Full Adoption of New Lipid Guidelines Would Put 13 Million More Patients on Statins

Researchers find that full implementation of recently released dyslipidemia management guidelines would help prevent 475,000 additional cardiovascular events.

Since publication of revised lipid guidelines by the American College of Cardiology (ACC)/American Heart Association (AHA) guideline expert panel in November 2013, many health care professionals throughout the United States have changed management strategies for patients with dyslipidemias. In the March 19, 2014 issue of the New England Journal of Medicine, a team of researchers evaluated the epidemiologic implications of full implementation of these new lipid guidelines.^1,2

The researchers used data collected by the National Health and Nutrition Examination Surveys (NHANES) between 2005 and 2010 to estimate the number of people included in the surveys who would be eligible for lipid-lowering treatment based on the new guidelines. These results were then extrapolated to the general US population of approximately 115.4 million adults aged 40 to 75 years.¹

Their results indicated that 56.0 million adults are eligible for statin treatment under the new guidelines, up from 43.2 million based on the Third Adult Treatment Panel (ATP III) guidelines of the National Cholesterol Education Program. Expressed in proportional terms, the number of statin-eligible patients has increased from just greater than one-third (37.5%) to nearly half (48.6%) of the US adult population.¹

The new guidelines have met with resistance in some quarters due to the dramatic changes in treatment they have introduced (see Table below). For instance, instead of recommending lipid-lowering therapy at specific cutoff values, as did the ATP III guidelines, the new guidelines recommend use of 10-year cardiovascular risk to identify patients as candidates for treatment. In addition, the new guidelines recommend use of high-intensity statin therapy over other lipid-lowering treatments.^1-3

Using the results of the latest meta-analysis,⁴ the authors of the NEJM study estimated that statin use reduces the relative risk of experiencing a cardiovascular event by approximately 25%. Using this estimate, they calculated that the increased use of lipid-lowering therapy that would be brought about by full implementation of the ACC/AHA guidelines would prevent 475,000 additional cardiovascular events. Although investigators noted that the vast majority (90%) of reduction in cardiovascular events would occur among older adults between the ages of 60 and 75, the investigators did not define over what period of time the reduction in cardiovascular events would accrue.¹

The new study suffered from some limitations. For instance, it included a relatively small number (3773) of NHANES participants with usable cholesterol data. In addition, the researchers’ reliance on the 10-year cardiovascular event estimation tool, which may not be accurate in some populations, may detract from the quality of the study’s conclusions. Nonetheless, the potential to prevent nearly 500,000 cardiovascular events remains a compelling reason to adopt and fully implement the new guidelines.¹

Table

Comparison of Guidelines^2,3

ATP-III

ACC/AHA

Under the ATP-III guidelines, after failure of dietary control, the following patients were candidates for lipid-lowering medication:

• Patients with diabetes (either type 1 or type 2)
• Patients with baseline LDL levels ≥130 mg/dL and a 10-year cardiovascular risk of 10% to 20%
• Patients with LDL levels ≥160 mg/dL and 10-year cardiovascular risk as low as 10%
• Baseline LDL level of 190 mg/dL, regardless of the 10-year cardiovascular risk

The ACC/AHA guidelines recommend lipid-lowering medication (preferably with high-intensity statin therapy) for 4 groups of patients:

• Patients with clinical atherosclerotic cardiovascular disease (ASCVD) including any of the following: Acute coronary syndromes A history of myocardial infarction Stable or unstable angina Coronary or other arterial revascularization Stroke Transient ischemic attack Peripheral arterial disease presumed to be of atherosclerotic origin
• Patients with an LDL level ≥190 mg/dL without treatment
• Patients 40 to 75 years of age with diabetes (either type 1 or type 2)
• Patients 40 to 75 years of age with a 10-year risk of cardiovascular events ≥7.5%

ACC/AHA, American College of Cardiology (ACC)/American Heart Association (AHA) guideline expert panel; ATP III, Third Adult Treatment Panel guidelines of the National Cholesterol Education Program.

References

1. Pencina MJ, Navar-Boggan AM, D’Agostino RB, et al. Application of new cholesterol guidelines to a population-based sample. N Engl J Med. 2014

2. NHLBI. ATP III Update 2004: Implications of Recent Clinical Trials for the ATP III Guidelines. www.nhlbi.nih.gov/guidelines/cholesterol/atp3upd04.htm. Accessed March 21, 2014.

3. Stone NJ, Robinson J, Lichtenstein AH, et al. 2013 ACC/AHA guideline on the treatment of blood cholesterol to reduce atherosclerotic cardiovascular risk in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines.. Circulation. 2013 Nov 12. 2013.

4. Taylor F, Huffman MD, Macedo AF, et al. Statins for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev. 2013.

5. Kolata G. New York Times. Risk Calculator for Cholesterol Appears Flawed. www.nytimes.com/2013/11/18/health/risk-calculator-for-cholesterol-appears-flawed.html?_r=0. Accessed March 21, 2014.