Abstract 164: Diagnostic and Prognostic Value of the B-Type Natriuretic Peptide in Elderly Patients with Suspected Heart Failure in the Emergency Room
Background Few studies have been performed concerning the B-type natriuretic peptide (BNP) in the elderly population, but it is used as a diagnostic and prognostic factor of heart failure (HF). This study seeks to evaluate its value and accuracy as a biomarker in elderly patients with suspected HF.
Methods Retrospective Cohort Study. From March 2003 to November 2008, 318 ptients with suspected HF were evaluated. The overall number of patients evaluated included 224 who met the inclusion criteria at the age of 60 years or over. A BNP dosage was performed using the POCT Biosite method, and the Framingham score was used as gold standard. For all patients, one and two-dimensional Doppler echocardiography and chest X-ray were performed. Clinical data on the patients were obtained from the records. In order to adjust accuracy in subgroups with specific clinical characteristics, a multivariate analysis was done with logistic regression, and also in the analysis of risk of mortality.
Results BNP presented an AUC (0.93) (CI 0.88 to 0.97), Sensitivity (S) (74) and Specifity (E) (88.9), Positive Predictive Value (PPV) (95.5), Negative Predictive Value (NPV) (52.2). The stratified analyses of the BMI>30 subgroup presented S (54.1), NPV (46.9) and median BNP of 217; in the subgroup Endogenous Creatinine Clearance (ECC) < 30: E (0.75), NPV (75) and median of BNP, 944; subgroup > 80 years, Area Under the Curve (AUC) (0.94), S (83.1), E (90.5) and median BNP of 453. Mean time of survival (30, 180 and more than 180 days): 27 months for the systolic heart failure (SHF) group, 52 months for the Heart Failure with Preserved Ejection Fraction (HFPEF) group; at the end of the study over 50% of the group - non HF (NHF) had survived. Median BNP (gold standard): 595 pg/mL for the SHF group, 369 pg/mL for the HFPEF group and 38 pg/mL for NHF. Once the study was ended, 70 deaths were recorded in the group above the age of 60 years and 99 from the initial sample.
Conclusions BNP presented significant accuracy for the diagnosis of HF in patients 60 years or older, in the emergency room, and remained an independent predictor of mortality when fitted according to individual parameters. It is suggested that a formula be modeled to fit the cutoff point of BNP in order to increase its accuracy.
- © 2012 by American Heart Association, Inc.