PFA Blood Test Results Explained


The PFA (Platelet Function Assay) blood test is used to measure the aggregation and adhesion of platelets. It is a rapid and accurate screening test that is used to detect a wide variety of medical conditions that may affect how platelets clump together.

When Is the PFA Blood Test Ordered?

Here are just some of the reasons why the test may be ordered and what the results of the test may mean.

1. To identify platelet dysfunction.
This is typically in those who have a history of bleeding excessively. The results of the PFA blood test can be used to diagnose acquired or inherited dysfunction of the platelets so that a treatment plan can be developed. Willebrand disease, blood vessel injuries, and other conditions are commonly detected with this test.

2. To screen for pre-surgical risks.
A surgeon does not necessarily wish to proceed with a surgery if there is a high risk of excessive bleeding. In this instance, there doesn’t need to be a clotting dysfunction, inherited or acute, for this test to be used. Individuals who take NSAID medications or aspirin on a regular basis may also be interrupting their clotting factors and would create excessive bleeding during an invasive procedure.

3. To determine if there is an aspirin resistance.
Low dose aspirin therapies are common today to thin the blood. This helps to reduce the chances of a cardiac event without the need for a drug like warfarin. When aspirin therapies are prolonged, the body can begin to develop a resistance to the drug and this may actually increase the chances of a heart attack or stroke occurring. Although this PFA blood test option isn’t always recommended, it is an option.

4. To monitor a current therapy.
Anti-platelet therapies are given to some patients after a heart attack or stroke occurs so that blood clotting can be inhibited. Although most patients receiving this kind of therapy don’t receive any monitoring at all, the PFA blood test can help to provide a doctor with the information that may be needed to adjust a treatment plan. This is especially important when anticoagulants are being used to reduce clotting for certain surgical procedures, such as an organ transplant or trauma surgery.

What Do My Test Results Mean?

The results of the PFA blood test must be interpreted by the ordering doctor because of the numerous reasons behind why it may have been ordered. If there is excessive bleeding suspected, for example, then a platelet disorder may have been discovered and further testing to determine the cause of the disorder will be required. It may also be an indication that kidney failure has occurred or a patient has developed MDS.

The test results can also measured temporary conditions that are acquired. This includes detecting abnormal functioning after a cardiac bypass surgery that is lengthy or from the abuse or overuse of NSAID medications or aspirin. Antidepressants, some allergy medications, and even some antibiotics are also known to affect PFA blood test results.

Here’s What You Need To Know

Not everyone will need to have the PFA blood test. Only when someone is taking certain medications, requires certain surgeries, or has experienced excessive bleeding will this test be ordered. It is not generally considered to be a screening tool, so expect to have further testing occur if the PFA results are positive.

There may be other platelet measurement tests available besides the PFA blood test. Sometimes a different test will be ordered before the PFA. When the PFA is used as a secondary option, it generally means that a medical provider is attempting to confirm the results of the first test. If there is a discrepancy between the two tests, then further testing may occur.

Finally, a person’s platelet function can actually change over time. Some of the conditions that are detected by the PFA blood test are inherited, but some can develop acutely at any time during life. It can even develop as a co-existing condition thanks to a chronic disease that is resistive to treatments.

If platelet dysfunction occurs because of a medication that is being taken, the problem will typically go away once the medication is stopped. In this circumstance, a doctor will weigh the benefits of the therapy to this side effect to determine how long the medication should be taken. In return, the PFA blood test will allow a medical provider to begin developing a treatment plan that can manage bothersome symptoms and potentially improve patient health.