Investigation of Risk Factors Related to the Development of Hepatic Dysfunction in Patients with a Low and Moderate Cardiac Risk During Open-Heart Surgeries.

Objective: To determine the possible risk factors associated with hepatic dysfunction during open-heart surgeries.
Methods: After excluding 71 patients, 307 patients with possible low and moderate cardiac risk who underwent either coronary artery bypass graft surgery (CABG) (n=176) or valve repair surgery (mitral valve, mitral and aortic valves and/or tricuspid valve) (n=131) were investigated prospectively during a 6-month period. Hyperbilirubinemia is defined as an occurrence of a plasma total bilirubin concentration >34 µmol/L (2 mg/dL) in any measurement during the postoperative period; the patients were divided into groups with or without postoperative hyperbilirubinemia. The collected parameters were: alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin (TBil), gamma-glutamyl transpeptidase (GGT) and albumin. The parameters were collected preoperatively and postoperatively on days 1, 3 and 7. Preoperative, intraoperative, and postoperative risk factors were investigated. Logistic regression analysis was performed to identify the risk factors for postoperative hyperbilirubinemia.
Results: Postoperative hyperbilirubinemia was observed in 7 of 176 patients (4%) who underwent CABG, and in 11 of 131 patients (8.4%) who underwent valve replacement surgeries. Independent risk factors for early postoperative hyperbilirubinemia were found as: ejection fraction (EF), aortic cross-clamp (ACC) time, intensive care unit stay and extubation time (P<0.001). In comparison to CABG procedures, postoperative hyperbilirubinemia was observed more frequently in patients undergoing valve surgeries (P=0.027).
Conclusion: Low EF and prolonged ACC time are significant independent risk factors for early postoperative hyperbilirubinemia during open-heart surgeries with cardiopulmonary bypass. Valve surgeries show a higher incidence of hyperbilirubinemia in comparison to CABG.