RESUMO
OBJECTIVES: To investigate whether admission B-type natriuretic peptide levels predict the development of acute kidney injury in acute coronary syndromes. DESIGN: Prospective study. SETTING: Single-center study, 13-bed intensive cardiac care unit at a University Cardiological Center. PATIENTS: Six-hundred thirty-nine acute coronary syndromes patients undergoing emergency and urgent percutaneous coronary intervention. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We measured B-type natriuretic peptide at hospital admission in acute coronary syndromes patients (55% ST-elevation myocardial infarction and 45% non-ST-elevation myocardial infarction). Acute kidney injury was classified according to the Acute Kidney Injury Network criteria: stage 1 was defined as a serum creatinine increase greater than or equal to 0.3 mg/dL from baseline; stage 2 as a serum creatinine increase greater than two- to three-fold from baseline; stage 3 as a serum creatinine increase greater than three-fold from baseline, or greater than or equal to 4.0 mg/dL with an acute increase greater than 0.5 mg/dL, or need for renal replacement therapy. Acute kidney injury was developed in 85 patients (13%) and had a higher in-hospital mortality than patients without acute kidney injury (14% vs 1%; p < 0.001). B-type natriuretic peptide levels were higher in acute kidney injury patients than in those without acute kidney injury (264 [112-957] vs 98 [44-271] pg/mL; p < 0.001) and showed a significant gradient according to acute kidney injury severity (224 [96-660] pg/mL in stage 1 and 939 [124-1,650] pg/mL in stage 2-3 acute kidney injury; p < 0.001). The risk of developing acute kidney injury increased in parallel with B-type natriuretic peptide quartiles (5%, 9%, 15%, and 24%, respectively; p < 0.001). When B-type natriuretic peptide was evaluated, in terms of capacity to predict acute kidney injury, the area under the curve was 0.702 (95% CI, 0.642-0.762). CONCLUSIONS: In patients hospitalized with acute coronary syndromes, B-type natriuretic peptide levels measured at admission are associated with acute kidney injury as well as its severity.