Age and gender distributions of coronary artery calcium detected by electron beam tomography in 35,246 adults

Electron beam tomagraphy (EBT) is a noninvasive method used to detect coron ary artery calcium (CAC). Due to the age-associated increase in incidence a nd magnitude of CAC, interpretation of results can be difficult, The purpos e of this study was to develop a set of age- and gender-stratified CAC dist ributions to serve as standards for the clinical interpretation of EBT scan s. Between 1993 and 1999, 35,246 asymptomatic subjects, 30 to 90 years of a ge, were self-referred for CAC screening using an Imatron EBT scanner. CAC score was calculated based on the number, areas, and peak computed tomograp hic density for each detected calcific lesion. CAC score in each coronary a rtery was equal to the sum of all lesions for that artery and the total CAC score was equal to the sum of the score of each artery. Total CAC scores w ere assigned to a percentile according to age and gender, CAC scores were r eported at the 10th, 25th, 50th, 75th, and 90th percentiles for 16 age and/ or gender groups. The prevalence of CAC increased with age for men and wome n. The extent of CAC differed significantly between men and women in the sa me age group. In summary, this study reports the distribution of CAC score by age and gender. Knowledge of the distribution of CAC, the effect of age on the total CAC score as well as the differences in total CAC scores that exist between men and women of similar age will assist the clinician in int erpreting EBT CAC results. (C) 2001 by Excerpta Medico, Inc.