Thromboelastography in off-pump coronary artery bypass grafting.

Background: Thromboelastography enables complete evaluation of the process of clot initiation, the structural characteristics of the formed clot and its stability. Many previous studies have assessed the predictive role of thromboelastography in on-pump cardiac surgery, but there are no clear guidelines on its use in off-pump coronary artery bypass. The aim of this study was to evaluate the use of thromboelastography and its relevance during the postoperative period following off-pump coronary artery bypass.

Methods: This was a one-year prospective study on 55 patients undergoing off-pump coronary artery bypass for coronary artery disease. Thromboelastography was performed as a bedside investigation in the cardiothoracic and vascular surgery intensive care unit.

Results: The association between maximum amplitude and total blood loss <500 mL compared to blood loss >500 mL was statistically significant (p < 0.001). Using receiver operator characteristic curve analysis, it was seen that with increasing maximum amplitude values, a decrease in blood loss was observed. A cutoff value of maximum amplitude <49.63 mm was regressed to have a predicted sensitivity of 100% and a predicted specificity of 89.3% for prediction of blood loss >500 mL.

Conclusions: Thromboelastographic parameters show a reliable correlation with increased blood loss in off-pump coronary artery bypass grafting, and predict patients with an increased chance of blood requirement as well as those at risk of a hypercoagulable state.