Quantification of coronary artery calcium by electron beam computed tomography for determination of severity of angiographic coronary artery disease in younger patients

Department of Epidemiology, University of Michigan, Ann Arbor 48109.

OBJECTIVES. This study attempted to 1) evaluate five quantitative measures of coronary artery calcium and determine which best agreed with coronary artery disease severity at angiography; and 2) determine optimal quantity cutpoints to distinguish among no, mild and significant disease. BACKGROUND. Coronary artery calcium identified noninvasively by electron beam computed tomography is a sensitive marker for atherosclerosis. Quantitative assessments of calcium could distinguish among patients with no, mild and significant disease in clinical, screening and research settings. METHODS. One hundred sixty patients, 23 to 59 years old, underwent coronary angiography and electron beam computed tomography. Coronary artery calcium was defined as dense (> 130 Hounsfield units) foci > or = 2 mm2 on the tomogram. Regression and receiver operating characteristic analyses were used to evaluate five quantitative measures of calcium as predictors of the largest stenosis in the coronary arteries and to identify optimal cutpoints for distinguishing among disease categories. No disease was defined as no stenosis, mild disease as 10% to 49% diameter stenosis in one or more major branches and significant disease as > or = 50% diameter stenosis in one or more major branches. RESULTS. All measures evaluated performed well. With calcific area as the quantitative measure, the best cutpoint for discriminating between patients with and without disease was the presence of calcium: sensitivity 81%, specificity 86% and overall accuracy 83%. The best cutpoint for discriminating between patients with and without significant disease was 18 mm2: sensitivity 86%, specificity 81% and accuracy 83%. CONCLUSIONS. Because the ranges of calcium quantity overlapped across disease categories, no cutpoints would distinguish among categories with absolute certainty. However, selected cutpoints could rule out disease in most healthy subjects and identify most patients with significant disease.

This article has been cited by other articles:

				A. E. Cassidy-Bushrow, L. F. Bielak, P. F. Sheedy II, S. T. Turner, I. J. Kullo, X. Lin, and P. A. Peyser Coronary Artery Calcification Progression Is Heritable Circulation, July 3, 2007; 116(1): 25 - 31. [Abstract] [Full Text] [PDF]

				N. Takahashi and K. T. Bae Quantification of Coronary Artery Calcium with Multi-Detector row CT: Assessing Interscan Variability with Different Tube Currents—Pilot Study Radiology, July 1, 2003; 228(1): 101 - 106. [Abstract] [Full Text] [PDF]

				R. Erbell, T. Budde, G. Kerkhoff, S. Mohlenkamp, and A. Schmermund Understanding the pathophysiology of the arterial wall: which method should we choose? Electron beam computed tomography Eur. Heart J. Suppl., September 1, 2002; 4(suppl_F): F47 - F53. [Abstract] [PDF]

				B. K. Nallamothu, S. Saint, L. F. Bielak, S. S. Sonnad, P. A. Peyser, M. Rubenfire, and A. M. Fendrick Electron-Beam Computed Tomography in the Diagnosis of Coronary Artery Disease: A Meta-analysis Arch Intern Med, March 26, 2001; 161(6): 833 - 838. [Abstract] [Full Text] [PDF]

				D. M. Shavelle, M. J. Budoff, D. H. LaMont, R. M. Shavelle, J. M. Kennedy, and B. H. Brundage Exercise testing and electron beam computed tomography in the evaluation of coronary artery disease J. Am. Coll. Cardiol., July 1, 2000; 36(1): 32 - 38. [Abstract] [Full Text] [PDF]

				H.-C. Yoon, J. G. Goldin, L. E. Greaser III, J. Sayre, and G. C. Fonarow Interscan Variation in Coronary Artery Calcium Quantification in a Large Asymptomatic Patient Population Am. J. Roentgenol., March 1, 2000; 174(3): 803 - 809. [Abstract] [Full Text] [PDF]

				K. E. Watson, M. L. Abrolat, L. L. Malone, J. M. Hoeg, T. Doherty, R. Detrano, and L. L. Demer Active Serum Vitamin D Levels Are Inversely Correlated With Coronary Calcification Circulation, September 16, 1997; 96(6): 1755 - 1760. [Abstract] [Full Text]

				Y. Arad, L. A. Spadaro, K. Goodman, A. Lledo-Perez, S. Sherman, G. Lerner, and A. D. Guerci Predictive Value of Electron Beam Computed Tomography of the Coronary Arteries : 19-Month Follow-up of 1173 Asymptomatic Subjects Circulation, June 1, 1996; 93(11): 1951 - 1953. [Abstract] [Full Text]