Hypercoagulability in relation to coronary artery bypass graft patency and clinical outcome.

Objective. Hypercoagulability evaluated with thrombelastography (TEG) has been reported to be associated to thrombembolic events in patients undergoing coronary artery bypass graft surgery (CABG). The objective of this study was to test the hypothesis that graft patency and post-CABG thrombembolic events are related to the pre-surgical TEG status. Design. 124 patients scheduled for CABG were matched according to mean age, gender and mean left ventricular ejection fraction in two groups defined by their pre-surgical TEG status (TEG-hypercoagulable and TEG-normocoagulable). Three months after the operation graft patency was assessed with multidetector computed tomography (MDCT). Major adverse cardiovascular and cerebral events (MACCE) were recorded for a median period of 7 months (range 3 to 37 months) after CABG. Results. A total of 359 grafts were analyzed, 186 in TEG-hypercoagulable and 173 in TEG-normocoagulable patients. Frequency of bypass graft occlusion was not significantly different between the two groups (TEG-hypercoagulable = 21 and TEG-normocoagulable = 18, p = 0.9). The number of MACCE was significantly higher in the TEG-hypercoagulable compared to the TEG-normocoagulable group (TEG-hypercoagulable = 30% and TEG-normocoagulable = 9% p = 0.004). Conclusions. Hypercoagulability, as evaluated by TEG in patients undergoing CABG is associated with an increased risk of post-surgical thrombembolic events, however not accompanied by augmented coronary bypass graft failure.