Cigarette smoking remains a strong risk factor even in the presence of CAC score of zero.S4.4.2-50,S4.4.2-51 In asymptomatic dia- betes mellitus, a CAC score of zero is associated with a favorable 5-year prognosis; but after 5 years, the risk of mortality increases significantly for diabetic individuals even in the presence of a baseline CAC score of zero.S4.4.2-52 In patients with a family history of ASCVD, CAC score of zero may impart less short-term benefit from statin therapy, but considering a high lifetime risk, long-term Table 8. Selected Examples of Candidates for CAC Measurement Who Might Benefit From Knowing Their CAC Score Is Zero CAC Measurement Candidates Who Might Benefit From Knowing Their CAC Score Is Zero Patients reluctant to initiate statin therapy who wish to understand their risk and potential for benefit more precisely Patients concerned about need to reinstitute statin therapy after discontinuation for statin-associated symptoms Older patients (men, 55-80 y of age; women, 60-80 y of age) with low burden of risk factorsS4.4.2-25 who question whether they would benefit from statin therapy Middle-aged adults (40-55 y of age) with PCE-calculated 10-year risk of ASCVD 5% to <7.5% with factors that increase their ASCVD risk, although they are in a borderline risk group Caveats: If patient is intermediate risk and if a risk decision is uncertain and a CAC score is performed, it is reasonable to withhold statin therapy unless higher risk conditions such as cigarette smoking, family history of premature ASCVD, or diabetes mellitus are present, and to reassess CAC score in 5-10 years. Moreover, if CAC is recommended, it should be performed in facilities that have current technology that delivers the lowest radiation possible. ASCVD indicates atherosclerotic cardiovascular disease; CAC, coronary artery calcium; LDL-C, low-density lipoprotein cholesterol; and PCE, pooled cohort equations. 