# Secretoneurin plasma levels are decreased after catheter ablation for atrial fibrillation—patients with AF produce lower SN levels than healthy individuals: the SAFE registry

## TL;DR

This study found that patients with atrial fibrillation have lower levels of a neuropeptide called secretoneurin compared to healthy individuals, and these levels drop further after ablation, possibly predicting recurrence.

## Contribution

The study is the first to show that post-ablation secretoneurin levels correlate with atrial fibrillation recurrence.

## Key findings

- Plasma secretoneurin levels decreased after catheter ablation for atrial fibrillation.
- Lower postprocedural secretoneurin levels were associated with AF recurrence.
- Secretoneurin levels in AF patients were lower than in healthy individuals.

## Abstract

Secretoneurin (SN) is a neuropeptide that counterbalances disorders of cell calcium cycling via calmodulin and thus may be involved in arrhythmogenesis. We aimed to associate plasma standard biomarkers and SN levels before, during, and after catheter ablation for atrial fibrillation (AF) with various clinical and paraclinical variables, foremost AF recurrence.

We prospectively enrolled consecutive patients undergoing catheter ablation for AF in University Hospital Ostrava between March 2023 and January 2024. SN was analyzed from venous, left atrial, and coronary sinus blood with the ELISA method. Plasma SN levels were compared before, during, and after ablation and with those of healthy individuals, with nonparametric tests. ClinicalTrials.gov ID: NCT05794464.

A total of 137 patients (64% males, age 63 ± 11) and 34 healthy individuals (38% males, mean age 31 ± 7.1) were included in the analysis. Plasma SN levels were significantly lower after the catheter ablation as compared with SN levels before (34.0 ± 15.1 and 40.0 ± 17.3 pmol/L, p = 0.032). Healthy individuals produced higher plasma SN levels (50.7 ± 15.3 pmol/L) as compared with those in patients with AF both before and after catheter ablation (p = 0.0068, p < 0.001). Furthermore, lower postprocedural levels of SN were associated with AF recurrence (p = 0.035). The C-statistic for SN after the procedure to separate presence or absence of AF recurrence was 0.65 with bootstrap 95% CI 0.5–0.8. Of note, SN after the procedure correlated with plasma NT-proBNP levels (p < 0.001). PFA caused greater myocardial damage than did RFA (p < 0.001); inflammatory markers were increased post procedurally in both the RFA and the PFA group. Subclinical intravascular hemolysis occurred in the PFA group.

Plasma secretoneurin levels are decreased after catheter ablation for atrial fibrillation; patients with AF produce lower SN levels than healthy individuals. Lower postprocedural levels of SN are associated with AF recurrences.