Pulmonary vein isolation with a pulsed field system leads to lower levels of miR-23a-3p in the left atrial blood compared to a cryoballoon.

Atrial fibrillation (AF) is the most common arrhythmic disease in humans, with its incidence rising over the past decade. Novel treatment options for AF include pulsed field ablation (PFA) of the pulmonary veins through electroporation. While this technique is thought to be less damaging to surrounding tissue, the acute effects of PFA on the atrium are only incompletely understood. An analysis of circulating microRNAs (miRs) potentially released by local tissue damage due to PFA, in comparison to other standard ablation procedures, has not yet been performed. Small RNA sequencing analysis was performed on left atrial blood samples from four patients after PFA and five patients after cryoballoon ablation (CBA). In this pilot analysis, 154 miRs were stably detected across all samples. The expression of the two miRs with the lowest p-values was validated in 20 PFA cases versus 25 CBA cases via real-time PCR. We found hsa-miR-23a-3p to be significantly less abundant in plasma in the left atrium after PFA compared to CBA. The circulating miR signature in the left atrium is differentially affected by PFA compared to CBA. This finding potentially influences the use of miRs as biomarkers for prediction of outcomes after ablation.