While screening of all children for cholesterol disorders remains controversial, all adults should have their lipids checked before middle age. Patients with documented atherosclerosis and diabetes mellitus deserve the most scrutiny of their lipids since these patients are at the highest risk for suffering additional manifestations in the near term and thus have the most to gain from lipid lowering. Additional risk reduction measures for atherosclerosis are discussed in Chapter 10; lipid lowering should be just one aspect of a program to reduce the progression and effects of atherosclerosis.
The best screening and treatment strategy for adults who do not have ASCVD is less clear. Several algorithms have been developed to guide the clinician in treatment decisions, but management decisions must always be individualized based on the patient’s risk to maximize net benefit.
The 2018 American Heart Association/American College of Cardiology (AHA/ACC)/Multi-society guidelines recommend screening of all adults aged 20 years or older for high blood cholesterol. The 2016 United States Preventive Services Task Force (USPSTF) guidelines recommend beginning at age 20 years only if there are other cardiovascular risk factors such as tobacco use, diabetes, hypertension, obesity, or a family history of premature CVD. For men without other risk factors, screening is recommended beginning at age 35 years. For women and for men aged 20 to 35 without increased risk, the USPSTF makes no recommendation for or against routine screening for lipid disorders. Although there is no established interval for screening, screening can be repeated every 5 years for those with average or low risk and more often for those whose levels are close to therapeutic thresholds.
Individuals without CVD should have their 10-year risk of CVD calculated, with lifetime risk also considered. Although those with LDL cholesterol greater than 190 mg/dL (4.91 mmol/L) are recommended for treatment independent of their 10-year risk of CVD, all other patients are recommended for treatment based on their overall cardiovascular risk. While other calculators (such as SCORE or QRISK) may be more appropriate for other parts of the world, the best method for estimating 10-year risk in the United States is the Pooled Cohort Equations. First introduced in the 2013 ACC/AHA guidelines, the Pooled Cohort Equations include separate equations for White and Black patients and estimate the 10-year risk of heart attack, stroke, and cardiovascular death. This represents an improvement over the older Framingham 10-year calculator (eTable 28–2), which includes CHD but not stroke risk. The ACC/AHA risk estimator can be found at http://www.cvriskcalculator.com/, and mobile apps are available for download. While it has been shown to overestimate risk in some modern populations, including those with at least moderate socioeconomic status, the ACC/AHA risk estimator remains an excellent starting point for a risk discussion. Recalibrated versions of the calculator are available for countries across the world. The LIFE-CVD model is the best for illustrating lifetime risk and benefit of therapy (https://www.u-prevent.com/en-GB/HealthyCalculator/HealthyCalculator).