B-type natriuretic peptide and risk of contrast-induced acute kidney injury in acute ST-segment-elevation myocardial infarction: a substudy from the HORIZONS-AMI trial.

BACKGROUND Contrast-induced acute kidney injury (CI-AKI) after percutaneous coronary intervention is associated with adverse short- and long-term outcomes. However, identification of patients at risk for CI-AKI is challenging. Using a large contemporary randomized trial database of patients with ST-segment-elevation myocardial infarction, we therefore sought to examine whether admission B-type natriuretic peptide (BNP) levels predict the development of CI-AKI. METHODS AND RESULTS A total of 979 ST-segment-elevation myocardial infarction patients enrolled in the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial had BNP levels measured in the emergency room prior to primary percutaneous coronary intervention as part of the study protocol. CI-AKI was defined as a relative increase in serum creatinine of ≥25%, or an absolute increase of ≥0.5 mg/dL, occurring within 48 hours after contrast administration. Logistic regression analysis was used to estimate the association of admission BNP with development of CI-AKI. CI-AKI occurred in 131 patients (13.3%). Baseline BNP was a significant univariable correlate of CI-AKI (odds ratio 1.31, 95% confidence interval, 1.14-1.51; P=0.0001). After multivariable adjustment for clinical, laboratory, and angiographic variables, BNP remained a significant independent predictor of CI-AKI (1.29 [1.10, 1.51]; P<0.001). Significant net reclassification improvement was achieved by addition of BNP to the current clinical risk prediction model (net reclassification improvement=0.177; P<0.001) and to the Mehran Risk Score (net reclassification improvement=0.100; P=0.015). CONCLUSIONS Measurement of serum BNP at hospital admission may help identify patients who are at risk for developing CI-AKI after primary percutaneous coronary intervention in ST-segment-elevation myocardial infarction. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00433966.