Myeloperoxidase (MPO)

- Elevated MPO levels predict the risk of heart disease in subgroups otherwise associated with low risk

- Elevated MPO levels independently predict the risk of future cardiovascular events in patients presenting with an acute coronary syndrome

- Individuals with elevated MPO levels are more than 2x as likely to experience cardiovascular mortality

- MPO enhances cardiovascular risk prediction when used independently or alongside standard biomarker testing such as hsCRP8

- MPO levels are not likely to be elevated due to chronic infections or rheumatologic disorders due to the fact that free MPO in the blood is a specific marker of vascular inflammation and vulnerable plaque/erosions/fissures.

Treatment Considerations:

These treatment considerations are for educational purposes only. Specific treatment plans should be provided and reviewed by the treating practitioner.

Assess LDL-C levels.

If not at goal, consider lipid-lowering therapy, ideally with a statin-based regimen if not contraindicated.

Assess risk for pre-diabetes/diabetes.

If abnormal fasting glucose or oral glucose tolerance test, consider PPAR agonists, metformin or DPP-IV inhibitor if not contraindicated. 

Assess the presence of coronary artery disease (CAD) with imaging techniques such as carotid intima media thickness testing (CIMT) or coronary artery calcium scoring.

- Consider aspirin therapy if not contraindicated.

- Consider clopidogrel if history of CAD (i.e., myocardial infarction or revascularization) and/or a history of cerebrovascular disease (i.e., TIA or stroke).

Assess dental health (periodontal disease).

Refer to dentist to identify gum disease. NOTE: Poor dental health may cause significant inflammation and is associated with the presence of atherosclerosis.

Assess HDL-C levels.

If not at goal, consider niacin or fenofibrate therapy.

Assess CoQ10 levels.

Recent evidence suggests that low ApoA1 and/or HDL-C levels are associated with low CoQ10 levels10.

Assess smoking habits.

NOTE: Smoking cessation is essential as individuals who smoke are at increased risk of heart disease and blood clots.

Assess blood pressure.

If not at goal, consider initiating, or titrating, anti-hypertensive therapy. NOTE: An elevated blood pressure may contribute to endothelial dysfunction and coronary disease formation.

Assess lifestyle habits.

Consider diet/exercise/weight reduction efforts if appropriate.

Assess the presence of inflammatory conditions such as Crohn’s disease, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

NOTE: Chronic inflammatory diseases may exhibit elevated MPO values due to increased vascular disease associated with these conditions. For example, RA is associated with a 5x increased risk for myocardial infarction.

Assess the presence of vasculitis.

NOTE: MPO values may be elevated in individuals with vasculitis as it is characterized by increased vascular inflammation.

Assess the presence of bone marrow dyscrasias.

NOTE: MPO values may be elevated in individuals with chronic lymphocytic leukemia or other leukemias, that cause increased white blood cell destruction.

Assess level of exercise.

NOTE: MPO values may be elevated in marathon runners and extreme athletes and may identify those with increased oxidative stress and basal levels of inflammation.

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If asymptomatic, with all of the above factors ruled out, an elevated MPO value may in fact be the patient’s baseline. MPO levels should be monitored every 3-6 months.