Carotid artery evaluation and coronary calcium score: which is better for the diagnosis and prevention of atherosclerotic cardiovascular disease?

In recent clinical practice guidelines for risk assessment for a first atherosclerotic cardiovascular disease (ASCVD) event, it is not routinely recommended to measure carotid intima-media thickness (CIMT) or the coronary calcium score (CACS). The aim of this study was to elucidate the effect of combining carotid artery evaluation and CACS as surrogate markers or predictive values. A total of 938 patients (562 male (59.9%), mean age 61.5 +/- 11.6 years) with ASCVD (n= 690) or without (n= 248) were enrolled in this study. The diagnosis of ASCVD was established with CT angiography. These patients had undergone carotid scanning (HP Sonos-5500; Philips, Bothell, WA, USA) at St. Mary's Hospital between September 2003 and March 2009. ASCVD outcomes were evaluated with a median follow-up of 1451 days. Thirty participants experienced initial ASCVD events during this study. Another 118 patients suffered secondary ASCVD events. After propensity score matching, multivariate analysis revealed that CACS was associated with ASCVD [Odds ratio 1.002, 95% confidence interval (CI) 1.002-1.003, P< 0.001]. For primary prevention in patients without ASCVD, we found that carotid plaques [Hazard ratio (HR) 2.409, 95% CI 1.093-5.309, P= 0.029] are also associated with ASCVD events. Carotid plaques are also associated with ASCVD events with regard to secondary prevention [HR 1.723, 95% CI 1.188-2.499, P= 0.004] in patients with ASCVD. We propose that CACS assessment is useful in the diagnosis of, and as a surrogate marker of ASCVD in patients with risk factors. Our results also suggest that carotid artery evaluation may have a valuable predictive method in primary and secondary ASCVD prevention and risk assessment. Therefore, although there are no synergic effects of combining carotid artery evaluation and CACS, carotid ultrasound seems to be a better predictive method for assessing ASCVD events than CACS.