Collect

One 2.0 ml Greiner Sodium Citrate Tube (not a standard BD Tube)

Note: Preferred needle size for venipuncture is 21g but 22g is acceptable. 23g is unacceptable.

Unacceptable Conditions

  • Specimen greater than 4 hrs old
  • Spun specimen
  • Specimen drawn in incorrect Tube
  • Specimen collected using 23g venipuncture needle due to the negative impact of the small bore size on platelets
  • Specimen held at temperature other than room temperature

Storage/Transport Temperature

Room temperature

Stability (from collection to initiation)

Ambient: 4 hrs, uncentrifuged

Performed

Sun-Sat

Remarks

Must be unspun and delivered to the laboratory within 4 hrs of draw

MUST BE HAND DELIVERED TO THE LAB

Department

Coagulation

Performed

Sun-Sat

Methodology

VerifyNow Platelet Function Analyzer

Interpretive Data

PRU < 210 may indicate an increased risk of bleeding but optimal prevention of acute adverse coronary events.

PRU = 210-240 may indicate that it is reasonable to go to surgery if there is an urgent need, but some increased risk of bleeding may still persist. This represents an adequate PRU for platelet inhibition for the prevention of coronary events following PCI with stent implantation. 

PRU >240 may indicate that the patient is a non-responder, or no significant residual inhibition in a patient who has had their Plavix discontinued. 

In the setting of percutaneous coronary intervention (PCI) with stent implantation and clopidogrel therapy, prospective outcome studies have shown that high residual in vitro platelet reactivity, as measured by the VerifyNow P2Y12 assay, is an independent risk factor for adverse cardiac events. Based upon receiver-operating characteristic (ROC) curve analyses, an optimal cut-off point for predicting adverse outcomes appears to be P2Y12 reaction units (PRU) of greater than 235-240 (depending upon the study; area under the curve (AUC) = 0.62-0.71; sensitivity = 60-81%; specificity = 53-78%; negative predictive value = 94.3-99%; positive predictive value = 12-81%).

References:
Breet, Nicoline J., et.al. Comparison of Platelet Function Tests in Predicting Clinical Outcome in Patients Undergoing Coronary Stent Implantation. JAMA. February 24, 2010. Volume 303, No. 8, 754-761.

Patti, Giuseppe, et.al. Point-of-Care Measurement of Clopidogrel Responsiveness Predicts Clinical Outcome in Patients Undergoing Percutaneous Coronary Intervention: Results of the ARMYDA-PRO (Antiplatelet therapy for Reduction of Myocardial Damage during Angioplasty-Platelet Reactivity Predicts Outcome) Study. J Am Coll Cardiol 2008; 52: 1128-33).

Price, Matthew J., et.al. Prognostic Significance of Post-Clopidogrel Platelet Reactivity assessed by a Point-of -Care assay on Thrombotic Events After Drug-Eluting Stent Implantation. European Heart Journal. February 10, 2008, pp. 1-9.

Marcucci, Rosella, et.al. Cardiovascular Death and Nonfatal Myocardial Infarction in Acute Coronary Syndrome Patients Receiving Coronary Stenting Are Predicted by Residual Platelet Reactivity to ADP Detected by a Point-of-Care Assay: A 12-Month Follow-Up. Circulation. 2009; 119:237-242.
 
Douketis JD, Alex C. Spyropoulos AC, Spencer FA , et al. Perioperative Management of Antithrombotic Therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines CHEST 2012; 141:e326S–e350S.

S Brar, J ten Berg, et al. Impact of Platelet Reactivity on Clinical Outcomes After Percutaneous Coronary Intervention: A Collaborative Meta-Analysis of Individual Participant Data, Journal of the American College of Cardiology, 2011, vol.58, no. 19 pp 1945-1954.

CPT Codes

86676
Collection

Collect

One 2.0 ml Greiner Sodium Citrate Tube (not a standard BD Tube)

Note: Preferred needle size for venipuncture is 21g but 22g is acceptable. 23g is unacceptable.

Unacceptable Conditions

  • Specimen greater than 4 hrs old
  • Spun specimen
  • Specimen drawn in incorrect Tube
  • Specimen collected using 23g venipuncture needle due to the negative impact of the small bore size on platelets
  • Specimen held at temperature other than room temperature

Storage/Transport Temperature

Room temperature

Stability (from collection to initiation)

Ambient: 4 hrs, uncentrifuged

Performed

Sun-Sat

Remarks

Must be unspun and delivered to the laboratory within 4 hrs of draw

MUST BE HAND DELIVERED TO THE LAB

Department

Coagulation
Ordering

Performed

Sun-Sat

Methodology

VerifyNow Platelet Function Analyzer
Result Interpretation

Interpretive Data

PRU < 210 may indicate an increased risk of bleeding but optimal prevention of acute adverse coronary events.

PRU = 210-240 may indicate that it is reasonable to go to surgery if there is an urgent need, but some increased risk of bleeding may still persist. This represents an adequate PRU for platelet inhibition for the prevention of coronary events following PCI with stent implantation. 

PRU >240 may indicate that the patient is a non-responder, or no significant residual inhibition in a patient who has had their Plavix discontinued. 

In the setting of percutaneous coronary intervention (PCI) with stent implantation and clopidogrel therapy, prospective outcome studies have shown that high residual in vitro platelet reactivity, as measured by the VerifyNow P2Y12 assay, is an independent risk factor for adverse cardiac events. Based upon receiver-operating characteristic (ROC) curve analyses, an optimal cut-off point for predicting adverse outcomes appears to be P2Y12 reaction units (PRU) of greater than 235-240 (depending upon the study; area under the curve (AUC) = 0.62-0.71; sensitivity = 60-81%; specificity = 53-78%; negative predictive value = 94.3-99%; positive predictive value = 12-81%).

References:
Breet, Nicoline J., et.al. Comparison of Platelet Function Tests in Predicting Clinical Outcome in Patients Undergoing Coronary Stent Implantation. JAMA. February 24, 2010. Volume 303, No. 8, 754-761.

Patti, Giuseppe, et.al. Point-of-Care Measurement of Clopidogrel Responsiveness Predicts Clinical Outcome in Patients Undergoing Percutaneous Coronary Intervention: Results of the ARMYDA-PRO (Antiplatelet therapy for Reduction of Myocardial Damage during Angioplasty-Platelet Reactivity Predicts Outcome) Study. J Am Coll Cardiol 2008; 52: 1128-33).

Price, Matthew J., et.al. Prognostic Significance of Post-Clopidogrel Platelet Reactivity assessed by a Point-of -Care assay on Thrombotic Events After Drug-Eluting Stent Implantation. European Heart Journal. February 10, 2008, pp. 1-9.

Marcucci, Rosella, et.al. Cardiovascular Death and Nonfatal Myocardial Infarction in Acute Coronary Syndrome Patients Receiving Coronary Stenting Are Predicted by Residual Platelet Reactivity to ADP Detected by a Point-of-Care Assay: A 12-Month Follow-Up. Circulation. 2009; 119:237-242.
 
Douketis JD, Alex C. Spyropoulos AC, Spencer FA , et al. Perioperative Management of Antithrombotic Therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines CHEST 2012; 141:e326S–e350S.

S Brar, J ten Berg, et al. Impact of Platelet Reactivity on Clinical Outcomes After Percutaneous Coronary Intervention: A Collaborative Meta-Analysis of Individual Participant Data, Journal of the American College of Cardiology, 2011, vol.58, no. 19 pp 1945-1954.
Administrative

CPT Codes

86676