Coronary Artery Calcification Compared With Carotid Intima-Media Thickness in the Prediction of Cardiovascular Disease Incidence

The Multi-Ethnic Study of Atherosclerosis (MESA)
Aaron R. Folsom, MD; Richard A. Kronmal, PhD; Robert C. Detrano, MD, PhD; Daniel H. O’Leary, MD; Diane E. Bild, MD; David A. Bluemke, MD, PhD; Matthew J. Budoff, MD; Kiang Liu, PhD; Steven Shea, MD; Moyses Szklo, MD, DrPH; Russell P. Tracy, PhD; Karol E. Watson, MD, PhD; Gregory L. Burke, MD
Arch Intern Med. 2008;168(12):1333-1339.
Background Coronary artery calcium (CAC) and carotid intima-media thickness (IMT) are noninvasive measures of atherosclerosis that consensus panels have recommended as possible additions to risk factor assessment for predicting the probability of cardiovascular disease (CVD) occurrence. Our objective was to assess whether maximum carotid IMT or CAC (Agatston score) is the better predictor of incident CVD.
Methods A prospective cohort study of subjects aged 45 to 84 years in 4 ethnic groups, who were initially free of CVD (n = 6698) was performed, with standardized carotid IMT and CAC measures at baseline, in 6 field centers of the Multi-Ethnic Study of Atherosclerosis (MESA). The main outcome measure was the risk of incident CVD events (coronary heart disease, stroke, and fatal CVD) over a maximum of 5.3 years of follow-up.
Results There were 222 CVD events during follow-up. Coronary artery calcium was associated more strongly than carotid IMT with the risk of incident CVD. After adjustment for each other (CAC score and IMT) and traditional CVD risk factors, the hazard ratio of CVD increased 2.1-fold (95% confidence interval [CI], 1.8-2.5) for each 1–standard deviation (SD) increment of log-transformed CAC score, vs 1.3-fold (95% CI, 1.1-1.4) for each 1-SD increment of the maximum IMT. For coronary heart disease, the hazard ratios per 1-SD increment increased 2.5-fold (95% CI, 2.1-3.1) for CAC score and 1.2-fold (95% CI, 1.0-1.4) for IMT. A receiver operating characteristic curve analysis also suggested that CAC score was a better predictor of incident CVD than was IMT, with areas under the curve of 0.81 vs 0.78, respectively.
Conclusion Although whether and how to clinically use bioimaging tests of subclinical atherosclerosis remains a topic of debate, this study found that CAC score is a better predictor of subsequent CVD events than carotid IMT.
Author Affiliations: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis (Dr Folsom); Collaborative Health Studies Coordinating Center, University of Washington, Seattle (Dr Kronmal); Department of Radiological Sciences, University of California at Irvine (Dr Detrano); Caritas Carney Hospital, Dorchester, Massachusetts (Dr O’Leary); Division of Prevention & Population Sciences, National Heart, Lung, and Blood Institute, Bethesda, Maryland (Dr Bild); Departments of Radiology (Dr Bluemke) and Epidemiology (Dr Szklo), Johns Hopkins University School of Medicine, Baltimore, Maryland; Division of Cardiology, Los Angeles Biomedical Research Institute at Harbor–UCLA Medical Center, Torrance, California (Dr Budoff); Department of Preventive Medicine, Northwestern University Medical School, Chicago, Illinois (Dr Liu); Departments of Medicine and Epidemiology, Columbia University, New York, New York (Dr Shea); Departments of Pathology and Biochemistry, University of Vermont, Colchester (Dr Tracy); Division of Cardiology, UCLA School of Medicine, Los Angeles, California (Dr Watson); and Division of Public Health Sciences, Wake Forest University Health Sciences, Winston-Salem, North Carolina (Dr Burke).