On November 12, 2013, a joint task force for the American College of Cardiology and American Heart Association released new guidelines for treating high blood cholesterol to reduce the risk of atherosclerotic cardiovascular disease (ASCVD) in adults.1
This document arrives after several years of intense deliberation, 12 years after the third Adult Treatment Panel (ATP III) guidelines,2 and 8 years after an ATP III update recommending that low-density lipoprotein cholesterol (LDL-C) levels be lowered aggressively (to less than 70 mg/dL) as an option in patients at high risk.3 It represents a major shift in the approach to and management of high blood cholesterol and has sparked considerable controversy.
In the following commentary, we summarize the new guidelines and the philosophy employed by the task force in generating them. We will also examine some advantages and what we believe to be several shortcomings of the new guidelines. These latter points are illustrated through case examples.
IN RANDOMIZED CONTROLLED TRIALS WE TRUST
In collaboration with the National Heart, Lung, and Blood Institute of the National Institutes of Health, the American College of Cardiology and American Heart Association formed an expert panel task force in 2008.
The task force elected to use only evidence from randomized controlled trials, systematic reviews, and meta-analyses of randomized controlled trials (and only predefined outcomes of the trials, not post hoc analyses) in formulating its recommendations, with the goal of providing the strongest possible evidence.
The authors state that “By using [randomized controlled trial] data to identify those most likely to benefit [emphasis in original] from cholesterol-lowering statin therapy, the recommendations will be of value to primary care clinicians as well as specialists concerned with ASCVD prevention. Importantly, the recommendations were designed to be easy to use in the clinical setting, facilitating the implementation of a strategy of risk assessment and treatment focused on the prevention of ASCVD.”3 They also state the guidelines are meant to “inform clinical judgment, not replace it” and that clinician judgment in addition to discussion with patients remains vital.
During the deliberations, the National Heart, Lung, and Blood Institute removed itself from participating, stating its mission no longer included drafting new guidelines. Additionally, other initial members of the task force removed themselves because of disagreement and concerns about the direction of the new guidelines.
These guidelines, and their accompanying new cardiovascular risk calculator,4 were released without a preliminary period to allow for open discussion, comment, and critique by physicians outside the panel. No attempt was made to harmonize the guidelines with previous versions (eg, ATP III) or with current international guidelines.
WHAT’S NEW IN THE GUIDELINES?
The following are the major changes in the new guidelines for treating high blood cholesterol:
- Treatment goals for LDL-C and non-high-density lipoprotein cholesterol (non-HDL-C) are no longer recommended.
- High-intensity and moderate-intensity statin treatment is emphasized, and low-intensity statin therapy is nearly eliminated.
- “ASCVD” now includes stroke in addition to coronary heart disease and peripheral arterial disease.
- Four groups are targeted for treatment (see below).
- Nonstatin therapies have been markedly de-emphasized.
- No guidelines are provided for treating high triglyceride levels.
The new guidelines emphasize lifestyle modification as the foundation for reducing risk, regardless of cholesterol therapy. No recommendations are given for patients with New York Heart Association class II, III, or IV heart failure or for hemodialysis patients, because there were insufficient data from randomized controlled trials to support recommendations. Similarly, the guidelines apply only to people between the ages of 40 and 75 (risk calculator ages 40–79), because the authors believed there was not enough evidence from randomized controlled trials to allow development of guidelines outside of this age range.
FOUR MAJOR STATIN TREATMENT GROUPS
The new guidelines specify four groups that merit intensive or moderately intensive statin therapy (Table 1)1:
- People with clinical ASCVD
- People with LDL-C levels of 190 mg/dL or higher
- People with diabetes, age 40 to 75
- People without diabetes, age 40 to 75, with LDL-C levels 70–189 mg/dL, and a 10-year ASCVD risk of 7.5% or higher as determined by the new risk calculator4 (which also calculates the lifetime risk of ASCVD).
Below, we will address each of these four groups and provide case scenarios to consider. In general, our major disagreements with the new recommendations pertain to the first and fourth categories.