Atherosclerotic cardiovascular disease (ASCVD) is common. Lowering low density lipoprotein cholesterol (LDL-C) significantly reduces ASCVD events including myocardial infarction, stroke and cardiovascular death. The number of patients needed to treat to prevent an event over 5 years varies by baseline risk and magnitude of LDL-C reduction, from less than 10 for high-risk ASCVD patients receiving high-intensity therapy to about 100 for intermediate-risk patients taking moderate-intensity statins for primary prevention.
The American Heart Association (AHA) and the American College of Cardiology published new guidelines for management of blood cholesterol on November 10, 2018. Lipid profiles are recommended for adults undergoing risk assessment for atherosclerotic cardiovascular disease (ASCVD) and for children with obesity or family history of early ASCVD.
For primary prevention in patients with LDL-C of 190mg/dL or higher, high-intensity statin therapy is recommended to reduce LDL-C by more than 50% and to less than 100 mg/dL. For primary prevention in all other patients aged 40to 75 years, the decision to actively treat lipids is largely based on risk estimated from the ACC/AHA Pooled Cohort Equations CV Risk Calculator, which now labels low risk as less than 5% over 10years, borderline as 5%to 7.4%, intermediate as 7.5% to 19.9%,and high as 20%or higher. Patients with intermediate-risk should achieve more than 30% reduction, while high-risk patients should initiate statin therapy with a goal of more than 50% LDL-C reduction. Patients aged 40 to 75 years who also have diabetes and LDL-C of 70 mg/dL or higher should receive moderate-intensity statin therapy.
Pharmacologic lipid management is strongly recommended, even without risk calculation, in patients with clinical ASCVD. Stratified LDL-C goals have been reintroduced for patients with clinical ASCVD. First, reduce LDL-C by greater than 50% using high- intensity statins. Reduction of LDL-C level is a secondary goal after reduction of LDL-C percentage is achieved. Patients with very high risk ASCVD have a second goal of reducing LDL-C to less than 70 mg/dL. If this cannot be achieved with a high intensity statin, ezetimibe or a PCSK9 inhibitor (alirocumab and evolocumab) is recommended.
Clinical Status | Age Range | Statin Intensity | LDL-C % Reduction Goal | LDL-C Level Goal (mg/dL) |
Primary Prevention | ||||
LDL > 190 | 20-75 | High | 50 or > | <100 |
Diabetes LDL>70 | 40-75 | Moderate | 30 or > | |
High Risk, LDL >70 | 40-75 | High | 50 or > | |
Intermed Risk,LDL >70 | 40-75 | Moderate | 30 or > | |
Secondary Prevention | ||||
Very high risk ASCVD | >18 | High | 50 or > | <70 |
All other ASCVD | >18 | High | 50 or > |
The new guideline does not recommend or prefer that lipid profiles be obtained while fasting in the initial evaluation of patients because nonfasting test results are sufficient for assessing prognosis. Nonfasting calculated LDL-C is adequate unless triglycerides are greater than400mg/dL, which requires a repeat test while fasting.
References
1. Wilson PWF, Polonsky TS, Miedema MD, et al. Systematic review for the 2018 AHA/ACC/AACVPR/ AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol [published online November 10, 2018].J AmColl Cardiol. doi:10.1016/j.jacc.2018.11.004
2. Grundy SM, Stone NJ, Bailey AL, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/ APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol [published online November 10, 2018]. J AmColl Cardiol. doi:10.1016/j.jacc.2018.11.003
3. Doran B, Guo Y, Xu J, et al. Prognostic value of fasting versus nonfasting low-density lipoprotein cholesterol levels on long-term mortality. Circulation. 2014;130(7):546-553.
4. Alenghat FJ and Davis AM, Management of Blood Cholesterol, JAMA Clinical Guidelines Synopsis. (published on line Feb 4, 2019) doi:10.1001/jama.2019.0015