p.21 抽出テキスト

June 18/25, 2019 Circulation. 2019;139:e1082–e1143. DOI: 10.1161/CIR.0000000000000625 e1102

CLINICAL STATEMENTS AND GUIDELINES mg/dL (particularly when accompanied by persistently elevated triglycerides), and elevated Lp(a) denote high lifetime risk for ASCVD and favor initiation of statin therapy. The presence of family history of ASCVD, premature menopause, and patients of South Asian race appear to convey a higher baseline risk and are stronger candidates for statin therapy. Conditions associated with systemic inflammation (chronic inflammatory disorders, metabolic syndrome, chronic renal disease, and elevated hsCRP) appear to predispose to atherothrombotic events, which reasonably justifies statin therapy in intermediate-risk patients.

4.4.1.4. Coronary Artery Calcium Substantial advances in estimation of risk with CAC scoring have been made in the past 5 years. One purpose of CAC scoring is to reclassify risk identification of patients who will potentially benefit from statin therapy. This is especially useful when the clinician and patient are uncertain whether to start a statin. Indeed, the most important recent observation has been the finding that a CAC score of zero indicates a low ASCVD risk for the subsequent 10 years.S4.4.1.4-1–S4.4.1.4-8 Thus, measurement of CAC potentially allows a clinician to withhold statin therapy in patients showing zero CAC. There are exceptions. 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 inflammatory conditions such as HIV, may still be associated with substantial 10-year risk.S4.4.1.4-9–S4.4.1.4-12 Nevertheless, a sizable portion of middle-aged and older patients 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 after 5 to 10 years.S4.4.1.4-14–S4.4.1.4-16 CAC measurement has no utility in patients already treated with statins. Statins are associated with slower progression of overall coronary atherosclerosis volume and reduction of high-risk plaque features, yet statins increase the CAC score.S4.4.1.4-17 A prospective randomized study of CAC scoring showed improved risk factor modification without an increase in downstream medical testing or cost.S4.4.1.4-18 In MESA (Multi-Ethnic Study of Atherosclerosis), CAC scanning delivered 0.74 to l.27 mSv of radiation, which is similar to the dose of a clinical mammogram.S4.4.1.4-19 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.

COR LOE Recommendations

I A 1.  In adults at intermediate-risk, statin therapy reduces risk of ASCVD, and in the context of a risk discussion, if a decision is made for statin therapy, a moderate-intensity statin should be recommended.S4.4.2-1–S4.4.2-8

I A 2.  In intermediate-risk patients, LDL-C levels should be reduced by 30% or more, and for optimal ASCVD risk reduction, especially in high-risk patients, levels should be reduced by 50% or more.S4.4.2-1,S4.4.2-4–S4.4.2-9

I B-NR 3.  For the primary prevention of clinical ASCVD* in adults 40 to 75 years of age without diabetes mellitus and with an LDL-C level of 70 to 189 mg/dL (1.7 to 4.8 mmol/L), the 10-year ASCVD risk of a first “hard” ASCVD event (fatal and nonfatal MI or stroke) should be estimated by using the race- and sex-specific PCE, and adults should be categorized as being at low risk (<5%), borderline risk (5% to <7.5%), intermediaterisk (≥7.5% to <20%), and high-risk (≥20%).S4.4.2-10,S4.4.2-11

I B-NR 4.  Clinicians and patients should engage in a risk discussion that considers risk factors, adherence to healthy lifestyle, the potential for ASCVD risk-reduction benefits, and the potential for adverse effects and drug–drug interactions, as well as patient preferences, for an individualized treatment decision.S4.4.2-12–S4.4.2-14

IIa B-R 5.  In intermediate-risk adults, risk-enhancing factors favor initiation or intensification of statin therapy.S4.4.2-6,S4.4.2-15–S4.4.2-22

IIa B-NR 6.  In intermediate-risk or selected borderline-risk adults, if the decision about statin use remains uncertain, it is reasonable to use a CAC score in the decision to withhold, postpone or initiate statin therapy.S4.4.2-15,S4.4.2-17,S4.4.2-23

IIa B-NR 7.  In intermediate-risk adults or selected borderline-risk adults in whom a CAC score is measured for the purpose of making a treatment decision, AND ▪  If the coronary calcium score is zero, it

is reasonable to withhold statin therapy and reassess in 5 to 10 years, as long as higher risk conditions are absent (diabetes mellitus, family history of premature CHD, cigarette smoking); ▪  If CAC score is 1 to 99, it is reasonable to initiate statin therapy for patients ≥55 years of age; ▪  If CAC score is 100 or higher or in the

75th percentile or higher, it is reasonable to initiate statin therapy.S4.4.2-17,S4.4.2-23

Downloaded from http://ahajournals.org by on October 7, 2026