The role of ProBNP in differentiation of cardiogenic and non-cardiogenic syncope: A diagnostic accuracy study

Objective: The significance of diagnosing the root reason for syncope and taking therequired preventive or treatment measures cannot be overlooked when it comes tooutcome prediction. This study endeavors to examine the role of proBNP in differentiatingcardiogenic and non-cardiogenic syncope in patients presenting to the emergencydepartment (ED).Methods: We prospectively performed a cross-sectional study on patients presentingwith acute syncope. All the patients for this investigation were followed up until thedefinite cause of their syncope (cardiac or non-cardiac) was diagnosed and the screeningperformance characteristics of proBNP in differentiation of cardiogenic and noncardiogenic syncope were evaluated.Results: Three hundred patients with syncope were studied (۶۴.۷% male). In the end,the cause of syncope was determined to be cardiogenic in ۱۳۳ cases (۴۴.۳%). The areaunder the ROC curve of proBNP in the differentiation of cardiogenic syncope from noncardiogenic was estimated to be ۷۸.۹ (۹۵% CI: ۷۳.۵ – ۸۴.۳). The optimal cut-off point forproBNP in this regard was ۱۴۳.۵ pg/mL point. Sensitivity, specificity, positive and negativepredictive values, and positive and negative likelihood ratios of proBNP in the mentionedcut-off point were ۷۵.۳۹% (۹۵% CI: ۶۷.۶۱–۸۲.۷۳), ۷۵.۴۴% (۹۵% CI: ۶۸.۰۷–۸۱.۶۲), ۷۱.۱۲%(۹۵% CI: ۶۲.۸۲–۷۸.۲۶), ۷۹.۷۴% (۹۵% CI: ۷۲.۴۶–۸۵.۵۴), ۲.۴۶ (۹۵% CI: ۱.۸۶–۳.۲۵), and ۰.۲۵(۹۵% CI: ۰.۱۸–۰.۳۴), respectively.Conclusion: The accuracy of proBNP in differentiation of cardiogenic and non-cardiogenicsyncope is fair. ProBNP concentration equals to or higher than ۱۴۳.۵ pg/mL can differentiatecardiogenic syncope from non-cardiogenic with ۷۵% sensitivity and ۷۶% specificity. Itseems that its use for this purpose should be considered with caution and along with othertools

Keywords:

Syncope , Causality , Pro-brain natriuretic peptide , Heart failure , Emergency medicine , Diagnosis