Frequently asked questions about the PLAC portfolio

The PLAC® Test for Lp-PLA2 Activity is a test cleared by the Food and Drug Administration. In patients with no history of cardiac events, it provides additional prognostic information to doctors and medical staff, detecting hidden risk for coronary heart disease (CHD).

Questions and answers to the questions asked most frequently about CHD and the PLAC Test for Lp-PLA2 Activity appear in this section. If you would like additional information, please contact us.

Am I at risk for having a heart attack?

Doctors assess the risk for a heart attack or other cardiac events. They assess this risk based on several standard factors:

  • Diabetes
  • Cigarette smoking
  • High blood pressure
  • High cholesterol or cholesterol level at the borderline of high
  • Family history of early heart disease
  • Overweight
  • Metabolic syndrome

Although these risk factors are watched routinely, patients still can be at risk for cardiac events. You or a loved one may be concerned about risk for coronary heart disease. If so, talk with your doctor about the risk factors and the PLAC® Test for Lp-PLA2 Activity.

My cholesterol level is normal. Am I still at risk for a heart attack?

Although total cholesterol levels measure normal, high, or low, more clarity is needed. To protect the heart, cholesterol levels should be kept as low as possible. Patients should get an understanding of the levels of low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol. They should also be aware of other risk factors.

Many efforts to reduce high cholesterol levels are available. Even so, the heart attack rates are high. In a study of patients hospitalized for CHD-related events, roughly half of heart attacks occurred in patients with LDL levels below 100. Roughly a quarter of heart attacks occurred in patients with LDL levels below 70.1 So it may be important to consider other tests to identify increased risk for CHD events. Be sure to discuss your cholesterol levels with your doctor. Also ask whether other tests that include PLAC activity testing are needed.

Can I lower my risk for having a heart attack?

The coronary heart disease (CHD) events rate decreased between the years 1980 and 2000. Of the decrease, 44% was related to changes in risk factors.2,3 Your doctor may be able to lower your risk for heart attack. He or she can detect risks early and prescribe changes for those risks.

Your doctor may prescribe lifestyle changes, such as diet or exercise. He or she may also order prescription or over-the-counter medicine.

Perhaps you are concerned about your risk for a heart attack or other CHD event. If so, please talk with your doctor. He or she can discuss how the PLAC® Test for Lp-PLA2 Activity and preventive measures can help reduce your CHD risk.

What is the PLAC® Test for Lp-PLA2 Activity?

The PLAC Test for Lp-PLA2 Activity is a new test cleared by the Food and Drug Administration. In clinical studies, the test was found to help identify risk for coronary heart disease (CHD) in patients with no history of cardiovascular events. The test is performed in a laboratory. Using a standard blood specimen or sample, it measures the activity of Lp-PLA2 (lipoprotein-associated phospholipase A2). Lp-PLA2, an enzyme, contributes to inflammation of blood vessels and formation of plaque in the arteries. Lp-PLA2 is a marker specific to the blood vessels. In the presence of plaque that is prone to rupture, it is highly elevated.4

How does the PLAC® Test for Lp-PLA2 Activity differ from other tests my doctor may order, like cholesterol testing?

Many efforts to reduce high cholesterol levels are available. Even so, the heart attack rates are high. In a study of patients hospitalized for CHD-related events, roughly half of heart attacks occurred in patients with LDL levels below 100. Roughly a quarter of heart attacks occurred in patients with LDL levels below 70.1 A substudy (study within a study) of Lp-PLA2 was completed.5 It showed that a high result from the PLAC Test for Lp-PLA2 Activity predicted CHD events better than cholesterol results (low HDL and high LDL) and even better than high blood pressure results.6

The PLAC Test for Lp-PLA2 Activity is used with medical evaluation and assessment of patient risk. With that, it provides added prediction for risk beyond standard risk factors. Taken together, this prediction helps to identify patients who remain at risk for CHD events.

The risk for each patient should be considered along with all available medical information. Consult with your doctor about your cardiac risks.

HDL, high-density lipoprotein; LDL, low-density lipoprotein.

Why might my doctor order the PLAC® Test for Lp-PLA2 Activity for me?

Perhaps you have no history of cardiovascular events. In that case, your doctor may order the PLAC Test for Lp-PLA2 Activity to assess risk factors. These factors may extend beyond standard risk factors, like cholesterol levels and blood pressure. Assessing all risk factors may help to lower your concern and your doctor’s about your risk for coronary heart disease events.

Should everyone be tested with the PLAC® Test for Lp-PLA2 Activity?

No. The PLAC Test for Lp-PLA2 Activity should be ordered for patients with no history of cardiovascular events. The predictive ability of the PLAC Test for Lp-PLA2 Activity has not been studied in patients in a secondary prevention setting. Your physician can help you understand your cardiac risk factors. He or she can also determine whether the PLAC Test for Lp-PLA2 Activity is suitable for you.

What do my PLAC® Test for Lp-PLA2 Activity results mean?

High PLAC activity is found in plaque deposits that are unstable. Because they are unstable, they are more prone to rupturing. Studies show that a PLAC Test for Lp-PLA2 Activity result ≥225 nmol/min/mL points to an increased risk of CHD events. These coronary heart disease, or CHD, events can include heart attack, revascularization (such as stent placement or coronary artery bypass grafting), or death from a cardiac event, even in patients with normal cholesterol levels.

A PLAC Test for Lp-PLA2 Activity result below 225 indicates that you are at lower risk for a CHD event.

The PLAC Test for Lp-PLA2 Activity has a validated cut point of 225 nmol/min/mL

A PLAC Test for Lp-PLA2 Activity result at or above 225 indicates an increased risk for a CHD event.

In addition to other factors, depending on your gender and race, your risk may be higher or lower than the test result. Study results show that the PLAC Test for Lp-PLA2 Activity result at or above the 225 cut point had an absolute risk of 5-year CHD events of 7.7% in men and 7.6% in blacks, and a 2.2 relative risk increase in women, which increased further in black women.

Always consult with your doctor about the results of your PLAC Test for Lp-PLA2 Activity.

Will my insurance plan pay for the PLAC® Test for Lp-PLA2 Activity?

Currently, the PLAC Test for Lp-PLA2 Activity is a covered service with the following health plan providers. It is not limited to only them, however.

  • CareFirst BlueCross BlueShield (MD)
  • CIGNA
  • Health Alliance (MI)
  • Lovelace Health Plan (NM)
  • PreferredOne Community Health Plan (MN)
  • Priority Health (MI)
  • SelectHealth/Intermountain Health (UT)
  • TRICARE Military Health System
  • UPMC Health Plan (PA)

Other health plans are reimbursing for the PLAC Test for Lp-PLA2 Activity but have not issued a formal coverage policy (for example, Coventry Health Care, Inc). The PLAC Test for Lp-PLA2 Activity is also available to patients insured through Medicare and Medicaid.

Diadexus, with its laboratory partners, is working actively to expand insurance coverage for the PLAC Test for Lp-PLA2 Activity with health plans across the United States. Please refer to What does the PLAC® Test for Lp-PLA2 Activity cost? to learn more about what the PLAC Test for Lp-PLA2 Activity costs.

For questions about health insurance coverage (from you or your doctor) or if your health plan has denied a claim for the PLAC Test for Lp-PLA2 Activity, please contact us at customercare@diadexus.com or 1-877-752-2837 for assistance.

What does the PLAC® Test for Lp-PLA2 Activity cost?

Billing for the PLAC Test for Lp-PLA2 Activity is handled directly by the laboratory that completes the testing. The list price for the PLAC Test for Lp-PLA2 Activity is set by the performing laboratory. Patient cost will vary based upon a number of considerations, including coverage by health plan, participation status of the performing laboratory (“in network” versus “out of network”), benefit design, deductibles, co-payment, and coinsurance.

For more information about the list price, insurance participation, and billing policies for the PLAC Test for Lp-PLA2 Activity, please contact the laboratory your doctor has selected to perform the test.

Which laboratories offer the PLAC® Test for Lp-PLA2 Activity?

The PLAC Test for Lp-PLA2 Activity is new. Because of that, it may not be available at your routine laboratory yet. For a growing number of hospital laboratories, regional laboratories, and national laboratories that offer the PLAC Test for Lp-PLA2 Activity, please contact Diadexus or call 1-877-752-2837.

How do I get tested for PLAC activity?

Discuss your interest in the PLAC® Test for Lp-PLA2 Activity with your doctor.

For information on laboratories that offer the PLAC Test for Lp-PLA2 Activity, please refer to Which laboratories offer the PLAC Test for Lp-PLA2 Activity?

What do I need to do to prepare for having the PLAC® Test for Lp-PLA2 Activity?

Unlike with cholesterol testing, you do not need to fast 12 hours prior to having your blood drawn.

Most prescribed medicines do not interfere with the PLAC Test for Lp-PLA2 Activity. Please check with your doctor about any need to stop your medicines prior to testing.

Who should I contact for advice about the results of my PLAC® Test for Lp-PLA2 Activity?

As with all medical services, direct questions about your test results to your doctor. Diadexus cannot speak directly with patients about test results. If your doctor has questions about interpreting the test results, he or she can contact the laboratory that performed the test.