The American College of Cardiology and the American Heart Association today released a new clinical practice guideline for the treatment of blood cholesterol in people at high risk for cardiovascular diseases caused by atherosclerosis, or hardening and narrowing of the arteries, that can lead to heart attack, stroke or death.
The guideline identifies four major groups of patients for whom cholesterol-lowering HMG-CoA reductase inhibitors, or statins, have the greatest chance of preventing stroke and heart attacks. The guideline also emphasizes the importance of adopting a heart-healthy lifestyle to prevent and control high blood cholesterol.
"The new guideline uses the highest quality scientific evidence to focus treatment of blood cholesterol on those likely to benefit most," said Neil J. Stone, MD, Bonow professor of medicine at Northwestern University Feinberg School of Medicine and chair of the expert panel that wrote the new guideline. "This guideline represents a departure from previous guidelines because it doesn't focus on specific target levels of low-density lipoprotein cholesterol, commonly known as LDL, or 'bad cholesterol,' although the definition of optimal LDL cholesterol has not changed. Instead, it focuses on defining groups for whom LDL lowering is proven to be most beneficial."
The new guideline recommends moderate- or high-intensity statin therapy for these four groups:
- Patients who have cardiovascular disease;
- Patients with an LDL, or "bad" cholesterol level of 190 mg/dL or higher;
- Patients with Type 2 diabetes who are between 40 and 75 years of age; and
- Patients with an estimated 10-year risk of cardiovascular disease of 7.5 percent or higher who are between 40 and 75 years of age (the report provides formulas for calculating 10-year risk).
In terms of clinical practice, physicians can use risk assessment tools in some cases to determine which patients would most likely benefit from statin therapy, rather than focusing only on blood cholesterol to determine which patients would benefit.
"The likely impact of the recommendations is that more people who would benefit from statins are going to be on them, while fewer people who wouldn't benefit from statins are going to be on them," Dr. Stone said. Doctors may also consider switching some patients to a higher dose of statins to derive greater benefit as a result of the new guidelines.
The guideline was prepared by a panel of experts based on an analysis of the results of randomized controlled trials. The panel was charged with guiding the optimal treatment of blood cholesterol to address the rising rate of cardiovascular disease, currently the leading cause of death and disability in the U.S.
The panel chose to focus on the use of statins after a detailed review of other cholesterol-lowering drugs. "Statins were chosen because their use has resulted in the greatest benefit and the lowest rates of safety issues. No other cholesterol-lowering drug is as effective as statins," said Dr. Stone. He added that there is a role for other cholesterol-lowering drugs, for example, in patients who suffer side effects from statins.
The report also stresses the importance of lifestyle in managing cholesterol and preventing heart disease. "The cornerstone of all guidelines dealing with cholesterol is a healthy lifestyle," said Dr. Stone. "That is particularly important in the young, because preventing high cholesterol later in life is the first and best thing someone can do to remain heart-healthy. On the other hand, if someone already has atherosclerosis, lifestyle changes alone are not likely to be enough to prevent heart attack, stroke, and death, and statin therapy will be necessary."
In addition to identifying patients most likely to benefit from statins, the guideline outlines the recommended intensity of statin therapy for different patient groups. Rather than use a "lowest is best" approach that combines a low dose of a statin drug along with several other cholesterol-lowering drugs, the panel found that it can be preferable to focus instead on a healthy lifestyle along with a higher dose of statins, eliminating the need for additional medications.
"The focus for years has been on getting the LDL low," said Dr. Stone. "Our guidelines are not against that. We're simply saying how you get the LDL low is important. Considering all the possible treatments, we recommend a heart-healthy lifestyle and statin therapy for the best chance of reducing your risk of stroke or heart attack in the next 10 years."
The guidelines are intended to serve as a starting point for clinicians. Some patients who do not fall into the four major categories may also benefit from statin therapy, a decision that will need to be made on a case-by-case basis. The expert panel that wrote the report was convened by the National Heart, Lung, and Blood Institute of the National Institutes of Health. At the invitation of the NHLBI, the American Heart Association and American College of Cardiology assumed the joint governance, management and publication of this guideline, along with four other prevention guidelines, in June. Committee members volunteered their time and were required to disclose all healthcare-related relationships, including those existing one year before the initiation of the writing project.
The full text of the report, "2013 ACC/AHA Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults," will be published in future print issues of the of the Journal of the American College of Cardiology and the American Heart Association's journal Circulation. It will also be accessible today on the ACC website and AHA.