For example, CAC scores of zero in persistent cigarette smokers, patients with diabetes mellitus, those with a strong family history of ASCVD, and possibly chronic inflam- matory conditions such as HIV, may still be associated Neverthe- less, a sizable portion of middle-aged and older pa- tients have zero CAC, which may allow withholding of statin therapy in those intermediate risk patients who would otherwise have a high enough risk according to the PCE to receive statin therapy (Figure 2). Most patients with CAC scores 100 Agatston units have a 10-year risk of ASCVD 7.5%, a widely accepted threshold for initiation of statin therapy.S4.4.1.4-13 With increasing age, 10-year risk accompanying CAC scores of 1 to 99 rises, usually crossing the 7.5% threshold in later middle age.S4.4.1.4-13 When the CAC score is zero, some investigators favor remeasurement of CAC af- CAC measurement has no utility in patients already treated with statins. Statins are associated with slower progression of over- all coronary atherosclerosis volume and reduction of high-risk plaque features, yet statins increase the CAC A prospective randomized study of CAC scoring showed improved risk factor modification without an increase in downstream medical testing or In MESA (Multi-Ethnic Study of Athero- sclerosis), CAC scanning delivered 0.74 to l.27 mSv of radiation, which is similar to the dose of a clinical CAC scans should be ordered by a clinician who is fully versed in the pros and cons of diagnostic radiology. 4.4.2. Primary Prevention Adults 40 to 75 Years of Age With LDL-C Levels 70 to 189 mg/dL (1.7 to 4.8 mmol/L) Primary Prevention Recommendations for Adults 40 to 75 Years of Age With LDL Levels 70 to 189 mg/dL (1.7 to 4.8 mmol/L) Referenced studies that support recommendations are summarized in Online Data Supplement 16. 