Predictive Value of N-Terminal Pro B-Type Natriuretic Peptide for Short-Term Outcome of Cardioversion in Patients with First-Diagnosed or Paroxysmal Atrial Fibrillation Presenting to the Emergency Department

<b>Background</b>: Atrial fibrillation (AF) is a common arrhythmia in the emergency department (ED). We investigated the role of N-terminal pro b-type natriuretic peptide (NT-proBNP) in predicting both the outcome of AF cardioversion and the risk of AF recurrence or persistence on the 8th (D8) and 30th (D30) day post-cardioversion. <b>Methods</b>: This prospective, observational study evaluated patients with recent-onset AF, managed by either pharmacological (PC) or electrical cardioversion (EC) in the ED. Patients were treated either immediately or electively after 3 weeks of anticoagulation. NT-proBNP assessments were performed prior to cardioversion. <b>Results</b>: Of the 148 patients enrolled, 56% had paroxysmal AF, 85% underwent immediate cardioversion and 72% received EC. Successful cardioversion to sinus rhythm (SR) was achieved in 85% of patients. Patients with successful cardioversion and those who remained free from AF on D8 had lower NT-proBNP levels compared to patients with failed cardioversion or with AF recurrence or persistence on D8 [day of cardioversion, D0: SR vs. non-SR, 387 (127-1095) pg/mL vs. 1262 (595-2295), <i>p</i> = 0.004; D8: SR vs. non-SR, 370 (127-1095) vs. 1366 (718-2295), <i>p</i> = 0.002]. In multivariate analysis, higher logNT-proBNP was associated with higher risk of cardioversion failure [OR, 95%CI: 4.80 (1.58-14.55), <i>p</i> = 0.006] and AF recurrence or persistence on D8 [OR, 95%CI: 3.65 (1.06-12.59), <i>p</i> = 0.041]. ROC analysis confirmed the predictive ability of NT-proBNP for both outcomes (D0: AUC 0.735, <i>p</i> < 0.001; D8: AUC 0.761, <i>p</i> < 0.001). A cut-off value of NT-proBNP > 580 pg/mL was able to predict failure of AF conversion and occurrence of recurrent/persistent AF at D8. <b>Conclusions</b>: NT-proBNP is a promising biomarker for identifying patients presenting to the ED with recent-onset AF who run a greater risk of cardioversion failure and post-discharge AF recurrence/persistence in the immediate and short term.