Heparin anticoagulation in patients undergoing off-pump and on-pump coronary bypass surgery

Area of Science:

• Cardiovascular Surgery
• Anesthesiology
• Hematology

Background:

• Coronary artery bypass graft (CABG) surgery is a common procedure for coronary artery disease.
• On-pump CABG (OPCAB) involves cardiopulmonary bypass, while off-pump CABG (OPCAB) is performed without it.
• Anticoagulation management is critical in both CABG and OPCAB procedures.

Purpose of the Study:

• To analyze and compare the coagulation data of patients undergoing on-pump CABG versus off-pump CABG (OPCAB).
• To evaluate the efficacy and safety of a specific heparin anticoagulation regimen in OPCAB patients.

Main Methods:

• A randomized prospective trial comparing CABG and OPCAB patients.
• Administration of heparin anticoagulation: 400 U x kg(-1) for CABG, and 180 U x kg(-1) plus 3000 U every 30 min for OPCAB.
• Collection of perioperative coagulation parameters including platelet count, fibrinogen, PT, PTT, ACT, and TEG.
• Measurement of residual heparin activity using an anti-Xa assay in a subset of patients.

Main Results:

• The OPCAB anticoagulation regimen achieved a peak ACT of 445 +/- 73 s, preserving platelet counts and fibrinogen levels.
• Residual heparin effect (anti-Xa activity of 0.2 U x ml(-1)) was detected up to 2 hours post-surgery in OPCAB patients.
• OPCAB patients showed similar TEG index, chest tube drainage, and transfusion rates compared to CABG patients, despite residual anticoagulation.

Conclusions:

• The heparin anticoagulation regimen used in OPCAB does not induce an immediate hypercoagulable state.
• Lower total doses of heparin and protamine were used in the OPCAB group.
• A residual heparin effect was observed in the early postoperative period for OPCAB patients, without adverse outcomes.