Randomized comparison of contact force-guided versus conventional circumferential pulmonary vein isolation of atrial fibrillation: prevalence, characteristics, and predictors of electrical reconnections and clinical outcomes
We prospectively investigated the differences in pulmonary vein reconnections (PVRs) and clinical outcomes between contact force (CF)-guided and conventional circumferential PV isolation (CPVI) of atrial fibrillation (AF). One hundred twenty consecutive AF patients (63 ± 10 years; 88 males) undergoing an initial CPVI were randomized to ablation with a target CF of 20 g (CF group; n = 60) or that with operators blinded to the CF information (blind group; n = 60). The CF group had fewer PVRs (0.67 ± 0.91/patient vs. 1.16 ± 1.16/patient; P = 0.007), a lower incidence of persistent PVRs (13.2 vs. 41.2 %; P < 0.001), and a shorter procedural time for the CPVI (50 vs. 56 min; P = 0.019) than the blind group. The mean CF was higher in the CF group than the blind group (18.0 vs. 16.1 g; P < 0.001), with the most significant difference observed along the posterior right-sided PVs (P-RPVs) and anterior left-sided PVs (A-LPVs). In logistic regression models, the mean CF was a negative predictor of PVRs along the P-RPVs and A-LPVs in the blind group (odds ratios, 0.728 and 0.786; P < 0.001 and 0.007), while no significant predictor was identified in the CF group or elsewhere in the blind group. In the Kaplan-Meier analysis, the arrhythmia-free survival rate at 12 months was 89.9 % in the CF group and 88.2 % in the blind group, respectively (P = 0.624). CF-guided CPVI can reduce PVRs and the procedural time and be particularly beneficial along regions where a relatively low CF tends to be applied: the P-RPVs and A-LPVs. The comparable clinical outcomes may be due to the learning curve effect obtained by the CF-guided technique and repeated provocation of dormant PV conduction.