Authorship of the 2018 cholesterol guidelines was chaired by Scott Grundy, M.D., Ph.D., and the guidelines were written and reviewed by a panel of 24 experts from 12 health organizations, including Amit Khera, M.D. Explaining the significance of these guidelines, Drs. Grundy and Khera here share their thoughts on what has changed from the previous version of the guidelines issued five years ago.
As in nearly every facet of medicine, nothing is black and white when it comes to cholesterol management and cardiac health. This is clearly highlighted by the 2018 Guidelines for Treatment of Blood Cholesterol, published in Circulation by a joint task force of the American Heart Association and the American College of Cardiology.
The 2018 guidelines incorporate key updates in four specific categories from the previous November 2013 edition, which turned the tables on how doctors should approach prevention and treatment of high cholesterol. We used to treat low-density lipoprotein (LDL, or bad cholesterol) like a target, with a specific number, much like high blood pressure. The goal was to use statins and lifestyle modifications to hit the “magic number” of lower than 100 mg/dL in the blood for high-risk patients.
The 2013 guidelines dramatically altered the perspective from target number-based treatment to focus on four broader groupings of patients for whom cholesterol treatment with statin drugs is recommended, a point which, despite historic controversy from lack of clinical direction, remains in the 2018 guidelines:
- People with known atherosclerotic cardiovascular disease (ASCVD), such as heart attack, stroke, etc.
- Individuals with very high cholesterol levels – LDL cholesterol greater than 190 mg/dL
- People with diabetes with LDL >= 70 mg/dL
- Those between the ages of 40 and 75 with LDL 70–189 mg/dL and 10-year ASCVD risk ≥ 7.5 percent
However, four key factors were emphasized in the 2018 guidelines that leveraged advances in the 2013 version, giving doctors and patients more support in treatment decision-making.
Nearly one-third of U.S. adults have high LDL, which contributes to the risk of stroke and heart attack. The evidence is overwhelming that cholesterol management, including the use of statins, is essential for cardiovascular health, a fact that is emphasized by the 2018 guidelines.
4 key updates in the 2018 cholesterol guidelines
Personalization of treatment
Detailed and personalized care plans can help target optimal treatment for select patients, which we hope will encourage more patients to proactively manage their controllable risk factors. The 2018 guidelines divide individuals into four groups, estimating the spectrum of risk that a patient will experience a cardiovascular event in the next 10 years based on his/her ASCVD score. Risk is calculated by an ACC/AHA risk calculator that considers risk factors such as: gender, age, cigarette smoking, blood pressure, diabetes, cholesterol, and HDL-cholesterol. The risk categories include.
● Low risk: less than 5 percent
● Borderline risk: 5 to less than 7.5 percent
● Intermediate risk: 7.5 to less than 20 percent
● High risk: greater than or equal to 20 percent
For patients within the intermediate-risk group, the AHA and ACC recommend that doctors and patients evaluate whether key risk-enhancing factors/conditions are present, which may suggest the need to be more aggressive in treating risk factors as they help dictate a personalized preventive cardiology care plan. These factors/conditions are:
- Metabolic syndrome
- Biomarkers for genetic high cholesterol
- Blood pressure
- Chronic kidney disease
- Early menopause
- Family history of heart attack/stroke at an early age
- High cholesterol in range of 160 mg/dL or above
- Inflammatory conditions (AIDS, rheumatoid arthritis, psoriasis)
- Race/ethnicity (Asian, Indian)
Another major advance of the 2018 updates is that the authors addressed treatment personalization gaps for multiple racial and ethnic groups. The 2013 guidelines spotlighted African-Americans, whose risk tends to be higher than that of Caucasians, whereas the 2018 version expanded the focus to also include more specific factors in South Asians’ risk, potential overestimation of risk for East Asians, and overarching variations in estimated risk due to country of origin, socioeconomic factors, and cultural factors.
For secondary prevention, interventions intended to avert future events in those that have already had a heart attack or stroke – when statins alone are ineffective to reduce risk – the 2018 guidelines recommend adding on a second, nonstatin drug, either ezetimibe (a drug that has been validated for effectiveness in clinical trials) or proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, powerful drugs developed, in part, at UT Southwestern and which have been proven effective for secondary prevention in two large clinical trials.
As a general rule, PCSK9 inhibitors are costly medications and should be prescribed only when ezetimibe, a generic drug, is not effective enough; they are recommended for those in the intermediate-to high-risk categories.
Coronary artery calcium scanning
Coronary artery calcium (CAC) scanning, or coronary calcium scoring, is a valuable tool in predicting a patient’s future heart disease risk, and the guidelines expanded the use and endorsement of this test. This noninvasive imaging test, which delivers about the same amount of radiation as a mammogram, measures calcified plaque deposits in the coronary arteries.
In patients on the high end of the intermediate-risk scale, it might be tempting to start statin therapy right away. However, if a CAC scan returns with a zero score and there are no other cardiovascular risk factors at play, statin therapy might be deferred.
Children and young adults
While young people were not mentioned in the 2013 guidelines, the 2018 updates emphasize that having high cholesterol at any age can significantly increase the risk of heart disease over a person’s lifetime. Early assessment can help young people and their families make healthy lifestyle changes and/or start taking appropriate medications to prevent early onset cardiovascular events, including heart attacks and certain types of ischemic strokes.
Some cardiologists suggest screening children as young as 2 if they have a family history of high cholesterol in order to flag genetic conditions that require intervention. The general consensus is that around age 9 to 11 is an appropriate time to begin screening children with no known risk factors, with another round of screening between ages 17 and 21.
For young adults (ages 20 to 39), the guidelines emphasize the importance of heart-healthy living, including diet, exercise, and healthy weight considerations, which can make an enormous difference over the long term. There is not yet a strong body of research on the long-term effects of statin therapy, so statins, ezetimibe, and PCSK9 inhibitors are reserved only for patients at high risk.
Cholesterol management is a long-term health consideration that can drastically alter the trajectory of one’s life. The recently released 2018 cholesterol guidelines expand upon the framework of the previous editions to provide a more complete picture of health that accounts for changes in patient involvement, data collection, and medical expertise.
As community physicians and cardiologists begin to implement these new guidelines, it is our hope that more patients will become educated and engaged, actively involved in the management of their care.