Postcardiotomy Acute Liver Injury: A Retrospective Cohort

Objectives: To evaluate the incidence of acute liver injury (ALI) after cardiac surgery with cardiopulmonary bypass (CPB) according to the most commonly used diagnostic definitions and to assess its association with postoperative complications and outcomes. Design: Retrospective observational cohort study. Setting: Tertiary cardiac surgery center. Participants: A total of 2,038 consecutive adult patients undergoing cardiac surgery with CPB. Interventions: No interventions were performed; exposure consisted of undergoing cardiac surgery with CPB. Liver injury was classified according to 3 established definitions: severe ischemic liver injury (SIELI, defined as alanine aminotransferase [ALT] >500 IU/L), hypoxic hepatitis (HH, defined as aspartate aminotransferase [AST] or ALT >20 times the upper limit of normal), and acute liver failure (ALF, defined as serum bilirubin >1.5 mg/dL associated with international normalized ratio >1.5 and/or AST/ALT >10 times the upper limit of normal). Measurements and Main Results: SIELI occurred in 19 patients (0.9%), HH in 26 patients (1.3%), and ALF in 544 patients (26.7%). Patients who developed either HH or SIELI experienced significantly higher rates of reoperation and bleeding complications, and they required more transfusions of red blood cells, fresh-frozen plasma, and platelets compared with patients without liver injury. In contrast, ALF—according to the applied definition—was not associated with adverse prognostic implications. Conclusions: The incidence and prognostic value of postoperative liver injury strongly depend on the diagnostic definition adopted. HH and SIELI identify a small subset of patients with markedly increased morbidity, whereas ALF, as currently defined, appears to lack prognostic relevance in this surgical setting. Prospective studies are needed to clarify risk factors and pathophysiologic mechanisms underlying perioperative liver injury after cardiac surgery.