On Nov. 12, 2013, the American Heart Association (AHA) and the American College of Cardiology (ACC) released four new sets of clinical practice guidelines to assist primary care clinicians in identifying adults who may be at high risk for developing atherosclerotic cardiovascular disease (ASCVD) and who may benefit from lifestyle changes or drug therapy for prevention.1
MPR offers a four-part series summarizing the new guidelines and discussing how they differ from earlier recommendations.
This article—the third in the series—features an interview with Robert Eckel, MD, Professor of Medicine, Division of Endocrinology, Metabolism and Diabetes and Cardiology, and Director of the Adult General Clinical Research Center at the University of Colorado, Aurora, Colo.
Part Three of a Special Four-Part Series.
Dr. Eckel is a co-author of the Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults. This Guideline differs sharply from the earlier National Cholesterol Education Program’s Adult Treatment Panel III (ATP III) report.2
Below, Dr. Eckel addresses controversies surrounding the new recommendations and explains the rationale behind them.
What are the key features of the new guidelines, and how do they differ from previous recommendations?
Our recommendations differ significantly from earlier guidelines, which focused on treat-to-cholesterol target as a way of reducing ASCVD risk—in other words, the goal of treating patients with CVD to less than 100 mg/dL or the optional goal of less than 70 mg/dL. We concluded that there is no strong evidence to support these specific LDL or non-HDL targets for either primary or secondary prevention of ASCVD.
Rather, the new guidelines look at the whole patient, not only numbers. We created a global risk assessment algorithm that includes LDL cholesterol, but also age, sex, systolic blood pressure, smoking, and diabetes.
The tool calculates the patient’s 10-year risk, which is compared to a person of the same age and sex with no risk factors.3 Patients at high risk should be treated with anticholesterol medications.
Which agents are recommended in the guidelines?
Are there specific patient populations that would benefit from statin therapy?
I would like to emphasize that the guidelines focus only on adults between 40 and 75 years old because the strongest evidence supports these interventions in those age groups.
Within that parameter, there are four major primary- and secondary-prevention groups in which the benefit of statin treatment outweighs the risk of adverse events:
- Patients with clinically relevant ASCVD should receive high-intensity statin therapy (defined as a daily dose that lowers cholesterol level by approximately >50% on average). Examples of such agents would be rosuvastatin 20 to 40 mg or atorvastatin 80 mg. But if adverse events occur as a result of high-intensity statin treatment, the guidelines advise trying a moderate-intensity statin (defined as a drug that lowers LDL cholesterol 30% to <50% on average).
- Patients with primary LDL cholesterol levels of at least 190 mg/dL should also be treated with high-intensity statins.
- Patients with type 1 or type 2 diabetes mellitus and an LDL level of at least 70 mg/dL should receive a moderate-intensity statin. But those with a 10-year ASCVD risk exceeding 7.5% should be treated with a high-intensity statin.
- Patients without evidence of CVD or diabetes, but whose 10-year risk of ASCVD is at least 7.5%, and whose LDL cholesterol levels are between 70 mg/DL and 189 mg/dL should receive either a moderate- or a high-intensity statin.
The fourth recommendation seems to imply that individuals with normal cholesterol may end up on statins if they have other risk factors. Does this not expose people to unnecessary potential adverse effects?
The fourth recommendation is controversial because our goal-setting no longer hinges on cholesterol levels but on overall risk.
In formulating this recommendation, we used strong evidence, including pooled cohort equations, to predict the future risk of an ASCVD first cardiovascular event, such as myocardial infarction or stroke.
To look at any of the articles in this series, click below.
|Part 1: Cardiovascular Risk Assessment|
|Part 2: Lifestyle Management|
|Part 3: Panel Member Addresses Controversies Surrounding New Cholesterol Guideline|
|Part 4: Management of Overweight and Obesity in Adults|