- Lipoprotein-Associated Phospholipase A2 Predicts Future Cardiovascular Events in Patients With Coronary Heart Disease Independently of Traditional Risk Factors, Markers of Inflammation, Renal Function, and Hemodynamic Stress - (http://atvb.ahajournals.org/content/26/7/1586.long)
About
Majority of heart attacks and strokes are caused by plaque rupture. And plaques are made of fats, cholesterol, and other substances found in blood. It is but natural that high cholesterol, especially high LDL Cholesterol, can increase your chances of cardiovascular disease. However, if you think testing only for cholesterol levels can help predict your cardiovascular disease risk accurately, you are way off the mark. Surprisingly, 50 percent of heart attacks occur in people with normal cholesterol.
Doctors are now resorting to an additional laboratory blood test that will increase their ability to predict cardiovascular risk. The test is called PLAC test.
What is a PLAC test?
PLAC test is a simple blood test to ensure your heart health. The test measures the amount of an enzyme called lipoprotein-associated phospholipase A2 (Lp-PLA2) in your blood stream. This enzyme has been found by researchers to indicate inflammation of the artery. Arterial inflammation makes heart attack or stroke more likely.
Incidentally, this is the only test cleared by FDA to detect risk for coronary heart disease and ischemic stroke.
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The Cause of Heart attack and Stroke
Cardiovascular disease is the class of disease that involves the heart, blood vessels (of the brain and kidney too) or both. The main cause of cardiovascular disease, or simply, heart disease, is atherosclerosis and high blood pressure. Atherosclerosis is a condition in which plaque builds up in the arteries. Over time, the plaque can harden or rupture. When this happens, arteries narrow and reduce the flow of oxygen-rich blood to the heart.
Insufficient blood flow to the heart muscle results in heart attack.
If the plaque ruptures, it forms a clot. The clot can cause a stroke.
How can PLAC test predict heart disease?
Lp-PLA2 enzyme is made by macrophages, a type of white blood cells. In the blood stream, this enzyme mainly circulates bound to LDL cholesterol. When LDL undergoes oxidation in the artery wall, Lp-PLA2 generates a number of chain reactions that result in production of chemicals that cause plaques in the artery wall. This leads to atherosclerosis. The chemicals produced in the chain reactions stimulate macrophage proliferation, which in turn produce more of Lp-PLA2. This is shown as elevated PLAC in your blood test result.
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If your PLAC test result is 200 ng/mL or greater, you need to see a doctor. To be more specific –
- Low values: 151 nmol/min/mL or less
- Medium values: 152 to 194 nmol/min/mL
- High values: 195 nmol/min/mL or greater
It would otherwise be very difficult to know if you have CVD as the disease does not show any early symptoms; so you wouldn’t know when your arteries are inflamed. Hence the PLAC test to assess the risk for heart attack and stroke.
PLAC test is not the exclusive predictor of CVD
The thing is the PLAC test is not a stand-alone test for heart disease. It is rather used as a supportive information when used with other diagnostic tools and clinical evaluation. For example, an elevated PLAC test result along with an LDL-cholesterol level of less than 130 mg/dL gives may suggest 2 to 3 times the risk of having coronary heart disease (CHD) compared to lower PLAC test results.
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Similarly, if you have high blood pressure and show an elevated PLAC test result, you know that there is a 6 to 7 fold increase in your risk for stroke.
Do you need the PLAC test?
If you have two or more of the following risk factors for CVD indicated by World Heart Federation, you definitely need to get the PLAC test done.
- High blood pressure
- High cholesterol
- Obesity and physical inactivity
- Diet high in saturated fat
- Diabetes
- Excessive alcohol use
- Exposure to tobacco
- Family history and ethnicity
- Advanced age (more than 45 for men and more than 55 for women)
Cost of PLAC test
Not all labs do the PLAC test in India. Among the few who do the test are Metropolis (nationwide network), Allied Biotechnology (in Andhra Pradesh and Thane), SRL Diagnostics in Mumbai, and Medivision Diagnostic Centre in Cochin.
The cost of PLAC test in India varies from lab to lab.
With over 3 million deaths from cardiovascular diseases every year, India is fast becoming the heart disease capital of the world. That said, detection rates for CVD has also increased over the years, both in rural as well as urban areas. PLAC test is definitely one of the ways we can drop the ‘heart disease capital’ label soon.
