Incidence and prevalence of abnormal liver associated enzymes in patients with atrial fibrillation in a routine clinical care population

UNLABELLED: The prevalence of elevated liver enzymes has not been described in patients with atrial fibrillation (AF) who may be more likely to develop these abnormalities due to comorbidities and medications. As signals of liver injury lead to termination of drug development programs, an attempt to better define the background prevalence would aid in interpreting these elevations in the setting of exposure to a new drug. The aim of this study was to estimate the prevalence and incidence of alanine aminotransferase (ALT) elevations in a cohort with AF. METHODS: Retrospective cohort of patients with AF using the outpatient medical record of the University of Pennsylvania Health System (UPHS). Primary outcomes were prevalence and incidence of ALT elevations (>40 U/L). We also examined the prevalence of risk factors for ALT elevations. RESULTS: Liver enzymes were measured at least once in 1630 of 2151 patients (76%). The prevalence of ALT >40 U/L was 27.6% (95%CI 25.7-29.5%). The incidence of new ALT elevations was 14.5/100 person-years (95%CI 13.0-16.1) for ALT > 40 U/L and 2.1/100 person-years (95%CI 1.6-2.8) for ALT elevations above twice the upper limit of normal (ULN). New persistent ALT elevations above twice the ULN were identified in 0.2% of patients. CONCLUSION: Elevated ALT is common among patients with AF, although new and persistent elevation greater than twice the ULN is uncommon. In the setting of a new drug, these factors make it difficult to delineate drug-induced liver injury from incident elevations due to comorbidities.