Cross-sectional investigation of activated clotting time after administration of different intravenous heparin doses in patients undergoing on-pump coronary artery bypass graft surgery

Introduction

Achieving optimal anticoagulation during coronary artery bypass graft (CABG) surgery remains a challenge, with variations in heparin response attributed to differences in demographic and clinical factors. Deviations from the target activated clotting time (ACT) during CABG have been linked to adverse outcomes. This study aimed to assess the impact of different intravenous heparin doses on ACT in patients undergoing on-pump CABG.

Methods

A cross-sectional study was conducted on 54 patients scheduled for CABG surgery with cardiopulmonary bypass in 2021. ACT measurements were taken 5 min after the initial bolus dose of 200 IU/kg and a secondary dose of 100 IU/kg heparin. Demographic and clinical data, including ACT measures, hemoglobin levels, bypass time, and mortality, were collected.

Results

The study population predominantly comprised of male patients, with a mean age of 61.18 ± 8.81 years. The patients received 4 (3–4) grafts over 75 (65–80) minutes. Baseline ACT was 149.91±17.48 s, increasing to 410 (359–472) and 604 (542–679) seconds after the initial and additional heparin, respectively. Only 22.2 % of the study subjects achieved target ACT>480 s with 200 IU/kg, and the remaining 77.8 % required an additional 100 IU/kg heparin to reach the target ACT. No cases of heparin resistance, mortality, or dropouts were reported at the end of the study. Preoperative and postoperative hemoglobin levels were positively correlated (r = 0.59, p < 0.0001).

Conclusion

A 300 IU/kg heparin dose appears safer than lower doses for initiating cardiopulmonary bypass in on-pump CABG. Preoperative hemoglobin optimization may help minimize perioperative hemoglobin drop. Further research is needed to refine dosing strategies and personalize CABG management.