Higher Thrombelastograph platelet reactivity in cardiac surgery patients than in blood donors

OBJECTIVES: Platelet reactivity, evaluated by Thrombelastograph (TEG) predicts the recurrence of ischemic events in patients undergoing percutaneous coronary intervention (PCI). The aim of this study was to investigate the platelet hyperreactivity and the variability in platelet reactivity due to ADP in cardiac surgery patients and donors.

METHODS: Preoperative blood samples from 22 patients undergoing CABG surgery and 43 blood donors were analysed by the TEG Platelet Mapping assay. Maximal platelet reactivity and platelet reactivity response to ADP stimulation (MAADP) were evaluated.

RESULTS: Maximal platelet reactivity (MAThrombin) and MAADP was higher in the CABG patients than in the blood donors, p=0.001 for MAThrombin and p<0.0001 for MAADP. Six patients (27.2%) had a MAThrombin above the normal reference range compared to only one (2.3%) of the healthy donors (p=0.005).

CONCLUSIONS: The identification of a higher subpopulation of CABG patients compared to donors presenting with platelet reactivity above the normal range together with increased platelet responsiveness to ADP may reflect the higher risk for ischemic events in this cohort.