Autonomic imbalance and structural remodeling predict recurrence after AF ablation: prospective analysis combining HRV and clinical parameters

Background

Predictors of atrial fibrillation (AF) recurrence after catheter ablation remain incompletely understood. While structural atrial remodeling is a recognized determinant of outcome, the contribution of pre-procedural autonomic nervous system activity has not been fully clarified. We aimed to evaluate whether autonomic imbalance assessed by heart rate variability (HRV), together with clinical and echocardiographic parameters, predicts arrhythmia recurrence after AF ablation.

Methods

This prospective single-center study included consecutive patients undergoing first-time AF ablation between November 2022 and December 2024. Clinical characteristics, echocardiographic parameters, and procedural data were collected prospectively.

A 5-minute pre-procedural ECG recording obtained in sinus rhythm was analyzed using Kubios HRV software. HRV assessment included time-domain, frequency-domain, and nonlinear indices derived from normal-to-normal RR intervals after exclusion of ectopic beats.

The primary endpoint was AF recurrence during 12-month follow-up, assessed by outpatient visits and ECG Holter monitoring. Predictors were analyzed using univariate logistic regression followed by LASSO-regularized multivariable modeling. Model discrimination was assessed using receiver operating characteristic (ROC) analysis.

Results

A total of 484 patients were included in the clinical cohort, with HRV analysis available in 187 patients. Patients with AF recurrence were older and demonstrated greater structural remodeling, reflected mainly by larger left atrial diameter.

Significant differences in autonomic parameters were observed between groups. Patients with recurrence demonstrated lower heart rate compared with patients maintaining sinus rhythm. Frequency-domain analysis showed lower LF/HF ratio in patients with recurrence, indicating a shift toward increased parasympathetic modulation. Nonlinear HRV indices, including SD2/SD1 ratio and HF power in normalized units (HFnu), were also significantly associated with recurrence.

In multivariable analysis combining clinical and HRV parameters, incorporation of the time-domain HRV parameter RMSSD, reflecting short-term vagally mediated variability, improved model performance. The final LASSO-derived model demonstrated good discriminatory ability for prediction of recurrence (AUC = 0.76).

Conclusion

AF recurrence after catheter ablation is associated with both structural atrial remodeling and pre-procedural autonomic imbalance. HRV-derived markers, particularly RMSSD reflecting parasympathetic modulation, provide incremental predictive value beyond conventional clinical parameters. Integration of autonomic and structural characteristics may improve pre-procedural risk stratification and patient selection for AF ablation.AUC