Cooling down or moving on - acute systemic inflammatory response across contemporary catheter ablation procedures for atrial fibrillation

Introduction

Pulmonary vein isolation (PVI) is an established rhythm control strategy for atrial fibrillation (AF). Different energy sources may induce variable peri-procedural inflammatory responses, the clinical relevance of which remains insufficiently defined.

Purpose

This study aimed to compare peri-procedural inflammatory response between pulsed field ablation (PFA) and cryoballoon ablation (CBA) using validated inflammatory indices.

Methods

In this single-center registry, patients with paroxysmal or persistent AF undergoing first-time PVI between July 2022 and January 2025 were included. Venous blood samples were collected at admission and on the morning after the procedure. The following biomarkers were assessed pre- and post-procedure: systemic immune-inflammation index (SII), systemic inflammation response index (SIRI), aggregate index of systemic inflammation (AISI), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), and inflammation score (INFLA). High-sensitivity troponin I (hsTnI) was measured as a marker of myocardial injury.

Results

A total of 175 patients were included (median age 64 years, IQR 56–69; 63% male; 64% paroxysmal AF). PFA was performed in 103 patients and CBA in 72. Baseline characteristics were comparable, except for a higher prevalence of paroxysmal AF in the CBA group (p=0.001), and more frequent history of heart failure and beta-blocker therapy in the PFA group (p=0.001).

Post-procedural analysis showed a significant rise in inflammatory biomarkers in the CBA group: SII (p<0.001), SIRI (p=0.022), AISI (p=0.011), NLR (p<0.001), PLR (p=0.009), and INFLA score (p=0.009), while MLR did not reach statistical significance (p=0.168). After adjustment for baseline values, SII and NLR remained significantly higher in the CBA group (SII: PFA median 592.3 [IQR 451–895] vs. CBA median 797.2 [IQR 619.5–1099], p=0.001; NLR: PFA 3.30 [IQR 2.5–4.6] vs. CBA 3.9 [IQR 3.1–5.1], p=0.001). SIRI and AISI showed a trend toward lower values with PFA, whereas PLR, MLR, and INFLA score showed no consistent differences. Post-procedural hsTnI levels differed significantly between groups, being higher in the PFA group (PFA 5673 ng/L [IQR 3798–8672] vs. CBA 5385 ng/L [IQR 3962–6729], p=0.042). No significant differences in inflammatory indices or hsTnI were observed among different PFA systems.

Conclusion

The acute systemic inflammatory response appears more pronounced after CBA compared with PFA, particularly reflected by SII and NLR changes. Further studies are needed to determine whether these differences translate into clinically meaningful outcomes, including long-term AF recurrence.Study population baseline characteristics