Impact of continuous ECG monitoring after catheter ablation of persistent atrial fibrillation in patients with left ventricular systolic dysfunction - long term results from a single-centre registry

Abstract Background Catheter ablation of atrial fibrillation (AFCA) has emerged as standard treatment in patients (pts) with heart failure (HF) and left ventricular systolic dysfunction (LVSD). However, contribution of AF to LVSD (AF-mediated cardiomyopathy) varies significantly across the diverse HF population. Identifying patients who are most likely to benefit from AFCA and optimizing treatment strategies still remain a clinical challenge. Purpose To determine the impact of continuous ECG monitoring on the long-term outcomes of AFCA in pts with persistent AF and LVSD, and to assess independent predictors of echocardiographic response to AFCA. Methods Consecutive pts with LVSD who underwent catheter ablation of persistent AF and concomitant implantable loop recorder insertion for continuous ECG monitoring between January 2016 and February 2022 were included for analysis if they met the following criteria: i) LVEF<50% in sinus rhythm at predischarge echocardiographic examination; and ii) echocardiographic follow-up (FU) of at least 12 months. Pts were followed for AF recurrence (>30s episode occurring after 90-day blanking period), AF burden and change in LVEF at 12 months. Response to AFCA was defined as an improvement of LVEF by ≥10% or recovery of LVEF during FU. Results A total of 160 pts (65±11 years; 21% female) were included and followed for a median of 36.2 (IQR 18.6-49.6) months. The mean baseline LVEF was 36±8%, 98% of pts had persistent AF, 17% of pts required repeated AFCA. At 12-month FU, LVEF improved to 46±10% (p<0.001), 102 pts (64%) responded to AFCA. Ninety pts (56%) presented with LVEF improvement ≥10%, 76 pts (48%) with LVEF normalization. The median absolute change in LVEF from baseline was overall +9.9% (IQR 1.8 to 17.0%), +15.9% (IQR 10.0 to 20.0%) in the responder vs. -1.1% (IQR -4.8 to 3.8%) in the non-responder group (p=0.027). The overall AF recurrence rate was 29.4% and the median AF burden 6.6% (IQR 3.7 to 9.5%) at 12-month post-AFCA. Compared to non-responders, responders had a significantly lower AF recurrence rate (23.5 vs. 39.7%; p=0.025) and AF burden (3.8 vs. 12.0%; p=0.030). They were significantly younger (63 vs. 68 years; p=0.005), had less frequent structural heart disease (37% vs. 64%; p=0.001) and a shorter history of HF (1.5 vs. 2.9 years; p=0.050). Absence of previous HF hospitalization (OR 0.652; 95% CI 0.411 - 0.923; p=0.014) and median AF burden (OR 0.971; 95% CI 0.960 – 0.994; p=0.021) predicted echocardiographic response to AFCA. Conclusion Persistent AF frequently causes or contributes to LVSD. Rhythm control with AFCA results in significant improvement of LV systolic function, particularly in younger pts without underlying structural heart disease. Long-term continuous ECG monitoring is key to determine AF burden, which showed to be an independent predictor of echocardiographic response to AFCA in our study cohort.Definition of the study group Baseline characteristics