Acute Pulmonary Vein Isolation Rate Research Articles

Left Atrial Posterior Wall Isolation with Pulsed Field Ablation in Persistent Atrial Fibrillation.

Left atrial posterior wall isolation (LAPWI) may improve rhythm control in addition to pulmonary vein isolation (PVI) in persistent atrial fibrillation (persAF) patients undergoing catheter ablation (CA). However, LAPWI may be challenging when using thermal energy sources. This study aimed to investigate the efficacy and safety of LAPWI performed by non-thermal pulsed field ablation (PFA) in CA for persAF. Consecutive persAF patients from two German centers were prospectively enrolled. There were two study cohorts: (1) the LAPWI cohort, which included PFA-guided (re-)PVI with LAPWI for first-time and/or repeat ablation procedures; and (2) a comparative persAF cohort with a PFA PVI-only approach without LAPWI for first-time ablation within the same timeframe. Patients were followed up by routine Holter ECGs. In total, 79 persistent AF patients were included in the study: 59/79 patients were enrolled in the LAPWI cohort, including 16/59 index (27%) and 43/59 repeat ablation procedures (73%). Sixteen patients (16/79; 21%) were in the PVI-only cohort without LAPWI. Of the patients treated with LAPWI, procedure time and fluoroscopy time was 91 ± 30 min and 15 ± 7 min, respectively. The acute PVI rate was 100% in all first-time ablation patients (32 patients (16 PVI only, 16 PVI plus LAPWI), 196/196 PVs). Of the 43 re-do patients in the LAPWI cohort, re-PVI was necessary in 33% (14/43) of patients (27 PVs; 1.9 PV per-patient); in 67% (29/43), all PVs were isolated, and antral ablation of the PV ostia was performed in 48% (14/29). LAPWI was performed successfully in all 59 (100%) patients of the LAPWI cohort. Two minor complications occurred. No esophageal lesion was detected in the LAPWI cohort (n = 33/59 (56%) patients underwent endoscopy). After 354 ± 197 days of follow-up, freedom from atrial arrhythmias was 79.3% (95-CI: 62-95%) in the complete LAPWI cohort (n = 14/59 (24%) on AAD: class Ic n = 9, class III n = 5). There was no difference regarding acute procedural and clinical outcome compared to the PVI-only cohort. LAPWI guided by PFA is feasible and safe in patients undergoing CA for persAF and shows favorable outcomes. In the context of durable PVI, PFA-guided LAPWI may be an effective adjunctive treatment option.

Pulsed field ablation based pulmonary vein isolation utilizing a simplified approach

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) is a novel non-thermal energy source with promising safety and efficacy advantages compared to standard ablation technologies. Purpose We aimed to develop a safe, effective and fast pulmonary vein isolation (PVI) utilizing a single shot PFA catheter via a single femoral vein puncture and a venous closure system approach. Methods Forty-eight consecutive AF patients underwent first-time PVI via PFA under deep sedation. A single ultrasound guided femoral vein puncture and a single transseptal puncture was utilized for left atrial access. After pulmonary vein (PV) angiography eight pulse trains (2kV/2.5 sec, bipolar, biphasic, each 4x basket/flower configuration) were delivered to each PV. Extra pulse trains in the flower configuration (8x) were added to the posterior wall for very wide antral circumferential ablation (vWACA). Continuous intraluminal esophageal temperature (TESO) was monitored with a s-shaped esophageal temperature probe. A venous closure system was utilized on the single access site. A Donati suture was performed. The pressure bandage was removed after 1h. Results Patients (mean age: 64 +/-11 years) presented with AF (paroxysmal 58% or persistent AF (42%). A total of 192 PV were identified and isolated via PFA (100%). A mean of 40 pulse trains for PVI and vWACA have been used. The mean procedural time was 27 +/- 7 minutes, the mean catheter dwell time was 14 +/- 6 minutes and the median fluoroscopy time was 6 +/- 2 minutes. No relevant esophagus temperature rise occurred. One patient (2%) experienced a transient phrenic nerve palsy which recovered until the end of the procedure. Two patients (4%) experienced a superficial bleeding which was treated by a figure of eight suture. No severed hematoma, transfusion or intervention was necessary. No pericardial effusion or tamponade occurred. Conclusion The combination of a single vein single transseptal puncture approach resulted in a 100% rate of acute PVI and an extraordinary fast procedure and dwell time. The rate of periprocedural complications was low.

Six-month follow-up after pulmonary vein isolation using pulsed field ablation for paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) has recently been introduced as a novel routine ablation technology for paroxysmal atrial fibrillation (PAF). Only a few small clinical studies have been published on the mid- and long-term outcome. Herein, we present the six-month clinical outcomes of PFA in PAF. Methods In PAF patients, PVI in conscious sedation using a steerable sheath and a pentaspline over-the-wire basket and flower PFA catheter was performed. In a subset of patients, pre- and post-ablation high-density bipolar voltage 3D maps (Carto 3D) were performed. Procedural parameters, acute success, in-hospital safety and arrhythmia recurrence were assessed over 6-month follow-up. Efficacy was evaluated by freedom from a ≥ 30-sec. recurrence of AF/atrial flutter (AFL)/atrial tachycardia (AT). Follow-up included 7-day Holter ECGs and/or telephonic interviews at days 90 and 180 after ablation. Results his study included a total of 108 patients (mean age: 65±10 years; 44% female). Mean CHA2DS2-VASc-score was 2,3±1,7. Median duration since first AF diagnosis was 21 [IQR: 3 to 58] months. Pre- and post-ablation high-density maps were performed in 36/108 (33%) of patients. Skin-to skin procedure time was 78±35 min. Fluoroscopy time and dosis area product were 19±7 min and 5,56±4,64 Gy.cm2, respectively. Left atrial dwell time of the PFA catheter was 27±11 min. Acute pulmonary vein isolation rate was 100% of PVs using PFA only. Primary adverse events occurred in 3.7% of patients (1 groin hematoma, 2 pericardial tamponades, 1 stroke with lethal outcome). Five patients were lost to FU. During a mean FU of 205±84 days, 81 of 103 patients (79%) remained free of any symptomatic or documented AF/AFL/AT episode after a single procedure. In 22 (21%) patients at least one episode of AF/AFL/AT was documented. In 6/22 (27%) patients, a re-do procedure was performed. In 2/6 (33%) patients, a reconduction of the PVs (1 LIPV, 1 posterior carina on both sides) was seen. In the remaining 4/6 (67%) patients, during re-do procedure typical or atypical flutter was treated, in presence of durable PV isolation. Conclusions PVI using PFA results in a reasonable 6-month atrial arrhythmia recurrence rate and safety profile. The success rate may be reduced due to the long duration since first AF diagnosis. PV reconduction rate during re-do procedure was 33% in a limited number of patients.

Safety and efficacy of pulmonary vein isolation using pulsed field ablation with or without 3D mapping system for paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) has recently been introduced as a novel routine ablation technology for paroxysmal atrial fibrillation (PAF). PFA can be performed "cryo-style" using fluoroscopy only, or additional pre- and post-ablation high-density 3D bipolar voltage maps can be performed to assess lesion formation and acute pulmonary vein isolation. We compared 6-month outcome after PFA using fluoroscopy only (X-ray) vs. PFA guided by 3D mapping (3D). Methods In PAF patients, PVI in conscious sedation using a steerable sheath and a pentaspline over-the-wire basket and flower PFA catheter was performed. In a subset of patients, pre- and post-ablation high-density bipolar voltage 3D maps (Carto 3D) were performed. Procedural parameters, acute success, in-hospital safety and arrhythmia recurrence were assessed over 6-month follow-up. Efficacy was evaluated by freedom from a ≥ 30-sec. recurrence of AF/atrial flutter (AFL)/atrial tachycardia (AT). Follow-up included 7-day Holter ECGs and/or telephonic interviews at days 90 and 180 after ablation. Results This study included a total of 101 patients (mean age: 65±10 years; 42% female) in whom 6-month follow-up data were available. There were no selection criteria for the use of 3D mapping. Pre- and post-ablation high-density maps were performed in 34/101 (34%) of patients. Mean CHA2DS2-VASc-score was 2,1±1,6. Median duration since first AF diagnosis was 21 [3-60] months. Skin-to skin procedure time was 56±20 in the X-ray group vs. 118±22 min in the 3D group, respectively (p<0,0001). Fluoroscopy time was 17±7 in the X-ray group vs. 21±6 in the 3D group, respectively (p<0,01). Acute pulmonary vein isolation rate was 100% in both groups. Primary adverse events occurred in 0% of patients in the X-ray group vs. 2/34 (6%) in the 3D group (2 pericardial tamponades), respectively (p=ns). During a mean follow-up of 204±82 days, 54/67 (81%) in the X-ray group vs. 27/34 (79%) in the 3D group remained free of any symptomatic or documented AF/AFL/AT episode after a single procedure (p=ns). In 4/13 (31%) patients in the X-ray group, a re-do procedure was performed, 2 patients had durable PVI with typical or atypical atrial flutter, 1 patient had reconnection of both posterior carinae and 1 patient had typical atrial flutter degenerating in AF. In 3/7 (43%) patients in the 3D group, a re-do procedure was performed, 2 patients had durable PVI with typical or atypical atrial flutter and 1 patient had reconnection of the LIPV. Conclusions PVI using PFA with or without 3D mapping system resulted in a similar 6-month atrial arrhythmia recurrence rate and safety profile. Procedure and fluoroscopy times were significantly shorter in the fluoroscopy only group.

Differences in acute outcomes and complications of pulmonary vein isolation using pulsed field ablation with or without 3D mapping system for paroxysmal atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed field ablation (PFA) has recently been introduced as a novel routine ablation technology for paroxysmal atrial fibrillation (PAF). It is also used as off-label therapy for persistent AF. PFA can be performed "cryo-style" using fluoroscopy only, or additional pre- and post-ablation high-density 3D bipolar voltage maps can be performed to assess lesion formation and acute pulmonary vein isolation. We compared acute outcome after PFA using fluoroscopy only (X-ray) vs. PFA guided by 3D mapping (3D). Methods In patients with AF, PVI in conscious sedation using a steerable sheath and a pentaspline over-the-wire basket and flower PFA catheter was performed. In a subset of patients, pre- and post-ablation high-density bipolar voltage 3D maps (Carto 3D) were performed. Procedural parameters, acute success and in-hospital safety were assessed. Results A total of 4 operators treated 218 patients (mean age 66 years (range 35–86), female 43%, mean BMI 28 kg/m2 (range 20-42), mean CHA2DS2-VaSc score of 2,5 (range 0-7), first-time ablation 93%, paroxysmal AF/persistent AF/re-do 72/21/7%). Mean duration since first AF diagnosis was 42 months (range 1-336). Most procedures were performed under deep conscious sedation without intubation (99%). There were no selection criteria for the use of 3D mapping. Pre- and post-ablation high-density maps were performed in 28% of cases. Skin-to skin procedure time was 54±22 in the X-ray group vs. 123±35 min in the 3D group, respectively (p<0,0001). Fluoroscopy time was 17±7 in the X-ray group vs. 20±6 in the 3D group, respectively (p<0,01). Acute pulmonary vein isolation rate was 100% in both groups. There were no phrenic nerve palsies or esophageal complications. Major complications (3,7%) were pericardial tamponade (2,8%) and stroke (0,9%); one stroke resulted in death (0,5%). They occurred in 3,2% of patients in the X-ray group (3 pericardial tamponades, 2 strokes) vs. 4,8% in the 3D group (3 pericardial tamponades), respectively (p=ns). Minor complications (1,4%) were vascular (0,5%) and transient ischemic attack (TIA) (0,9%). Conclusions In a large, single center cohort of unselected patients, PVI using PFA with or without 3D mapping system resulted in a similar acute outcome and safety profile. Procedure and fluoroscopy times were significantly shorter in the fluoroscopy only group. There were no PFA-specific complications, but the frequency of catheter complications in this relatively old patient population demonstrates that there is still room for improvement.

PO-01-035 SIX-MONTH FOLLOW-UP AFTER PULMONARY VEIN ISOLATION USING PULSED FIELD ABLATION FOR PAROXYSMAL ATRIAL FIBRILLATION

Pulsed field ablation (PFA) has recently been introduced as a novel routine ablation technology for paroxysmal atrial fibrillation (PAF). Only a few small clinical studies have been published on the mid- and long-term outcome. Here, we present the six-month clinical outcomes of PFA in PAF. In PAF patients, PVI in conscious sedation using a steerable sheath and a pentaspline over-the-wire basket and flower PFA catheter was performed. In a subset of patients, pre- and post-ablation high-density bipolar voltage 3D maps (Carto 3D) were performed. Procedural parameters, acute success, in-hospital safety and arrhythmia recurrence were assessed over 6-month follow-up. Efficacy was evaluated by freedom from a 30-sec. recurrence of AF/atrial flutter (AFL)/atrial tachycardia (AT). Follow-up included 7-day Holter ECGs and/or telephonic interviews at days 90 and 180 after ablation. This study included a total of 108 patients (mean age: 65±10 years; 44% female). Mean CHA2DS2-VASc-score was 2.3±1,7. Median duration since first AF diagnosis was 21 [IQR: 3 to 58] months. Pre- and post-ablation high-density maps were performed in 36/108 (33%) of patients. Skin-to skin procedure time was 78±35 min. Fluoroscopy time and dosis area product were 19±7 min and 5.56±4.64 Gy.cm2, respectively. Left atrial dwell time of the PFA catheter was 27±11 min. Acute pulmonary vein isolation rate was 100% of PVs using PFA only. Primary adverse events occurred in 3.7% of patients (1 groin hematoma, 2 pericardial tamponades, 1 stroke with lethal outcome). Five patients were lost to FU. During a mean FU of 205±84 days, 81 of 103 patients (79%) remained free of any symptomatic or documented AF/AFL/AT episode after a single procedure. In 22 (21%) patients at least one episode of AF/AFL/AT was documented. In 6/22 (27%) patients, a re-do procedure was performed. In 2/6 (33%) patients, a reconduction of the PVs (1 LIPV, 1 posterior carina on both sides) was seen. In the remaining 4/6 (67%) patients, during re-do procedure typical or atypical flutter was treated, in presence of durable PV isolation. PVI using PFA results in a reasonable 6-month atrial arrhythmia recurrence rate and safety profile. The success rate may be reduced due to the long duration since first AF diagnosis. PV reconduction rate during re-do procedure was 33% in a limited number of patients.

PO-02-121 IMPACT OF PULMONARY VEIN OVALITY AND OCCLUSION STATUS MEASURED BY THE NOVEL DIELECTRIC-BASED MAPPING SYSTEM ON ACUTE VEIN ISOLATION DURING CRYOBALLOON ABLATION

Cryoballoon ablation (CBA) has been widely accepted as a major technic for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF). PV anatomy is an important factor to obtain circumferential balloon adhesion that results in vein occlusion to achieve acute PVI. The KODEX-EPD (Philips, Amsterdam, Netherlands) is a dielectric-based electroanatomic mapping system that can display a panoramic (PANO) view of the left atrium and evaluate PV occlusion without other imaging modalities. Prior studies demonstrated that high PV ovality is the potential mechanism of impeding the formation of durable lesion. However, the accuracy of PV ovality assessed by KODEX-EPD system and how it influences the performance of the PV occlusion tool and acute PVI are still unknown. To assess the PV occlusion and PV ovality using the KODEX-EPD system, and to evaluate the accuracy of them and their impact on acute PVI. We enrolled 10 patients who underwent primary CBA for paroxysmal AF using KODEX-EPD system, all of them had a pre-procedural cardiac CT or MRI. Ovality index (OI) was defined as the ratio of the PV maximum diameter divided by PV minimum diameter which was measured by KODEX-EPD system under PANO view and on CT/MRI images under sagittal view. An evaluation of PV occlusion was obtained using the KODEX-EPD Occlusion Viewer and intracardiac echography on each CB-PV engagement. Single shot PVI was defined as the isolation of PV at the first freezing attempt after complete occlusion of the PV. Fifty-eight balloon-PV engagements in 39 PVs were analyzed. Consistent occlusion status between KODEX and ICE were obtained in 50 (86%) engagements [complete occlusion: 30/34 (88%), incomplete occlusion 20/24 (83%)]. The OI of PV with incomplete occlusion by KODEX is significantly larger than that with complete occlusion (2.0±0.5 vs 1.6 ±0.4. p=0.03). Representative cases are shown in Figure1A and B. Single shot PV isolation was achieved in 33 of 39 PVs (84%). All of them showed complete occlusion status in KODEX, and OI of PV with single shot isolation was significantly smaller than that without single shot isolation (1.6±0.4 vs 2.1±0.4, p=0.003). A positive correlation was found between the OI measured by KODEX and CT/MRI (Figure1C). The evaluation of PV anatomy and occlusion status using the novel dielectric-based mapping system is feasible and may facilitate CB ablation of AF. Higher PV ovality is associated with incomplete PV occlusion and lower acute PVI rate.

The Efficacy and Safety of Cryoballoon Versus Radiofrequency Ablation for the Treatment of Atrial Fibrillation: A Meta-Analysis of 15 International Randomized Trials.

The purpose of this study was to evaluate the efficacy and safety of cryoballoon versus radiofrequency ablation for the treatment of atrial fibrillation (AF) by systematically reviewing randomized controlled trials (RCTs). Databases of Pubmed, Web of science, Embase, and Cochrane Library were searched for published studies up to June 31, 2022. Only RCTs comparing the efficacy and safety of cryoballoon vs radiofrequency ablation for the treatment of AF were enrolled in meta-analysis. Fifteen RCTs characterizing 2709 patients were finally included. Meta-analysis found that cryoballoon ablation was associated with a similar proportion of patients free from AF [risk ratio (RR): 1.02; 95% confidence interval (CI): 0.93 to 1.12, P = 0.65]. Acute pulmonary vein isolation rate [RR: 1.0; 95% CI: 0.98 to 1.01, P = 0.64] and fluoroscopy time (weighted mean difference: -0.03; 95% CI: -4.35 to 4.28; P = 0.99) were not statistically significant difference. The procedure time was shorter in the cryoballoon ablation (CBA) group (weighted mean difference : -18.76; 95% CI: -27.27 to -10.25; P < 0.0001). Transient phrenic nerve palsy was uniquely observed in the CBA group (RR = 6.66; 95% CI: 2.82 to 15.7, P < 0.0001) and resolved in all during the follow-up period, total complication was similar in both groups (RR = 1.24; 95% CI: 0.86 to 1.79, P = 0.24). Although the procedure time was shorter in CBA group, the efficacy and safety were similar in each group. Compared with radiofrequency ablation for the treatment of AF, patients receiving cryoballoon ablation have similar outcomes. CBA is associated with a shorter duration of procedure.

Ablation index for pulmonary vein isolation: Inter-operator reproductibility

Atrial fibrillation (AF) ablation outcome is still operator dependent. Ablation Index (AI) is a new lesion quality marker that has demonstrated to allow acute durable pulmonary vein (PV) isolation followed by a high single-procedure arrhythmia-free survival. This prospective, multi-center study was designed to evaluate the inter-operator reproducibility of acute PV isolation guided by the AI. A total of 490 consecutive patients with paroxysmal (80.4%) and persistent (19.6%) AF underwent first time PV encircling and were divided in four study groups according to operator preference in choosing the ablation catheter (a contact force (ST) or contact force sourrounding flow (SF) catheter) and the AI setting (330 at posterior wall and 450 at anterior wall or 380 at posterior wall and 500 at anterior wall). Radiofrequency energy was delivered to produce a wide area circumferential ablation around the proximal part of each PV's ostium or around ipsilateral PVs. In all patient radiofrequency was delivered targeting interlesion distance ≤ 6 mm. Procedure (ST330 129 ± 44 min, ST380 144 ± 44 min, SF330 120 ± 72 min, SF380 125 ± 73 min, P < 0.001) and fluoroscopy time (ST330 542 ± 285 s, ST380 540 ± 416 s, SF330 257 ± 356 s, SF380 379 ± 454 s, P < 0.001) significantly differed among the four study groups, whereas the rate of first-pass PV isolation (ST330 90 ± 16%, ST380 87 ± 19%, SF330 90 ± 17 min, SF380 91 ± 15 min, P = ns) was similar. A complication was observed in 7 (1,4%) patients without any difference among the four study groups. Ablation protocol respecting strict criteria for contiguity and quality lesion results in high and comparable rate of acute PV isolation among operator with different skill performing ablation with different procedure and fluoroscopy times.

Reduction of radiation and contrast agent exposure in a cryoballoon ablation procedure with integration of electromagnetic mapping and intracardiac echocardiography: a single center experience.

Pulmonary vein isolation (PVI) with cryoballoon ablation (CBA) is routinely guided by fluoroscopy and utilizes contrast injection to ensure catheter positioning and pulmonary vein occlusion. Non-fluoroscopic imaging techniques including electromagnetic mapping (EM) and intracardiac echocardiography (ICE) have demonstrated reduced fluoroscopy times and contrast exposure. Utilization of color flow Doppler to evaluate vein occlusion with the balloon has not been evaluated as an alternative to contrast injection. In this study we evaluate the effectiveness of cryoablation guided by EM and ICE along with color Doppler to achieve PVI. We designed a retrospective cohort study comparing patients who were treated before and after implementation of EM (Carto 3, Biosense Webster) and ICE during CBA (AF Solutions, Medtronic). We analyzed patients receiving CBA with fluoroscopy plus EM and ICE (group 2; N = 24) versus fluoroscopy alone (group 1; N = 25). Procedural success was defined as freedom from atrial fibrillation or other atrial arrhythmias at 1year post ablation. Primary outcomes were radiation time and contrast exposure. Procedural success was achieved in all cases. Total fluoroscopy time was reduced from 22.4 ± 9.8min to 8.9 ± 5.1min (P < 0.001) in patients receiving CBA guided by EM and ICE. Furthermore, exposure to contrast media was significantly lower at 75.4 ± 24.1ml and 16.5 ± 21.1ml (P ≤ 0.001) in group 1 and group 2, respectively. Neither the number of required cryotherapy treatments nor procedure duration was negatively impacted by the implementation of non-fluoroscopic techniques. The 1-year success rate was identical between both groups at 72% and 79%. There was no difference in complication rates. This single-center cohort study demonstrates that CBA guided by EM and ICE can markedly reduce radiation and contrast exposure with excellent rates of acute PVI. This technique may be particularly effective in patients sensitive to intravenous contrast exposure.

Reproducibility of acute pulmonary vein isolation guided by the ablation index.

Atrial fibrillation (AF) ablation outcome is still operator dependent. Ablation Index (AI) is a new lesion quality marker that has been demonstrated to allow acute durable pulmonary vein (PV) isolation followed by a high single-procedure arrhythmia-free survival. This prospective, multicenter study was designed to evaluate the reproducibility of acute PV isolation guided by the AI. A total of 490 consecutive patients with paroxysmal (80.4%) and persistent AF underwent first time PV encircling and were divided in four study groups according to operator preference in choosing the ablation catheter (a contact force [ST] or contact force surround flow [STSF] catheter) and the AI setting (330 at posterior and 450 at anterior wall or 380 at posterior and 500 at anterior wall). Radiofrequency was delivered targeting interlesion distance ≤6mm. The rate of first-pass PV isolation (ST330 90 ± 16%, ST380 87 ± 19%, STSF330 90 ± 17%, STSF380 91 ± 15%, P=.585) was similar among the four study groups, whereas procedure (ST330 129 ± 44minutes, ST380 144 ± 44minutes, STSF330 120 ± 72minutes, STSF380 125 ± 73minutes, P < .001) and fluoroscopy time (ST330 542 ± 285 seconds, ST380 540 ± 416 seconds, STSF330 257 ± 356 seconds, STSF380 379 ± 454 seconds, P<0.001) significantly differed. The difference in the rate of first-pass isolation was not statistical different (P =.06) among the 12 operators that performed at least 15 procedures. An ablation protocol respecting strict criteria for contiguity and quality lesion results in high and comparable rate of acute PV isolation among operator performing ablation with different catheters, AI settings, procedure, and fluoroscopy times.

Second-generation cryoballoon for pulmonary vein isolation in patients with pulmonary vein abnormality: Safety, efficacy and lessons from re-ablation procedures

Second generation cryoballoon (CB) has been shown to be effective for treatment of paroxysmal and persistent atrial fibrillation (AF). However, the fixed size of the non-compliant balloon may limit its use in patients with pulmonary vein (PV) abnormalities. In this study we investigated the acute success, procedural complications and long term outcome of CB based PV isolation (PVI) in patients with PV abnormality. A total of 238 patients [64.8 ± 11.1 years; 91 paroxysmal (38.2%), 147 persistent AF (61.8%)] underwent PVI using the second generation CB without preprocedural imaging. In 43/238 (18.1%) patients PV abnormality (left common PV in 26, right middle PV in 20) was observed. All targeted veins including abnormal PVs were isolated (100%). Transient phrenic nerve palsy (PNP) occurred in one (2.3%) patient in the PV anomalous group and 6 (3.0%) in the control group (p = NS). There was no other adverse event including PV stenosis, atrio-esophageal fistula or cerebrovascular events related to the procedure. During mean follow-up of 11.8 ± 5.4 month a total of 59 patients (24.7%) had atrial tachyarrhythmia (ATA) recurrence [27 (11.3%) had AT recurrence]. In the PV anomalous group, 20/43 (46.5%) patients had ATA recurrence compared to 39/195 (20%) in the control group (p < 0.001). AT recurrence was observed in 27 (11.3) patients [11 (25.5%) in the PV anomalous group and 16 (8.2%) in controls respectively, p = 0.003]. In patients with PV abnormality CB-based AF ablation results in a similar acute PVI rate but a higher ATA recurrence rate during follow up as compared to patients without PV abnormality.

Nonfluoroscopic catheter ablation of paroxysmal atrial fibrillation.

Radiofrequency catheter ablation of atrial fibrillation (AF) is one of the most complex ablation procedures. Both patients and operators are exposed to scattered radiation. This study evaluated the safety and efficacy of intracardiac echo (ICE)-guided pulmonary vein isolation (PVI) without fluoroscopy. We retrospectively analyzed the data of 481 consecutive patients with paroxysmal AF undergoing radiofrequency PVI with the CARTO 3 system (Biosense Webster, Diamond Bar, CA, USA). ICE-guided PVI without fluoroscopy and without CT/MRI integration (Nonfluoro group) was performed for 245 patients, and conventional fluoroscopy-guided PVI (Fluoro group) was performed for 236 patients. The primary safety endpoint was the incidence of major adverse events. The primary efficacy endpoint was freedom from AF during follow-up. Secondary endpoints included procedure duration, fluoroscopy duration, and acute PVI rate. Mean procedure times between groups were similar (108.8 ± 18.2minutes in the Non-fluoro group vs 113.6 ± 26.8minutes in the Fluoro group; P=not significant [NS]). Acute PVI was achieved in all patients, with mean radiofrequency application times of 43.4 ± 7.5 and 44.4 ± 10.7minutes for the Nonfluoro and Fluoro groups, respectively (P=NS). The incidence of cardiac tamponade was 1.2% (3/245 patients) in the Nonfluoro group and 0.8% (2/236 patients) in the Fluoro group (P=NS). During 15.2 ± 4.1 months of follow-up, after a single procedure, AF recurrence was documented in 65 of 245 (26.5%) patients and 61 of 236 (25.8%) patients in the Nonfluoro and Fluoro groups, respectively (P=NS). Nonfluoroscopic ICE-guided catheter ablation of AF without prior cardiac image integration or angiography is feasible and safe. PVI without fluoroscopy did not affect procedure duration or long-term efficacy.

VP122 Cryoballoon Versus Radiofrequency Ablation For Atrial Fibrillation

INTRODUCTION:Pulmonary vein isolation (PVI) is a new effective treatment for atrial fibrillation (AF) (1). The standard of care for ablation methods using radiofrequency (RF) is time-consuming and technically challenging (2), and restricted to a few specialized centers, which causes the limited availability of ablation therapy (3). Therefore, cryoballoon (CB) ablation has been developed to shorten and simplify the procedure. The objective of this systematic literature review and meta-analysis was to compare the effectiveness of cryoballoon ablation (CBA) with radiofrequency ablation (RFA) for the treatment of AF.METHODS:We searched the Cochrane Library and PubMed from 2009 to October 2016 to screen the eligible literature according to the inclusion and exclusion criteria. The effectiveness measures were the acute pulmonary vein (PV) isolation rate, procedure time, complications and the proportion of patients free from AF (follow-up &gt; 3 months). Meta-analysis and descriptive statistics were used in this study.RESULTS:A total of seventeen articles with 5,806 cases (2,288 from CBA group, 3,518 from RFA group) from seven different countries were reviewed and analyzed. Pooled analyses indicated that CBA was more beneficial in terms of procedural time (Standard mean difference, SMD = -.501; 95%CI: -.893– -.109; P&lt;.05) for RFA; but the acute PV isolation rate (Odds ratio, OR = .06; 95 percent Confidence Interval, CI: .03–.13; P &lt; .05) in RFA was higher than for CBA; also, after median follow-up of 14 months (range 9–28 months), the proportion of patients free from AF (OR = .965; 95 percent CI:.859—1.085; P = .554) and the total complication rates (OR = .937; 95 percent CI:.753–1.167; P = .562) were not significantly different between CBA and RFA.In the four randomized controlled trials (RCTs) of the seventeen studies, the proportion of patients free from AF (OR = .951; 95 percent CI:.752–1.202; P = .672) and the complications (OR = 1.521; 95 percent CI:.570–4.058; P = .402) were not significantly different between CBA and RFA.CONCLUSIONS:Overall, compared with RFA for the treatment of patients with AF, CBA had similar clinical effectiveness on the proportion of people free from AF and the number of complications, and yet greater improvement in total procedure time referred for CBA and higher acute PVI rate referred for RFA.

216-34: Cryoablation without pulmonary vein mapping in paroxysmal atrial fibrillation: a comparison with a standard approach

Purpose: Cryoablation is an effective technique for pulmonary vein isolation (PVI) in treatment for paroxysmal AF (PAF). The Artic Front Advance is the second generation device with high rates of acute and chronic success. Rates of acute PVI are as high as 98% with cryoablation alone and it is unclear whether pulmonary vein mapping increases the long term clinical outcomes of the procedure. Method used: Consecutive patients undergoing first ablation for PAF were included in a single centre, retrospective, non-randomised study. The choice of PV mapping was left to the discretion of the operator. Summary of results: Patient demographics were similar between the 2 groups. 110 patients were evaluated (60 Cryo-map and 50 Cryo-no map). Procedure, fluoroscopy and Cryoablation times were all shorter in Cryo-no map vs Cryo map: 82 ± 17 vs 111 ± 29 minutes, 20 ± 10 vs 30 ± 13 minutes and 1433 ± 158 vs 1796 ± 359 seconds respectively (p all <0.01). Freedom from AF at 12 months was similar between Cryo-no map (80.5%) vs. Cryo-map (75.5%). Mean time to recurrence was similar between the 2 groups: 10.6 months with Cryo-Map vs 10.4 months with Cryo-no map (p = 0.55).

The long-term efficacy of cryoballoon vs irrigated radiofrequency ablation for the treatment of atrial fibrillation: A meta-analysis

ObjectivesThe main purpose of this meta-analysis was to compare the long-term efficacy of cryoballoon ablation (CBA) with irrigated radiofrequency catheter ablation (RFCA) for the treatment of atrial fibrillation (AF). MethodsThe Medline, Cochrane Library and Embase Database were searched for clinical studies published up to October 2014. Studies that fulfilled our predefined inclusion criteria were included. The primary clinical outcome was the proportion of patients free from AF (follow-up≥3months), and the secondary clinical outcomes included acute pulmonary vein (PV) isolated rate, fluoroscopy time, procedure time and complications. ResultsAfter a literature search in the major databases, three randomized controlled trials (RCTs) and eight retrospective trials with a total of 1216 patients were identified. Pool-analysis demonstrated that, as compared RFCA, CBA was associated with a similar proportion of patients free from AF at a mean 16.5months follow-up (66.9% vs 65.1%; relative risk [RR]: 1.01; 95% CI: 0.94 to 1.07, P=0.87). Acute PV isolation rate (RR: 0.92; 95% CI: 0.82 to 1.03) and fluoroscopy time (weighted mean difference WMD: −8.60; 95% CI: −18.29 to 3.69) were not statistically significant difference. The procedure time was shorter in CBA group ([WMD]: −31.94; 95% CI: −60.43 to −3.45). Transient phrenic nerve palsy was uniquely observed in the CBA group (5.4%, P<0.00001) and resolved in all during the follow-up period, total complication was similar in both groups (RR: 1.30; 95% CI: 0.91 to 1.85). ConclusionsCBA was as effective as RFCA for the treatment of atrial fibrillation during long-term follow-up with comparable procedural features.

Comparison of the First and Second Cryoballoon

Background— Cryoballoon (CB) ablation results in &gt;70% freedom from atrial fibrillation at 1 year. Single-center data of the first (CBG1) and second (CBG2) cryoballoon, recently introduced, were analyzed to compare safety and efficacy. Methods and Results— From March 2011 to December 2012, CB ablation with spiral mapping was performed consecutively in 484 patients with symptomatic atrial fibrillation. CBG1 was used in 364 of 484 (75%) and CBG2 in 120 of 484 (25%) patients. Periprocedural data were analyzed. Acute pulmonary vein (PV) isolation with CB only was achieved in 99.86% and 100% of veins with CBG1 and CBG2, respectively ( P =0.43). Number of applications until PV isolation decreased significantly with CBG2 (1.45±0.81 versus 1.28±0.64; P =0.001). Procedural, left atrial, and fluoroscopy time were reduced by −5%, −11%, and −15% ( P &lt;0.05), respectively. Two balloons were used less frequently. Time to isolation decreased significantly with 23-mm (48 versus 33 seconds; P &lt;0.0001) and 28-mm CBG2 (76 versus 52 seconds; P &lt;0.0001). Early PV reconduction rarely occurred with CBG2 (2.6% versus 0.42%; P =0.0023). In-hospital atrial fibrillation recurrence rates were similar. Balloon temperatures were significantly warmer with 23-mm CBG2 and a trend for colder balloon temperature with 28-mm CBG2 were observed compared with their predecessors. Comparable low rates of phrenic nerve palsy were recorded (1.1% versus 1.7%; P =0.64). Esophageal temperatures were similar. Major complication rates were low (3.3% versus 3.33%; P =1.0). Conclusions— CBG2 attains high rates of acute PV isolation within a significant faster and less complex procedure. Time to isolation is shorter, and PV isolation is achieved with fewer applications using CBG2. These enhancements were not at the cost of complications. Long-term success rates remain to be demonstrated.

Initial experience of three-minute freeze cycles using the second-generation cryoballoon ablation: acute and short-term procedural outcomes

The second-generation cryoballoon (CB-A) (Arctic Front Advance, Cryocath, Medtronic, MN, USA) might significantly improve procedural outcome with respect to the first-generation balloon. These technological improvements might also question the current recommendation of the need a 4-min freeze to achieve durable pulmonary vein isolation (PVI). The main aim of the study was to analyze the procedural efficacy of a 3-min freeze-thaw cycles with the CB-A balloon in the terms of rates of acute PVI and 6-month outcome. Patients having undergone CB-A for PAF or early persistent AF, with 3-min freeze-thaw cycles were consecutively included in our analysis. Acute procedural success was measured in terms of the rate of PVI. Short-term follow-up was evaluated by the means of 24-h Holters and clinical examinations at regular intervals. Fifty-two consecutive patients (35 male (67%); mean age, 59.8 ± 10.5) were included. Mean procedure and fluoroscopy times were 96 ± 15 and 13.2 ± 8.3min, respectively. Mean time from groin puncture to catheter extraction was 60.4 ± 20min. After a mean of 1.5 freeze cycles per vein of 3min in duration, all 208 (100%) PVs could be isolated with the CB-A. A total 192 (91%) veins were isolated during the first freeze. At a mean of 5.7-month follow-up, 82% of patients were free of AF. CB-A is effective in producing PVI by using 3-min-duration freeze cycles. After a mean of 1.5 freeze per vein, freedom from AF was achieved in 82% of patients at 6-month follow-up.

Pulmonary Vein Isolation Using a Second‐Generation Cryoballoon Catheter: A Randomized Comparison of Ablation Duration and Method of Deflation

Optimal cryoballoon ablation parameters for pulmonary vein (PV) isolation remain to be defined. We conducted a randomized preclinical trial to compare 2- versus 4-minute ablation lesions and assess the safety of active (forced) cryoballoon deflation. Thirty-two dogs underwent PV isolation with a second-generation 23 mm cryoballoon catheter. The left superior (LSPV) and inferior (LIPV) PVs were randomized in a factorial design to (1) a single 2- versus 4-minute cryoapplication, and (2) passive versus active cryoballoon deflation. Animals were survived for 30 days, after which histopathologic analysis was performed. Acute PV isolation was attained in 89.8% of PVs after a single application (93.8% LSPV, 85.2% LIPV; P = 0.2823). Mean time to PV isolation was 29.5 ± 18.5 seconds. Although 4-minute lesions were associated with a thicker neointima than 2-minute lesions (223.8 μm versus 135.6 μm; P = 0.007), no differences were observed in procedural characteristics (freezing temperature, rewarming time), rates of acute PV isolation, or the achievement of complete circumferentially transmural lesions at 30 days (78.7% overall; 86.2% for 2 minutes vs 70.0% for 4 minutes; P = 0.285). Active deflation was associated with faster balloon rewarming but not with significant differences in mean or maximum neointimal thickness. A single application with the second-generation cryoballoon catheter results in a high rate of PV isolation. The degree of vascular injury was not increased by active balloon deflation and no differences in acute efficacy or mature transmural circumferential lesions were observed with 2- versus 4-minute applications.

Energy titration strategies with the endoscopic ablation system: lessons from the high-dose vs. low-dose laser ablation study

To assess the effects of low-dose (LD) and high-dose (HD) ablation on acute and chronic success in patients with atrial fibrillation (AF). While the concept of visually guided pulmonary vein isolation (PVI) has been established little is known on energy titration using laser ablation. In 60 patients with AF, PVI using the endoscopic ablation system (EAS) was performed in two groups. Visually guided ablation was carried out after obtaining optimal tissue contact with 5.5-8.5 W in the LD group and with >8.5 W in the HD group. Acute PVI after a single visually guided circular lesion set was achieved in 89% (HD) and 69% (LD), respectively, (P = 0.0004). In 70 and 39% of patients all PVs were isolated after a single ablation circle in the HD and LD group, respectively, (P = 0.009). After gap ablation all PVs were isolated with the EAS. More energy was deployed (6483 ± 1834 vs. 5306 ± 2258 Ws; P ≤ 0.0001) with less applications (31.6 ± 8 vs. 35.2 ± 15 applications per PV; P = 0.03) leading to shorter procedure times (128 ± 17 vs. 154 ± 38 min; P = 0.001). During median follow-up of 311 days (261-346) recurrence rate was 17 and 40% in the HD and LD group, respectively. In both groups one phrenic nerve palsy was observed. For the first time, it was demonstrated that high ablation power affects acute and chronic outcomes. High-dose laser balloon ablation allows for an acute PVI rate of 89% solely by visually guided circular ablation and is associated with a chronic success rate of 83% after a single procedure.