Long-term outcome
During 100±28 months of follow-up, the LINE-group had superior arrhythmia-free survival after the index ablation compared to the EGM-group (Logrank test: P=0.0001, Figure 1A ). SR maintenance was consistently higher in the LINE-group compared to the EGM-group (LINE-group vs. ECG-group; year 1: 79% vs. 42%; year 3: 63% vs. 31%; year 5: 60% vs. 25%; year 8: 54% vs. 19%). AA recurrence subtypes were similar between the LINE-group vs. EGM-groups (LINE-group vs. ECG-group; AF-only recurrence: 11 [46%] vs. 28 [66%]; AT-only: 5 [21%] vs. 7 [17%]; AF and AT 8 [33%] vs. 7 [17%], p=0.21 Figure 2 ). In addition, the pattern of AF recurrence was comparable between the two groups (LINE-group vs. ECG-group; PsAF recurrence 8 [42%] vs. 15 [44%], p=1.00).
Among 24 (46%) and 42 (81%) patients of AAs recurrence in LINE and EGM-group, 24 (100%) and 34 (81%) of patients underwent the re-do procedures with 1.6±0.7 and 2.0±1.0 procedures (p=0.02). In LINE-group, mean number of reconnected PVs were 2.8±0.9 PVs/patient, and reconnection of roof and MI lines was observed in 9 (38%) and 13 (54%) patients during the second procedure. All reconnected PVs were successfully re-isolated and bidirectional block was established across all lines. EGM-guided ablation was added in 7 (29%) patients. In EGM-group, all reconnected PVs (2.9±0.9 PVs/patient) were also successfully re-isolated, and additional roof and MI lines were created in 24 (71%) and 27 (79%) patients during the second procedure. Non-PV foci, (including SVC in a subset) were detected in 21 (36%) patients. The incidence of non-PV triggers was comparable between the two groups (LINE-group vs. EGM-group: 8 [36%] vs. 13 [38%], p=0.92). However, multiple ATs were more frequently induced during the second procedure in EGM-group (LINE-group vs. EGM-group: 7 [21%] vs. 0 [0%], p=0.03). After taking multiple procedures into account (1.8±0.9 procedures), 66/104 (63%) maintained SR in this population. AAs-free survival was remained significantly higher in LINE-group as compared to EGM-group after the last procedure (LINE-group vs. EGM-group: year 1: 96% vs. 88%; year 3: 92% vs. 71%; year 5: 83% vs. 62%; year 8: logrank test: 88% vs. 65%, p=0.045, Figure 1B ). In addition, fewer CA procedures were required to maintain SR in the LINE-group as compared to EGM-group (1.6±0.7 vs. 2.0±1.0, p=0.02).