Abstract
BACKGROUND: Elevations of hepatic transaminase (serum alanine transaminase [ALT] and serum aspartate aminotransferase [AST]) levels in patients with acute coronary syndrome (ACS), although transient, may result in exclusions from clinical efficacy trials due to suspected liver disease. The aim of this study was to evaluate the concentrations of serum transaminases in ACS and relate these to currently accepted AST/ALT exclusion criteria from clinical trials. METHODS: One hundred consecutive patients with ACS were prospectively examined. Blood samples for AST, ALT, total bilirubin and troponin I concentration were obtained at the time of admission and after 6, 12 and 24 hours. RESULTS: Eighty percent of patients had elevated AST, and 47% ALT; 43% of patients characterized AST concentration > 3 × upper limit of normal (ULN) in at least one measurement, while 8% of patients presented ALT concentration > 3 × ULN. AST presented higher concentrations when compared to ALT, resulting in a high De-Ritis ratio at every time point. No significant or high correlations were found between the concentrations of serum transaminases, De-Ritis ratio and troponin I. Two different cut-off values of troponin I were adopted to define the amount of infarcted myocardium that distinguished 28-31% of individuals with "large infarction". Among these patients, approximately 93% presented AST concentrations > 3 × ULN. CONCLUSIONS: Hepatic transaminases are often elevated in ACS, with the majority of patients with more extensive myocardial injury presenting high concentrations of AST. In the setting of ACS, current transaminase thresholds for liver dysfunction used in clinical trials may lead to excessive and inadequate exclusions of patients with larger infarcts from such trials.