Homocysteine Level, Serum Form

Summary Of Evidence

N/A

Analysis of Evidence

N/A

Indications:

Elevated serum levels of the amino acid homocysteine are associated with increased risk of cardiovascular (CV) and cerebrovascular disease events as well as an increased risk of osteoporosis. Treatment of the elevated homocysteine level in the absence of an established causal relationship between hyperhomocysteinemia and these entities has been empiric supplementation with vitamin B-6, B-12 and folic acid. Hyperhomocysteinemia may also be present with vitamin B12 and folate deficiencies associated with anemia. In these instances the elevated homocysteine confirms the vitamin deficiency as the source of anemia.

No studies demonstrate that such vitamin supplementation, while lowering the serum homocysteine levels, also reduces the risks for CV or cerebrovascular events or osteoporosis. The Heart Outcomes Prevention Evaluation (HOPE) 2 investigators reported that "...combined daily administration...[of the vitamins] for 5 years had no beneficial effect on major vascular events in a high risk population with vascular disease." The Norwegian Vitamin Trial (NORVIT) investigators found that "Treatment with B vitamins did not lower the risk of recurrent CV disease after acute myocardial infarction. A harmful effect from combined B vitamin treatment was suggested." In their 2004 report, Lange H, et. al, reported that B vitamin supplementation to lower homocysteine levels, after coronary stenting, may increase the risk of in-stent restenosis and the need for target vessel revascularization.

• Homocysteine levels will be covered by Medicare to confirm vitamin B12 or folate deficiency.
• In the absence of evidence that treatment of hyperhomocysteinemia reduces CV events, this test can only be covered in patients with known vascular disease or risk thereof (based upon abnormal lipid metabolism, high blood pressure (BP) or diabetes mellitus (DM)) for the purpose of risk stratification. In this circumstance it will be covered only once per lifetime.

 Limitations:

• When used to determine the risk of developing atherosclerotic CV disease, measurement of serum homocysteine levels in the absence of known vascular disease, hyperlipidemia or DM will be denied as screening.
• Serum homocysteine levels for the evaluation of treatment of hyperhomocysteinemia in patients with CV risk factors will be denied as not medically necessary.