Assessment of three point-of-care platelet function assays in adult trauma patients.

BACKGROUND: Antiplatelet (AP) medication use is common among trauma patients and is associated with poor outcomes. Management options for platelet dysfunction in trauma patients are controversial, expensive, and potentially harmful. Although light transmission platelet aggregometry is considered the standard test to assess platelet function, it is cumbersome and not generally available. Currently, there are no widely accepted platelet function point-of-care tests for acute trauma. STUDY DESIGN: Prospective observational study from 2014 to 2015. Baseline Multiplate aggregometry aspirin area under the platelet aggregation curve (ASPI AUC), Thrombelastography Platelet Mapping percent inhibition of arachidonic acid (TEG-PM AA), and VerifyNow Aspirin Test (ARU) were compared for ability to detect any AP medication use (aspirin or clopidogrel), platelet dysfunction, and identify patients at risk for intracranial hemorrhage (ICH) progression by calculating the area under receiver operating characteristic curves (AUC), sensitivity, specificity, and positive and negative predictive values. Adenosine diphosphate assays were similarly evaluated. RESULTS: Sixty-four patients were enrolled, 25 were taking AP medications. AP patients were older (71.6 versus 35.0 y, P < 0.001) and received more platelet transfusions, but other baseline characteristics were similar. Median ASPI AUC (22.0 versus 53.5 P < 0.001) and VerifyNow ARU (503.5 versus 629.0, P < 0.001) were lower, whereas TEG-PM AA (51.8% versus 18.3%, P < 0.001) was higher in AP patients. Multiplate ASPI AUC, TEG-PM AA percent inhibition, and VerifyNow ARU could identify AP medication use (AUC: 0.90, 0.77, and 0.90, respectively). Adenosine diphosphate assays did not correlate with AP medication use in this population. TEG-PM AA percent inhibition and VerifyNow ARU correlated well with Multiplate ASPI AUC to identify platelet dysfunction (AUC: 0.78, 0.89, respectively). ICH occurred in 29 patients; 12 of which had progression of their injury. ASPI AUC (AUC: 0.50) and VerifyNow ARU (AUC: 0.59) did not correlate, and TEG-PM AA percent inhibition (AUC: 0.66) minimally correlated with progression. CONCLUSIONS: Multiplate, TEG-PM, and VerifyNow are useful point-of-care tests which identify AP medication use and platelet dysfunction in trauma patients. Initial TEG-PM AA percent inhibition may be associated with risk for ICH progression. However, additional large, prospective studies are needed.