B-type natriuretic peptide vs. cardiac risk scores for prediction of outcome following major orthopedic surgery

Abstract

Aims: The clinical role of B-type natriuretic peptide (BNP) in preoperative evaluation is not clear. We designed a prospective study to investigate the predictive value of BNP in comparison with established clinical risk scores for the outcome of major orthopedic surgery.

Methods: Overall 242 elderly patients [80 (74-85) years] undergoing orthopedic surgery were included. Inhospital cardiovascular events and 1-year mortality were the main endpoints.

Results: In total 20 (8.3%) patients had major cardiovascular events (MACE) and 41 (21.1%) died in 1 year. Logistic regression analysis for prediction of cardiac events and 1-year mortality, respectively, revealed a significant prognostic value for the BNP (P < 0.001 and P = 0.041), Goldman (P = 0.013 and P = 0.003), Lee (P = 0.022 and P = 0.200), Detsky (P < 0.001 and P < 0.001), and functional capacity indices (P = 0.034 and P = 0.001). BNP cutoff 149 ng/ml improved discrimination of all scores to predict MACE, and BNP cutoff 89 ng/ml improved discrimination of all scores to predict 1-year mortality (Net Reclassification Improvement, P values < 0.05 in all cases). Age [hazard ratio (HR): 1.100, 95% confidence interval (CI): 1.039-1.166, P = 0.001] and BNP (HR: 1.002, 95% CI: 1.000-1.003, P = 0.041) were independent associates of 1-year mortality.

Conclusion: Preoperative levels of BNP compare favorably with the Goldman, Lee, Detsky, and functional capacity indices for prognosis of orthopedic surgery. Implementation of natriuretic peptides in cardiac risk scores is promising.