ASSESSMENT OF THE PERIOPERATION RISK WITH VerifyNow ARU® TOOL IN PATIENTS AFTER CORONARY BYPASS ON PROLONGED ASPIRIN TREATMENT

Abstract

Aim. During perioperation time of coronary bypass grafting (CBG) to evaluate diagnostical significance of platelet functional activity by the system VerifyNow ARU® in assessment of high hemorrhagic and ischemia risk patients on prolonged aspirin treatment.Material and methods. Totally, 32 patients included, that were preparing for planned primary operation of CBG. In perioperation time all patients were taking acetylsalicylic acid 75-100 mg/day. Platelet function was assessed in 3 days before surgical intervention with VerifyNow ARU® (Accumetrics, USA).Results. Depending on the ARU level, all patients were selected into two groups. First group (1), consisted of 11 patients, included those with the highest antiplatelet effect of aspirin, the second (2) included all the rest. Mean value of VerifyNow among all selection, in groups 1 and 2 was, respectively, 505,9±87,3, 425,2±21,7 and548,2±78,2 ARU. Comparison groups were comparable in clinical and anamnestic properties. By the values of intraoperation blood loss (509,1±30,2 mL in the 1st group versus 515,8±50,1 mL in the second, p=0,30) and postoperation blood loss (drainage flow during 6 hours was 115,9±42,2 mL in the 1st group vs. 111,8±38,5 mL in the 2nd, p=0,87; during 12 hours 188,6±83,9 mL in 1st vs. 187,4±93,0 mL, resp., p=0,89; during 24 hours — 218,2±110,2 mL vs. 253,6±142,6 mL, resp., p=0,70) comparison groups did not differ. In correlation assessment there was tendency found of the platelets reactivity level with 6-hour blood loss (p=0,09). This data was confirmed by the results of linear regression analysis, that showed negative correlation of blood loss volume and VerifyNow results. In five patients (15,6%) postoperation period complicated with coronary flow instability and development of myocardial infarction, confirmed by dynamics of myocardial damage markers. All five patients were in the second and third terciles of VerifyNow, in lower tercile of VerifyNow there were no any perioperational coronary events (p=0,14).Conclusion. Results of the analysis demonstrate that the assessment of functional activity of platelets by VerifyNow assay can be applied as laboratory criteria for prediction of postoperation blood loss and perioperation ischemia events in CBG operations at the background of prolonged aspirin therapy.

Keywords

• prolonged aspirin therapy
• perioperation complications
• aorticcoronary bypass grafting
• system verifynow aru