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Background: The aims of this analysis were: to evaluate the impact of timing of ablation on the rate of atrial arrhythmias recurrence, verify if the timing of ablation impact differently in patients with paroxysmal and persistent AF., Methods: Three thousand two hundred and five patients (60.5 ± 10 years, female 28.4%%, 78.8%% paroxysmal AF) were included in the analysis. All patients underwent only cryoballoon (CB) pulmonary vein (PV) isolation during the index procedure., Results: The mean procedure time was 102.8 ± 50 min, with a mean fluoroscopy time of 26.3 ± 49 min. Acute PV isolation was achieved in 11760/11793 (99.7%) PVs. A total of 91 (2.8%) patients experienced a procedure-related complication. During the observation period 913/3205 (28.5%) patients had at least one atrial arrhythmias episode: 28% of patients with paroxysmal AF vs 33% of patients with persistent AF. In multivariate analysis, persistent AF together with time from symptomatic AF diagnosis to ablation, female sex, and ablation time showed to be significant predictors for AF recurrence. In particular, months from first symptomatic AF episode > 18 months was a significant predictor of AF recurrence (HR = 1.23, 95% CI = 1.03-1.46, p = 0.020). In patients with paroxysmal AF, the multivariate analysis confirmed that months from first symptomatic AF episode > 18 month was an independent predictor of AF recurrence together with age > 62 years and female sex. In patients with persistent AF, the time from persistent AF showed to be significant predictor for AF recurrence., Conclusions: In this multicenter analysis, time from first symptomatic AF episode > 18 months was a significant predictor of AF recurrence after CB PV isolation., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Recently, a new cryoballoon (CB) technology (POLARx; Boston Scientific) has come onto the market. Preliminary data have shown that its acute safety and efficacy are similar to those of the first-generation CB. The aim of this study was to assess the medium-term outcome of pulmonary vein isolation (PVI) with the POLARxTM CB in a large multicenter registry., Methods: We prospectively collected data on 125 consecutive patients with paroxysmal atrial fibrillation (AF) who underwent PVI by means of a novel CB system. Two cases of transient phrenic nerve palsy occurred, with full recovery in the 48h post procedure; no major procedure-related adverse events were reported. During the 90-day blanking period, 4 (3.2%) patients experienced an early recurrence. After the blanking period, over a mean follow-up of 411 ± 62 days, 19 patients (15.2%) suffered an AF/atrial tachycardia (AT) recurrence. The 1-year freedom from AF/AT recurrence was 86.4% (n = 17): 10 (8%) patients had an AF recurrence, 6 (4.8%) had an AT occurrence and 1 (0.8%) suffered both events. Patients with AF/AT recurrences had both a shorter deflation time and total deflation time. Moreover, CB ablations with measured TTI < 90 s and TTI < 60 s were more frequent in patients without AF/AT recurrence (88.5% and 77.4%, respectively) than in those who experienced at least one AF/AT recurrence (67.5% and 55.0%, p = .001 and p = .005, respectively)., Conclusion: The novel POLARx cryo-balloon system is safe and effective for PV isolation, displaying a 1-year freedom from atrial arrhythmia recurrence of 86.4%, which is in line to that reported with AFA-Pro CB or RF ablation., Clinical Trial Registration: Catheter Ablation of Arrhythmias with a High-Density Mapping System in Real-World Practice (CHARISMA). URL: http://clinicaltrials.gov/ Identifier: NCT03793998. Registration date: January 4, 2019., (© 2023 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Purpose: A new cryoballoon (CB) technology (POLARx™; Boston Scientific) for pulmonary vein (PV) isolation in patients with atrial fibrillation (AF) has recently been introduced. The aim of this study was to evaluate procedural and biophysical parameters resulting in acute PV isolation when using this new CB., Methods: We assessed the first 69 consecutive patients indicated for AF ablation who underwent PV isolation by means of a novel CB system. Procedural metrics were prospectively recorded., Results: A total of 274 PVs were targeted in 69 patients. PV isolation was achieved in all patients by means of cryoablation alone. The median time to isolation (TTI) was 44 [31-68] s (median temperature at TTI =  - 49 [- 53 to - 41] °C). The median duration of CB ablation was 180 [180 to 240] s. The median nadir temperature was - 56.0 [- 61 to - 52] °C, and the median thaw time to 0 °C was 18 [15-21] s. The median grade of PV occlusion was 4 [3 to 4]. On the basis of ROC analysis, we defined the following cut-off values for acute PV isolation: - 56 °C for nadir temperature (sensitivity = 73.3%, specificity = 64.6%, AUC = 0.716; positive predictive value = 88.1%), 30 s for TTT (60.2%, 53.3%, 0.578; 79.7%), thaw time > 17 s (65.3%, 70.0%, 0.709; 86.9%), and grade of PV occlusion = 4 (79.4%, 66.7%, 0.738; 88.5%). No major procedure-related adverse events were observed at 30-day post-procedure., Conclusions: The new POLARx™ CB appears to be effective and safe. A nadir temperature of - 56 °C, a thaw time to 0 °C ≥ 17 s, and complete PV occlusion were the best predictors of acute PV isolation., Clinical Trial Registration: Catheter Ablation of Arrhythmias with a High-Density Mapping System in Real-World Practice (CHARISMA). URL: http://clinicaltrials.gov/Identifier : NCT03793998. Registration date: January 4, 2019., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: Low-voltage activity beyond pulmonary veins (PVs) may contribute to the failure of ablation of atrial fibrillation (AF) in the long term. We aimed to assess the presence of gaps (PVG) and residual potential (residual antral potential [RAP]) within the antral scar by means of an ultra-high-density mapping (UHDM) system., Methods: We studied consecutive patients from the CHARISMA registry who were undergoing AF ablation and had complete characterization of residual PV antral activity. The Lumipoint™ (Boston Scientific) map-analysis tool was used sequentially on each PV component. The ablation endpoint was PV isolation (PVI) and electrical quiescence in the antral region., Results: Fifty-eight cases of AF ablation were analyzed. A total of 86 PVGs in 34 (58.6%) patients and 44 RAPs in 34 patients (58.6%) were found. In 16 (27.6%) cases, we found at least one RAP in patients with complete absence of PV conduction. RAPs showed a lower mean voltage than PVG (0.3 ± 0.2 mV vs. 0.7 ± 0.5 mV, p < .0001), whereas the mean number of electrogram peaks was higher (8.4 ± 1.4 vs. 3.2 ± 1.5, p < .0001). The percentage of patients in whom RAPs were detected through Lumipoint™ was higher than through propagation map analysis (58.6% vs. 36.2%, p = .025). Acute procedural success was 100%, with all PVs successfully isolated and RAPs completely abolished in all study patients. During a mean follow-up of 453 ± 133 days, 6 patients (10.3%) suffered an AF/AT recurrence., Conclusion: Local vulnerabilities in antral lesion sets were easily discernible by means of the UHDM system in both de novo and redo patients when no PV conduction was present., (© 2022 Wiley Periodicals LLC.)

Background: The antral region of pulmonary veins (PV)s seems to play a key role in a strategy aimed at preventing atrial fibrillation (AF) recurrence. Particularly, low-voltage activity in tissue such as the PV antra and residual potential within the antral scar likely represent vulnerabilities in antral lesion sets, and ablation of these targets seems to improve freedom from AF. The aim of this study is to validate a structured application of an approach that includes the complete abolition of any antral potential achieving electrical quiescence in antral regions., Methods: The improveD procEdural workfLow for cathETEr ablation of paroxysmal AF with high density mapping system and advanced technology (DELETE AF) study is a prospective, single-arm, international post-market cohort study designed to demonstrate a low rate of clinical atrial arrhythmias recurrence with an improved procedural workflow for catheter ablation of paroxysmal AF, using the most advanced point-by-point RF ablation technology in a multicenter setting. About 300 consecutive patients with standard indications for AF ablation will be enrolled in this study. Post-ablation, all patients will be monitored with ambulatory event monitoring, starting within 30 days post-ablation to proactively detect and manage any recurrences within the 90-day blanking period, as well as Holter monitoring at 3, 6, 9, and 12 months post-ablation. Healthcare resource utilization, clinical data, complications, patients' medical complaints related to the ablation procedure and patient's reported outcome measures will be prospectively traced and evaluated., Discussion: The DELETE AF trial will provide additional knowledge on long-term outcome following a structured ablation workflow, with high density mapping, advanced algorithms and local impedance technology, in an international multicentric fashion. DELETE AF is registered at ClinicalTrials.gov (NCT05005143)., (© 2022 The Authors. Clinical Cardiology published by Wiley Periodicals LLC.)

Purpose: Highly localized impedance (LI) measurements during atrial fibrillation (AF) ablation have emerged as a viable real-time indicator of tissue characteristics and the consequent durability of the lesions created. We investigated the impact of catheter-tissue contact force (CF) on LI behavior during pulmonary vein isolation (PVI)., Methods: Forty-five consecutive patients of the CHARISMA registry undergoing de novo AF radiofrequency (RF) catheter ablation with a novel open-irrigated-tip catheter endowed with CF and LI measurement capabilities (Stablepoint™ catheter, Boston Scientific) were included., Results: A total of 2895 point-by-point RF applications were analyzed (RF delivery time (DT) = 8.7±4s, CF = 13 ±±8 g, LI drop = 23 ±±7 Ω). All PVs were successfully isolated in an overall procedure time of 118 ±±34 min (fluoroscopy time = 13 ±±8 min). The magnitude of LI drop weakly correlated with CF (r = 0.13, 95% confidence interval (CI): 0.09 to 0.16, p < 0.0001), whereas both CF and LI drop inversely correlated with DT (r = -0.26, 95%CI: -0.29 to -0.22, p < 0.0001 for CF; r = -0.36, 95%CI: -0.39 to -0.33, p < 0.0001 for LI). For each 10 g of CF, LI drop markedly increased from 22.4 ± 7 Ω to 24.0 ± 8 Ω at 5 to 25 g CF intervals (5-14 g of CF vs 15-24 g of CF, p < 0.0001), whereas it showed smooth transition over 25 g (24.8 ± 7Ω at ≥ 25 g CF intervals, p = 0.0606 vs 15-24 g of CF). No major complications occurred during the procedures or within 30 days., Conclusions: CF significantly affects LI drop and probable consequent lesion formation during RF PVI. The benefit of higher contact (> 25 g) between the catheter and the tissue appears to have less impact on LI drop., Trial Registration: Catheter Ablation of Arrhythmias With High Density Mapping System in the Real World Practice (CHARISMA). URL: http://clinicaltrials.gov/ Identifier: NCT03793998., (© 2022. The Author(s).)

Purpose: Ablation index (AI) is a radiofrequency lesion quality marker. The AI value that allows effective and safe pulmonary vein isolation (PVI) is still debated. We evaluated the incidence of acute and late PV reconnection (PVR) with different AI settings and its predictors., Methods: The Ablation Index Registry is a multicenter study that included patients with paroxysmal/persistent atrial fibrillation (AF) who underwent first-time ablation. Each operator performed the ablation using his preferred ablation catheter (ThermoCool® SmartTouch or Surround Flow) and AI setting (380 posterior-500 anterior and 330 posterior-450 anterior). We divided the study population into two groups according to the AI setting used: group 1 (330-450) and group 2 (380-500). Incidence of acute PVR was validated within 30 min after PVI, whereas the incidence of late PVR was evaluated at repeat procedure., Results: Overall, 490 patients were divided into groups 1 (258) and 2 (232). There was no significant difference in the procedural time, fluoroscopy time, and rate of the first-pass PVI between the two study groups. Acute PVR was observed in 5.6% PVs. The rate of acute PVR was slightly higher in group 2 (64/943, 6.8%, PVs) than in group 1 (48/1045, 4.6% PVs, p = 0.04). Thirty patients (6%) underwent a repeat procedure and late PVR was observed in 57/116 (49%) PVs (number of reconnected PV per patient of 1.9 ± 1.6). A similar rate of late PVR was found in the two study groups. No predictors of acute and late PVR were found., Conclusion: Ablation with a lower range of AI is highly effective and is not associated with a higher rate of acute and late PVR. No predictors of PV reconnection were found., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: A very high-power short-duration (vHPSD) strategy of radiofrequency (RF) ablation aims to minimize conductive heating and increase resistive heating. This study aimed to clarify the contribution of contact force (CF) and temperature and their interrelationship in making an adequate lesion with the vHPSD catheter., Methods: We enrolled 46 consecutive patients undergoing first catheter ablation for atrial fibrillation (AF). The vHPSD ablation was performed applying 90 W, for 4 s, with an irrigation of 8 ml/min. During an application, an impedance drop (ID) ≥10 Ω was regarded as an adequate lesion formation., Results: The mean procedural time was 95 ± 15 min. First-pass isolation was reached in 89% of patients and at the end of the procedure all pulmonary veins were isolated. No steam pop nor procedural complication occurred. A total of 3829 qualified RF points were analyzed and the median values of ID, CF and maximum temperature were respectively 10.6 (IQR 8.6-13.1) Ohm, 9 (5.8-13.8) g, 46.8 (44.1-49.8) °C. The mean ID significantly increased in parallel with the increasing CF as well as with the increasing maximum temperature. In the multivariable analysis only the CF and the maximum temperature were independent predictors of ID. From receiver operating characteristic curve analysis, a CF of 8 g and a maximum temperature of 47°C are the optimal cutoff discriminatory value for adequate lesion formation., Conclusions: The vHPSD ablation is highly effective and safe. The CF and the maximum temperature are independent predictors of adequate lesion formation assessed by means of ID., (© 2021 Wiley Periodicals LLC.)

Background: Highly localized impedance (LI) measurements during atrial fibrillation (AF) ablation have recently emerged as a viable real-time indicator of tissue characteristics and durability of the lesions created. We report the outcomes of acute and long-term clinical evaluation of the new DirectSense algorithm in AF ablation., Methods: Consecutive patients undergoing AF ablation were included in the CHARISMA registry. RF delivery was guided by the DirectSense algorithm, which records the magnitude and time-course of the impedance drop. The ablation endpoint was pulmonary vein isolation (PVI), as assessed by the entrance and exit block., Results: 3556 point-by-point first-pass RF applications of >10 s duration were analyzed in 153 patients (mean age=59 ± 10 years, 70% men, 61% paroxysmal AF, 39% persistent AF). The mean baseline LI was 105 ± 15 Ω before ablation and 92 ± 12 Ω after ablation (p < .0001). Both absolute drops in LI and the time to LI drop (LI drop/τ) were greater at successful ablation sites (n = 3122, 88%) than at ineffective ablation sites (n = 434, 12%) (14 ± 8 Ω vs 6 ± 4 Ω, p < .0001 for LI; 0.73 [0.41-1.25] Ω/s vs. 0.35[0.22-0.59 Ω/s, p < .0001 for LI drop/τ). No major complications occurred during or after the procedures. All PVs had been successfully isolated. During a mean follow-up of 366 ± 130 days, 18 patients (11.8%) suffered an AF/atrial tachycardia recurrence after the 90-day blanking period., Conclusion: The magnitude and time-course of the LI drop during RF delivery were associated with effective lesion formation. This ablation strategy for PVI guided by LI technology proved safe and effective and resulted in a very low rate of AF recurrence over 1-year follow-up., (© 2021 Wiley Periodicals LLC.)

Background: Optimal pulmonary vein (PV) occlusion, usually verified with selective contrast injection, is mandatory to obtain an effective PV isolation during cryoballoon (CB) ablation., Aim of the Study: The purpose of this study was to verify the feasibility and the accuracy of a new dielectric sensing system in assessing PV occlusion during CB ablation in patients with atrial fibrillation (AF)., Methods: We enrolled 28 consecutive patients with paroxysmal or persistent AF. After transseptal access, a detailed image reconstruction of left atrium and PVs was achieved with an octapolar or decapolar mapping catheter (Achieve catheter, Medtronic Inc.) and KODEX-EPD system (EPD Solutions, a Philips company). The degree of PV occlusion with the inflated Arctic Front Advance Cryoballoon (Medtronic Inc.) was verified using the new "occlusion tool" software module (EPD Solutions, a Philips company) and compared to an angiogram obtained with contrast medium injection in each PV., Results: A total of 105 PV CB occlusion were tested. The new occlusion tool software module showed a 91% sensitivity and 76% specificity in assessing a complete PV occlusion verified with contrast medium injection. The positive predictive value was 80%, and the negative predictive value was 88.6%. Mean procedure time was 81 ± 17 minutes. Mean fluoroscopy time was 6 ± 2 minutes. No 30-day complications were observed., Conclusion: The new dielectric imaging system was able to assess the degree of PV occlusion during a CB ablation with good sensitivity and specificity., (© 2020 Wiley Periodicals LLC.)

Aims: The aims of this study were to determine the rate and the predictors of early recurrences of atrial fibrillation (ERAF) after cryoballoon (CB) ablation and to evaluate whether ERAF correlate with the long-term outcome., Methods and Results: Three thousand, six hundred, and eighty-one consecutive patients (59.9 ± 10.5 years, female 26.5%, and 74.3% paroxysmal AF) were included in the analysis. Atrial fibrillation recurrence, lasting at least 30 s, was collected during and after the 3-month blanking period. Three-hundred and sixteen patients (8.6%) (Group A) had ERAF during the blanking period, and 3365 patients (Group B) had no ERAF. Persistent AF and number of tested anti-arrhythmic drugs ≥2 resulted as significant predictors of ERAF. After a mean follow-up of 16.8 ± 16.4 months, 923/3681 (25%) patients had at least one AF recurrence. The observed freedom from AF recurrence, at 24-month follow-up from procedure, was 25.7% and 64.8% in Groups A and B, respectively (P < 0.001). ERAF, persistent AF, and number of tested anti-arrhythmic drugs ≥2 resulted as significant predictors of AF. In a propensity score matching, the logistic model showed that ERAF 1 month after ablation are the best predictor of long-term AF recurrence (P = 0.042)., Conclusion: In patients undergoing CB ablation for AF, ERAF are rare and are a strong predictor of AF recurrence in the follow-up, above all when occur >30 days after the ablation., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Introduction: Recently, a novel technology able to measure local impedance (LI) and tissue characteristics has been made available for clinical use. This analysis explores the relationships among LI and generator impedance (GI) parameters in atrial fibrillation (AF) patients. Characterization of LI among different ablation spots and procedural success were also evaluated., Methods and Results: Consecutive patients undergoing AF ablation from the CHARISMA registry at five Italian centers were included. A novel radiofrequency (RF) ablation catheter with a dedicated algorithm (DIRECTSENSE™) was used to measure LI and to guide ablation. The ablation endpoint was pulmonary vein (PV) isolation. We analyzed 2219 ablation spots created around PVs in 46 patients for AF ablation. The mean baseline tissue impedance was 105.8 ± 14 Ω for LI versus 91.8 ± 10 Ω for GI (p < .0001). Baseline impedance was homogenous across the PV sites and proved higher in high-voltage areas than in intermediate- and low-voltage areas and the blood pool (p < .001). Both LI and GI displayed a significant drop after RF delivery, and absolute LI drop values were significantly larger than GI drop values (14 ± 8 vs. 3.7 ± 5 Ω, p < .0001). Every 5-point increment in LI drop was associated with successful ablation (odds ratio = 3.05, 95% confidence interval: 2.3-4.1, p < .0001). Conversely, GI drops were not significantly different comparing successful versus unsuccessful sites (3.7 ± 5 vs. 2.8 ± 4 Ω, p = .1099). No steam pops or major complications occurred during or after the procedures. By the end of the procedures, all PVs had been successfully isolated in all patients., Conclusions: The magnitude of the LI drop was more closely associated with effective lesion formation than the GI drop., (© 2020 Wiley Periodicals LLC.)

Background: Ablation index (AI) is a new lesion quality marker that has been demonstrated to allow a high single-procedure arrhythmia-free survival in single-center studies. This prospective, multi-center study was designed to evaluate the reproducibility of pulmonary vein (PV) isolation guided by the AI., Methods: A total of 490 consecutive patients with paroxysmal (80.4%) and persistent AF underwent first time PV isolation and were divided in four study groups according to operator's preference in choosing the ablation catheter (a contact force (ST) or contact force surround flow (STSF) catheter) and the AI setting (330-450 or 380-500 at anterior wall or posterior wall, respectively)., Results: At 12 months a high rate of freedom from AF recurrences was observed in patients with both paroxysmal and persistent AF (91% vs 83.3%; P = .039). There was no difference in the rate of AF recurrence among the four study groups (4.5% in group ST330-450, 12.2% in group ST 380-500, 14.9% in group STSF330-450, 9.4% in group STSF380-500; P = .083). Recurrence was also similar between patients treated with a ST (8%) or STSF catheter (12.1%; P = .2), and within patients targeting an AI settings of 330 to 450 (10.9%) or 380 to 500 (10.3%; P = .64). In patients with paroxysmal AF, there was no difference (P = .12) in the 1-year freedom from AF recurrence among 14 operators that performed ≥10 ablation procedure., Conclusions: An ablation protocol respecting strict criteria for contiguity and quality lesion resulted in high rate of 1-year freedom from AF recurrence, irrespective of the ablation catheters, AI settings, and operator., (© 2020 Wiley Periodicals LLC.)

Background: 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., Methods: 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 ≤6 mm., Results: 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 ± 44 minutes, ST380 144 ± 44 minutes, STSF330 120 ± 72 minutes, STSF380 125 ± 73 minutes, 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., Conclusions: 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., (© 2019 Wiley Periodicals, Inc.)

Aims: Pulmonary vein isolation (PVI), the standard for atrial fibrillation (AF) ablation, is most commonly applied with radiofrequency (RF) energy, although cryoballoon technology (CRYO) has gained widespread use. The aim was to compare the second-generation cryoballoon and the irrigated RF energy regarding outcomes and safety., Methods and Results: Of 4657 patients undergoing their first AF ablation, 982 with CRYO and 3675 with RF energy were included from the Swedish catheter ablation registry and the Atrial Fibrillation Ablation Long-Term registry of the European Heart Rhythm Association of the European Society of Cardiology. The primary endpoint was repeat AF ablation. The major secondary endpoints included procedural duration, tachyarrhythmia recurrence, and complication rate. The re-ablation rate after 12 months was significantly lower in the CRYO vs. the RF group, 7.8% vs. 11%, P = 0.005, while freedom from arrhythmia recurrence (30 s duration) did not differ between the groups, 70.2 % vs. 68.2%, P = 0.44. The result was not influenced by AF type and lesion sets applied. In the Cox regression analysis, paroxysmal AF had significantly lower risk for re-ablation with CRYO, hazard ratio 0.56 (P = 0.041). Procedural duration was significantly shorter with CRYO than RF, (mean ± SD) 133.6 ± 45.2 min vs. 174.6 ± 58.2 min, P < 0.001. Complication rates were similar; 53/982 (5.4%) vs. 191/3675 (5.2%), CRYO vs. RF, P = 0.806., Conclusion: The lower re-ablation rates and shorter procedure times observed with the cryoballoon as compared to RF ablation may have important clinical implications when choosing AF ablation technique despite recognized limitations with registries., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2018. For permissions, please email: journals.permissions@oup.com.)

Purpose: Reconnection of pulmonary veins (PVs) remains common following radiofrequency catheter ablation for atrial fibrillation (AF). Ablation Index (AI) is a novel ablation quality marker that incorporates stability, contact force (CF), time, and power in a weighted formula. Its use seems to improve lesion durability. This is a prospective, single-arm registry to investigate on the safety and mid-term efficacy of AF ablation guided by the AI., Methods: One hundred fifty-six consecutive patients (mean age 58 ± 10 years, 49% males, 44% with structural heart disease) referred for paroxysmal (124) or persistent (32) AF underwent antral PV isolation using a surround flow CF-sensing catheter guided by the AI. Radiofrequency was delivered targeting interlesion distance ≤ 6 mm and Ablation Index of 330-350 at posterior wall and 400-450 at anterior wall., Results: Mean overall procedure time was 95 ± 30 min with a mean fluoroscopy time of 5 ± 6 min. Mean ablation time was 26 ± 10 min, 627/628 targeted PV were isolated. One pericardial effusion and two groin hematomas were reported; none required intervention. During a mean follow-up of 14 ± 6 months, 17 (10.8%) (9% paroxysmal AF vs 22% persistent AF, p = 0.09) patients had an atrial arrhythmia recurrence., Conclusions: PV ablation guided by AI resulted feasible, achieving a high rate of isolated PVs, with a low complication rate, and allowed a high single-procedure arrhythmia-free survival at 14 months.

Background: Real-time visualization of the electrical activity of the pulmonary veins (PV) is not always possible in the setting of atrial fibrillation (AF) cryoballoon ablation. We investigated the relation between the effective documentation of time to PV isolation and the clinical outcome in a cohort of patients with paroxysmal AF who underwent cryoballoon ablation., Methods: One thousand forty two consecutive patients were enrolled. An inner lumen mapping catheter was typically used to visualize real-time electrical activity inside the PVs., Results: Time to PV isolation was documented in all targeted PVs in 391 patients (Group 1), in 651 patients it was not possible to record PV potentials and assess time to PV isolation in at least one PV (Group 2). In Group 1 a longer procedure duration and ablation time were observed, while a longer fluoroscopy time was observed in Group 2. After a mean follow-up of 14 ± 11 months, 209/1042 (20%) patients had an atrial arrhythmia recurrence (20.2% in Group 1, 19.9% in Group 2, p = 0.25). Complications occurred in 54/1042 (5.2%) patients without any difference among the two study groups., Conclusion: In our retrospective analysis, in about two thirds of patients undergoing cryoballoon ablation it was not possible to acutely assess time to PV isolation in all PVs. However, one-year freedom from clinically symptomatic atrial tachyarrhythmia was similar to that of patients in which time to PV isolation was documented in all targeted veins., Clinical Trial Registration: clinicaltrials.gov (NCT01007474)., (Copyright © 2018. Published by Elsevier B.V.)

Background: Our aim was to evaluate the clinical outcome of paroxysmal atrial fibrillation (AF) ablation with contact force technology, using an automated lesion tagging system (VISITAG TM module) with strict criteria of catheter stability.Methods and Results:We enrolled 200 consecutive patients who underwent pulmonary vein isolation (PVI) in 11 centers and were followed up for 12 months. The stability setting was within 3 mm for ≥10 s and for ≥15 s in 47% and 53% of patients, respectively. A mean of 67.2±21.9 VISITAGs was acquired. Freedom from atrial tachyarrhythmias at follow-up was 77.5% (155/200), and the contiguity between lesions was associated with a higher chronic success rate (96% vs. 77.1%; log-rank P=0.036). Radiofrequency (RF), fluoroscopy times, and recurrence rates at the 12-month follow-up were significantly lower than in a comparison group of 80 patients without VISITAG TM module (42.7±14.5 vs. 50.9±23.6 min; P=0.032; 11.6±7.8 vs. 18.4±12.8 min; P=0.003 and 22.5% vs. 41.2%; P=0.02). Two major complications (1 cardiac tamponade and 1 minor stroke) were observed only in the control group., Conclusions: Paroxysmal AF ablation with contact force technology and strict criteria of stability using the VISITAG module was a safe procedure, associated with an improvement in efficiency and a reduction of atrial tachyarrhythmia recurrence at the 12-month follow-up compared with manual annotation. Contiguity between lesions seemed to enhance effectiveness outcomes.

Introduction: Pulmonary vein (PV) isolation is the cornerstone of catheter ablation in patients with atrial fibrillation (AF). Surround flow and contact force (CF) measurement capabilities might enhance procedure efficacy and safety. We report on the safety and midterm efficacy of a novel ablation catheter for PV isolation in patients with AF., Methods and Results: Two hundred thirty-three consecutive patients (57 ± 11 years, 76% males, 51% with structural heart disease), referred for paroxysmal (157) or persistent (76) AF, underwent PV isolation by a surround flow catheter with CF measurement capability in four centers. Ablation was guided by electroanatomic mapping allowing radiofrequency (RF) energy delivery in the antral region aiming at PV isolation. Mean overall procedure time was 100 ± 42 minutes with a mean fluoroscopy time of 6 ± 5 minutes. Mean ablation time was 31±15 minutes; 99% of the targeted veins were isolated. The mean CF value during ablation was 13 ± 4 g. Intraprocedural early (30 minutes) PV reconnection occurred in 12% PVs, and all PVs were effectively reisolated. One pericardial effusion and five groin hematomas were reported. During a mean follow-up of 12 ± 6 months, 30 (12.9%) (10% paroxysmal AF vs. 18% persistent AF, P = 0.07) patients had an atrial arrhythmias recurrence., Conclusions: In this multicenter registry, RF ablation using a new surround flow catheter, with CF sensor, resulted as feasible, achieving a high rate of isolated PVs. Procedural and fluoroscopy times and success rates were comparable with other techniques with a low complication rate., (© 2017 Wiley Periodicals, Inc.)

Purpose: Left atrial volume (LA) and pulmonary vein (PV) anatomy may potentially relate to technical challenges in achieving stable and effective catheter position in case of atrial fibrillation (AF) ablation by means of "one-shot" catheters. The aim of this study was to investigate whether LA volume and PV anatomy, evaluated by computed tomography (CT) or magnetic resonance (MR) prior to ablation, predict acute and midterm outcome of AF ablation by nMARQ™., Methods: We included 75 patients (mean age 58 ± 11 years, 67 % male) with symptomatic paroxysmal AF. All patients underwent CT/MR scanning prior to catheter ablation to evaluate LA volume and PV anatomy. All the patients underwent PV isolation by nMARQ™, an open-irrigated mapping and radiofrequency (RF) decapolar ablation catheter. Ablation was guided by electroanatomic mapping allowing RF energy delivery in the antral region of PVs from ten irrigated electrodes simultaneously., Results: Mean LA volume was 75 ± 40 ml. A normal anatomy (4 PVs) was documented in 40 (53 %) patients and abnormal anatomy (common truncus or accessory PVs) in 35 patients. Mean procedural and fluoroscopy times were 94 ± 55 and 8 ± 5 min, respectively, without significant differences among patients with normal or abnormal anatomy (92 ± 45 vs 95 ± 64 min, p = 0.85 and 6 ± 3 vs 8 ± 4 min, p = 0.65, respectively). Mean ablation time was 14 ± 3 min, and 99 % of the targeted veins were isolated with a mean of 23 ± 5 RF pulses per patient. After a mean follow-up of 17 ± 8 months, 23 (31 %) patients had an atrial arrhythmia recurrence. Neither LA volume nor PV anatomy was a predictor of outcome., Conclusions: LA volume and PV anatomy did not affect procedural data and outcome in patients who underwent PV isolation by an open-irrigated mapping and RF decapolar ablation catheter.

Background: Three months of empirical antiarrhythmic drug (AAD) therapy after atrial fibrillation ablation (AFA) is a common practice to prevent early arrhythmia recurrence; the data of influence of this practice on longer term ablation outcomes is limited., Purpose: The aim of this study was to perform a meta-analysis of published controlled trials comparing temporary AAD therapy after AFA with no AAD therapy in patients after AFA. The primary outcome was recurrence of arrhythmia., Results: 1Eight prospective trials were included. Among 2952 patients, 1991 (67 %) had paroxysmal AF, and 967 (32.7 %) had persistent AF. In total, 1502 patients were treated with AADs and 1450 patients served as a control group (no AAD therapy). Various class IC-III antiarrhythmics were used. Length of AAD administration varied between 6 and 12 weeks after start of AFA. The follow-up duration ranged from 1.5 to 17 months after stopping medication. Among AAD treated patients, the recurrence of arrhythmia rate was 30.69 vs. 33.79 % in control patients (odd ratio 0.86, 95 % CI 0.71-1.06, P = 0.15). In patients who received largely amiodarone, there was a trend for difference in recurrence of atrial arrhythmia (odds ratio 0.60, 95 % CI 0.34-1.09, P = 0.09)., Conclusions: Short-term post pulmonary vein isolation (PVI) AAD therapy does not substantially reduce overall recurrence of AF after ablation.

Background: Pulmonary vein (PV) isolation is the cornerstone of catheter ablation in patients with atrial fibrillation (AF). "Single-shot" ablation devices have been recently engineered., Objectives: We report on the safety and efficacy of a novel ablation catheter for PV isolation in patients with AF., Methods: One hundred eighty consecutive patients (58 ± 10 years, 125 male, 31% with structural heart disease) referred for paroxysmal (140) or persistent (40) AF underwent PV isolation by an open-irrigated mapping and radiofrequency (RF) decapolar ablation catheter in 7 centers. Ablation was guided by electroanatomic mapping, allowing RF energy delivery in the antral region of PVs from 10 irrigated electrodes simultaneously., Results: Mean overall procedure time was 113 ± 53 minutes with a mean fluoroscopy time of 13.1 ± 8.4 minutes. The use of a preablation PV imaging related to a significant reduction in fluoroscopy time (from 14.7 ± 9.7 to 8.7 ± 6.6, P < .001). Mean ablation time was 12.5 ± 5.1 minutes, and 98% of the targeted veins were isolated with a mean of 23.4 ± 6.3 RF pulses per patient. In only 4 patients (2.2%) a single-point ablation strategy was required to achieve PV isolation. One groin hematoma and 1 PV stenosis were reported. During a mean follow-up of 13.9 ± 8.2 months 38 of 140 patients (27%) with paroxysmal AF and 12 of 40 patients (30%) with persistent AF had an atrial arrhythmia relapse (P = .671)., Conclusions: In this multicenter registry, irrigated multielectrode RF ablation proved feasible, achieving a high rate of isolated PVs. Procedural and fluoroscopy times and success rates were comparable with other techniques, with a low complication rate., (Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Purpose: Catheter-tissue contact is critical for effective lesion creation in radiofrequency catheter ablation (RFCA). In a multicenter prospective study, we assessed the relationship between catheter contact force (CF) during RFCA for paroxysmal atrial fibrillation (AF) and clinical recurrences over a mid-term follow-up., Methods: All patients underwent RFCA for paroxysmal AF by antral pulmonary vein (PV) isolation, aiming at entry and exit conduction block in all PVs. A new open-irrigated tip catheter with CF sensing (SmartTouch(TM), Biosense Webster Inc. CA) was used. All patients were followed for at least 12 months and the relationship between CF and clinical outcomes assessed., Results: One year follow-up was available in 92/95 of the patients enrolled. Acute PV isolation was achieved in 100 % of the veins. Mean CF during RFCA was 12.2 ± 3.9 g. Mean force-time integral (FTI) was 733 ± 505 gs. Following the 3-month blanking period, 17 (18 %) patients experienced at least 1 atrial tachyarrhythmia relapse. There was no statistical difference in mean CF (13 ± 3.4 g vs 12 ± 4 g, p = 0.32) and mean FTI (713 ± 487 gs vs 822 ± 590 gs, p = 0.42) between patients with and without arrhythmia recurrences. Recurrences were recorded in 22 % of patients achieving a mean FTI value below the median of 544 gs and in 15 % of patients with a mean FTI value above the median (p = 0.64)., Conclusions: RFCA with CF data during PV isolation for paroxysmal AF improves physician's knowledge on catheter-tissue contact. In the present dataset, however, higher CF values did not impact mid-term clinical RFCA outcome.

Aims: Catheter-tissue contact is critical for effective lesion creation in radiofrequency catheter ablation (RFCA). In a multicentre prospective study, we assessed the effect of direct contact force (CF) measurement on acute procedural parameters during RFCA of atrial fibrillation (AF)., Methods and Results: A new open-irrigated tip catheter with CF sensing (SmartTouch™, Biosense Webster Inc.) was used. All the patients underwent the first ablation procedure for paroxysmal AF with antral pulmonary vein (PV) isolation, aiming at entry and exit conduction block in all PVs. Ninety-five patients were enroled in nine centres and successfully underwent ablation. Overall procedure time, fluoroscopy time, and ablation time were 138.0 ± 67.0, 14.3 ± 11.2, and 33.8 ± 19.4 min, respectively. The mean CF value during ablation was 12.2 ± 3.9 g. Force time integral (FTI) analysis showed that patients achieving a value below the median of 543.0gs required longer procedural (158.0 ± 74.0 vs. 117.0 ± 52.0 min, P = 0.004) and fluoroscopy (17.5 ± 13.0 vs. 11.0 ± 7.7 min, P = 0.007) times as compared with those in whom FTI was above this value. Patients in whom the mean CF during ablation was >20 g required shorter procedural time (92.0 ± 23.0 vs. 160.0 ± 67.0 min, P = 0.01) as compared with patients in whom this value was <10 g. Four groin haematomas were the only complications observed., Conclusion: Contact force during RFCA for PV isolation affects procedural parameters, in particular procedural and fluoroscopy times, without increasing complications.

Background: The aim of this study was to investigate the efficacy of catheter ablation in the treatment of persistent atrial fibrillation (AF) and the predictors of arrhythmia recurrence., Methods: Absence of atrial tachyarrhythmia (AT) recurrence during a mid-term follow-up was correlated with several clinical and procedural characteristics in a population of 82 patients aged 20-70 years who had experienced at least one documented relapse of persistent AF during a single trial of antiarrhythmic drug therapy. Electrophysiological success of ablation was declared when all identified PVs were isolated (confirmation of entry and exit block). Patients were followed for a maximum of 24 months after the blanking period with outpatient visits, ECG recordings, 24-hour Holter monitoring, and weekly transtelephonic monitoring for 30s., Results: Electrophysiological success was documented in 38/82 (46.3%) patients. During a mean follow-up of 24.7 ± 4.2 months, 69/82 (84.1%) patients presented at least one episode of AT after the 2 month blanking period. According to univariate and multivariate logistic regression analyses, only an electrophysiologically successful ablation significantly correlated with the absence of documented AT relapse (OR 5.32, 95% CL 1.02-27.72; p=.0472)., Conclusions: Mid-term outcome of a single procedure of catheter ablation without the adjunction of antiarrhythmic drug therapy is poor in patients with persistent AF. Documented PV isolation is useful to increase the success rate of circumferential PV ablation even in persistent AF patients., (Copyright © 2013. Published by Elsevier Ireland Ltd.)

Introduction: Aim of this study was to compare efficacy and safety of the new ThermoCool Surround Flow® catheter (SFc) versus the ThermoCool® (TCc) in achieving persistent circumferential electrical isolation of the pulmonary veins (PVs) in patients with paroxysmal atrial fibrillation (AF)., Methods and Results: This multicenter, randomized, controlled study enrolled patients suffering from paroxysmal AF. Randomization was run in a one-to-one fashion between radiofrequency ablation by TCc or SFc. Aim of PVs ablation was documentation of electrical isolation with exit/entrance block recorded on a circular catheter. Among the 106 enrolled patients, 52 (49.0%) were randomized to TCc and 54 (51.0%) to SFc. Total volume of infused saline solution during the procedure was lower in the SFc than in TCc group (752.7 ± 268.6 mL vs 1,165.9 ± 436.2 mL, P < 0.0001). Number of identified and isolated PVs was similar in the 2 groups. Number of PVs remaining isolated 30 minutes after ablation was higher in the SFc than in TCc group (95.2% vs 90.5%, P < 0.03), mainly driven by acute ablation result in the left PVs (96.1% vs 89.7%, P < 0.04). Complications were seldom and observed only in the TCc group (0% vs 3.84%, P < 0.03). At 6-month follow-up SFc patients reported a trend toward less AF recurrences compared to those in the TCc group (22.9% vs 27.0%, P = 0.69)., Conclusion: PV isolation by SFc lowered the rate of left PV early reconnections and reduced the volume of infused saline solution while maintaining the safety profile of AF ablation., (© 2012 Wiley Periodicals, Inc.)

Background: The role of pulmonary veins (PV) isolation in patients with persistent atrial fibrillation (AF) is still debated. The aim of this study was to evaluate the adjunctive role of PV isolation in patients with persistent AF who underwent circumferential PV ablation (anatomical approach)., Methods: We treated 97 consecutive patients presenting with drug-refractory persistent AF by an anatomical approach (group A, n = 36, mean age = 60 +/- 8 years, 29 males) or an integrated approach (group B, n = 61, mean age 59 +/- 10 years, 48 males). In all patients, radiofrequency (RF) ablation was performed by means of a nonfluoroscopic navigation system, in order to anatomically create circumferential lines around the PV. In group B, the persistence of PV potentials was ascertained with a multipolar circular catheter. If PV potentials persisted, RF energy targeting the electrophysiological breakthroughs was delivered to disconnect the PV. Past a 2-month period of observation, success was defined as absence of any atrial tachyarrhythmia recurrence lasting >30 seconds., Results: Total procedure duration (220 +/- 62 minutes vs 140 +/- 43 minutes, P < 0.001), fluoroscopy time (35 +/- 15 minutes vs 17 +/- 9 minutes, P < 0.001), and RF delivery time (48 +/- 22 minutes vs 27 +/- 9 minutes, P < 0.001) were significantly longer in group B than in group A. One cardiac perforation occurred in group A. After 15 +/- 9.1 months, 21 patients in group A (58%) and 34 patients in group B (56%) were free of atrial tachyarrhythmia recurrence (P = 0.9)., Conclusions: In patients with persistent AF, who underwent an anatomical approach, electrophysiological confirmation of PV disconnection significantly increased the fluoroscopy and procedural times, without effect on the long-term outcomes.

Background: Data on the procedural safety of pulmonary vein radiofrequency catheter ablation for atrial fibrillation (AF) are as yet scant., Objective: The aims of the present study were to prospectively evaluate the incidence of early complications of pulmonary vein ablation for AF in an unselected population of consecutive patients, and to identify possible predictors., Methods: From April 2005 to October 2006, data from 1,011 consecutive patients who were undergoing radiofrequency catheter ablation for every type of AF in 10 Italian centers were collected. All complications occurring from the admission of the patient up to the 30th day were considered., Results: No procedure-related death was observed. Complications occurred in 40 patients (3.9%): 12 (1.2%) had peripheral vascular complications, 8 (0.8%) had conservatively treated pericardial effusion, 6 (0.6%) had cardiac tamponade (successfully drained), 5 (0.5%) had cerebral embolisms, 4 (0.4%) presented pulmonary vein stenosis >50%, and 5 (0.5%) presented other isolated adverse events. History of coronary artery disease (odds ratio 5,603, 95% confidence interval 1,559 to 20,139, P < .008) characterized patients who presented with hemorrhagic complications., Conclusion: Early complications of pulmonary vein catheter ablation seem to be fewer than in the early years of AF ablation, but still occur in 3.9% of procedures.

Background: Pulmonary veins (PVs) play a pivotal role in initiating and perpetuating atrial fibrillation (AF). We investigated if PV electrical isolation from the left atrium is required for curing AF., Methods and Result: Fifty-one patients with paroxysmal or persistent AF underwent circumferential radiofrequency ablation of PV ostia performed with an anatomic approach. The end point of the ablation procedure was the recording of low peak-to-peak bipolar potentials (<0.1 mV) inside the lesions. Left atrium pacing was used to assess the conduction between the PVs and the left atrium. During a mean follow-up period of 16.6+/-3.9 months, 41 patients (80.4%) were free of atrial arrhythmias. When patients with and without AF recurrence were analyzed, no significant difference was observed in the mean number of PVs in which the ablation end point was reached (3.4+/-1.2 versus 3.7+/-0.87) and PVs isolated (1.5+/-1.4 versus 1.6+/-1). We noted that, although in 29 of 41 patients (71%) without AF recurrence, the ablation end point was reached in all PVs mapped, it was only possible to demonstrate the isolation of all PVs mapped in 2 patients. On the other hand, in 7 of 10 patients (70%) with AF recurrence, the ablation end point was reached in all PVs mapped, whereas one patient had all PVs isolated., Conclusions: Our findings show that with the use of a pure anatomic approach, it is possible to prevent AF in >80% of patients undergoing catheter ablation. Moreover, the isolation of PVs is not crucial for curing AF.

Radiofrequency (RF) catheter ablation has been proposed as a treatment of atrial fibrillation (AF). Several approaches have been reported and success rates have been dependent on procedural volume and operator's experience. This is the first report of a multicenter study of RF ablation of AF. We treated 44 men and 25 women with paroxysmal (n = 40) or persistent (n = 29), drug refractory AF. Circular pulmonary vein (PV) ostial lesions were deployed transseptally, during sinus rhythm (n = 42) or AF (n = 26), under three-dimensional electroanatomic guidance. Cavo-tricuspid isthmus ablation was performed in 27 (40%) patients. The mean procedure time was 215 +/- 76 minutes (93-530), mean fluoroscopic exposure 32 +/- 14 minutes (12-79), and mean number of RF pulses per patient 56 +/- 29 (18-166). The mean numbers of separate PV ostia mapped and isolated per patient were 3.9 +/- 0.5, and 3.8 +/- 0.7, respectively. Major complications were observed in 3 (4%) patients, including pericardial effusion, transient ischemic attack, and tamponade. At 1-month follow-up, 21 of 68 (31%) patients had had AF recurrences, of whom 8 required electrical cardioversion. After the first month, over a mean period of 9 +/- 3 (5-14) months, 57 (84%) patients remained free of atrial arrhythmias. RF ablation of AF by circumferential PV ostial ablation is feasible with a high short-term success rate. While the procedure and fluoroscopic exposure duration were short, the incidence of major cardiac complications was not negligible.