Translating AHA/ACC cholesterol guidelines into meaningful risk reduction

Medical therapy. The decision to start lipid-lowering therapy should be made after a physician–patient discussion that considers costs of therapy as well as patient preferences and values in the context of shared decision-making. Discussion should include a review of major risk factors (eg, cigarette smoking, elevated blood pressure, and the LDL-C level), the PCE risk score, the presence of risk-enhancing factors (TABLE 2¹), potential benefits of lifestyle changes and statin therapy, and the potential for adverse drug effects and drug–drug interactions.¹

If the estimated ASCVD risk is 7.5%-19.9%, starting moderate-intensity statin therapy is recommended. Risk-enhancing factors favor initiation of statin therapy, even in patients at borderline risk (5%-7.5%). If risk is uncertain, the CAC score can be used to facilitate shared decision-making.¹ The use of CAC is in agreement with the USPSTF statement that CAC can moderately improve discrimination and reclassification, but has an unclear effect on downstream health care utilization.¹⁵ Importantly, CAC should not be measured routinely in patients already taking a statin because its primary role is to facilitate shared decision-making regarding initiation of statin therapy.¹⁶

If the 10-year ASCVD risk is ≥ 20%, high-intensity statin therapy is advised, without need to obtain the CAC score. If high-intensity statin therapy is advisable but not acceptable to, or tolerated by, the patient, it might be reasonable to add a nonstatin drug (ezetimibe or a bile-acid sequestrant) to moderate-intensity statin therapy.¹

Risk-enhancing factors (TABLE 2¹) apply to intermediate- and borderline-risk patients. Importantly, these factors include membership in specific ethnic groups, conditions specific to females, and male–female distinctions in risk. Risk-enhancing factors also incorporate biomarkers that are often measured by lipid specialists, such as lipoprotein(a) (Lp[a]) and apolipoprotein B (ApoB).¹

Lp(a) is an atherogenic particle, akin to an LDL particle, that consists of a molecule of apolipoprotein (a) (a nonfunctional mimic of a portion of plasminogen) covalently bound to ApoB, like the one found on the LDL particle. Lp(a) is proportionally associated with an increased risk for ASCVD and aortic stenosis at a level > 50 mg/dL.¹⁷ A family history of premature ASCVD is a relative indication for measuring Lp(a).¹

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