Abstract 4045: The Diagnostic and Prognostic Value of NT-proBNP in Diabetic Patients with Dyspnea: A ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) Sub-study
Background: Patients with diabetes mellitus (DM) are at increased risk for heart failure (HF) and structural heart disease, even in the absence of HF. The utility of amino-terminal pro-brain natriuretic peptide (NT-proBNP) for diagnostic evaluation in this population is unknown. We assessed the diagnostic and prognostic utility of NT-proBNP for the evaluation of dyspneic subjects with and without DM.
Methods: The PRIDE study enrolled 599 dyspneic subjects in an urban emergency department to examine the utility of NT-proBNP (Elecsys® proBNP, Roche Diagnostics, Indianapolis, IN) measurement. A diagnosis of DM was established based on presenting history, hospital records, or both. The diagnosis of HF was determined by blinded study physicians using available hospital records. Vital status was assessed at 1 year.
Results: Of 599 subjects, 157 (26.2%) were diabetic; DM was an independent risk factor for acute HF (OR=2.97, 95% CI=1.5–5.7). In those with HF, median concentrations of NT-proBNP were similar in subjects with and without DM (4784 vs 3382 pg/ml, P=0.934). In dyspneic subjects without HF, median concentrations of NT-proBNP were significantly higher in those with DM than in those without (242 vs 115 pg/ml, P=0.01). However, these differences were no longer significant after adjusting for covariates known to influence peptide levels such as age or renal function. ROC analysis of NT-proBNP for the diagnosis of acute HF in diabetic subjects demonstrated an area under the curve of 0.95. Using age-adjusted cut-points NT-proBNP was 92% sensitive and 90% specific for the diagnosis of acute HF in diabetic subjects, while a cut-point of 300 pg/ml had a negative predictive value (NPV) of 95%. At a cut-point of 986 pg/ml, NT-proBNP was 82% sensitive and 51% specific for prediction of mortality at 1 year in diabetic subjects, with a 93% NPV. NT-proBNP ≥986 pg/ml was the strongest predictor of one-year death among dyspneic diabetic subjects (HR=3.42; 95% CI=1.1–10.7).
Conclusion: NT-proBNP is valuable for the diagnostic and prognostic evaluation of diabetic subjects with dyspnea.