Effect of recombinant human brain natriuretic peptide on acute kidney injury after coronary artery bypass grafting: a retrospective comparative cohort study

BACKGROUND: Acute kidney injury (AKI) is a common complication of coronary artery bypass grafting (CABG) that results in worse prognosis. Studies have shown that recombinant human brain natriuretic peptide (rh-BNP) reduces renal injury. However, its treatment effects for AKI in patients underwent cardiac surgery are unclear. This study sought to explore the efficacy of rh-BNP in patients with AKI after bypass surgery. METHODS: This study included patients with AKI diagnosed within 4 days after CABG during the period January 2016 to December 2020. AKI was defined according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria. The clinical characteristics and outcomes were collected. Patients were divided into BNP and non-BNP groups according to whether rh-BNP was injected intravenously after the operation. Multivariable logistic regression was adjusted the confounding effects between clinical characteristics and rh-BNP. Propensity score matching (PSM) was used to perform a sensitivity analysis. RESULTS: A total of 395 patients, including 56 and 339 patients in the BNP and non-BNP groups, respectively, were included in this study. The decreasing trend of postoperative serum creatinine levels (P<0.001) and postoperative urine volume (P=0.001) within 4 days of surgery were independent associated with rh-BNP. From PSM, 175 patients, including 44 and 131 patients in the BNP and non-BNP groups, respectively, were included in this study. The decreasing trend of postoperative serum creatinine levels in the BNP group was significantly stronger than that in the non-BNP group (0.04±0.28 vs. −0.16±0.36, P=0.001). The postoperative urine volume within 4 days of surgery of the BNP group was higher than that of the non-BNP group (11.3±2.8 vs. 9.11±2.66, P<0.001). The cumulative dosage of diuretics after the procedure did not differ between the BNP and non-BNP groups {60 [40, 80] vs. 60 [40, 120], P=0.852}. CONCLUSIONS: Rh-BNP can reduce creatinine levels and increases postoperative urine volume to improve renal function in patients.