COMPARISON OF ELECTRON-BEAM COMPUTED-TOMOGRAPHY SCANNING AND CONVENTIONAL RISK FACTOR ASSESSMENT FOR THE PREDICTION OF ANGIOGRAPHIC CORONARY-ARTERY DISEASE

Objective. To determine whether electron beam computed tomography (CT) adds to conventional risk factor assessment in the prediction of angi ographic coronary artery disease. Background. Electron beam CT scannin g can be used to predict the severity of coronary atherosclerosis, but whether it does so independently of conventional risk factors is uncl ear. Methods. Electron beam CT scans were performed and conventional r isk factors were measured in 290 men and women undergoing coronary art eriography for clinical indications. The association of the electron b eam CT-derived coronary artery calcium store and conventional risk fac tors with the presence and severity of angiographically defined corona ry atherosclerosis was analyzed by logistic regression and receiver-op erator characteristics analysis. Results. Age, the ratio of total chol esterol to high-density lipoprotein (HDL) cholesterol and the coronary calcium score were significantly and independently associated with th e presence of any coronary disease and obstructive coronary disease. I n association with any coronary disease, odds ratios for age, the rati o of total cholesterol to HDL cholesterol and calcium score, highest q uartile vs. lowest quartile, were 6.01 (95% confidence interval 2.87 t o 12.56), 3.14 (1.56 to 6.31) and 94.08 (21.06 to 420.12), respectivel y. For obstructive coronary disease, highest quartile vs. lowest quart ile, the respective odds ratios for age, the ratio of total cholestero l to HDL and calcium score were 3.86 (1.86 to 8.00), 4.11 (1.98 to 8.5 2) and 34.12 (12.67 to 91.86). Male gender was also significantly asso ciated with any coronary disease (odds ratio 2.19, p = 0.04) and obstr uctive coronary disease (odds ratio 2.07, p = 0.04). Cigarette smoking was significantly associated with any coronary disease (odds ratio = 2.74, p = 0.004), and diabetes was significantly associated,vith obstr uctive disease (odds ratio 3.16, p = 0.01). After adjustment for the c oronary calcium score and other risk factors, it was determined that t riglycerides, family history and hypertension were not significantly a ssociated with any disease state. A coronary calcium score greater tha n or equal to 80 (Agatston method) was associated with an increased li kelihood of any coronary disease regardless of the number of risk fact ors, and a coronary calcium score greater than or equal to 170 was ass ociated with an increased likelihood of obstructive coronary disease r egardless of the number of risk factors (p < 0.001). Conclusion. Elect ron beam CT scanning offers improved discrimination over conventional risk factors in the identification of persons with any angiographic co ronary disease or angiographic obstructive coronary disease. (J Am Coi l Cardiol 1998;32:673-9) (C) 1998 by the American College of Cardiolog y.