P6252Diagnostic and prognostic accuracy of preoperative NT-proBNP added to revised cardiac risk index in elderly patients with hip fracture

Abstract

Abstract Background The identification of patients at highest risk after surgery for hip fracture could be of clinical value to implement post-operative actions to lessen mortality. We sought to investigate the utility of Revised Cardiac Risk Index (RCRI) and NT-proBNP in this scenario. Methods Patients older than 75 years with hip fracture treated with surgery were prospectively included. The end-point was overall mortality at 30 days. Results We enrolled 410 patients surgically-treated for hip fracture, 31 (7.6%) died during the 30-day follow-up. Patients who died were 3.5 years older (95% CI 1.3 to 5.6); p=0.001, and had a lower prevalence of diabetes mellitus.The prevalence of heart failure was more prevalent among patients who died: difference of proportions 35.7% (95% CI 16.0 to 55.3); p<0.001 and more patients were not in sinus rhythm with a difference of 25.4% (95% CI 5.6 to 45.1); p<0.001. Adding NT-proBNP to a logistic regression model with RCRI as an independent variable, improved the diagnostic and prognostic metrics, with significant changes in specificity (0.59 vs 0.70, p<0.001) and predictive values: positive likelihood ratio (LR) 1.89 vs 2.49, p<0.001, negative LR 0.38 vs 0.33, p<0.001. The C-statistic (0.69 vs 0.77, p=0.002) and the net reclassification improvement were also improved. Conclusion Adding preoperative NT-proBNP to RCRI to appraise the risk of overall 30-day mortality rate after hip surgery improves the prediction accuracy of RCRI alone.