Carotid plaque, compared with carotid intima-media thickness, more accurately predicts coronary artery disease events: a meta-analysis.

OBJECTIVES We conducted the meta-analysis to compare the diagnostic accuracies of carotid plaque and carotid intima-media thickness (CIMT) measured by B-mode ultrasonography for the prediction of coronary artery disease (CAD) events. METHODS Two reviewers independently searched electronic databases to identify relevant studies through April 2011. Both population-based longitudinal studies with the outcome measure of myocardial infarction (MI) events and diagnostic cohort studies for the detection of CAD were identified and analyzed separately. Weighted summary receiver-operating characteristic (SROC) plots, with pertinent areas under the curves (AUCs), were constructed using the Moses-Shapiro-Littenberg model. Meta-regression analyses, using parameters of relative diagnostic odds ratio (DOR), were conducted to compare the diagnostic performance after adjusting other study-specific covariates. RESULTS The meta-analysis of 11 population-based studies (54,336 patients) showed that carotid plaque, compared with CIMT, had a significantly higher diagnostic accuracy for the prediction of future MI events (AUC 0.64 vs. 0.61, relative DOR 1.35; 95%CI 1.1-1.82, p=0.04). The 10-year event rates of MI after negative results were lower with carotid plaque (4.0%; 95% CI 3.6-4.7%) than with CIMT (4.7%; 95% CI 4.2-5.5%). The meta-analysis of 27 diagnostic cohort studies (4.878 patients) also showed a higher, but non-significant, diagnostic accuracy of carotid plaque compared with CIMT for the detection of CAD (AUC 0.76 vs. 0.74, p=0.21 for relative DOR). CONCLUSIONS The present meta-analysis showed that the ultrasound assessment of carotid plaque, compared with that of CIMT, had a higher diagnostic accuracy for the prediction of future CAD events.