Coronary heart disease (CHD) is the single largest cause of death in the United States. Although the mortality rate due to CHD is on the decline, CHD still kills about 500,000 Americans annually. It is estimated that nearly 70% of all Americans have some degree of atherosclerotic narrowing of their coronary arteries. Elevated LDL cholesterol levels, as well as decreased HDL cholesterol levels are independent risk factors for premature CHD in our society. Prospective studies indicate that diet treatment or diet and drug therapy which lowers LDL cholesterol reduces subsequent CHD morbidity and mortality. The National Cholesterol Education Program (NCEP) and the American Heart Association (AHA) have identified LDL cholesterol levels as the primary target for reduction in CHD morbidity and mortality. The NCEP Adult Treatment Panel has developed guidelines The Are You at Risk Poster Download this PDF (476 KB) for the diagnosis and treatment of individuals over 20 with elevated blood cholesterol levels associated with an increase in LDL cholesterol levels. See the "Are You At Risk" poster for a summary of the NCEP Guidelines related to the diagnosis, treatment and monitoring of CHD risk.

Current Laboratory Measurement of LDL Cholesterol Levels

Daniel Wohlgelernter, M.D. "The Need for Direct LDL Testing" The recommendation that cholesterol values be used as the primary criterion for treatment decisions in patients with elevated cholesterol levels, makes the need for accurate measurement a national public health imperative as reviewed by the NCEP Laboratory Standardization Panel. The Friedewald formula was originally published in 1972 and serves as the basis for the conventional determination of LDL cholesterol. The Friedewald formula requires three assays, and results in a calculation of LDL as follows: LDL cholesterol equals the total cholesterol minus Case History:  Lack of compliance with fasting requirement the sum of HDL cholesterol and VLDL cholesterol. There are several inherent problems with the Friedewald formula. The variability inherent in three assays is additive, patients are required to fast for 12 to 14 hours before laboratory testing, and the Freidewald LDL calculation is not accurate for triglycerides over 400 mg/dL. The new millenium brings us new methodologies for the measurement and monitoring of lipid disorders. We now have available direct, homogeneous assays for LDL cholesterol Table:  Patient populations in which the use of Freidewald formula for estimating LDL cholesterol is problematic assessment. Performing the direct LDL assay means you have no variability from performing three assays such as is necessary with the Freidewald calculation, patients do not have to fast prior to laboratory testing, and with the direct measurement of LDL, accurate values can be obtained even with triglycerides over 400 mg/dL. These advantages provide the basis for better assessment and management of patients with dyslipidemias.

Lipid Testing Reimbursement Update

Edwin H. Allen, J.D. "Alignment of Medicare Coverage Policies with Standards for Medical Care" New federal rules establishing national coverage policies for 23 groups of clinical laboratory tests are almost complete. The national coverage policies were developed by a committee of representatives from 19 organizations representing medical care providers, laboratories, and manufacturers of diagnostic products, who met with the Health Care Finance Administration (HCFA) for a series of negotiated rulemaking sessions. One of the 23 groups of tests for which a coverage policy has been developed is comprised of seven tests for lipids. The coverage policy for lipids describes in detail under what circumstances a specific lipid test may be ordered and how frequently a test may be used to be covered by Medicare. A proposed rule including the new national coverage policies was published in the Federal Register in March of 2000 and made available for public comment. Fewer than 60 comments to the proposed rule were received during the comment period and none were critical of the policy for lipid tests. Review of the comments and preparation of the final rule are on track under HCFA's schedule. Once the final rule is published, the new national coverage policies will then become effective 12 months after publication. An additional 12 months after the effective date will be allowed for providers and Medicare contractors to make claims processing system changes. Therefore, the new policies will most likely be in effect for all Medicare contractors sometime in 2002. The availability of Medicare coverage that is consistent with the current medical practice associated with the treatment of anti-lipid therapy is very close at hand. For more information on direct LDL testing, please visit the Genzyme Corporation web site at www.genzymediagnostics.com or call (617) 769-3690.

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