The association between the level of serum conjugated bilirubin and mortality in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention

Background Even with percutaneous coronary intervention(PCI),patients with ST-segment elevation myocardial infarction(STEMI)faced a substantial mortality.We aimed to evaluate the relationship between the level of bilirubin and mortality in patients with STEMI undergoing PCI.Methods Patients with the diagnosis of STEMI and subsequently treated with PCI was enrolled retrospectively in Guangzhou Eighth People's Hospital,from March2013 to October 2019.The primary clinical outcome was in-hospital death,and the secondary clinical outcome was one-year mortality.Results Overall,844 patients were included.The receiver-operation characteristics(ROC)curves analysis showed a higher discriminative ability for conjugated bilirubin(CB=0.805,95%CI:0.703-0.907,P<0.001)in predicting in-hospital death,compared to total bilirubin(TB).Patients were divided into a lower CB group(CB<5.7 umol/L,n=656)and a higher CB group(CB≥5.7 umol/L,n=188).There were 6(0.9%)patients died in the lower CB group,and 17(9.0%)patients died in the higher CB group(P<0.001).In the univariate Logistic regression analysis,CB≥5.7 umol/L were associated with in-hospital death(OR=10.77,P<0.001).After adjusting confounding factors,CB≥5.7 umol/L was independently correlated with in-hospital death(OR=5.13,95%CI:1.67-15.75,P=0.004).During one-year follow-up,there were 69(10.5%)patients died in the lower CB group and40(21.3%)patients died in the higher CB group(log-rank=41.90,P<0.001).The multivariate Cox regression analysis showed that CB≥5.7 umol/L was independently associated with one-year mortality(HR=2.45,95%CI:1.37-4.40,P=0.003).Conclusions CB could be a feasible biomarker in differentiating high-risk STEMI patients treated with PCI.