Preoperative N-terminal pro-B-type natriuretic peptide for prediction of acute kidney injury after non-cardiac surgery: A retrospective cohort study

2020 pre-print withdrawn
Acute kidney injury (AKI) is associated with poor outcomes after non-cardiac surgery. Whether preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) predicts AKI after non-cardiac surgery is unclear. Methods We conducted a retrospective study on patients whose NT-proBNP concentrations were measured before non-cardiac surgery at a tertiary academic hospital between 2008 and 2018. Multivariable logistic regression was used to investigate the predictive role of preoperative NT-proBNP
more » ... postoperative AKI defined by the Kidney Disease: Improving Global Outcomes creatinine criteria. Results Some 6.1% (444 of 7248) of patients developed AKI within 1 week after surgery. Preoperative NT-proBNP was an independent predictor of AKI after adjustment for clinical variables (odd ratio comparing top to bottom quintiles 2.29, 95% confidence interval [CI] 1.47-3.65, p<0.001 for trend; odd ratio per 1-unit increment in natural log transformed NT-proBNP 1.27, 95% CI 1.16-1.39). Compared with clinical variables alone, the addition of NT-proBNP modestly improved the discrimination (change in area under the curve from 0.764 to 0.773, p=0.005) and reclassification (continuous net reclassification improvement 0.210, 95% CI 0.111-0.308; integrated discrimination improvement 0.0044, 95% CI 0.0016-0.0072) of AKI and non-AKI cases. Conclusions Preoperative NT-proBNP concentrations provided predictive information for AKI in a cohort of patients undergoing non-cardiac surgery, independent of and incremental to conventional risk factors. Prospective studies are required to confirm this finding and examine its clinical impact. Background Acute kidney injury (AKI) is a common and important complication in patients undergoing non-cardiac surgery. A systematic review reported a 13.4% pooled incidence of AKI following major abdominal surgery [1] . Similar incidences were reported in orthopaedic and thoracic surgery [2, 3] . Postoperative increases in serum creatinine have been associated with increased morbidity, mortality, length of hospital stay and health care costs [2, 4-6], even those not meeting the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines consensus criteria for AKI diagnosis [7] . Early identification of patients at high risk of postoperative AKI is a prerequisite for developing strategies to ameliorate or prevent perioperative renal injury. In the past decade, several preoperative risk prediction models for AKI following non-cardiac surgery were developed [2, [8] [9] [10] [11] [12] [13] . These models are all based solely on conventional clinical and laboratory-based variables. Recent studies have associated cardiac biomarkers B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) with risk of AKI in several medical settings [14] [15] [16] [17] [18] and in cardiac surgery [19] . Moreover, natriuretic peptides are established and guideline-recommended biomarkers for perioperative cardiovascular risk assessment in patients with elevated baseline risks undergoing non-cardiac surgery [20] [21] [22] [23] [24] [25] . However, whether preoperative NT-proBNP could help to predict postoperative AKI in these patients is less clear. Considering the complex interactions between cardiac and renal dysfunction [26], we hypothesised that preoperative NT-proBNP could be associated with the development of AKI after mixed types of non-cardiac surgery and could improve AKI prediction beyond conventional clinical risk factors. This study aims to test the hypothesis to provide evidence for the use of NT-proBNP in assessing AKI risk before non-cardiac surgery. Methods This retrospective cohort study was conducted in Southern Medical University Nanfang Hospital, a tertiary academic hospital in Guangzhou, China. The institutional review board
doi:10.21203/rs.2.23625/v1 fatcat:pfhqdbvmz5ekdo5xjgsqvzckm4