The Death Risk Factors of Patients Undergoing Re-Exploration For Bleeding or Tamponade After Isolate Off-Pump Coronary Artery Bypass Grafting: A Case-Control Study

BACKGROUND The purpose of the study is to identify off-pump patients who are at higher risk of mortality after re-exploration for bleeding or tamponade. METHODS We analyzed the data of 3256 consecutive patients undergoing isolated off-pump coronary artery bypass grafting (OPCABG) in our heart center from 2013 through 2020. Fifty-eight patients underwent re-exploration after OPCABG. The 58 patients were divided into death group and survival group according to their discharge status. Propensity score matching (PSM) was performed to analysis the risk factors of death. 15 pairs of cases of two groups were matched well. RESULTS The mortality rate of patients underwent re-exploration after OPCABG for bleeding or tamponade was 27.59% (16/58). In the raw data, we found the patients in death group had higher body mass index (BMI) (P = 0.030), higher cardiac troponin T (cTnT) (P = 0.028) and higher incidence of heart failure before OPCABG (P = 0.003). After PSM, the levels of lactic acid before and after re-exploration (P = 0.028 and P < 0.001) were higher in death group. And the levels of creatinine (P = 0.002) and cTnT (P = 0.017) were higher in the death group after re-exploration. The death group had longer reoperation time (P = 0.010). In addition, the perioperative utilization rate of intra-aortic ballon pump (IABP) (P = 0.027), continuous renal replacement therapy (CRRT) (P < 0.001) and platelet transfusion (P = 0.017) were higher than survival group. CONCLUSIONS The mortality rate of patients undergoing re-exploration for bleeding or tamponade after isolated OPCABG is high. More attention should be paid to patients with above risk factors and appropriate measures should be taken in time.