High activated clotting time, or venous graft, or off-pump coronary artery bypass grafting? Too early to call off the party!

Off-pump coronary artery bypass grafting using continuous heparin infusion

“…Longer ACT (more than 350 seconds) is avoided during PCI as it does not increase stent patency rate but increases bleeding complications. Similarly in DOOR study, ACT more than 400 seconds in the OPCAB group may have caused increased bleeding without improving graft patency 8, 9. It may be concluded that ACT less than 350 seconds (between 200 and 300 seconds) may be optimal for OPCAB with least incidence of postoperative myocardial infarction and minimal intra-operative blood loss 12…”

“…A study from Korea revealed that ACT more than 350 seconds are associated with paradoxically higher incidences of peri-operative myocardial infarction 7 . In DOOR study, ACT longer than 400 seconds was maintained in OPCAB group and may have resulted in higher rate of vein graft failure due to paradoxical platelet activation 8 . Prolonged ACT increases blood loss during OPCAB without improving graft patency 9 .…”

“…So the normal response to a lower ACT is to supplement a higher dose of bolus heparin. Higher dose of heparin may increase the heparin half life with increase of ACT above 350 seconds with detrimental effects on graft patency due to platelet activation 8, 9, 12…”

“…Recent OPCAB study suggests that longer than 350 seconds of ACT during OPCAB is associated with significantly higher incidence of postoperative myocardial infarction 7 . Maintaining a shorter ACT level during OPCAB may have an added benefit of minimizing blood loss during the procedure 7, 8. ACT more than 400 seconds was maintained in OPCAB group in recently published Danish off-pump versus on on-pump revascularization (DOOR) study.…”

“…ACT more than 400 seconds was maintained in OPCAB group in recently published Danish off-pump versus on on-pump revascularization (DOOR) study. It was concluded by the authors of DOOR study that higher level of anticoagulation during OPCAB may result in increased bleeding without improving graft patency 8, 9…”