B-Type Natriuretic Peptide is Predictive of Postoperative Events in Orthopedic Surgery

Background: Clinical assessment is not always sufficient to predict postoperative (PO) cardiac complications. B-type natriuretic peptide (BNP) has an important prognostic value in patients with heart failure. Its value as a predictor of events in orthopedic surgeries has not yet been tested. Objective: To assess the value of BNP in predicting cardiac complications in the PO period of orthopedic surgeries. Methods: A total of 208 patients undergoing surgical treatment of femur fracture and hip or knee arthroplasty were prospectively evaluated. Of these, 149 (71.6%) were women and the mean age was 72.6 +/- 8.8 years. In the preoperative period, the patients underwent conventional clinical assessment and their surgical risk was estimated according to the American Society of Anesthesiologists' (ASA) classification. BNP was determined in the preoperative period, and its ability to predict PO cardiac events (death; acute myocardial infarction; unstable angina; atrial fibrillation; ventricular tachycardia; or heart failure) was analyzed using multivariate logistic regression analysis. Results: Seventeen patients (8.0%) experienced cardiac events. Median BNP was significantly higher in these patients in comparison to those without cardiac events (93 [interquartile range 73-424] vs 26.6 [13.2-53.1], p = 0.0001). BNP was the main independent predictor of events (p = 0.01). The ASA classification was not an independent predictor. Analysis of the ROC curve demonstrated that for a cut-off point of 60 pg/ml, BNP showed sensitivity of 76.0% and specificity of 79.0% in the prediction of events, with an area under the curve of 83.0%. Conclusion: BNP is an independent predictor of PO cardiac events in orthopedic surgeries. (Arq Bras Cardiol 2010;95(6):743-748)