Comparison of different methods to evaluate the effect of aspirin on platelet function in high-risk patients with ischemic heart disease receiving dual antiplatelet treatment

Am J Clin Pathol. 2007 Jul;128(1):143-9. doi: 10.1309/0G1PEJ00J8KP8357.

Abstract

Patients with coronary artery disease (CAD) receiving aspirin therapy with a residual platelet reactivity (RPR) may be at increased risk of ischemic vascular events. Point-of-care (POC) methods PFA-100 (Dade-Behring, Marburg, Germany) and VerifyNow (Accumetrics, San Diego, CA) assays have been suggested as rapid tools to evaluate RPR. We compared PFA-100 closure times by collagen/epinephrine and VerifyNow Aspirin assays with light transmission aggregation (LTA) induced by 1 mmol/L of arachidonic acid in 484 patients with CAD undergoing percutaneous coronary intervention and receiving dual antiplatelet therapy. RPR was detected in 30.0% of patients by LTA, in 32.4% by PFA-100, and in 14.3% by VerifyNow. Significant correlations were found among 3 methods (all P < .0001). In relation to the presence or absence of RPR by LTA and PFA-100, by LTA and VerifyNow, and by PFA-100 and VerifyNow, samples were significantly concordant (all P < .0001). Assuming LTA as the reference method, PFA-100 and VerifyNow showed sensitivity of 62.1% and 39.3% and specificity of 80.2% and 96.4%, respectively. The cutoff values for POC methods need to be defined for clinical use.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Angioplasty, Balloon, Coronary
  • Arachidonic Acid / pharmacology
  • Aspirin / pharmacology*
  • Blood Platelets / drug effects*
  • Blood Platelets / physiology
  • Clopidogrel
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myocardial Ischemia / blood
  • Myocardial Ischemia / drug therapy*
  • Platelet Aggregation Inhibitors / therapeutic use*
  • Platelet Function Tests / methods*
  • Point-of-Care Systems
  • Sensitivity and Specificity
  • Ticlopidine / analogs & derivatives
  • Ticlopidine / therapeutic use

Substances

  • Platelet Aggregation Inhibitors
  • Arachidonic Acid
  • Clopidogrel
  • Ticlopidine
  • Aspirin