Initial clinical experience of pulmonary vein isolation using the ultra-low temperature cryoablation catheter for patients with atrial fibrillation.

BACKGROUND: The iCLAS ultra-low temperature cryoablation (ULTC) system has recently been brought to the market. A combination of a newly exploited cryogen and interchangeable stylet enables flexible and continuous lesion creation in atrial fibrillation (AF) ablation. The use of an esophageal warming balloon is recommended when using the system to reduce the potential for collateral esophageal injury. OBJECTIVE: To describe the initial clinical experience when using ULTC in the AF treatment without general anesthesia (GA). METHODS: Consecutive patients undergoing AF ablation using ULTC under deep sedation without GA were enrolled. We assessed the procedural data focusing on "single-shot isolation" defined as successful pulmonary vein (PV) isolation after the first application. Esophagogastroduodenoscopy was systematically performed the day after ablation. RESULTS: A total of 27 AF patients (67% paroxysmal AF) were analyzed. Onehundred four out of 106 PVs (98.1%) were isolated solely using ULTC. The mean procedure time was 79 ± 30 min. The mean number of applications per PV was 2.6 ± 1.0. Single-shot isolation was achieved in 57 PVs (54%) varying across PVs from left superior to inferior PVs (40%-64%). The single procedure 6-month recurrence-free rate was 84%. No major complication (cerebrovascular event, pericardial effusion/tamponade, esophageal damage on esophagogastroduodenoscopy) occurred. A single transient phrenic nerve palsy occurred during the right superior PV ablation, which had recovered by the 3-month follow-up appointment. CONCLUSIONS: AF ablation using the novel ULTC system seemed feasible without GA and enabled a >50% single-shot isolation rate. The promising safety profile has to be confirmed in large-scale studies.

Impact of body mass index on cryoablation of atrial fibrillation: Patient characteristics, procedural data, and long-term outcomes.

INTRODUCTION: Ablation of atrial fibrillation in the context of obesity can be challenging. We sought to evaluate the role of cryoballoon pulmonary vein isolation (CB-PVI) in obese patients with symptomatic atrial fibrillation (AF). METHODS: Patients with a BMI ≥ 25 kg/m2 and symptomatic AF who underwent CB-PVI were retrospectively enrolled. Three groups were defined (G1: BMI of 25-29 kg/m2 ; G2: BMI of 30-34 kg/m2 ; G3: BMI ≥ 35 kg/m2 ). RESULTS: 600 patients were included (59% male; 66 ± 11 years old); 337, 149, and 114 were assigned to G1, G2, and G3, respectively. Acute procedural success was recorded in 99.7% of patients. Procedural and fluoroscopy time were comparable but the radiation dose was significantly higher in G3. Procedural complications were 3% in G1, 5.4% in G2, and 8.8% in G3 (p = .01). The overall freedom from AF after 1-year was 77%. G3 had a significantly worse 1-year success rate compared to G1 and G2 (G3: 66.5% vs. G1: 78.4%; p = .015 and vs. G2: 82.5%; p = .008) with reduced 1-year success in paroxysmal AF (G1: 84.0%; G2: 86.3%; and G3: 69.6%) but not in persistent AF (G1: 68.7%; G2: 77.4%; and G3: 62.1%). G3 showed similar success rates irrespective of AF form (PAF: 69.6% vs. persAF 62.1%; p = .501). CONCLUSION: Cryoballoon ablation in obese patients can be effective with an acceptable safety profile, 77% of patients were in stable SR at 1 year. Severe obese patients (BMI ≥ 35) showed reduced procedural safety and 1-year success rate. In association with life style modification, CB ablation may represent a strategy to enhance rhythm control in the context of obesity.

Validation of lesion durability following pulmonary vein isolation using the new third-generation laser balloon catheter in patients with recurrent atrial fibrillation.

BACKGROUND: The second- and third-generation endoscopic ablation systems (EAS2 and EAS3) have been launched in recent years. We aimed to assess the lesion durability as well as gap localization using the multigenerational novel technologies in patients with recurrent atrial fibrillation (AF). METHODS: Consecutive patients who underwent second ablation for recurrent AF following the initial pulmonary vein isolation (PVI) with EAS2 or EAS3 were retrospectively investigated. The persistent durability of PVI, gap localization at the second procedure, and procedural/anatomical features of durable PVI were analyzed. RESULTS: Among 225 patients treated with EAS3 (N = 125) and EAS2 (N = 100), 34 patients (EAS3: 13 patients, 50 PVs, EAS2: 21 patients, 82 PVs) underwent a second procedure because of recurrent AF mean 11.9 ± 9.3 months after the initial procedure. Persistent isolation of all four PVs was recorded in 6 (46.2%) patients in EAS3 group and 4 (19.1%) patients in EAS2 group (p = 0.130). Ninety-one out of 132 (68.9%) PVs were persistently isolated with a higher rate in EAS3 group (82.0% vs. EAS2 group: 61.0%, p = 0.0113). A total of 45 gaps were recorded in 41 PVs. Right superior PV (RSPV) was the predominantly common reconnected vein (15 gaps, 14 PVs) irrespective of generations (EAS3: 4 gaps in 3 PVs and EAS2: 12 gaps in 11 PVs). Logistic multivariate regression analysis revealed ablation without reduced energy dose (5.5-7 W) as an independent predictor of durable PVI [adjusted OR: 3.70, 95% CI (1.408-10.003)], p = 0.008]. CONCLUSION: The technical innovation resulted in a higher lesion durability in EAS3-guided PVI in patients with recurrent AF. The most common gap location was found at RSPV in successor EASs. Ablation without reduced energy was a predictor of durable PVI in successor EASs.

Increased procedural safety of cryoballoon pulmonary vein isolation with a double 120 s freeze protocol.

BACKGROUND: Recently a double 120 s freeze cryoballoon (CB) pulmonary vein isolation (PVI) protocol proved to be non inferior to a double 240 s freeze protocol in terms of atrial fibrillation (AF) recurrences. We hypothesized that this approach could also result in an increased procedure safety. METHODS: Eighty consecutive patients treated with a double 120 s freeze protocol (Group CB120) were compared with 80 previous consecutive patients treated with a single 240 s freeze protocol (Group CB240). Procedures were performed with a temperature probe to monitor the luminal esophageal temperature (LET), using a cut off for cryoenergy interruption of 15°C. During ablation at the septal pulmonary veins (PVs), the phrenic nerve (PN) function was monitored by pacing. RESULTS: In CB120 and CB240 the rate of single shot isolation was similar in all PVs. Time to isolation was not different between the two groups. Mean minimal esophageal temperature was lower in LSPV and LIPV of the CB240 group. A total of 4/80 patients (5%) of the CB120 group experienced a PN injury, but no persistent form was recorded; 11/80 patients (14%) of the CB240 group experienced a PN injury, three in a persistent form (p = .10). A LET <15°C was recorded in 3/80 patients (4%) in the CB120 group and in 16/80 patients (20%) in the CB240 group (p < .01). Composite rate of energy-related safety events (LET <15°C and PN injury) was significantly lower in the CB120 (34% vs. 9%, p < .01). CONCLUSIONS: Safety of second generation CB PVI can be increased using a double 120 s freeze protocol.

Optimizing cryoballoon pulmonary vein isolation: lessons from >1000 procedures- the Frankfurt approach.

AIMS: Cryoballoon (CB) pulmonary vein isolation (PVI) is an accepted ablation strategy for rhythm control in atrial fibrillation (AF). We describe efficacy and safety in a high volume centre with a long experience in the use of the second-generation CB (CB2). METHODS AND RESULTS: Consecutive paroxysmal AF (PAF) or persistent AF (persAF) patients undergoing CB2-PVI were enrolled. Procedural data, efficacy, and safety issues were systematically collected. The 28 mm CB2 was used in combination with an inner lumen spiral catheter, a luminal oesophageal temperature (LET) probe was used with a cut-off of 15°C, the phrenic nerve (PN) monitored during septal PVs ablation. Freeze duration was mainly set at 240 s with a bonus application in case of delayed time-to-isolation (TTI > 75 s). A total of 1017 CB2 procedures were analysed (58% male, 66 ± 12 years old, 70% with PAF). 3964 PVs were identified, 99.8% PVs isolated using solely the 28 mm CB. Mean procedure time was 69 ± 25 min, TTI during the first application was recorded in 77% of PVs after a mean of 48 ± 31 s. We recorded 0.2% cardiac tamponade, 4.8% PN injury (1.6% of PN palsy), and 19% of LET < 15°C. Among 725 patients with follow-up data, 84% with PAF and 75% with persAF were in stable SR at 1 year. Shorter freezing duration and longer TTI were procedural predictors for recurrence. CONCLUSION: Cryoballoon procedures are fast and associated with a benign safety profile. Shorter TTI and longer freeze durations are associated with sinus rhythm during follow-up.

Cryoballoon Versus Laserballoon: Insights From the First Prospective Randomized Balloon Trial in Catheter Ablation of Atrial Fibrillation.

BACKGROUND: Pulmonary vein isolation (PVI) represents the cornerstone in atrial fibrillation ablation. Cryoballoon and laserballoon catheters have emerged as promising devices but lack randomized comparisons. Therefore, we sought to compare efficacy and safety comparing both balloons in patients with persistent and paroxysmal atrial fibrillation (AF). METHODS: Symptomatic AF patients (n=200) were prospectively randomized (1:1) to receive either cryoballoon or laserballoon PVI (cryoballoon: n=100: 50 paroxysmal atrial fibrillation + 50 persistent AF versus laserballoon: n=100: 50 paroxysmal atrial fibrillation + 50 persistent AF). All antiarrhythmic drugs were stopped after ablation. Follow-up included 3-day Holter-ECG recordings and office visits at 3, 6, and 12 months. Primary efficacy end point was defined as freedom from atrial tachyarrhythmia between 90 and 365 days after a single ablation. Secondary end points included procedural parameters and periprocedural complications. RESULTS: Patient baseline parameters were not different between both groups. In all (n=200) complete PVI was obtained and the entire follow-up accomplished. Balloon only PVI was obtained in 98% (cryoballoon) versus 95% (laserballoon) requiring focal touch-up in 2 and 5 patients, respectively. Procedure but not fluoroscopy time was significantly shorter in the cryoballoon group (50.9±21.0 versus 96.0±20.4 minutes; P<0.0001 and 7.4±4.4 versus 8.4±3.2 minutes, P=0.083). Overall, the primary end point of no atrial tachyarrhythmia recurrence was met in 79% (cryoballoon: 80.0% versus laserballoon: 78.0%, P=ns). No death, atrio-esophageal fistula, tamponade, or vascular laceration requiring surgery occurred. In the cryoballoon group, 8 transient but no persistent phrenic nerve palsy were noted compared with 2 persistent phrenic nerve palsy and one transient ischemic attack in the laserballoon group. CONCLUSIONS: Both balloon technologies represent highly effective and safe tools for PVI resulting in similar favorable rhythm outcome after 12 months. Use of the cryoballoon is associated with significantly shorter procedure but not fluoroscopy time.

Cryoballoon pulmonary vein isolation in treating atrial fibrillation using different freeze protocols: The "ICE-T 4 minutes vs 3 minutes" propensity-matched study (Frankfurt ICE-T 4 vs. 3).

BACKGROUND: Time-to-isolation (TTI) guided second-generation cryoballoon (CB2) ablation has been shown to be effective for pulmonary vein isolation (PVI). OBJECTIVE: The objective of this paper is to compare the safety and clinical outcome of CB2 PVI using the TTI guided 4 minutes vs 3 minutes freeze protocol. METHODS: This was a propensity-matched study based on an institutional database. Symptomatic atrial fibrillation (AF) patients who underwent CB2 PVI and systematic follow-up were consecutively included. RESULTS: A total of 573 patients were identified, of them 214 (107 matched-pairs) symptomatic AF (paroxysmal AF: 61%, persistent AF: 39%) patients (age: 67.7 ± 11.2 years) were analyzed. The baseline characteristics were comparable between the two groups. Procedural time was significantly longer in the 4 minutes group compared to 3 minutes group (67.2 ± 21.8 vs 55.9 ± 16.9 minutes, P < .0001). During a mean follow-up of 2 years, the 4 minutes group was associated with a significantly higher rate of freedom from arrhythmia recurrence compared with the 3 minutes group (66.4% vs 56.1%, P = .009), which was mainly driven by patients with persistent AF. The multivariate regression showed that the 4 minutes freeze was the independent predictor of freedom from arrhythmia recurrence. During the repeat procedure, the 4 minutes group was associated with a significantly higher rate of durable PVI. There was no difference regarding procedural adverse events between the two groups. CONCLUSION: As compared with the 3 minutes freeze, the TTI guided 4 minutes freeze is associated with a significantly higher rate of arrhythmia-free and durable PVI without compromising the safety profile, patients with persistent AF may benefit from the TTI guided 4 minutes freeze more pronouncedly.

Phrenic nerve injury in atrial fibrillation ablation using balloon catheters: Incidence, characteristics, and clinical recovery course.

AIMS: Systematic data on phrenic nerve palsy (PNP) associated with contemporary balloon ablation techniques (cryoballoon [CBA] vs laser balloon [LBA]) are sparse. We aimed to investigate the incidence, characteristics, and clinical recovery course in patients with PNP who underwent CBA or LBA. METHODS AND RESULTS: A total of 2433 consecutive patients who underwent balloon-based pulmonary vein isolation (CBA: n = 1720 and LBA: n = 713) were retrospectively identified. PNP was classified into (a) transient (recovery before discharge) or (b) persistent (within 6 months, 6-12 months, and >12 months) according to clinical recovery course. In general, PNP occurred significantly more often in CBA 71/1720 (4.2%) than LBA 11/713 (1.5%) (P = .003). The rate of transient PNP was significantly higher in CBA (3.0%, n = 45) than LBA (0.1%, n = 1, P = .004). The rate of persistent PNP did not significantly differ between two groups (CBA: 1.2% vs LBA: 1.4%, P = .89). The rate of persistent PNP which recovered within 6 months was similar (CBA: 17.4% vs LBA 18.2%, P = 1.000). However, the rates of persistent PNP which recovered within 6 to 12 months (CBA: 2.9% vs LBA 27.3%, P = .0171) and more than 12 months (CBA: 7.3% vs LBA 45.5%, P = .0034) were significantly higher in LBA. CONCLUSION: PNP occurred more often in CBA than LBA, however, the majority of PNP in CBA was transient whereas the majority of PNP in LBA was persistent. Either balloon technology is not superior in terms of long-term PNP.

Catheter ablation of atrial fibrillation using ablation index-guided high power (50 W) for pulmonary vein isolation with or without esophageal temperature probe (the AI-HP ESO II).

BACKGROUND: High-power, short-duration ablation for pulmonary vein isolation (PVI) in the treatment of atrial fibrillation (AF) facilitates the procedure and improve effectiveness; however, esophageal injury remains a safety concern. OBJECTIVE: The purpose of this study was to investigate the role of luminal esophageal temperature (LET) monitoring during high-power ablation for PVI in terms of endoscopic esophageal lesion. METHODS: Patients with symptomatic AF underwent ablation index-guided high-power (AI-HP) PVI (50 W; AI anterior wall/posterior wall: 550/400). In the first consecutive set of patients, an insulated esophageal temperature probe was used for LET monitoring (cutoff LET >39°C) (group A). In the second consecutive set of patients, the probe was not used (group B). All patients were scheduled to undergo esophageal endoscopy 1-3 days after ablation. RESULTS: A total of 120 patients (60 group A; 60 group B) were included in the study (mean age 67.8 years; 64% male). Baseline characteristics and procedural outcomes were similar between the 2 groups. Procedural PVI was achieved in all patients. First-pass PVI rate was 96.6%. Mean procedural radiofrequency (RF) time was 11.5 minutes, mean procedural time was 55.5 minutes, and fluoroscopic time was 5.6 minutes. Mean contact force at the LA posterior wall was 23 g, and mean RF ablation time at the LA posterior wall was 3.2 minutes. Two patients in group A and 1 patient in group B had endoscopic small esophageal lesions (P = .99). No serious procedural adverse events were observed. CONCLUSION: Among patients undergoing AI-HP (50 W) PVI, the incidences of ablation-related endoscopic esophageal lesion in patients with and those without use of a temperature probe for LET monitoring (cutoff 39°C) were comparably low.

EP Laboratory Nightmare: Catheter Ablation of Malignant Premature Ventricular Complex Complicated by Left Main Injury.

We present a case of ventricular fibrillation triggered by a premature ventricular complex. During ablation from the left coronary cusp, the ablation catheter dislodged inside left main coronary artery, thus resulting in cardiac arrest. We immediately performed angioplasty and stent implantation, and the procedure was accomplished with a guiding catheter left inside the vessel. (Level of Difficulty: Intermediate.).

Incidence and pattern of conduction gaps after pulmonary vein isolation with the endoscopic ablation system.

PURPOSE: Durable pulmonary vein isolation (PVI) is the goal of atrial fibrillation (AF) ablation. The endoscopic ablation system (EAS) is associated with a high rate of persistent PVI. The aim of this study was to analyze the incidence and pattern of conduction gaps in patients with arrhythmia recurrence after an EAS-guided PVI. METHODS: Repeat ablations after an EAS-guided PVI were analyzed. After PV angiograms, PV reconnection was assessed. Radiofrequency ablation was delivered at the earliest pulmonary vein (PV) activation site (gap) with the goal of PV re-isolation. First, the incidence of reconnected PVs per patient was assessed. Second, the gap pattern according to the individual PV quadrant was analyzed. RESULTS: Fifty-nine out of 373 (16%) patients underwent a second procedure after index EAS. PV reconnection was observed in 71/230 (31%) PVs without statistically significant differences between individual PVs. A higher incidence of gaps was found for right PVs (49 vs. 27; p 0.0006). The carina between the superior and inferior PV presented a low incidence of gaps (18 vs. 56, p < 0.0001). Gaps were also predominant at the AS segment of the RSPV (11 gaps). No predictors of reconnection were found, except the higher total amount of application in the reconnected right inferior PV (26.03 ± 1.30 vs. 32.04 ± 2.89; p 0.0396). CONCLUSION: EAS-guided PVI results in a 72% durable PVI rate in patients with AF recurrences without difference between individual PVs. More of the gap was found in the right PVs especially in the anterosuperior segment of the RSPV.

Impact of Cryoballoon Freeze Duration on Long-Term Durability of Pulmonary Vein Isolation: ICE Re-Map Study.

OBJECTIVES: This study sought to evaluate the durability of pulmonary vein isolation (PVI) after 2 different freeze durations by using time-to-effect guided (ICE-T) second generation cryoballoon (CB2) ablation strategy in patients with atrial fibrillation (AF) undergoing repeat procedure. BACKGROUND: CB2 represents a powerful technology for PVI. Recently, the ICE-T CB2 ablation strategy targeting a 240-s single freeze demonstrated fast and efficient PVI. To further optimize safety and efficacy, a shortened 3-min freeze duration has been suggested, but PVI durability remains unclear. METHODS: Between May 1, 2013 and December 31, 2017, all CB2 ablations followed the ICE-T concept (target freeze: 240 s or 180 s). Patients undergoing a second procedure for arrhythmia recurrence were analyzed. Two groups were defined based on the index freeze duration (group A: 240 s vs. group B: 180 s). In all repeat procedures a 3-dimensional left-atrial map was obtained. Durability of PVI and localization of conduction gaps were compared. RESULTS: Of 788 total patients, 106 (13%) underwent a second procedure (group A: 80 of 604 vs. group B: 26 of 184) after a mean of 377 days. There was no difference regarding PV occlusion and time-to-isolation in the index procedure between the 2 groups. No major complications occurred. During the second procedure, significantly more patients demonstrated durable isolation of all PV in group A (61% vs. 35%; p = 0.02) along with a significantly increased rate of PVI durability (88% vs. 69%, per vein; p < 0.001). Left-sided PV did significantly benefit from 240-s freeze (reconnection left superior PV: 6% vs. 27%; p = 0.004, left inferior PV: 14% vs. 39%; p = 0.006). CONCLUSIONS: The ICE-T ablation strategy is associated with a high rate of durable PVI in patients with arrhythmia recurrence. Target freeze duration of 240 s versus 180 s is associated with significantly increased lesion durability, particularly at left-sided PV, without increasing complications.

Durability of cryoballoon left atrial appendage isolation: Acute and invasive remapping electrophysiological findings.

BACKGROUND: The left atrial appendage (LAA) has been identified as a potential source of atrial fibrillation (AF) and has been described as the "fifth" pulmonary vein (PV). We report our initial experience in LAA isolation (LAAI) using the cryoballoon (CB) and data on durability of CB-LAAI. METHODS: Patients treated with a CB-LAAI were retrospectively identified. Six weeks after electrical LAAI, patients were scheduled for staged percutaneous LAA closure. During the second procedure, a subset of patients underwent invasive remapping of the LAA. RESULTS: A total of 32 patients (21 males, 68 ± 10 years old) were treated with CB-LAAI. Acute LAAI was achieved in 29 of 32 (91%) patients: single-shot LAAI was observed in 18 of 32 (56%) patients. Acute procedural sustained LAAI was related with a significantly shorter time to LAAI (sustained LAAI: 84 ± 50 s vs nonsustained LAAI: 166 ± 76 s, P = 0.004). Mean procedure and fluoroscopy time were 61 ± 29 and 8 ± 6 min, respectively. One left-sided phrenic nerve palsy occurred. In 25 of 32 (78%) patients, a second procedure for percutaneous LAA closure device implantation was performed. In 22 patients, persistency of LAAI was tested: durable LAAI was documented in 16/22 patients (73%). CONCLUSION: In the present report, CB LAA isolation followed by staged LAA closure appeared to be safe and feasible but more data are required. Time to LAAI played a role in predicting acute sustained LAAI rate. CB LAA ablation leads to 73% of durable LAA isolation.

Analysis of procedural data of pulmonary vein isolation for atrial fibrillation with the second-generation laser balloon.

BACKGROUND: The procedural data of pulmonary vein (PV) isolation (PVI) for patients with atrial fibrillation using the second-generation laser balloon (LB2), which became available recently, remains unclear and were evaluated. METHODS: Thirty consecutive patients (116 PVs) underwent PVI using LB2 (LB2 group) and were matched to 30 patients (116 PVs) treated with the first-generation laser balloon (LB1 group). The left atrial isolated surface area (ISA) (ratio of the total isolated antral surface area excluding PV to the total isolated antral surface area including the posterior wall) was also measured after LB2 PVI. RESULTS: PVI was achieved in 103/116 (89%) PVs and 108/116 (93%) PVs in the LB2 and LB1 groups, respectively, after the initial circular ablation (P = 0.360) and in 115/116 (99%) PVs and 116/116 (100%) PVs in the LB2 and LB1 groups, respectively, at the end of the procedure (P = 1.000). PV occlusion grade, categorized by the degree of PV occlusion, was significantly better in the LB2 group than in the LB1 group (P < 0.001). Zero rotational maneuver was applicable in 23/116 (20%) PVs and 8/116 (7%) in the LB2 and LB1 groups, respectively (P = 0.007). There was no significant difference in the procedural time, fluoroscopic time, or complications. The mean ISA after LB2 PVI was 53 ± 14%. The application number was the only independent predictor of successful PVI after initial circular LB2 ablation (adjusted odds ratio 0.860; 95% confidence interval 0.764-0.968; P = 0.013). CONCLUSION: LB2 displays favorable PV occlusion characteristics and enables more zero rotational maneuvers.

HEartLight guided - PUre Pulmonary Vein Isolation Regardless of Concomitant Atrial Substrate: HEURECA Study.

BACKGROUND: It remains unclear whether left atrial low-voltage area (LALVA) affects atrial tachyarrhythmia recurrence after laser balloon pulmonary vein isolation (PVI) for atrial fibrillation (AF). We prospectively evaluated the outcome of laser balloon PVI in patients with and without LALVA (≤ 0.5 mV) together with surface/intracardiac electrophysiological criteria. METHODS: One hundred consecutive paroxysmal/persistent AF patients underwent laser balloon PVI. The relative extent of LALVA (extent of LALVA/left atrial surface area × 100 [%]: rLALVA), total p-wave duration in lead II (PWD), and time interval from the beginning of p-wave to the local activation in left atrial appendage (TTLAA) were assessed. Patients were divided into patients with LALVA (group A: 23 patients) and those without LALVA (group B: 77 patients). The primary endpoint was freedom from atrial tachyarrhythmia after the blanking periods. RESULTS: Complete PVI was achieved in 99/100 (99%) patients. PWD and TTLAA were longer in group A (both, P < 0.001). During 12 months' follow-up, survival free from atrial tachyarrhythmia recurrence was lower in group A (12/23 [52%] patients vs 67/77 [87%] patients, P < 0.001). Multivariate analysis identified rLALVA as the only independent predictor of atrial tachyarrhythmia recurrence. rLALVA correlated with PWD and TTLAA (r = 0.41, P < 0.001 and r = 0.60, P < 0.001, respectively). Receiver operating characteristic curve for rLALVA revealed PWD of 122 ms and TTLAA of 92 ms as the optimal cut-off value. CONCLUSION: LALVA was associated with poorer outcome after laser balloon PVI. Patients may be identified by longer PWD and TTLAA.

Compound motor action potential guided 240 seconds plus bonus freeze for safe and durable left atrial appendage isolation in patients with recurrent persistent atrial fibrillation: How to isolate the appendage with cryoballoon (the CMAP guided ICE-B protocol).

INTRODUCTION: Pulmonary vein isolation (PVI) is the cornerstone ablation strategy for treatment of atrial fibrillation (AF). Ablation outside the PVs is sometimes needed particularly in persistent or longstanding AF. This study reported left atrial appendage isolation (LAAI) using cryoballoon (CB) focusing on technical data and short-term clinical follow-up. METHODS AND RESULTS: Patients with recurrent persistent AF after multiple AF procedures were enrolled. LAAI was performed using the second generation CB guided by compound motor action potential (CMAP) and 240 seconds plus bonus freeze (ICE-B) protocol. Ten patients were included, median age was 69.5 (56-73) years, CHA2 DS 2 -VASc score was 3 (1.8-4), LA diameter was 44 (38.8-46.5) mm. All patients had a mean of three AF procedures before the LAAI procedure. All patients were under successful CMAP guidance. During the CB LAAI procedure, the median time to LAA isolation was 100 (76-270) seconds, minimal freeze temperature was -50 (-57 to -47)°C. A "pull-down (or pull-away)" CB maneuver was performed in all patients. Median fluoroscopic time was 4.8 (3.4-6.8) minutes and acute LAAI success rate was 100%. No phrenic nerve injury or other major complications were observed. At 6-week follow-up, remapping of the LAA showed durable isolation of all PVs (100%), all patients were scheduled for LAA occlusion. Six-month follow-up showed that 80% of patients were free from AF/AT recurrence. CONCLUSION: CMAP plus ICE-B guided LAAI using cryo-technology appears feasible and safe, results in durable LAAI, and shows promising clinical results in patients with recurrent persistent AF.

Low Risk of Pulmonary Vein Stenosis After Contemporary Atrial Fibrillation Ablation　- Lessons From Repeat Procedures After Radiofrequency Current, Cryoballoon, and Laser Balloon.

BACKGROUND: The incidence of pulmonary vein stenosis (PVS) after AF ablation following contemporary procedures remains unclear. We compared the incidence of PVS/narrowing (PVS/N) after PV isolation (PVI) for (1) 3-D mapping-guided wide-area encircling irrigated radiofrequency current (RFC) ablation; (2) first-third-generation big cryoballoon (CB1-3) ablation; and (3) laser balloon (LB) ablation.Methods and Results:All patients undergoing a second procedure between January 2012 and November 2016 were subgrouped according to index ablation (PVI): RFC; CB; or LB. PVS/N was classified using PV diameter ratio (second/index procedure) on selective PV angiogram performed before ablation: mild, 25-49%; moderate, 50-74%; or severe, ≥75%. A total of 344 patients (1,362 PV) were analyzed (RFC, n=211; 840 PV; CB1, n=21; 82 PV; CB2,3, n=64; 250 PV; LB, n=48; 190 PV). In the LB group, 45 patients (94%) were treated with dose ≥8.5 W. Second procedures were performed on average 14.9±14.1 months after the index procedure. Mild PVS/N was observed in 18.4%, 9.5% and 3.6% of PV in the LB, RFC and CB groups, respectively (P<0.01). Moderate PVS was recognized in 2 PV (0.1%; RFC, LB). Severe PVS was never observed, and no PV intervention/surgery was required. CONCLUSIONS: The risk for significant PVS is low after RFC/CB. The incidence of mild PVS/N was highest after standard-dose LB ablation and lowest after high-dose CB ablation.

Atrial fibrillation ablation using cryoballoon technology: Recent advances and practical techniques.

Atrial fibrillation (AF) affects 1-2% of the population, and its prevalence is estimated to double in the next 50 years as the population ages. AF results in impaired patients' life quality, deteriorated cardiac function, and even increased mortality. Antiarrhythmic drugs frequently fail to restore sinus rhythm. Catheter ablation is a valuable treatment approach for AF, even as a first-line therapy strategy in selected patients. Effective electrical pulmonary vein isolation (PVI) is the cornerstone of all AF ablation strategies. Use of radiofrequency (RF) catheter in combination of a three-dimensional electroanatomical mapping system is the most established ablation approach. However, catheter ablation of AF is challenging even sometimes for experienced operators. To facilitate catheter ablation of AF without compromising the durability of the pulmonary vein isolation, "single shot" ablation devices have been developed; of them, cryoballoon ablation, is by far the most widely investigated. In this report, we review the current knowledge of AF and discuss the recent evidence in catheter ablation of AF, particularly cryoballoon ablation. Moreover, we review relevant data from the literature as well as our own experience and summarize the key procedural practical techniques in PVI using cryoballoon technology, aiming to shorten the learning curve of the ablation technique and to contribute further to reduction of the disease burden.

Individualized cryoballoon energy pulmonary vein isolation guided by real-time pulmonary vein recordings, the randomized ICE-T trial.

BACKGROUND: The ideal energy dosing remains unclear in second-generation cryoballoon (CB) pulmonary vein isolation (PVI). We aimed to investigate the effect of an individualized dosing strategy based on time to PVI (TTI). OBJECTIVE: The purpose of this study was to prospectively investigate the safety and efficacy of individualized PVI using the second-generation CB guided by real-time pulmonary vein recordings. METHODS: Two groups were prospectively randomized: ICE-T group: if TTI <75 seconds, then no bonus freeze; and control group: acute PVI followed by 1 empiric bonus freeze. Freeze duration was set to 240 seconds. The primary end point was single procedure sinus rhythm after 12 months (blanking period 3 months). Secondary end points included procedural data, complications, and biomarker release. RESULTS: In total, 100 patients with paroxysmal atrial fibrillation were randomized. The primary end point was not different (88% vs 82%). Procedure and fluoroscopy times were significantly shorter in the ICE-T group (70 ± 20 minutes vs 89 ± 21 minutes; P < .001 and 10.6 ± 3.9 minutes vs 12.7 ± 5.5 minutes; P = .03). More complications occurred in the control group (n = 9 vs n = 3) (persistent phrenic nerve injury: n = 1 vs n = 0; transient phrenic nerve injury: n = 5 vs n = 2; esophageal lesions: n = 3 vs n = 1). Postablation troponin T levels were not different (ICE-T group vs control group: 1035 ± 402 ng/L vs 1219 ± 509 ng/L; P = .099), whereas a significantly lower lactic acid dehydrogenase release was observed in the ICE-T group (259 ± 47 U/L vs 282 ± 57 U/L; P = .038). Multivariate analysis identified a mean TTI of >43 seconds as the only independent predictor of recurrent atrial tachyarrhythmia. CONCLUSION: The individualized CB PVI strategy allows faster atrial fibrillation ablation without affecting the favorable clinical outcome. A short TTI appears to predict freedom from recurrent atrial tachyarrhythmia.