The utilization of carotid artery imaging beyond metabolic scores and high-sensitivity CRP in screening intermediate-to-high Framingham risk of asymptomatic Taiwanese population

Abstract

To compare the diagnostic accuracy of various cardiovascular screening tools in asymptomatic subjects with intermediate-to-high risk Framingham risk score (FRS). In addition, we also investigated whether carotid artery study could further add incremental value beyond metabolic abnormality and inflammatory marker in this issue. 1,200 asymptomatic subjects who underwent health evaluation were recruited in our study. FRS was calculated in all participants based on clinical variables, body surface electrocardiography, medical histories, and life styles. Metabolic scores, serum high-sensitivity C reactive protein (hs-CRP) level and carotid artery study in assessing intima-media-thickness (CIMT) and plaque were all obtained and compared to FRS. Comparison of diagnostic accuracy was then conducted among these different tools aiming at a more efficient screen in identifying intermediate-to-high FRS. Of all, 1,101 participants (mean age 50.6 ± 10.4, 38.6 % women) were finally entered in our study after exclusion of known cardiovascular diseases. By utilizing common carotid IMT (CCIMT) equal or larger than 1 mm, best specificity (98.27, 95 % CI 97.24-98.99) was achieved in identifying intermediate-to-high FRS subject. The most optimal cut-off in identifying intermediate-to-high FRS for metabolic scores, hs-CRP and CCIMT was 2, 0.101 mg/dL and 0.65 mm, respectively. Both receiver operating characteristic curve and likelihood ratio tests showed that information provided by carotid artery study further showed significant incremental value when superimposed on metabolic scores and hs-CRP (all p < 0.05) in screening intermediate-to-high FRS subjects. Though diagnostic accuracy may differ to some degree by using different cut-off values, a low metabolic score seemed to have the best sensitivity with abnormal CCIMT yielded highest specificity in screening a subject with future cardiovascular risks. Carotid artery study added significant clinical incremental value in discriminating projected risk beyond metabolic scores and hs-CRP.