Use of abciximab-modified thrombelastography in patients undergoing cardiac surgery

Thrombelastography (TEG) is a reliable coagulation monitoring system that can guide blood product transfusion in cardiac surgery. The maximum amplitude (MA) of TEG measures clot strength, which is dependent on both fibrinogen level and platelet function. Inhibition of platelet function with abciximab-fab is suggested to permit quantitative assessment of the contribution of fibrinogen to clot strength. We hypothesized that abciximab-modified TEG permits prediction of plasma fibrinogen levels and that the difference of standard MA and abciximab-modified MA (Delta MA) is a correlate for platelet function. We correlated abciximab-modified MA with plasma fibrinogen levels and Delta MA with platelet count in patients undergoing coronary revascularization. Correlation between plasma fibrinogen levels and abciximab-modified MA was significant (adjusted r(2): 0.8; P < 0.0001). Correlation of Delta MA with platelet count was not significant when calculated in millimeters (adjusted r(2): 0.04; P = 0.73). However, when Delta MA was calculated in dynes per square centimeter (Delta GMA), it correlated significantly with platelet count (adjusted r(2): 0.51; P < 0.0001). We conclude that abciximab-modified TEG may therefore help to discriminate between hypofibrinogenemia and platelet dysfunction as a cause of decreased MA. Implications: We examined the use of abciximab-modified thrombelastography in patients undergoing cardiac surgery. Modification of thrombelastography with abciximab-fab allows prediction of fibrinogen levels, despite coagulation altered by cardiac surgery. The difference of standard maximum amplitude and abciximab-modified maximum amplitude correlates with platelet function when expressed in dynes per square centimeter.