Lp-PLA2 appears to play a role in inflammation of blood vessels and is thought to help promote atherosclerosis. Some recent studies have shown that Lp-PLA2 is an independent risk factor for two cardiovascular diseases (CVD), coronary heart disease (CHD), and ischemic stroke. In these studies, increased concentrations of Lp-PLA2 are seen in many people who are diagnosed with CHD and ischemic stroke, regardless of other risk factors. These findings make this relatively new test potentially useful as one of a growing number of cardiac risk markers that are used to help determine a person's risk of developing CVD.
CVD causes more deaths in the U.S. each year than any other cause, according to the American Heart Association. CHD and ischemic stroke are both associated with the buildup of unstable fatty plaque deposits in the arteries that can lead to blockages in blood vessels and to heart attacks or brain damage. There are a variety of risk factors that have been identified as being associated with both conditions, including high blood pressure, diabetes, smoking, obesity, high cholesterol levels, increased LDL, and decreased HDL (high-density lipoprotein, the "good cholesterol").
Many people who have one or more risk factors will eventually develop CVD, but a significant number of additional people who have few or no identified risk factors will also develop CVD. This has lead researchers to look for other risk factors that might be either causing CVD or that could be used to determine lifestyle changes and/or treatments that could reduce a person's risk of CVD.
In addition to the traditional risk factors listed above, a low level of chronic, systemic inflammation and inflammation of blood vessels (vascular) is thought to contribute to overall risk for developing CVD. The hs-CRP test is associated with systemic inflammation; high levels are thought to increase CVD risk. The Lp-PLA2 test is associated with vascular inflammation, and high levels are thought to increase the chance of heart attack or stroke.
How is the sample collected for testing?A blood sample is obtained by inserting a needle into a vein in the arm.
Is any test preparation needed to ensure the quality of the sample?No test preparation is needed.
How is it used?The Lp-PLA2 test is sometimes used by a doctor along with other cardiac risk markers to help evaluate a person's risk of developing coronary heart disease (CHD) or to help determine the risk of having an ischemic stroke. It would typically be indicated for someone who was at a moderate to elevated risk for CHD or stroke, someone with one or more risk factors. For instance, it may be ordered when someone has normal or minimally elevated lipid levels and/or borderline high blood pressure (hypertension).
An Lp-PLA2 test may be ordered along with an hs-CRP test to evaluate a person's level of underlying inflammation and can be ordered when someone has an inflammatory condition, as it is not affected by systemic inflammation.
Lp-PLA2 is a new test that is not frequently ordered and its full clinical utility has yet to be established. It is intended to give a doctor additional information, not to replace testing cholesterol and other lipid levels.
Some researchers are exploring whether treatments to lower Lp-PLA2 levels may decrease a person's risk of CHD and ischemic stroke. If the risk is found to be lowered, then the Lp-PLA2 test may potentially be ordered more frequently and used to monitor a person's response to treatment and risk reduction.
When is it ordered?Lp-PLA2 is a new test that is not frequently ordered. Some doctors may order it along with other cardiac risk markers when someone has a family history of CHD, has metabolic syndrome, and/or is considered to be at a moderate to elevated risk for CHD or ischemic stroke.
The test may be useful when a person has an inflammatory condition and an hs-CRP test cannot be performed.
What does the test result mean?Significantly elevated Lp-PLA2 levels indicate an increased risk for developing CHD or of having an ischemic stroke and provide a doctor with additional information about the tested person's overall risk. The test is not diagnostic of CHD or ischemic stroke; it is a risk indicator. Many people with increased concentrations will not develop these conditions, and some with normal levels will.
Is there anything else I should know?While the findings from recent studies support the potential usefulness of Lp-PLA2 in CHD and ischemic stroke risk assessment, its ultimate clinical utility has yet to be established.
The Lp-PLA2 test is not widely available. In most cases, the blood sample will be sent to a reference laboratory and results will be available within a few days.
Quão mortais são os acidentes vasculares cerebrais?
De acordo com o Ministério da Saúde, o acidente vascular cerebral é a principal causa de morte no Brasil. Mais de 80% dos acidentes vasculares cerebrais são isquêmicos. Mais de 80% dos acidentes vasculares cerebrais são isquêmicos.
Todas as pessoas devem realizar o teste de Lp-PLA2?
Atualmente, este teste não é indicado nem recomendado para a população geral, pelas principais organizações de saúde, como teste de triagem ou como principal marcador de risco cardíaco primário. Seu medico irá prescrever o melhor teste para determinar o risco de desenvolvimento de DCV e fornecer-lhe informações sobre as mudanças necessárias para reduzir o risco.