Coronary artery calcium evaluation by electron beam computed tomography and its relation to new cardiovascular events

Electron beam computed tomography is widely used to screen for coronary art ery calcium (CAC), We evaluated the relation of CAC to future cardiovascula r disease events in 926 asymptomatic persons (735 men and 191 women, mean a ge 54 years) who underwent a baseline electron beam computed tomographic sc an. All subjects included in this report returned a follow-vp questionnaire 2 to 4 years (mean 3.3) after scanning, inquiring about myocardial infarct ion, stroke, and revascularizations, Sixty percent of men and 40% of women had a positive scan at baseline. Twenty-eight cardiovascular events occurre d and were confirmed by blinded medical record review. The presence of CAC (a total calcium score of >0) and increasing score quartiles were related t o the occurrence of new myocardial infarction (p <0.05), revascularizations (p <0.001), and total cardiovascular events (p <0.001). Those with scores at or above the median (score of 5) had a relative risk of 4.5 (p <0.01) fo r new events. From Cox regression models, adjusted for age, gender, and cor onary risk factors, the relative risks for those with scores of 81 to 270 a nd greater than or equal to 271 (compared with 0) for cardiovascular events were 4.5 (p <0.05) and 8.8 (p <0.001), respectively. These data support pr evious reports showing CAC to be a modest predictor of future cardiovascula r events. (C) 2000 by Excerpta Medica, Inc.