Prognostic value of serum total bilirubin in patients with acute coronary syndrome after percutaneous coronary intervention

Objective: To investigate the predictive value of serum total bilirubin (STB) level in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI). Methods: A total of 1273 consecutive patients treated with PCI in cardiology department, First Affiliated Hospital of Zhengzhou University from June 2009 to December 2010 were enrolled in this study. Patient' s fasting STB concentrations within 24 h after admission and other relevant clinical data were recorded. The patients were followed-up by telephone or in the Out-patient Department from August to November 2012. All end events were recorded. The primary end events were death resulted from various causes. The secondary end events were acute myocardial infarction, repeated PCI or coronary artary bapass grafting, readmission for angina pectoris, heart failure or stroke. The patients were divided into four groups according to the levels of STB: the subnormal low STB group (Gl: STB < 3. 4 μmol/L), the low limit of normal STB group (G2:3. 4 μmol/L≤STB≤10. 3 μmol/L), the upper limit of normal STB group (G3:10. 3 μmol/L < STB ≤17. 1 μmol/L) and the high level above normal STB group (G4; STB > 17. 1 μmol/L). Application of univariate and multivariate logistic regression analyses to explore factors associated with the prognosis. The survival rate was estimated using Kaplan-Meier survival curve. P < 0. 05 was considered as statistically significant difference. Results: (1) 1152 patients (90. 5%) were successfully followed-up. Mean followup time were (30. 4 ±5. 0) months, and 187 patients experienced end events (16. 2%), and 45 patients died (3. 9%). (2) The incidence of total end events in the four groups decreased with increase in STB (28. 8%, 17. 1%, 11. 2%, 8. 5%, X² = 22. 159, P <0. 01). There were no differences in incidence of primary end events between 4 groups (6. 6%, 4. 3%, 3. 0%, 2. 8%, x² = 2 366, P = 0. 500). (3) Multivariate logistic regression analysis showed that the incidences of total end events in G3 and G4 group were decreased to 56. 4% (OR = 0. 436, 95% CI: 0. 237-0. 804, P = 0. 008) and to 63. 6% (OR = 0. 364, 95% CI; 0.190-0.695, P = 0.002) respectively. (4) Kaplan-Meier survival curve analysis showed that there were significent differences in cumulative survival rates without end events between 4 groups (P < 0. 01). Conclusions: STB concentration is associated negatively with the end events in patients with ACS after PCI. But it is not associated with mortality.