Carotid ultrasound screening for coronary heart disease: results based on a meta-analysis of 18 studies and 44,861 subjects

Background Carotid artery ultrasound is a possible screening test for future coronary heart disease (CND) events to select individuals for preventive treatment. Objectives To assess the screening performance of carotid artery intima-media thickness (IMT) and carotid plaque in the identification of individuals with CHID. Methods Meta-analysis of case-control and cohort studies, reporting carotid IMT or plaque in individuals with and without CHD. Screening performance (detection rates [DRs] for specified false-positive rates [FPRs]) was assessed from the relative Gaussian distributions of IMT among individuals with and without CHID and from the proportion of affected and unaffected individuals with plaque. Results Eighteen studies, involving 2920 individuals with CHD (mean age range 46-73 years) and 41,941 without (aged 44-73 years) were included in the meta-analysis. For plaque the DR was 62% for an FPR of 30%; likelihood ratio (2.1 [95% CI 1.6-2.4]). For IMT, the DR was 65% for the same 30% FPR (IMT cut-off >= 0.82 mm); likelihood ratio 2.2 (1.9-2.5). The results were similar in case-control and cohort studies. Conclusion Neither carotid plaque nor IMT has a CHD screening performance that is sufficiently between affected and unaffected individuals to be a worthwhile screening test.