THE Food and Drug Administration (FDA) last December gave the green light to doctors to use a simple non-fasting blood test, called the PLAC test, that predicts heart attack in individuals with no history of heart disease because, according to the Centers for Disease Control and Prevention, almost two-thirds of women and one-half of men who die suddenly of a heart attack or other event caused by coronary heart disease (CHD) have no previous symptoms of heart disease, says the April 2015 issue of the Johns HopkinsScientific American — healthafter50.

The PLAC test measures the activity of an inflammatory enzyme called Lp-PLA2 — lipoprotein-associated phospholipase A2 — in the bloodstream.

Increased Lp-Pla2 activity signals the presence of vascular inflammation associated with atherosclerosis, the buildup of plaque within the artery walls — plaque buildup triggers an inflammatory response, causing increased Lp-PLA2.

Elevated Lp-PLA2 activity is associated with an increased risk of unstable arterial plaque that’s prone to tearing or rupturing — when a tear or a rupture occurs, a blood clot can form and block the artery that supplies blood to the heart, leading to a heart attack, adds the health letter.

The PLAC test is particularly accurate in women — especially black women, who have the highest rate of heart disease.

This test is also especially good news for black women because it’s particularly effective in discerning their cardiovascular disease risk — some statistics from the American Heart Association (AHA) and Centers for Disease Control and Prevention (CDCP) reveal why a better assessment of risk in black women has been sorely needed:

• Heart disease is the leading cause of death for black women.

• Almost 50,000 black women have coronary artery disease each year.

• About 7.5 percent of black women have coronary artery disease compared with 5.8 percent of white women.

• Approximately 37 percent of black women have high blood pressure.

For several years, doctors have been using another PLAC test, the PLAC ELISA Test.

Instead of measuring Lp-PLA2 activity, however, the PLAC ELISA Test measures the amount, or mass, of Lp-PLA2 in the blood — it is particularly useful in assessing even higher risk in patients who have already been identified as having moderate to high risk.

Several medical organizations, including the American Heart Association and the American Association of Clinical Endocrinologists, support using the PLAC ELISA test to assess coronary artery disease risk and for primary prevention of stroke in patients who have already been identified as being at risk.

While the new PLAC test by no means replaces cholesterol or similar tests, it gives doctors a tool to predict CHD — research has found that 50 percent of heart attacks occur in patients with normal cholesterol levels.

A 2008 review published in the American Journal of Cardiology found that patients who had the highest Lp- PLA2 measurements faced a doubling of coronary artery disease events as compared with those patients with the lowest levels.

Studies have shown that the higher the level of Lp-PLA2 activity, the higher the risk of cardiovascular event — even after adjusting for other risk factors, overactive Lp-PLA2 remained an independent risk factor, adds the health letter.

The FDA’s decision to widen the scope of PLAC measurements was based partly on data from the National Institutes of Health’s Reasons for Geographic and Racial Differences in Stroke study — the study demonstrated the test to be of superior value in accurately detecting CHD risk in women.

The study involved the use of the PLAC test on nearly 4,600 participants ages 45 to 92 with no history of CHD — about 58 percent of the participants were women, and 41.5 percent of participants were black. 

Results of the study included:

a) Seven percent of men and women whose PLAC test results were above the threshold of 225 nmol/min/mL (nanomoles per minute per milliliter) had a CHD event such as a heart attack or sudden cardiac arrest within five years of their tests, while 3.3 percent of participants with lower readings had heart events;

b) Participants whose Lp-PLA2 was lower than the 225 nmol/min/mL threshold were at lower risk of a CHD event; and

c) Black women had the most heart events when their Lp-PLA2 activity was above threshold.

Since women often fare worse than their male counterparts when it comes to events such as heart attack, including longer hospital stays and greater numbers of in-hospital deaths, experts have lauded the PLAC test as one of the best predictors of heart disease in black women — the hope is that the PLAC test will be better able than other tests to identify all women at risk before they have a CHD event.

Although some studies have shown that certain statins used to lower cholesterol, such as pravastatin, can reduce Lp-PLA2 activity and fibrates and other lipid-lowering drugs have shown some promise of lowering Lp-PLA2 activity and mass, some scientists still aren’t sure whether improving Lp-PLA2 measurements translates into real world benefits — more research is needed to determine whether the effects of statins and other therapies not only reduce Lp-PLA2 activity and mass but also prevent CHD events.

Another way for your doctor to assess your risk for cardiovascular disease is the high-sensitivity C-reactive protein(hsCRP) — it’s often used in conjunction with the PLAC test for a more thorough assessment.

According to the American Association of Clinical Endocrinologists (AACE), individuals whose CRP and Lp-PLA2 levels are both elevated have a very high cardiovascular risk, even if they have low or moderate cholesterol levels.

For the management of dyslipidemia and prevention of atherosclerosis, AACE recommends administering the PLAC ELISA and hsCRP tests along with lipid (cholesterol, triglycerides and other fats in the blood) testing to assess heart disease and stroke risk.

CRP is a protein produced in elevated levels by the liver in response to inflammation throughout the body — CRP levels higher than 3 mg/L (milligrams per liter) increase the odds of heart disease, regardless of other risk factors.

Some experts believe that CRP injures blood vessels and weakens them, making patients prime for a heart attack; others think CRP is simply a marker for blood vessel inflammation and the events that follow, but like the PLAC test, it’s also a valuable indicator of coronary heart disease in individuals without high blood cholesterol levels.

While learning you may be at risk for a heart attack or stroke can be troubling, the knowledge may be the incentive you need to make lifestyle changes, like improving your diet, getting more exercise, losing weight, reducing stress and stopping smoking — measures that could improve your heart health overall.

Also, your should ask your doctor if you’re a candidate for more aggressive therapy, such as statins, even if your cholesterol is low or normal, concludes the health letter.