The diagnostic significance of NT-proBNP and troponin I in emergency department patients presenting with palpitations

OBJECTIVE This prospective study investigated the diagnostic significance of the N-terminal pro-brain natriuretic (NT-proBNP) and troponin I peptides in emergency department patients presenting with palpitations. METHODS Two groups of patients with palpitations but without documented supraventricular tachycardia were compared: a group with supraventricular tachycardia (n = 49) and a control group (n = 47). Both groups were diagnosed using electrophysiological studies during the study period. Blood samples were obtained from all of the patients to determine the NT-proBNP and troponin I levels within the first hour following arrival in the emergency department. RESULT The mean NT-proBNP levels were 207.74±197.11 in supraventricular tachyarrhythmia group and 39.99±32.83 pg/mL in control group (p<0.001). To predict supraventricular tachycardia, the optimum NT-proBNP threshold was 61.15 pg/mL, as defined by the receiver operating characteristic (ROC) curve, with a non-significant area under the ROC curve of 0.920 (95% CI, 0.86-0.97, p<0.001). The NT-proBNP cut-off for diagnosing supraventricular tachycardia had 81.6% sensitivity and 91.5% specificity. Supraventricular tachycardia was significantly more frequent in the patients with NT-proBNP levels ≥61.15 pg/mL (n = 44, 90.9%, p>0.001). The mean troponin I levels were 0.17±0.56 and 0.01±0.06 pg/mL for the patients with and without supraventricular tachycardia, respectively (p<0.05). Of the 96 patients, 21 (21.87%) had troponin I levels ≥0.01: 2 (4.25%) in the control group and 19 (38.77%) in the supraventricular tachycardia group (p<0.001). CONCLUSION Troponin I and, in particular, NT-proBNP peptide were helpful for differentiating supraventricular tachycardia from non- supraventricular tachycardia palpitations. Further randomized, large, multicenter trials are needed to define the benefit and diagnostic role of NT-proBNP and troponin I in the management algorithm of patients presenting with palpitations in emergency departments.