The aim of the study is to sample SN before and after catheter ablation (CA) for atrial fibrillation (Afib) to predict the recurrence after CA. Also, the uric acid/albumin ratio will be assessed as a marker of Afib recurrence. Since the uric acid/albumin ratio has been shown to be predictive of Afib in patients with myocardial infarction moreover incidence of atrial fibrillation is higher in patients with gout. As a side branch marker for silent brain injury, neuron-specific enolase (NSE) and protein S100B will be evaluated. NSE showed in small trials a significant increase after catheter ablation, as well as S100B. The prognostic power is not clear yet. From the systematic review, the most powerful predictors seem to be N-terminal (NT)-prohormone B-type natriuretic peptide (NT-Pro-BNP/BNP), high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6) and Carboxy-terminal telopeptide of collagen type I. Biomarkers are divided into 3 main types: congestion, inflammation, and renal function.~Patients will be enrolled before catheter ablation/electrical cardioversion for Afib after signing IS, and the blood sampling will be performed the day before and the day after catheter ablation. In the electric cardioversion arm, the blood sampling will be performed before electrical cardioversion and 2h after the cardioversion before discharge.~Patients will be followed for recurrency - all patients will have a 24-hour ECG Holter and External loop recorder (MDT) for two weeks after the three months of the blanking period. Clinical outpatient control will ensue in the 4th, eighth,12, and 24 months.
Secretoneurin (SN) is a neuropeptide from the chromogranin family that influences intracellular calcium handling. SN suppresses calcium leakage from the sarcoplasmic reticulum through the ryanodine receptor. SN is a novel biomarker that has shown the potential to predict adverse arrhythmic events.