RESULTS

Patients’ clinical and echocardiographic characteristics

Patients’ clinical and echocardiographic characteristics are shown per group in Table 1. The mean duration of AF was 6 months, and mean LAD was 41 mm in both groups. Only the type of AADs used was found to differ significantly between the 2 groups, with Class III or IV AADs given more frequently to patients in the CBA group than to patients in the HBA group.

Patients’ electrophysiologic characteristics and details of the ablation procedures

Patients’ electrophysiologic characteristics and the procedure-related details are shown per group in Table 2. Complete PVI was achieved in all cases. AF termination occurred significantly less frequently during HBA than during CBA (19 [24%] vs. 31 [39%], P = 0.04). The energy application times were equivalent for the superior PVs, but for the inferior PVs, the energy application time was shorter in the HBA group than in the CBA group (LIPV: 145 ± 17 vs. 162 ± 28 seconds,P < 0.001; RIPV: 145 ± 17 vs. 162 ± 28 seconds,P <0.001). Touch-up RF applications were required to complete the PVI in 15 (19%) patients in the HBA group and 12 patients (15%) in the CBA group (P = 0.52), and a significant between-group difference was found in some sites requiring touch-up, with energy applications needed at the LSPV in 12 (15%) patients in the HBA group and at the RIPV in 5 (6%) patients in the CBA group. CTI ablation was performed significantly more often after CBA than after HBA (32 [41%] vs. 9 [11%], P < 0.001). No patient received additional LA substrate ablation targeting fractionated electrograms or low-voltage areas. There was no significant between-group difference in the procedure time.

ISAs

Representative voltage maps displaying ISAs achieved by HBA and by CBA are shown in Figure 3. As shown in Table 2, the total IASA + pLAWSA did not differ significantly between the HBA group and CBA group (42.2 ± 9.5 cm2 vs. 42.5 ± 11.5 cm2, P = 0.83). However, the total IASA after HBA was significantly larger than that after CBA (26.3 ± 11.0 cm2 vs. 21.4 ± 7.0 cm2, P < 0.001). Thus, the ISA after HBA was greater than that after CBA (61 ± 16% vs. 51 ± 12%, P< 0.001). Distribution of the ISAs resulting from each of the balloon systems is shown in Figure 4.

Complications

Periprocedural complications are shown per group in Table 3. The number of patients who suffered a complication did not differ significantly between the HBA group and CBA group (3 [4%] vs. 1 [1%],P = 0.62). Pericardial tamponade, pericarditis, and aspiration pneumonia occurred in 1 patient each in the HBA group, but all 3 patients recovered within 2 weeks after the procedure. Phrenic nerve paralysis occurred in 1 patient in the CBA group, and this resolved within 2 months after the procedure. There was no periprocedural death in either group.

Post-ablation antiarrhythmic therapies and outcomes, per study group

Post-ablation antiarrhythmic therapies and outcomes are shown in Table 4. Twenty-four (30%) HBA and 34 (43%) CBA patients were given 1 or more AADs after the procedure (P = 0.10). There was no between-group difference in the number of patients given a class I drug (2 [3%] vs. 7 [9%], respectively; P = 0.17), class III (amiodarone) drug (4 [5%] vs. 1 [1%], respectively; P = 0.17), or class IV (bepridil) drug (20 [25%] vs. 29 [37%], respectively; P = 0.12). beta-blockers were given to more patients in the CBA group than in the HBA group (23 [29%] vs. 6 [8%], respectively; P < 0.001).
During the median follow-up period of 18 (13, 26) months, 8 patients (10%) in the HBA group and 12 patients (15%) in the CBA group experienced AF recurrence (P = 0.34). Atrial tachycardia (AT) was observed in 1 patient (1%) in the HBA group and 2 patients (3%) in the CBA group. Kaplan-Meier curves for freedom from AF/AT recurrence are shown in Figure 5. Freedom from AF/AT recurrence was similar between patients who underwent HBA and those who underwent CBA (P = 0.69). AF/AT recurrence did not differ statistically between the HBA group and CBA group during the during the first 18 months after the procedure (11% vs. 18%, respectively, at 18 months; P = 0.26). None of the clinical or procedure-related variables were found to predict AF recurrence.