Perioperative assessment of platelet function by Thromboelastograph Platelet Mapping in cardiovascular patients undergoing non-cardiac surgery

Abstract

Five percent of patients on dual antiplatelet therapy after coronary artery stent implantation will need non-cardiac surgery within the first year of therapy, and many more will need surgery later on. A function assay that evaluates platelet reactivity and inhibition by drug therapy is beneficial for such patients. Platelet Mapping assay (PM) using the TEG analyzer was tested in surgical patients. After IRB approval, 60 patients on combined aspirin and clopidogrel therapy were consented and enrolled. The TEG maximal amplitude (MA) and the percentage (%) platelet inhibition were recorded and analyzed. Fifty-seven patients (mean age 65.7 ± 10.9 years) had preoperative data only. Distribution of preoperative ADP (43.6 ± 24.4%) and AA inhibition (52.8 ± 30.2%) was determined, as well as for the preoperative MA ADP (43.1 ± 15.9 mm) and MA AA (37.2 ± 19.6 mm), showing an offset of the effect of both medications starting from day 3. Patients with complete pre- and postoperative data were stratified depending on duration off antiplatelet therapy (≤3 days, 3-7 days and >7 days): n = 27, ADP % preop inhibition (43.2 ± 21.6%), ADP % postop inhibition (32.3 ± 18.3%), p = 0.048. Distribution of immediate pre- and post- ADP and AA % inhibitions, showing a possible reduction in Δ of inhibition for clopidogrel at 3 days, were also assessed.

Conclusion: According to the findings, the TEG PM assay might be a feasible approach to objectively evaluate the effects of aspirin and clopidogrel during the perioperative period and potentially guide drug management.