Abstract
BACKGROUND: We sought to evaluate the incremental prognostic benefit of carotid artery disease and subclinical coronary artery disease (CAD) features in addition to clinical evaluation in an asymptomatic population. METHODS: Over a 6-year period, 10-year Framingham risk score together with carotid ultrasound and coronary computed tomography angiography were evaluated for prediction of major adverse cardiac events (MACE). RESULTS: We enrolled 517 consecutive asymptomatic patients (63% male, mean age 64 ±10 years; 17.6% with diabetes). Median (interquartile range) coronary artery calcium score (CACS) was 34 (0-100). Over a median follow-up of 4.4 (3.4-5.1) years, there were 53 MACE (10%). Patients experiencing MACE had higher CACS, incidence of carotid disease, presence of CAD ≥50%, and remodeled plaque as compared with patients without MACE. At multivariable analyses, presence of CAD ≥50% (HR: 5.14, 95% CI: 2.1-12.4) and percentage of segments with remodeled plaque (HR: 1.04, 95% CI: 1.03-1.06) independently predicted MACE (P < 0.001). Models adding CAD ≥50% or percentage of segments with remodeled plaque resulted in higher discrimination and reclassification ability compared with a model based on 10-year FRS, carotid disease, and CACS. Specifically, the C-statistic improved to 0.75 with addition of CAD and 0.84 when adding percentage of segments with remodeled plaque, whereas net reclassification improvement indices were 0.86 and 0.92, respectively. CONCLUSIONS: In an asymptomatic population, CAD and plaque positive remodeling increase MACE prediction compared with a model based on 10-year FRS, carotid disease, and CACS estimation. In the diabetes subgroup, percentage of segments with remodeled plaque was the only predictor of MACE.