Pulmonary veins anatomical determinants of cooling kinetics during second-generation cryoballoon ablation.

AIM: The aim of the study was to investigate the role of anatomical characteristics of the pulmonary veins (PVs) determining cooling kinetics during second-generation cryoballoon ablation (CbA). METHODS AND RESULTS: we enrolled all consecutive patients who underwent CbA for symptomatic atrial fibrillation in our center from January 2019 to March 2019. All patients had complete computed tomography scans of the heart before the ablation. Anatomical characteristics were tested for prediction of a nadir temperature (NT) ≤ -48°C. Significant differences were noted among PV max diameter (20.8 ± 2.8 vs 18.5 ± 2.5 mm; P < .001); PV minimum diameter (15.2 ± 3.0 vs 13.0 ± 3.1 mm; P < .001); PV area (268.1 ± 71.9 vs 206.2 ± 58.7 mm2 ; P < .001); PV ovality (1.4 ± 0.3 vs 1.5 ± 0.3; P = .005); and PV trunk length (27.4 ± 7.4 vs 21.3 ± 6.5 mm; P < .001). A scoring system was created by assigning one point each ranging from 0 (best anatomical combination) to 5. In the group with a score of 0, 94.0% of the CbA could reach a NT ≤ -48°C whereas with a score of 5, only 29.0% (P < .001). Left superior pulmonary vein with short trunk length and acute angle of PV branch was significantly associated with warmer NT (11.8% satisfactory CbA; P = .003). Regarding right inferior pulmonary vein, trunk length (P = .004), maximum diameter (P = .044), and transverse angle (P = .008) were independently associated with good NT. CONCLUSION: Anatomical PV features are associated with cooling kinetics and an anatomical score could predict lower NT during second-generation CbA. Specific characteristics were identified for inferior PV. Although heart imaging is not mandatory prior CbA, it can be a useful tool to predict cooling kinetics.

Characteristics of the nonpulmonary vein foci induced after second-generation cryoballoon ablation for paroxysmal atrial fibrillation.

INTRODUCTION: Pulmonary vein isolation (PVI) using cryoballoon is effective for patients with paroxysmal atrial fibrillation (PAF); however, few reports have evaluated the non-pulmonary vein (PV) foci after cryoballoon ablation. We aimed to evaluate the characteristics of non-PV foci and predictors of atrial fibrillation (AF) recurrence after cryoballoon ablation. METHODS AND RESULTS: This was a single-center retrospective study of 647 patients with PAF who underwent initial PVI using a second-generation cryoballoon. After PVI, all patients underwent high-dose isoproterenol infusion to assess the existence of non-PV foci. Non-PV foci were observed in 211 patients (32.6%), which were most frequently observed in the superior vena cava. Higher age (odds ratio [OR] = 1.02; 95% confidence interval [CI] = 1.00-1.04; P = .025), female sex (OR = 1.65; 95% CI = 1.13-2.41; P = .009), and lower body mass index (OR = 0.95; 95% CI = 0.89-1.00; P = .049) were significantly associated with non-PV foci. The existence of non-PV foci was an independent predictor of AF recurrence (Hazard's ratio = 1.70; 95% CI = 1.12-2.60; P = .014). When non-PV foci were mappable and successfully ablated, patients with non-PV foci showed similar outcomes with those without non-PV foci (1-year AF-free survival rates of 88.5% vs 91.5%; P = .338). Conversely, when we failed to detect and eliminate non-PV foci because they had multiple origins and were not consistently inducible (multichanging non-PV foci), the 1-year AF-free survival rate was 56.4% even after substrate modification. CONCLUSION: Non-PV foci were observed in one-third of patients with PAF after cryoballoon ablation and were associated with AF recurrence. Catheter ablation for non-PV foci was effective when they were mappable; however, multichanging non-PV foci were associated with worse prognosis.

Predictors of durable electrical isolation in the setting of second-generation cryoballoon ablation: A comparison between left superior, left inferior, right superior, and right inferior pulmonary veins.

AIM: The aim of this study is to assess specific per-vein procedural predictors of pulmonary vein (PV) late reconnection in cryoballoon ablation (CbA) METHODS AND RESULTS: We enrolled 148 consecutive patients undergoing a redo procedure after a previous index CbA in our center. A reconnection in at least one PV was found in 80 patients (54.1%) and the most frequently reconnected PV was the right inferior pulmonary vein (RIPV). Overall, pulmonary vein reconnection (PVr) was associated with longer time to -40°C (Tt-40°C) (54.4 ± 21.7 vs 67.6 ± 27.6 seconds; P < .001), warmer nadir temperature (NT) (-49.7°C ± 5.4°C vs -46.5°C ± 5.8°C; P < .001) and temperature at 60 seconds (-41.8°C ± 4.5°C vs -39.8°C ± 4.2°C; P < .001). The performance of these predictors differed between the veins. In particular, a comparable behavior was observed for left superior pulmonary vein (LSPV) and right superior pulmonary vein (RSPV), where NT ≤ -48°C showed a sensibility and a specificity, respectively, of 62% and 65% and 71% and 72% in predicting durable PV isolation. For RIPV, NT ≤ -48°C showed a sensitivity of 74% but low specificity (53%). Tt -40°C less than 60 seconds showed good negative predictive values, respectively, 83.9% for LSPV, 94.9% for left inferior pulmonary vein (LIPV), 90.2% for RSPV, and 82.7% for RIPV. Previous predictors cannot be used for LIPV. CONCLUSIONS: Freezing behavior and reconnection rates differ significantly among the four PVs. Freezing temperature parameters strongly predict late PVr in superior PVs and are slightly different in RIPV but can be applied as well. LIPV freezing behavior is the most different. Its reconnection is uncommon even in the subset of worse freezing temperatures and specific CB predictors cannot be identified.

A systematic review and meta-analysis comparing second-generation cryoballoon and contact force radiofrequency ablation for initial ablation of paroxysmal and persistent atrial fibrillation.

INTRODUCTION: Cryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the preferred modalities for catheter ablation of atrial fibrillation (AF). Technological advances have improved procedural outcomes, warranting an updated comparison. We sought to evaluate the efficacy and safety of CBA-2nd generation (CBA-2G) in comparison to RFA-contact force (RFA-CF) in patients with AF. METHODS: MEDLINE, Cochrane, and ClinicalTrials.gov databases were searched until 03/01/2020 for relevant studies comparing CBA-2G versus RFA-CF in patients undergoing initial catheter ablation for AF. RESULTS: A total of 17 studies, involving 11 793 patients were included. There was no difference between the two groups in the outcomes of freedom from atrial arrhythmia (p = .67) and total procedural complications (p = .65). There was a higher incidence of phrenic nerve palsy in CBA-2G (odds ratio: 10.7; 95% confidence interval [CI]: 5.85 to 19.55; p < .001). Procedure duration was shorter (mean difference: -31.32 min; 95% CI: -40.73 to -21.92; p < .001) and fluoroscopy duration was longer (+3.21 min; 95% CI: 1.09 to 5.33; p = .003) in CBA-2G compared to RFA-CF. In the subgroup analyses of patients with persistent AF and >1 freeze lesion delivered per vein, there was no difference in freedom from atrial arrhythmia. CONCLUSIONS: In AF patients undergoing initial ablation, CBA-2G and RFA-CF were equally efficacious. The procedure duration was shorter, but with a higher incidence of phrenic nerve palsy in CBA-2G. In patients with persistent AF, there was no difference in the efficacy between CBA-2G or RFA-CF techniques.

Learning curves in atrial fibrillation ablation - A comparison between second generation cryoballoon and contact force sensing radiofrequency catheters.

OBJECTIVE: To examine the learning curves of atrial fibrillation (AF) ablation comparing the cryoballoon (CB) and radiofrequency (RF) catheters. METHODS: We performed a retrospective data analysis from the initiation of AF ablation program in our center. For CB ablation, a second generation 28 mm balloon was utilized and for RF ablation. RESULTS: A total of 100 consecutive patients (50 in each group) have been enrolled in the study (male 74%, mean age 58.9 ± 10 years, paroxysmal AF 85%). The mean procedure time was shorter for CB (116.6 ± 39.8 min) than RF group (191.8 ± 101.1 min) (p < 0.001). There was no difference in the mean fluoroscopy time, 24.2 ± 10.6 min in RF and 22.4 ± 11.7 min in CB group, (p = 0.422). Seven major complications occurred during the study; 5 in RF group (10%) and 2 in CB group (4%) (p = 0.436). After the mean follow up of 14.5 ± 2.4 months, 15 patients in RF group (30%) and 11 in CB group (26%) experienced AF recurrences (P = 0.300). CONCLUSION: When starting a new AF ablation program, our results suggest that CB significantly shortens procedure while fluoroscopy time and clinical outcomes are comparable to RF ablation.

Phrenic nerve injury during right inferior pulmonary vein ablation with the second-generation cryoballoon: A report of 2 cases and literature review. / 第2代冷冻球囊消融右下肺静脉致膈神经损伤2ä¾‹åŠæ–‡çŒ®å¤ä¹ .

The performance of the second-generation cryoballoon has been greatly improved compared to the first-generation.But it has not reduced the incidence of phrenic nerve injury, and even increased the incidence of this complication during ablation of the right inferior pulmonary vein. Two cases of phrenic nerve injury occurred when right inferior pulmonary vein was ablated with the second-generation cryoballoon in Department of Cardiovascular Medicine, Second Xiangya Hospital, Central South University. Based on literature review, the possible causes for phrenic nerve injury in our report were summarized to provide helpful information for operators aiming to reduce the occurrence of this complication related to the second-generation cryoballoon.

Anatomic predictors of late right inferior pulmonary vein reconnection in the setting of second-generation cryoballoon ablation.

INTRODUCTION: The right inferior pulmonary vein (RIPV) accounts as the most frequently reconnected vein after pulmonary vein isolation using second-generation cryoballoon ablation (CB-A). Our objective was to assess anatomic predictors of late RIPV reconnection based on preprocedural computed tomography scan. METHODS: Patients with a repeat procedure for atrial tachyarrhythmia recurrence after index CB-A procedure were included. A total of 129 RIPVs were evaluated for ostial diameters, ostial area, and branching pattern. Interior angle between RIPV and horizontal line in the frontal/transversal plane was used to measure the RIPV orientation: RIPV frontal/transversal angle, respectively. In addition, interior angle between RIPV and the line perpendicular on the septal intersection line at the level of the fossa ovalis, estimated as trans-septal (TS) puncture site, was measured in the frontal/transversal view: RIPV-TS frontal/transversal angle, respectively. RESULTS: Late vein reconnection was present in 36/129 RIPVs (28%). Warmer balloon nadir temperature (P = .01), more inferior (P < .001) and posterior (P < .01) RIPV orientation (ie, more positive RIPV frontal and RIPV transversal angle, respectively), and sharper RIPV-TS frontal angle (P < .001) were associated with late RIPV reconnection on univariate analysis. Independent variables after multivariate analysis were nadir temperature (odds ratio [OR], 1.12; 95% confidence interval [CI], 1.03-1.23; P = .013) and RIPV frontal angle (OR, 1.13, CI, 1.07-1.19; P < .001). CONCLUSION: Frontal RIPV orientation could significantly predict late RIPV electrical reconnection after CB-A. Therefore, preprocedural anatomic assessment of the RIPV might be useful to plan the correct ablation strategy.

Value of ultrasound for access guidance and detection of subclinical vascular complications in the setting of atrial fibrillation cryoballoon ablation.

AIMS: Vascular complications are the most common complications of atrial fibrillation (AF) ablation. Cryoballoon (CB) ablation for AF needs the insertion of a large 15 Fr sheath in the femoral vein. Our aim was to investigate the impact of vascular ultrasound (US) in guiding access and evaluating post-procedural subclinical complications in a large, multi-centre patient cohort that underwent CB ablation. METHODS AND RESULTS: A total cohort of 1435 consecutive patients were subdivided in 870 US -/-, 265 US -/+, and 300 US +/+ patients depending on US performance for: venipuncture guidance/post-procedural evaluation. Major clinical complications (requiring intervention and/or prolonged stay) were assessed. Irrespective of the clinical status, major US events were systematically determined in the subgroups with US evaluation 1 day post-procedure, if evidence of inadvertent artery puncture/cannulation (communication between artery and collection or artery-vein, regardless of the thrombosis state). Major clinical events were encountered in 1.7% (15/870), 1.1% (3/265), and 0% of patients in US -/-, US -/+, and US +/+ group, respectively (P = 0.02 between US -/- and US +/+ group). In the US -/- group, 5/10 (50%) of pseudo-aneurysms were diagnosed during readmission after a mean of 24 ± 11 days post-procedure. No delayed presentation was seen in the US -/+ group. Major US events during the US protocol post-procedure were seen in 3.8% (10/265) vs. 0.3% (1/300) of patients in US -/+ vs. US +/+ group, respectively, P = 0.004. CONCLUSION: US-guided venipuncture was associated with a near-to-zero risk of vascular complications in our patients undergoing CB ablation.

Over-the-needle trans-septal access using the cryoballoon delivery sheath and dilator in atrial fibrillation ablation.

BACKGROUND: In the setting of second-generation cryoballoon (CB2) ablation, left atrial (LA) access is generally achieved using a standard sheath (SS) that is exchanged for the 15Fr cryoballoon delivery sheath (CBS) and dilator over a long wire (CBS over-the-wire technique, CBS-W). Our objective was to evaluate the direct use of the CBS to gain LA access, by advancing the latter over the trans-septal needle (CBS over-the-needle technique, CBS-N), under transesophageal echocardiographic (TEE) guidance. METHODS: Consecutive patients who underwent CB2 ablation with the CBS-N technique were evaluated for feasibility of gaining LA access using TEE guidance and fluoroscopy views. Complications related to the LA access were compared with a matched CBS-W control group. Subanalysis (30 CBS-W vs 30 CBS-N patients) evaluated time-to-LA of the CBS: time from superior vena cava (with SS vs CBS) to LA insertion of the CBS, after exchange or directly, respectively. RESULTS: LA access could be achieved in all 505 patients of the CBS-N group, without technique modification or additional equipment. Challenging interatrial septa were noted in 13% of these patients: previous atrial septal defect repair (1%), hypermobile (10%), aneurysmal (1%), and abnormally thickened/fibrotic (1%). Incidence of complications was similar to the CBS-W group. Subanalysis showed a shorter time-to-LA in the CBS-N versus CBS-W group, 72 ± 46 seconds versus 293 ± 180 seconds, P < .001. CONCLUSIONS: Our study showed that the CBS-N technique is feasible and safe under echocardiographic guidance. Without sheath exchange, it simplifies the CB2 procedure, is less costly, time sparing, and might reduce the risk of air embolism.

Radiofrequency versus cryoballoon ablation for atrial fibrillation in the setting of left common pulmonary veins.

BACKGROUND: A left common pulmonary vein (LCPV) accounts as the most frequent pulmonary vein (PV) variation. Our aim was to compare the performance of radiofrequency (RF) versus second-generation cryoballoon (CB-A) ablation in patients with atrial fibrillation (AF) and LCPVs. METHODS: In a total cohort of 716 patients undergoing PV isolation with preprocedural CT-scanning, LCPV+ patients were selected with measurement of PV ostial area and trunk distance. All LCPV+ patients were matched between RF and CB-A group in a 1:1 ratio based on propensity scores, and compared for outcome. RESULTS: Left common pulmonary veins were found in 31% (88/283) RF versus 34% (146/433) CB-A patients, respectively, (P = .44). In the matched population of 83 LCPV+ patients in each group, electrical isolation could be achieved in all left-sided PVs. No significant difference was noted for the rate of AF/left atrial tachyarrhythmia (LAT) recurrence between RF and CB-A group (30% vs 28%, P = .86), with similar AF/LAT-free survival (log rank, P = .71). There were 48 patients with AF/LAT recurrence (29%) during the follow-up. Recurrence rate between paroxysmal versus persistent AF was 27/120 (22.5%) versus 21/46 (46%), P = .004. Cox proportional regression analysis withheld LA volume and persistent AF as independent variables to predict AF/LAT recurrence. No increased hazard for AF/LAT recurrence was observed for patients with a long (>15 mm) vs short (5-15 mm) LCPV trunk (OR 1.14, 95% CI 0.6-2.2, P = .7). CONCLUSIONS: In our study, equal efficacy and outcome was noted in LCPV+ patients between RF and CB-A technology.

Five-year experience with pulmonary vein isolation using the second-generation cryoballoon for treatment of persistent atrial fibrillation.

INTRODUCTION: We analyzed the procedural experience and clinical outcome after pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (AF) gained over 5 years using the second-generation cryoballoon (CB-Adv). METHODS AND RESULTS: For this retrospective study, we enrolled 281 patients undergoing PVI at our institution between 2012 and 2016. The analyzed period was divided into 5 calendar years. Follow-up data, including Holter electrocardiography recordings, were collected during outpatient clinic visits. The impact of several variables on outcome was evaluated by means of univariate and multivariate analyses and Cox proportional hazards regression models. The median procedure and fluoroscopy times over the years were 90 (72 of 114) and 15 (11 of 21) minutes, respectively. A continuous decline in complication rates and fluoroscopy and procedure times was observed in each subsequent year. During mid-term follow-up (33 [25 of 48] months), 178 (63.3%) patients were AF, atrial flutter, or atrial tachycardia free. Multivariate analysis revealed left atrial area (hazard ratio [HR] = 1.05; P < 0.001), female sex (HR = 2.53; P < 0.001), and common ostium (HR = 1.93; P < 0.001) as significant predictors of outcome. The overall 1-year success rate was 76.2%. A gradual decrease in the 1-year success rate (from 90.5% in 2012 to 67.9% in 2016) was mainly related to a steady increase of left atrial area in the entire cohort with successive years of the study. CONCLUSIONS: PVI using CB-Adv in patients with persistent AF is accompanied by a learning curve and facilitates a satisfactory outcome, followed by the proper selection of patients.

Ice or fire? Comparison of second-generation cryoballoon ablation and radiofrequency ablation in patients with symptomatic persistent atrial fibrillation and an enlarged left atrium.

INTRODUCTION: We aimed to compare arrhythmia recurrence rates after second-generation cryoballoon (CB-Adv) ablation and radiofrequency (RF) ablation in patients with symptomatic persistent atrial fibrillation (AF) and left atrial (LA) enlargement. METHODS AND RESULTS: Persistent AF patients with LA enlargement were compared using a propensity-score-matching algorithm, and 111 patients treated with CB-Adv ablation and 111 patients treated with RF ablation were selected. The primary endpoint was the first documented >30-second arrhythmia recurrence after a 3-month blanking period. Median LA area was comparable between the RF and CB-Adv groups (24.2 vs. 24.0 cm2 , P = 0.49). In addition to pulmonary vein isolation, roof lines (RLs) with bidirectional conduction block were created in 48 patients in the CB-Adv group and 49 patients in the RF group. Midterm outcome after single procedure is characterized by arrhythmia recurrences in 47 patients in the RF group and 32 patients in the CB-Adv group (P = 0.20). There were no differences in the number of AF recurrences in the two groups (38 vs. 32, P = 0.66), but there were more instances of LA tachycardia (LAT) in the RF group than in the CB-Adv group (11 vs. 0, P < 0.01). LAT recurrence in RF patients was associated with RL creation (9 with vs. 2 without, P < 0.01). Among patients in whom a RL was created, arrhythmia-free survival was lower in the RF group than in the CB-Adv group (44.9% vs. 79.2%, P < 0.01). CONCLUSIONS: Arrhythmia recurrence rates in the two groups during midterm follow-up were comparable. RL creation during CB-Adv ablation resulted in acceptable outcomes.

Second-generation cryoballoon ablation for treatment of persistent atrial fibrillation: Three-year outcome and predictors of recurrence after a single procedure.

INTRODUCTION: Data on long-term outcomes of cryoballoon (CB) ablation for treatment of persistent atrial fibrillation (AF) are sparse. Here, we report the first 3-year follow-up results and predictors of success for catheter ablation using the second-generation CB in patients with persistent AF. METHODS AND RESULTS: For this prospective observational study, we enrolled 101 patients ablated with the second-generation CB at our institution. The endpoint was the first documented recurrence (> 30 seconds) of AF, atrial flutter, or atrial tachycardia after a 3-month blanking period. Follow-up data were collected during outpatient clinic visits and included Holter-ECG recordings. The impact of several variables on recurrence was evaluated by means of univariate and multivariate analyses and Cox proportional hazards regression models. After a median follow-up of 37 (31 of 42) months, recurrence was documented in 30 patients (29.7%). The median procedure and fluoroscopy times were 120 (102 of 147) and 20 (16 of 27) minutes, respectively. Phrenic nerve palsy occurred in 2.0% of the patients. Among the 30 patients who experienced recurrence, 16 underwent repeat ablation in radiofrequency technique. Cox regression analysis showed that left atrial area > 21 cm2 and AF history duration > 2 years independently predicted recurrence. CONCLUSIONS: Sinus rhythm was maintained in a substantial proportion of patients even 3 years after CB ablation. Patients with a nonenlarged left atrium and short AF history had the best outcome.

Efficacy and safety of the second generation cryoballoon ablation for the treatment of paroxysmal atrial fibrillation in patients over 75 years: a comparison with a younger cohort.

AIMS: In this double centre, retrospective study, we aimed to analyse the 1-year efficacy and safety of cryoballoon ablation (CB-A) in patients older than 75 years compared with those younger than 75-years old. METHODS AND RESULTS: Fifty-three consecutive patients aged 75 years or older with drug-resistant paroxysmal AF (PAF) who underwent pulmonary vein isolation (PVI) by the means of second generation CB-A, were compared with 106 patients aged <75 years. The mean age in the study group (>75 years) was 78.19 ± 2.7 years and 58.97 ± 8.5 in the control group. At 1-year follow-up the global success rate was 83.6% and did not significantly differ between older (10/53) and younger patients (16/106) (81.1 vs. 84.9%, P = 0.54). Transient phrenic nerve palsy was the most common complication which occurred in eight patients in the younger group and in three in the older group (7.5 vs. 5.7%, respectively, P = 0.66). CONCLUSIONS: The results of our study showed that CB-A for the treatment of PAF is a feasible and safe procedure in elderly patients, with similar success and complications rates when compared with a younger population.

Pulmonary vein isolation in patients with paroxysmal atrial fibrillation : Long-term clinical outcomes with first- and second-generation cryoballoons.

BACKGROUND: The aim of this study was to evaluate the long-term success rates of pulmonary vein isolation (PVI) using only first-generation cryoballoon (CB-1) and second-generation CB (CB-2) in patients with paroxysmal atrial fibrillation (PAF). PATIENTS AND METHODS: A total of 114 drug-refractory patients with PAF (mean age: 62 ± 10 years; 62.3 % males) were enrolled. All index ablation procedures were performed using a 28-mm CB. All patients were scheduled for outpatient clinic visits, followed by 24-h or 7­day Holter electrocardiogram (EGC) evaluation. RESULTS: All PVs in the CB-1 group and 367 of 368 (99.7 %) PVs in the CB-2 group were completely isolated during the index procedure. The most commonly observed complication was phrenic nerve palsy in four (4.3 %) patients with CB-2. The mean follow-up period for CB-1 and CB-2 was 33.4 ± 14.9 and 27.2 ± 10.6 months, respectively. Freedom from AF was 42.9 % for CB-1 and 74.2 % for CB-2 at the end of the follow-up period. The European Heart Rhythm Association score improved in patients without AF recurrence after the procedure (2.8 ± 0.4 vs. 1.2 ± 0.5, p < 0.001), whereas no significant improvement was observed in the symptomatic status of patients with recurrence (2.8 ± 0.4 vs. 2.2 ± 0.9, p = 0.149). CONCLUSION: Second-generation CB provided significantly better clinical outcomes than its predecessor and was associated with low peri- and postprocedural complications.

Single 3-Minute versus Double 4-Minute Freeze Strategy for Second-Generation Cryoballoon Ablation: A Single-Center Experience.

INTRODUCTION: Second-generation cryoballoon (CB-Adv) ablation is highly effective in achieving pulmonary vein isolation (PVI) with promising mid-term clinical outcome. However, the ideal freezing strategy is still under debate. The aim of this study was to assess the efficacy of a single 3-minute approach compared to the conventional 4-minute plus bonus application using CB-Adv. METHODS AND RESULTS: One hundred and sixty patients (67% male; mean age 58.0 ± 13.3 years) underwent PVI using CB-Adv for paroxysmal atrial fibrillation (PAF). Among 160 patients, 80 received a single 3-minute approach (3-mns group), while the remaining 80 conventional 4-minute plus bonus-freeze (4-mns group). Mean procedure and fluoroscopy times were 90.6 ± 15.8 and 18.3 ± 6.9 in the 4-mns group, 75.2 ± 17.1 and 13.5 ± 8.7 in the 3-mns group (P < 0.001, respectively). First-freeze isolation rate was 91.6% in the 4- versus 90.6% in the 3-mns group (P = 0.78). Persistent phrenic nerve palsy (PNP) occurred in 6/80 (3.5%) in the 4-mns group and 4/80 in the 3-mns group (P = 0.75). The overall freedom from ATas 2 years after the procedure was 78.1% (125/160): 77.5% (62/80 patients) in the 3-mns and 78.8% (63/80 patients) in the 4-mns group (P = 0.82). In multivariate analysis, time to PVI and nadir temperature independently predicted ATa recurrences (P < 0.001). CONCLUSIONS: CB-Adv ablation for PAF is highly effective, resulting in 78% 2-year freedom from arrhythmic recurrences. A "single 3-minute strategy" showed equal efficacy as compared to the conventional 4-minute plus bonus freeze approach at 2-year follow-up, providing shorter procedure and fluoroscopy time. Nadir temperature and time to PVI were predictors of arrhythmic recurrences. "Bonus-freeze" strategy might be unnecessary.

Electrophysiological findings following pulmonary vein isolation using radiofrequency catheter guided by contact-force and second-generation cryoballoon: lessons from repeat ablation procedures.

AIMS: To assess the incidence of late pulmonary vein (PV) reconnection following index PV isolation (PVI) procedure initially achieved with radiofrequency contact-force catheter ablation (CFCA) and second-generation cryoballoon ablation (CB-AdvA). METHODS AND RESULTS: A total of 56 consecutive patients (41 male, 73.2%; mean age 60.8 ± 11.8 years) underwent a repeat ablation because of recurrent atrial tachyarrhythmias (ATas) after index PVI achieved with CFCA (30 patients) or CB-AdvA (26 patients). All repeat procedures were performed by the means of CFCA. In the CFCA group, among 119 PVs, 43 (36.1%) showed conduction gaps in 24 patients (1.8 per patient), whereas in the CB-AdvA group among 103 veins, 21 (20.4%) showed a PV reconnection in 18 patients (1.2 per patient) (P = 0.01). The left superior pulmonary vein was less frequently reconnected following CB-AdvA when compared with CFCA (2/25, 8% vs. 11/29, 37.9%; P = 0.01). In the CFCA group, the mean CF per-vein was lower in reconnecting veins when compared with those persistently isolated (10.9 ± 2.7 vs. 18.6 ± 3.1 g; P < 0.001). In the CB-AdvA group, late PV reconnection was associated with warmer nadir temperature (-48.9 ± 5.1 vs. -51.2 ± 4.7°C; P = 0.05) and longer time-to-isolation (71.1 ± 20.2 vs. 50.2 ± 32.9 s; P = 0.03). CONCLUSION: The rate of late PV reconnection is significantly lower following CB-AdvA when compared with CFCA as index procedure. Lower CF values and warmer nadir temperature with longer time to effect were more frequently associated with PV reconnections in the setting of CFCA and CB-AdvA.

One-year follow-up after second-generation cryoballoon ablation for atrial fibrillation in a large cohort of patients: a single-centre experience.

AIM: The second-generation cryoballoon (CB-Adv) is effective in achieving pulmonary vein isolation (PVI) with encouraging results. In this study, we assessed the single-procedure outcome on a 1-year follow-up period in a large sample of patients having undergone PVI for drug-resistant atrial fibrillation (AF) using the CB-Adv. METHODS AND RESULTS: A total of 393 patients (122 female, 31%; mean age 57.7 ± 12.9 years) with drug-refractory AF undergoing PVI using the novel CB-Adv were enrolled. Follow-up was based on outpatient clinic visits including Holter electrocardiograms. Recurrence of atrial tachyarrhythmias (ATas) was defined as a symptomatic or documented episode >30 s. A total of 1572 pulmonary veins (PVs) were identified and successfully isolated with 1.2 ± 0.3 mean freezes. Mean procedure and fluoroscopy times were 87.1 ± 38.2 and 14.9 ± 6.1 min, respectively. At a mean follow-up of 12 months, freedom from ATas after a single procedure was achieved in 85.8% of patients with paroxysmal atrial fibrillation and in 61.3% of patients with persistent AF (persAF). Similar success rates were observed between bonus freeze and single freeze strategies, 82.5 and 81.8%, respectively (P = 0.9). Multivariate analysis demonstrated that persAF (P = 0.04) and relapses during blanking period (BP) (P < 0.0001) were independent predictors of ATas recurrences. CONCLUSION: Freedom from any ATa can be achieved in 81.9% of patients after a single CB-Adv procedure in a large cohort of patients. A bonus freeze does not influence the clinical outcome, and reducing the duration of the cryoapplication to 3 min offers excellent results. Persistent AF and arrhythmia recurrence during the BP are strong predictors of AF recurrence.

One-Year Clinical Outcome of Pulmonary Vein Isolation Using the Second-Generation Cryoballoon: A Meta-Analysis.

BACKGROUND: The second-generation cryoballoon (CB-2G) is a promising technique to treat atrial fibrillation (AF). It is necessary to summarize and analyze the available data on 1-year clinical outcome of pulmonary vein isolation (PVI) with CB-2G. METHODS: PubMed and the Web of Science were searched in May 2015. Studies that reported the 1-year clinical success rates after PVI using CB-2G were included. The 1-year clinical success rates were pooled using the random-effect model. Complication rates and acute success rates were also analyzed. Subgroup analyses were conducted based on AF type and ablation strategy. RESULTS: Fifteen studies involving 2,363 AF patients met the inclusion criteria. The overall clinical success rate of PVI using CB-2G was 81%. A total of 82% of paroxysmal AF patients and 70% of persistent AF patients were in stable sinus rhythm 1 year after the procedure. The clinical success rates of the "no-bonus" strategy were 81% in all patients, 82% in paroxysmal AF patients, and 73% in persistent AF patients. The corresponding success rates of the "bonus" strategy were 81%, 83%, and 63%. Acute success rate was high. The overall rates of phrenic nerve palsy (PNP) and other procedure-related complications were 5.8% and 1.5%, respectively. Compared with "bonus" strategy, there was a trend of fewer PNPs in "no-bonus" strategy (4.6% vs 6.5%). CONCLUSIONS: CB-2G is highly effective in the treatment of both paroxysmal AF and persistent AF. The "no-bonus" strategy is as effective as the "bonus" strategy in terms of 1-year clinical outcome.

Circumferential pulmonary vein isolation as index procedure for persistent atrial fibrillation: a comparison between radiofrequency catheter ablation and second-generation cryoballoon ablation.

AIMS: To assess the 1 year efficacy of pulmonary vein isolation (PVI) as index procedure for persistent atrial fibrillation (PersAF) comparing conventional radiofrequency irrigated-tip catheter ablation (RFCA) using contact-force technology and ablation using the second-generation cryoballoon (CB-AdvA). METHODS AND RESULTS: One hundred consecutive patients (74 male, 74%; mean age 62.4 ± 9.6 years) with drug-refractory PersAF undergoing PVI using RFCA and CB-AdvA were enrolled. Follow-up was based on outpatient clinic visits including Holter-electrocardiograms. Recurrence of atrial tachyarrhythmias (ATas) was defined as a symptomatic or documented episode >30 s. Among 100 patients, 50 underwent RFCA whereas 50 CB-AdvA. Mean procedure and fluoroscopy times were 90.5 ± 41.7 vs. 140.2 ± 46.9 min and 14.5 ± 6.6 vs. 19.8 ± 6.8 min in the CB-Adv and in the RFCA group, respectively (P < 0.01). At 1 year follow-up, after a 3 months blanking period (BP), freedom from ATas off-drugs after a single procedure was 60% (28/50 patients) in the CB-Adv and 56% (27/50 patients) in the RFCA group (P = 0.71). Multivariate analysis demonstrated that PersAF duration (P = 0.01) and relapses during BP (P = 0.02) were independent predictors of ATa recurrences following the index procedure. CONCLUSION: Freedom from ATas following PersAF ablation with RFCA and CB-Adv is comparable at 1 year follow-up after a single procedure. Ablation with the CB-Adv is associated with shorter procedure time and radiation exposure as compared with RFCA. Atrial tachyarrhythmias occurrence during BP and longer time of PersAF seem to be significant predictors of arrhythmia recurrences after the index procedure.