The correlation between serum total bilirubin and outcomes in patients with different subtypes of coronary artery disease

The relation between serum total bilirubin (TBi) and mortality in patients with established coronary artery disease (CAD) remains undefined. We try to investigate the role of the subtypes of CAD in the association. A total of 3013 patients with angiographically obstructive CAD were enrolled. A retrospective analysis was conducted. Patients were divided into 3 groups as follows: stable CAD (SCAD), unstable angina pectoris (UAP) and acute myocardial infarction (AMI). The predictive values of TBi for 30-day and long-term mortality were assessed using logistic and Cox regression, respectively. Higher initial serum TBi levels were significantly associated with increased risk of short-term mortality (OR 2.35, 95% CI 1.15–4.77) in AMI group. However, the association was absent among patients with SCAD and UAP. Serum TBi was able to independently predict the long-term mortality in SCAD (HR 0.34, 95% CI 0.16–0.70) and UAP (HR 0.49, 95% CI 0.31–0.78) groups. However, there was no significant relation between TBi and long-term mortality in AMI groups. The different subtypes of CAD affected the relation between serum TBi and clinical prognosis. Initial serum TBi was positively correlated with short-term mortality of AMI patients, and negatively correlated with long-term mortality in SCAD or UAP patients.