A Novel Biomarker to Predict the Risk of Contrastinduced Nephropathy in Patients Undergoing Coronary Angiography: Total Bilirubin Phosphorus Ratio

Objective: Identifying patients at high risk for contrast-induced nephropathy (CIN) is essential for implementing effective preventive strategies. This study aimed to evaluate the predictive value of the total bilirubin-phosphorus ratio (TBPR) for CIN development. Methods: This retrospective, observational study included 2217 patients who underwent coronary angiography between June 2020 and January 2022. Patients were categorized into two groups based on CIN occurrence: those who developed CIN (Group 1) and those who did not (Group 2). Baseline characteristics, CIN status, and TBPR were compared between the groups. Results: CIN incidence was highest among patients with ST-elevation myocardial infarction (STEMI) (39.4%), followed by those with Non-STEMI (27.2%) and stable/unstable angina pectoris (12.1%) (p<0.05). Multivariate analysis identified advanced age, pre-procedural hydration, severe coronary artery disease, STEMI diagnosis, and a low TBPR as independent predictors of CIN. Patients who developed CIN had significantly lower TBPR values (0.133 vs. 0.214, p<0.001). Receiver operating characteristic curve analysis demonstrated that a TBPR threshold of <0.155 predicted CIN with 85% sensitivity and 63% specificity (area under the curve [AUC]: 0.759, p<0.001). In addition, TBPR was a stronger predictor of CIN than total bilirubin or phosphorus alone (AUC comparison, p<0.001). Conclusion: This study highlights TBPR as a potential independent predictor of CIN development.