Pre-Procedural N-Terminal Pro-B Type Natriuretic Peptide Predicts Contrast-Induced Acute Kidney Injury and Long-Term Outcome in Elderly Patients After Elective Percutaneous Coronary Intervention

The aim of the study is to evaluate the association of pre-procedural N-terminal pro-B type natriuretic peptide (NT-proBNP) with contrast-induced acute kidney injury (CI-AKI) and long-term outcomes in elderly patients undergoing elective percutaneous coronary intervention (PCI).A total of 540 patients aged ≥ 75 years who had undergone elective PCI between January 2012 and December 2015 were enrolled in this study. Admission NT-proBNP levels were measured before PCI. CI-AKI was defined as a relative increase in serum creatinine (SCr) of ≥50%, or an absolute increase of ≥ 0.3 mg/dL, occurring within 48 hours after contrast medium exposure. The predictive value of NT-proBNP for predicting CI-AKI was assessed by receiver operating characteristic (ROC) and multivariable logistic regression analysis.A total of 54 (10.0%) patients developed CI-AKI. The best cutoff value of NT-pro-BNP for detecting CI-AKI was 1133 pg/mL with 66.7% sensitivity and 70.8% specificity according to the ROC analysis (C statistic = 0.719; 95% CI, 0.679-0.756). Multivariable analysis demonstrated that Lg-NT-proBNP is significantly related to CI-AKI (odds ratio [OR] = 3.892; 95% CI, 1.996-7.590; P < 0.001). Cox regression analysis showed that Lg-NT-proBNP is associated with long-term mortality (adjusted hazard ratio [HR] = 2.158; 95% CI, 1.246-3.740; P = 0.006) during follow-up.Pre-procedural NT-proBNP is a significant and independent predictor of CI-AKI and long-term mortality in elderly patients following elective PCI, and the best cutoff point for predicting CI-AKI was 1133 pg/mL.