Modified thromboelastography evaluation of platelet dysfunction in patients undergoing coronary artery surgery

Area of Science:

• Cardiovascular Surgery
• Hematology
• Anesthesiology

Background:

• Anti-platelet therapy increases perioperative bleeding risk in cardiac surgery.
• Guidelines recommend discontinuing therapy 5-10 days before surgery, but this may increase myocardial infarction risk.
• The optimal timing for anti-platelet therapy cessation is patient-specific.

Purpose of the Study:

• To evaluate if preoperative thromboelastography (TEG) with platelet mapping can predict bleeding in patients on anti-platelet therapy undergoing coronary artery bypass grafting (CABG).

Main Methods:

• Prospective evaluation of 59 patients undergoing CABG on aspirin and clopidogrel therapy (25 on aspirin alone).
• TEG with platelet mapping performed immediately before surgery.
• Assessed correlation between platelet function and postoperative bleeding.

Main Results:

• Excessive bleeding occurred in 9/59 patients (24h post-surgery).
• Clopidogrel-induced platelet dysfunction, identified by platelet mapping, predicted excessive bleeding (78% sensitivity, 84% specificity, p=0.004).
• Aspirin-induced platelet dysfunction did not correlate with bleeding; high rates of non-responsiveness to both aspirin (44%) and clopidogrel (85%) were observed.

Conclusions:

• TEG with platelet mapping effectively predicts excessive postoperative blood loss in CABG patients with recent anti-platelet therapy.
• Non-responsiveness to anti-platelet agents, particularly clopidogrel, is common in this patient group.
• Aspirin's effect on platelet function did not impact postoperative bleeding in this study.