disease does not result in a substantial increase in the pred ictive value when used as a screening tool.