A Review of the 2019 ACC/AHA Updated Lipid Guidelines

Atherosclerotic cardiovascular disease (ASCVD) is one of the leading causes of death in the United States today. According to the American College of Cardiology (ACC) and American Heart Association (AHA) Task Force, managing elevated cholesterol is one of the the key elements to decreasing negative outcomes in this multifactorial disease state.

The ASCVD Risk algorithm is used to calculate a 10-year risk of heart disease or stroke and for recommendations of statin therapy. This algorithm calculates this risk by evaluating the following factors: history of ASCVD, low-density lipoprotein (LDL) cholesterol levels, age, current diagnosis of diabetes, sex, race, total cholesterol, high-density lipoprotein (HDL) cholesterol levels, medication controlled hypertension, and smoking history. Any history of the following conditions is considered a known history of ASCVD: acute coronary syndrome, myocardial infarction, stable angina, coronary revascularization, stroke, transient ischemic attack, peripheral arterial disease, or patients with very high LDL levels (>190).¹

Risk factors for ASCVD include smoking, dyslipidemia, diabetes, and hypertension. The cornerstone to preventing bad outcomes is focusing on a heart healthy lifestyle. According to the CDC, a heart healthy lifestyle revolves around maintaining a healthy weight, eating a well-rounded diet, exercising 3 to 5 times per week for 30-minute increments, avoiding tobacco products, and limiting alcohol use. ²

Assessment of ASCVD risk is crucial for primary prevention of cardiovascular disease. For those aged 20 to 39 years, traditional risk factors such as tobacco use, hypertension, or others, can be measured to identify whether lifestyle optimization or treatment is needed.³ For adults aged 20 to 39 years and 40 to 59 years, who are not at an elevated (> 7.5%) 10-year risk, an estimation of a lifetime or 30-year risk for ASCVD can be made.

Estimating ASCVD 10-year risk can be performed using an online risk calculator provided by ACC. The 2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease guidelines suggest the race and sex specific Pooled Cohort Equation to estimate 10- year ASCVD risk of asymptomatic adults ages 40 to 79 years. ³ Adults are categorized into low (<5%), borderline (5% to 7.5%), intermediate (>7.5% to <20%), or high (>20%) 10- year risk.

With the 2019 ACC/AHA guidelines for primary prevention of cardiovascular disease, statin treatment recommendations vary from previous guidelines. Patients’ aged 20 to 75 years and LDL > 190 mg/dl use high-intensity statin without risk assessment. ³ Moderate-intensity statin can be used in patients aged 40 to 75 years and with type 2 diabetes mellitus. High intensity statin in this patient population may be considered based on risk estimation. For patients aged 40 to 75 years and with LDL > 70 mg/dl and <190 mg/dl without diabetes, use risk estimator to identify intensity of statin.

Patients on statin therapy should be assessed for compliance, therapy effectiveness, and adverse effects. Fasting lipid levels should be checked to assess effectiveness. These should be compared to values prior to statin initiation. Adverse effects are usually experiences in the first 4 to 12 weeks of starting treatment. Common adverse effects include myalgia. Certain drug-drug interactions can increase risk of patients experiencing myalgia with statins. Patients should also be screened for type 2 diabetes mellitus.

Statins and a heart healthy lifestyle are able to manage the risks of ASCVD effectively; however, there are times when additional treatments are needed. Specifically, other agents should be considered in patients with a heavy history of ASCVD events or with multiple high-risk factors. Ezetimibe is often the second-line agent added to maximized statin therapy. Additional therapy can be considered if ezetimibe and statin combination therapy do not lower the LDL-C level below 70 mg/dL. The next agent considered is a proprotein convertase subtilisin/kexin type 9 inhibitor. ¹

Updated 2019 guidelines by ACC/AHA for primary prevention of cardiovascular disease shows different categories of patients and respective statin intensity treatment compared with previous guidelines. Identifying appropriate risk factors and category will help with selecting the appropriate intensity statin.

REFERENCES

• Grundy SM, Stone NJ, Bailey AL et al. 2018 Guideline on the Management of Blood Cholesterol. J Am Coll Cardiol. Nov 2018. DOI: 10.1016/j.jacc.2018.11.003.
• Preventing Heart Disease: Healthy Living Habits. Center for Disease Control and Prevention. https://www.cdc.gov/heartdisease/healthy_living.htm Reviewed August 10, 2015. Accessed October 17, 2019.
• 2019 ACC/AHA Guideline on the Primary Prevention of Cardiovascular Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. J Am Coll Cardiol 2019 March 17. [Epub ahead of print].