Baseline characteristics and procedural data
During the study period, 644 patients underwent AF/AT ablation procedures in our two centres, and 253 of them were performed with the Rhythmiaâ„¢ system. Seven patients were lost to follow-up. Finally, 246 patients were included, 135 of them (54.9%) constituted the HF group (Figure 1). In the HF group, 62 patients had preserved LVEF (46.3%), and 72 (53.7%) had reduced LVEF. One patient was excluded from subgroup analysis due to missing LVEF data.
The procedures were performed mostly in men (71.5%) with a median age of 64 years old (56-69). The clinical characteristics are detailed in Table 1. As expected, patients in the HF group had more comorbidities and were more symptomatic. Arrhythmias were also unequally distributed between the groups; AT and persistent AF were more frequent in the HF group, whereas 20% of the patients in the non-HF group had paroxysmal AF (p=0.005). The majority of the patients had already undergone a previous CA (59.3%) with no difference between groups. Patients with HF had more frequent history of non-PVI and non cavo-tricuspid isthmus ablation (p=0.04).
Procedures in the HF group were longer (p=0.01), with longer fluoroscopy duration (p<0.001), higher fluoroscopy dose (p<0.001), more maps (p=0.017), and longer mapping time (p<0.001), compared to procedures in the non-HF group. Conversely, the number of recorded electrograms (p=0.714), the RF duration (p=0.118), and the volume of infused serum (p=0.623) did not differ between the groups. A total of 285 ATs were analysed, including those occurring during ablation of persistent AF. Most of them were macro-reentries (58.9%) while the mechanism of 33 ATs remained undetermined (12.3%), with no difference between groups.