No abstract

Background: The efficacy of cryoballoon pulmonary vein isolation (Cryo-PVI) is equivalent to that of radiofrequency pulmonary vein isolation in patients with paroxysmal atrial fibrillation (AF). We aimed to compare the efficacy and safety profile of Cryo-PVI and high-power, short-duration (HPSD) radiofrequency catheter ablation (RFCA) in patients with AF. Methods: We prospectively randomized 314 patients with paroxysmal AF (men, 71.3%; 59.9±10.9 years old) to either the Cryo-PVI group (n=156) or HPSD-RFCA group (n=158). Cavotricuspid isthmus ablation and linear ablation from the superior vena cava to the right atrial septum in addition to pulmonary vein isolation were carried out in the majority of patients in the HPSD-RFCA group. The primary end point was AF recurrence after a single procedure; secondary end points were the recurrence pattern, cardioversion rate, follow-up heart rate variability, and response to antiarrhythmic drugs. Results: After a mean follow-up of 9.8±5.1 months, the clinical recurrence rate did not significantly differ between the two groups (log-rank P =0.840). The rate of recurrence as atrial tachycardia ( P >0.999), cardioversion ( P =0.999), and 3-month heart rate variability (high frequency; P =0.506) did not significantly differ. During the final follow-up, sinus rhythm was maintained without antiarrhythmic drugs in 70.5% of the Cryo-PVI group and 73.4% of the HPSD-RFCA group ( P =0.567). No significant difference was found in the major complication rate between the two groups (3.8% versus 0.6%; P =0.066), but total procedure time was significantly shorter in the Cryo-PVI group (78.5±20.2 versus 124.5±37.1 minutes; P <0.001). Conclusions: In patients with paroxysmal AF, the Cryo-PVI is an effective rhythm-control strategy with a shorter procedure time compared with the HPSD-RFCA. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03920917.

Background: Although myocardial thickness is an important variable for therapeutic catheter ablation of cardiac arrhythmias, quantification of wall thickness has been overlooked. We developed a software (AMBER) that measures 3D-myocardial thickness using a cardiac computed tomogram (CT) image, verified its accuracy, and tested its clinical feasibility. Methods: We generated 3D-thickness maps by calculating wall thickness (WT) from the CT images of 120 patients' hearts and a 3D-phantom model (PhM). The initial vector field of the Laplace equation was oriented to calculate WT with the field lines derived from the 3D mesh. We demonstrate the robustness of the Laplace WT algorithm by comparing with the real thickness of 3D-PhM, echocardiographically measured left ventricular (LV) WT, and regional left atrial (LA) WT reported from previous studies. We conducted a pilot case of catheter ablation for atrial fibrillation (AF) utilizing real-time LAWT map-guided radiofrequency (RF) energy titration. Results: AMBER 3D-WT had excellent correlations with the real thickness of the PhM (R = 0.968, p < 0.001) and echocardiographically measured LVWT in 10 patients (R = 0.656, p = 0.007). AMBER 3D-LAWT (n = 120) showed a relatively good match with 12 previously reported regional LAWT. We successfully conducted pilot AF ablation utilizing AMBER 3D-LAWT map-guided real-time RF energy titration. Conclusion: We developed and verified an AMBER 3D-cardiac thickness map measured by cardiac CT images for LAWT and LVWT, and tested its feasibility for RF energy titration during clinical catheter ablation.

Introduction: Whereas, high-power short-duration (HPSD) radiofrequency (RF) ablation is generally used in atrial fibrillation (AF) catheter ablation (CA), its efficacy, safety, and influence on autonomic function have not been well established in a large population. This study compared HPSD-AFCA and conventional power (ConvP)-AFCA in propensity score matched-population.Methods: In 3,045 consecutive patients who underwent AFCA, this study included 1,260 patients (73.9% male, 59 ± 10 years old, 58.2% paroxysmal type) after propensity score matching: 315 in 50~60W HPSD group vs. 945 in the ConvP group. This study investigated the procedural factors, complication rate, rhythm status, and 3-month heart rate variability (HRV) between the two groups and subgroups.Results: Procedure time was considerably short in the HPSD group (135 min in HPSD vs. 181 min in ConvP, p &lt; 0.001) compared to ConvP group, but there was no significant difference in the complication rate (2.9% in HPSD vs. 3.7% in ConvP, p = 0.477) and the 3-month HRV between the two groups. At the one-year follow-up, there was no significant difference in rhythm outcomes between the two groups (Overall, Log-rank p = 0.885; anti-arrhythmic drug free, Log-rank p = 0.673). These efficacy and safety outcomes were consistently similar irrespective of the AF type or ablation lesion set. The Cox regression analysis showed that the left atrium volume index estimated by computed tomography (HR 1.01 [1.00–1.02]), p = 0.003) and extra-pulmonary vein triggers (HR 1.59 [1.03–2.44], p = 0.036) were independently associated with one-year clinical recurrence, whereas the HPSD ablation was not (HR 1.03 [0.73–1.44], p = 0.887).Conclusion: HPSD-AFCA notably reduced the procedure time with similar rhythm outcomes, complication rate, and influence on autonomic function as ConvP-AFCA, irrespective of the AF type or ablation lesion set.

Background: Clinical recurrence after atrial fibrillation catheter ablation (AFCA) still remains high in patients with persistent AF (PeAF). We investigated whether an extra-pulmonary vein (PV) ablation targeting the dominant frequency (DF) extracted from electroanatomical map–integrated AF computational modeling improves the AFCA rhythm outcome in patients with PeAF.Methods: In this open-label, randomized, multi-center, controlled trial, 170 patients with PeAF were randomized at a 1:1 ratio to the computational modeling-guided virtual DF (V-DF) ablation and empirical PV isolation (E-PVI) groups. We generated a virtual dominant frequency (DF) map based on the atrial substrate map obtained during the clinical AF ablation procedure using computational modeling. This simulation was possible within the time of the PVI procedure. V-DF group underwent extra-PV V-DF ablation in addition to PVI, but DF information was not notified to the operators from the core lab in the E-PVI group.Results: After a mean follow-up period of 16.3 ± 5.3 months, the clinical recurrence rate was significantly lower in the V-DF than with E-PVI group (P = 0.018, log-rank). Recurrences appearing as atrial tachycardias (P = 0.145) and the cardioversion rates (P = 0.362) did not significantly differ between the groups. At the final follow-up, sinus rhythm was maintained without any AADs in 74.7% in the V-DF group and 48.2% in the E-PVI group (P &lt; 0.001). No significant difference was found in the major complication rates (P = 0.489) or total procedure time (P = 0.513) between the groups. The V-DF ablation was independently associated with a reduced AF recurrence after AFCA [hazard ratio: 0.51 (95% confidence interval: 0.30–0.88); P = 0.016].Conclusions: The computational modeling-guided V-DF ablation improved the rhythm outcome of AFCA in patients with PeAF.Clinical Trial Registration: Clinical Research Information Service, CRIS identifier: KCT0003613.