Failure of the Platelet Function Assay (PFA)-100 to detect antiplatelet agents

Surgery. 2015 Oct;158(4):1012-8; discussion 1018-9. doi: 10.1016/j.surg.2015.07.011. Epub 2015 Aug 20.

Abstract

Background: Antiplatelet therapy is a complicating factor in patients with traumatic brain injuries (TBI), as well as those with hemorrhagic cerebrovascular accidents (CVAs). Platelet Function Assay (PFA)-100 is a coagulation device that can detect platelet dysfunction caused by aspirin and adenosine diphosphate inhibition. Our retrospective study reviewed the effectiveness of PFA-100 in detecting platelet dysfunction caused by aspirin and clopidogrel and determined its clinical importance.

Methods: All patients with PFA-100 tests from January 2013 to February 2014 were collected. Diagnoses indicative of a TBI or CVA were chosen for analysis. Patients with a normal PFA-100 indicating no platelet dysfunction but with documented aspirin and/or clopidogrel use were selected. An extensive chart review was performed to determine the relevance to their clinical care.

Results: A total of 475 patients were evaluated with a PFA-100 from January 2013 to February 2014. PFA-100 detected platelet dysfunction as the result of pre-injury use of antiplatelet agents in TBI and CVA patients with a sensitivity of only 48.6% and a specificity of 74.8%. Had these antiplatelet medications been known during initial workup, these patients would have had a change in management that may have impacted their outcomes.

Conclusion: Despite its common usage, the PFA-100 is an unreliable tool to assist in the management of TBI and CVA patients. Additional investigation into alternative methods for detecting platelet dysfunction is warranted.

Publication types

  • Evaluation Study

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aspirin / adverse effects*
  • Blood Platelet Disorders / chemically induced
  • Blood Platelet Disorders / complications
  • Blood Platelet Disorders / diagnosis*
  • Brain Injuries / complications*
  • Brain Injuries / therapy
  • Clopidogrel
  • False Negative Reactions
  • Female
  • Humans
  • Male
  • Middle Aged
  • Platelet Aggregation Inhibitors / adverse effects*
  • Platelet Function Tests
  • Retrospective Studies
  • Stroke / complications*
  • Stroke / therapy
  • Ticlopidine / adverse effects
  • Ticlopidine / analogs & derivatives*

Substances

  • Platelet Aggregation Inhibitors
  • Clopidogrel
  • Ticlopidine
  • Aspirin