The role of NT-proBNP in the diagnostics and differentiation of cardiac and reflex syncope in adults: relative importance to clinical presentation and medical examinations.

Purpose: The aim of this study was to assess the clinical significance of N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations in the differentiation of patients with cardiac and reflex syncope.
Methods: The study included a group of 100 patients (56 women, 44 men), aged 18-77 years (mean 52.6 ± 16.7), with a history of reflex (group I) or cardiac syncope (group II). Diagnosis of syncope was performed according to the European Society of Cardiology (ESC) guidelines. In all patients, the concentration of NT-proBNP was measured.
Results: The assessment of NT-proBNP concentrations showed significantly higher concentrations in group II than in group I (448.7 ± 212.2 vs. 68.2 ± 64.1 pg/ml, P<0.0001). The receiver operating characteristic (ROC) curve analysis revealed that the concentration of NT-proBNP at 210.5 pg/ml may be a useful cut-off point which allows the prediction of cardiac syncope with 98 % specificity, 94 % sensitivity, and 94 % negative predictive value. In patients with cardiac arrhythmias and conduction abnormalities, the concentrations of NT-proBNP were higher in comparison to those without such disorders.
Conclusions: The concentration of NT-proBNP is useful in the diagnosis of syncope and may initially guide the diagnostic process. The NT-proBNP value exceeding 200 pg/ml seems to be the most rational in determining cardiac syncope.