Prognostic value of total bilirubin in patients with acute myocardial infarction: A meta-analysis

BACKGROUND: Experimental data obtained in animal models supported the protective role of bilirubin. However, clinical studies regarding the prognostic role of total bilirubin in patients with acute myocardial infarction (AMI) are conflicting. We, therefore, undertook this meta-analysis to evaluate the prognostic value of serum total bilirubin in AMI patients. METHODS: Relevant studies were searched from PubMed and EMBASE databases up to April 15, 2018. Studies evaluating the outcomes in relation to serum total bilirubin in AMI patients and reporting multivariable-adjusted risk estimate of the prognostic value were eligible. The outcome measures were major adverse cardiac events (MACEs), cardiovascular death, and all-cause mortality. RESULTS: Six studies involving 14,554 AMI patients were identified. Meta-analysis indicated that higher total bilirubin was associated with an increased risk of MACEs (risk ratio [RR] 1.65; 95% confidence intervals [CI] 1.25–2.19) and cardiovascular death (RR 2.12; 95%CI 1.24–3.64). However, higher serum total bilirubin did not significantly increase all-cause mortality risk (RR 1.31; 95%CI 0.75–2.28). Subgroup analyses by the types of AMI and study design supported the pooled results. CONCLUSIONS: Higher serum total bilirubin level is a predictor of MACEs and cardiovascular death in patients with AMI. However, interpretation of these findings should be with caution due to the impact of cardiac dysfunction after AMI.