Prognostic Impacts of Increases in Amino Transaminases Following Coronary Artery Bypass Grafting on Mortality

Abstract

Objective: To evaluate the prognostic impacts of postoperative increases in serum amino transaminases on 1-year mortality in patients who underwent coronary artery bypass graft.

Design: A retrospective analysis.

Setting: A tertiary care university hospital.

Participants: A total of 1,950 patients who underwent coronary artery bypass graft.

Interventions: None.

Measurements and main results: Aspartate amino transaminase and alanine amino transaminase ratios were calculated as the ratio between the peak aspartate amino transaminase and alanine amino transaminase within the first 5 post-operative days and their respective upper limit of normal values. A ratio of 2.0 was seen to be the minimum for which a difference in 1-year mortality could be detected in univariate analysis, when considering simultaneously both aspartate amino transaminase and alanine amino transaminase ratios. Multivariable analysis showed an association between an aspartate amino transaminase ratio > 2.0 and increased 1-year mortality (hazard ratio [HR] 2.68, 95% confidence interval [CI] 1.42-5.05, P = 0.002), and also between both an aspartate amino transaminase and alanine amino transaminase ratio > 2.0 and increased 1-year mortality (HR 3.90, 95% CI 1.87-8.14, P < 0.001). However, increases in alanine amino transaminase only above the upper limit of normal were not associated with increased 1-year mortality.

Conclusions: Postoperative increases in aspartate amino transaminase only and increases in both aspartate amino transaminase and alanine amino transaminase greater than twice the upper limit of normal were associated with increased 1-year mortality in patients undergoing coronary artery bypass graft.

Keywords: coronary artery bypass graft; one-year mortality; postoperative alanine amino transaminase; postoperative aspartate amino transaminase; ventriculo-aortic junction.