Heparin responsiveness during off-pump coronary artery bypass graft surgery: Predictors and clinical implications

Aim:To evaluate the clinical impact of reduced heparin responsiveness (HR _reduced) on the incidence of myocardial infarction (MI) following off-pump coronary artery bypass graft surgery (OPCAB), and to identify the predictors of HR _reduced.Methods:A total of 199 patients scheduled for elective OPCAB were prospectively enrolled. During anastomosis, 150 U/kg of heparin was injected to achieve an activated clotting time (ACT) of ≥ 300 s, and the heparin sensitivity index (HSI) was calculated. HSIs below 1.0 were considered reduced (HR _reduced). The relationships between the HSI and postoperative MI, cardiac enzyme levels and preoperative risk factors of HR _reduced were investigated.Results:There was no significant relationship between the HSI and cardiac enzyme levels after OPCAB. The incidence of MI after OPCAB was not higher in HR reduced patients. HR _reduced occurred more frequently in patients with low plasma albumin concentrations and high platelet counts.Conclusion:HR _reduced was not associated with adverse ischemic outcomes during the perioperative period in OPCAB patients, which seemed to be attributable to a tight prospective protocol for obtaining a target ACT regardless of the presence of HR _reduced.