Education
VerifyNow PRU Testing
Millions of Americans use aspirin and/or a P2Y12 inhibitor drug for anti-thrombotic therapy or thrombotic prophylaxis. However, studies show that up to 1 in 3 patients may not respond adequately to their antiplatelet medications and thus may be at significantly higher risk of heart attack, stroke, or other potentially life-threatening cardiovascular events. Conversely, patients who are hyper-responsive to these agents may be at greater risk of bleeding.
The Verify Now system is an FDA approved test to measure and quantitate platelet responsiveness to a variety of antiplatelet medications including aspirin or P2Y12 inhibitor drugs (e.g. clopidogrel, ticagrelor, prasugrel). Measuring patient responsiveness to antiplatelet medication may also help guide decisions on when surgery or other diagnostic or therapeutic intervention may be performed safely.
Verify Now measures patient responsiveness to aspirin or P2Y12 inhibitor drugs (e.g. clopidogrel, ticagrelor, prasugrel) using a citrated whole blood sample. Testing is useful for determining patient responsiveness to antiplatelet drug treatment, such as in patients with repeat thrombotic events who are already on anti-platelet therapy, to determine the residual effects of antiplatelet therapy prior to surgery or other therapeutic or diagnostic intervention or assess suspected patient noncompliance to therapy.
The VerifyNow PRU Test (CPT 85576) is designed to measure P2Y12 receptor blockade. Results of the PRU Tests are reported as P2Y12 Reaction Units (PRU). PRU measures the extent of platelet aggregation in the presence of a P2Y12 inhibitor Lower PRU levels are associated with expected antiplatelet effect.
<180 PRU – suggests P2Y12 inhibitor effect
180-376 PRU – suggests lack of P2Y12 inhibitor effect
The VerifyNow Aspirin (CPT 85576) Test is a qualitative test to aid in the detection of platelet dysfunction. The test is reported in Aspirin Reaction Units (ARU).
350-549 ARU – therapeutic range for platelet function.
550-700 ARU – non-therapeutic range for platelet function.
Testing is performed using a 2 mL Greiner Bio-One partial fill sodium citrate tube with 3.2% sodium citrate which cannot be refrigerated or sent to the laboratory via pneumatic tube system. Testing is ideally performed within 4 hours of specimen collection and patients should not be tested within 48 hours of the administration of eptifibatide (Integrilin®) or tirofiban (Aggrastat®), or 14 days following the administration of abciximab (ReoPro®).
Testing is now available at the St John Medical Center clinical laboratory and may be ordered using order names PRU P2Y12 VerifyNow Test and Aspirin VerifyNow Test. Testing will be available for St John Medical Center and for patients sent from physician offices for testing. Because of the special testing requirements, outpatients should present to the 5th floor draw site in the Siegfried Tower at 1923 S Utica, Monday through Friday, 8 AM - 8 PM for specimen collection.