To appreciate the significance of these reports it is necessary to examine the numbers in some detail. A striking feature of both studies was the unexpectedly low rates of major coronary events in persons who otherwise were projected to be at a relatively high risk. The first study (1) measured CAC in 4,903 healthy subjects and then followed them for an average of 4.3 years for a combined outcome of coronary event rates (including non-fatal myocardial infarction [MI], coronary bypass surgery, percutaneous coronary angioplasty, and coronary death), non-hemorrhagic stroke, and peripheral vascular surgery. Among all 4,903 subjects, 119 experienced ASCVD events; of the latter, only 34% were listed as “hard” coronary heart disease (CHD) (myocardial infarction + coronary death). In addition, only 40% of total CHD events were hard CHD events. Out of all subjects, 686 had CAC scores of 110 to 399 Agatston units; these scores signify at least moderate coronary atherosclerosis. In these subjects, event rates for total CHD events were only 1.3% per year, and for hard CHD events, only 0.58% per year. Another 450 subjects had CAC scores >400, which should indicate advanced coronary atherosclerosis; in these patients, event rates were 3.26% and 1.1% per year for total CHD and hard CHD, respectively. At the beginning of the study, subjects underwent Framingham risk scoring to determine 10-year risk for hard CHD events as described in the National Cholesterol Education Program’s Adult Treatment Panel III (NCEP ATP III) report (3). Among all subjects, 654 had a projected 10-year risk for hard CHD of <10% (or <1% per year); 506 scored a 10-year risk of 10% to 20% (1% to 2% per year); and 86 projected a >20% 10-year risk (>2% per year). In the intermediate-risk group (i.e., those projected to have 1% to 2% of hard events per year) hard CHD events were in fact only about 0.4% per year. Likewise those predicted to have a >2% per year risk for hard CHD showed an actual rate of only 0.9% per year. In both intermediate- and high-risk groups, only those with the highest CAC scores (upper tertile for projected risk ranges) had actual rates of hard CHD approaching the projected level of risk. Thus, CAC measurement clearly added information to the Framingham projection; furthermore, only in those in the highest tertile of CAC scoring for a given Framingham category did Framingham scoring accord with the observed rate.