Perioperative NT pro BNP can predict severe postoperative complications in elderly patients undergoing noncardiac surgery

Abstract

To develop a predictive model based on the perioperative plasma concentration of amino-terminal pro-brain natriuretic peptide (NT-pro BNP) in elderly patients to assess the risk of severe postoperative complications. Elderly patients (age ≥ 65 years) enrolled in this prospective observational study underwent general surgery. Plasma NT-Pro BNP concentration was measured before surgery and 2 h after surgery. Univariate and multivariate logistic regression analyses were used to identify the significant predictors. To evaluate the model performance, we applied the receiver operating characteristic (ROC) curve, Hosmer-Lemeshow test, and decision curve analysis (DCA) to evaluate the net clinical benefit. Prediction model was visualised by drawing nomogram and establishing web calculator. A total of 174 elderly patients were enrolled; 15 patients (8.6%) developed severe complications. The area under the ROC curve, sensitivity, and specificity of the two prediction models were 0.899 (95% CI 0.845-0.940), 86.67%, 91.82%, 0.956 (95% CI 0.902-0.985), 100%, and 81.42%, respectively. The net benefit of the post-model was higher than pre-model. We established two postoperative severe complication assessment models based on perioperative NT-Pro BNP levels for elderly patients with reliable accuracy. The nomogram and web calculator will be easy to use by clinicians and other researchers.Clinical significance: The biomarker, NT-pro BNP seem to correlate with some postoperative complications, however no studies have evaluated its relationship with severe postoperative complications in elderly patients. In this study, we evaluated the relationship between NT-pro BNP and severe postoperative complications in elderly patients, and established a prediction model and a web calculator based on the prediction model. Clinicians can easily use this prediction model to identify high-risk patients at an early stage.

Keywords: Amino-terminal pro-brain natriuretic peptide; Elderly patients; Nomogram; Postoperative complications; Prediction model; Web calculator.

Fig. 1

The diagram of flow chart.

Fig. 2

The result of DCA between Pre-model and Post-model. The sloping thin grey line is the net benefit of treating all men whether or not undergoing postoperative severe complication; the green line is the net benefit of treating men on the predicting of the Pre-model; the red line is the net benefit of treating men on the predicting of Post-model; the horizontal thick black line is the net benefit of treating no man. The DCA demonstrated that the Pre-model achieved higher clinical net benefit under the decision threshold probability lower than 0.3 compared to Post-model. In contrast, Post-model had a higher clinical net benefit when the decision threshold probability was greater than 0.3. DCA: decision curve analysis; NT-Pro BNP: N-terminal pro-B-type natriuretic peptide; Pre-model: the model based on preoperative NT-Pro BNP; Post-model: the model based on postoperative NT-Pro BNP.

Fig. 3

Nomogram (A) and ROC (B) of Pre-model and the web calculator (C). A: Through drawing a vertical line from corresponding variable to the top line (Points), the score of every variable and total score can be got. The predicted probability can be obtain by drawing a vertical line form the total points line to the bottom risk line. C In the web calculator developed by us, directly input the value of the corresponding variable on the left side, the result of prediction probability and 95% confidence interval will be output on the right side. ROC: receiver operating characteristic curve; ASA-PS: American Society of Anesthesiologists Physical Status; NT-Pro BNP: N-terminal pro-B-type natriuretic peptide; Pre-model: the model based on preoperative NT-Pro BNP.

Fig. 4

Nomogram (A) and ROC (B) of Pre-model and the web calculator (C). A: Through drawing a vertical line from corresponding variable to the top line (Points line), the score of every variable and total score can be got. The predicted probability can be obtain by drawing a vertical line form the total points line to the bottom risk line. C: In the web calculator developed by us, directly input the value of the corresponding variable on the left side, the result of prediction probability and 95% confidence interval will be output on the right side. ROC: receiver operating characteristic curve; ASA-PS: American Society of Anesthesiologists Physical Status; NT-Pro BNP: N-terminal pro-B-type natriuretic peptide; Post-model: the model based on postoperative NT-Pro BNP.