Diagnostic value of cardiac troponin I and N-terminal pro-B-Type Natriuretic Peptide in cardiac syncope

Objective
The study aims to evaluate the diagnostic accuracy of Cardiac Troponin I(cTnI) and N-terminal pro-B-Type Natriuretic Peptide (NT-proBNP) for identifying patients with cardiac syncope.

Methods
This is a prospective, single-center cohort study of patients presenting with syncope hospitalized from June 21,2018 to May 30, 2019. The Evaluation of Guidelines in Syncope Study (EGSYS), a syncope-specific diagnostic score, was used for diagnostic comparator.

Results
A total of 118 patients were enrolled (mean age: 69.1 ​± ​12.3 years, 40% female). Compared to patients with reflex, orthostatic, or unexplained syncope, patients adjudicated to have cardiac syncope showed significantly higher cTnI and NT-proBNP plasma concentrations (p ​< ​0.001 for each comparison). The area under the curve (AUC) of cTnI and NT-proBNP were moderate-to-good [0.77–0.78; 95% confidence interval (CI) 0.66–0.86], and was similar to that of EGSYS (0.71, 95%CI 0.60–0.80). Incorporation of cTnI and/or NT-proBNP into the existing EGSYS score significantly improved the diagnostic accuracy (EGSYS ​+ ​cTnI: AUC 0.83; 95%CI 0.74–0.90; EGSYS ​+ ​NT-proBNP: AUC 0.81; 95%CI 0.71–0.89; EGSYS ​+ ​cTnI ​+ ​NT-proBNP: AUC 0.83; 95%CI 0.73–0.90).

Conclusions
The cTnI and NT-proBNP levels were significantly higher in patients adjudicated to have cardiac syncope and the addition of both biomarkers to the EGSYS score significantly improved the diagnostic value for cardiac syncope.