Impact of cryoballoon application abortion due to phrenic nerve injury on reconnection rates: a YETI subgroup analysis.

AIMS: Cryoballoon (CB)-based pulmonary vein isolation (PVI) is an effective treatment for atrial fibrillation (AF). The most frequent complication during CB-based PVI is right-sided phrenic nerve injury (PNI) which is leading to premature abortion of the freeze cycle. Here, we analysed reconnection rates after CB-based PVI and PNI in a large-scale population during repeat procedures. METHODS AND RESULTS: In the YETI registry, a total of 17 356 patients underwent CB-based PVI in 33 centres, and 731 (4.2%) patients experienced PNI. A total of 111/731 (15.2%) patients received a repeat procedure for treatment of recurrent AF. In 94/111 (84.7%) patients data on repeat procedures were available. A total of 89/94 (94.7%) index pulmonary veins (PVs) have been isolated during the initial PVI. During repeat procedures, 22 (24.7%) of initially isolated index PVs showed reconnection. The use of a double stop technique did non influence the PV reconnection rate (P = 0.464). The time to PNI was 140.5 ± 45.1 s in patients with persistent PVI and 133.5 ± 53.8 s in patients with reconnection (P = 0.559). No differences were noted between the two populations in terms of CB temperature at the time of PNI (P = 0.362). The only parameter associated with isolation durability was CB temperature after 30 s of freezing. The PV reconnection did not influence the time to AF recurrence. CONCLUSION: In patients with cryoballon application abortion due to PNI, a high rate of persistent PVI rate was found at repeat procedures. Our data may help to identify the optimal dosing protocol in CB-based PVI procedures. CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/ct2/show/NCT03645577?term=YETI&cntry=DE&draw=2&rank=1 ClinicalTrials.gov Identifier: NCT03645577.

Novel cryoballoon ablation system for pulmonary vein isolation: multicenter assessment of efficacy and safety-ANTARCTICA study.

AIMS: Pulmonary vein isolation (PVI) either by balloon devices or radiofrequency forms the cornerstone of invasive atrial fibrillation (AF) treatment. Although equally effective cryoballoon (CB)-based PVI offers shorter procedure duration and a better safety profile. Beside the worldwide established Arctic Front Advance system, a novel CB device, POLARx, was recently introduced. This CB incorporates unique features, which may translate into improved efficacy and safety. However, multicentre assessment of periprocedural efficacy and safety is lacking up to date. METHODS AND RESULTS: A total of 317 patients with paroxysmal or persistent AF were included and underwent POLARx CB-based PVI in 6 centres from Germany and Italy. Acute efficacy and safety were assessed in this prospective multicenter observational study. In 317 patients [mean age: 64 ± 12 years, 209 of 317 (66%) paroxysmal AF], a total of 1256 pulmonary veins (PVs) were identified and 1252 (99,7%) PVs were successfully isolated utilizing mainly the short tip POLARx CB (82%). The mean minimal CB temperature was -57.9 ± 7°C. Real-time PVI was registered in 72% of PVs. The rate of serious adverse events was 6.0% which was significantly reduced after a learning curve of 25 cases (9.3% vs. 3.0%, P = 0.018). The rate of recurrence-free survival after mean follow-up of 226 ± 115 days including a 90-day blanking period was 86.1%. CONCLUSION: In this large multicentre assessment, the novel POLARx CB shows a promising efficacy and safety profile after a short learning curve.

Phrenic Nerve Injury During Cryoballoon-Based Pulmonary Vein Isolation: Results of the Worldwide YETI Registry.

BACKGROUND: Cryoballoon-based pulmonary vein isolation (PVI) has emerged as an effective treatment for atrial fibrillation. The most frequent complication during cryoballoon-based PVI is phrenic nerve injury (PNI). However, data on PNI are scarce. METHODS: The YETI registry is a retrospective, multicenter, and multinational registry evaluating the incidence, characteristics, prognostic factors for PNI recovery and follow-up data of patients with PNI during cryoballoon-based PVI. Experienced electrophysiological centers were invited to participate. All patients with PNI during CB2 or third (CB3) and fourth-generation cryoballoon (CB4)-based PVI were eligible. RESULTS: A total of 17 356 patients underwent cryoballoon-based PVI in 33 centers from 10 countries. A total of 731 (4.2%) patients experienced PNI. The mean time to PNI was 127.7±50.4 seconds, and the mean temperature at the time of PNI was -49±8°C. At the end of the procedure, PNI recovered in 394/731 patients (53.9%). Recovery of PNI at 12 months of follow-up was found in 97.0% of patients (682/703, with 28 patients lost to follow-up). A total of 16/703 (2.3%) reported symptomatic PNI. Only 0.06% of the overall population showed symptomatic and permanent PNI. Prognostic factors improving PNI recovery are immediate stop at PNI by double-stop technique and utilization of a bonus-freeze protocol. Age, cryoballoon temperature at PNI, and compound motor action potential amplitude loss >30% were identified as factors decreasing PNI recovery. Based on these parameters, a score was calculated. The YETI score has a numerical value that will directly represent the probability of a specific patient of recovering from PNI within 12 months. CONCLUSIONS: The incidence of PNI during cryoballoon-based PVI was 4.2%. Overall 97% of PNI recovered within 12 months. Symptomatic and permanent PNI is exceedingly rare in patients after cryoballoon-based PVI. The YETI score estimates the prognosis after iatrogenic cryoballoon-derived PNI. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03645577. Graphic Abstract: A graphic abstract is available for this article.

Clinical outcomes of cryoballoon ablation for pulmonary vein isolation: Impact of intraprocedural heart rhythm.

BACKGROUND: The current study sought to assess the impact of the intraprocedural heart rhythm (sinus rhythm [SR] vs. atrial fibrillation [AF]) on acute procedural characteristics, durability of pulmonary vein isolation (PVI) and long-term clinical outcomes of cryoballoon (CB) ablation. METHODS: A total of 195 patients with symptomatic paroxysmal (n = 136) or persistent AF (n = 59) underwent CB-based PVI. Ablation procedures were either performed in SR (SR group; n = 147) or during AF (AF group; n = 48). Persistent AF was more frequent in the AF group than in the SR group (62% vs. 20%). All other patient baseline characteristics did not differ between the two groups. RESULTS: The nadir temperature during the CB applications was significantly lower in the AF group than in patients in the SR group (-49 [interquartile range, -44; -54]°C vs. -47 [-42; -52]°C, p = 0.002). Median procedure and fluoroscopy times as well as the rate of real-time recordings were not different between the two groups. Repeat ablation for the treatment of atrial arrhythmia recurrence was performed in 60 patients (SR: 44 [30%] patients; AF: 16 [33%] patients), with a trend towards a lower rate of pulmonary vein reconnections in the AF group (p = 0.07). There was no difference in 3-year arrhythmia-free survival (p = 0.8). CONCLUSIONS: Cryoballoon-based PVI during AF results in lower nadir balloon temperatures and a trend towards a higher durability of PVI as compared to procedures performed in SR. The rate of real-time PVI recordings was not affected by the intraprocedural heart rhythm.

Novel Cryoballoon Ablation System for Single Shot Pulmonary Vein Isolation　- The Prospective ICE-AGE-X Study.

BACKGROUND: The arctic front cryoballoon (AF-CB) provides effective and durable pulmonary vein isolation (PVI) associated with encouraging clinical outcome. The POLARx cryoballoon incorporates unique features and design changes that may translate into improved efficacy, safety and further simplified balloon-based procedures. Efficacy and safety of the novel POLARx cryoballoon was compared to the fourth generation AF-CB (AF-CB4).Methods and Results:Twenty-five consecutive patients with paroxysmal or persistent atrial fibrillation were prospectively enrolled, underwent POLARx-based PVI (POLARx group) and were compared to 25 consecutive patients treated with the AF-CB4 (AF-CB4 group). All PVs were successfully isolated utilizing the POLARx and AF-CB4. A significant difference regarding the mean minimal cryoballoon temperatures reached using the AF-CB4 and POLARx (-50±6℃ vs. -57±7℃, P=0.004) was observed. Real-time PVI was visualized in 81% of POLARx patients and 42% of AF-CB4 patients (P<0.001). Utilizing the POLARx, a trend towards shorter median procedure time (POLARx: 45 [39, 53] min vs. AF-CB4: 55 [50, 60] min; P=0.062) was found. No differences were observed between AF-CB4 and POLARx concerning catheter maneuverability, catheter stability and periprocedural complications. CONCLUSIONS: The novel POLARx showed similar safety and efficacy compared to the AF-CB4. A higher rate of real-time PV recordings and significantly lower minimal balloon temperatures were observed using the POLARx.

Stroke and left atrial thrombi after cryoballoon ablation of atrial fibrillation: incidence and predictors. Results from a long-term follow-up.

Stroke after catheter ablation (CA) of atrial fibrillation (AF) is a potential complication with long term consequences. Aim of this study was to determine incidence and potential predictors of stroke and left atrial appendage (LAA) thrombi after AF ablation with cryo-energy. Two hundred nine consecutive patients with symptomatic drug refractory AF (65% male; 61 ± 11 yo, 69% paroxysmal AF, mean CHA2DS2-VASc score 2 ± 1.4) were enrolled between October 2012 until December 2015. Long term follow-up was performed with outpatient clinic visits at 6-month intervals. Incidence of stroke after CA was 1.4% (3/209 pts) at long term follow-up. Two out of 3 pts experienced stroke during the first 3 month after CA and one after 36 months. At long term follow-up LAA thrombi were found in two patients (1%) that were on therapeutic oral anticoagulation. Recurrence of AF was found in 4 out of 5 pts with stroke or LAA thrombi. Patients with stroke or LAA thrombi did not differed from those without in term of age, gender, CV risk factors, LA size and AF type. They differed only for EHRA score (2.4 vs 1.3, p = 0.01) before CA. At multivariate analysis after correction for age, gender, LA size, LVEF and AF type, only EHRA score (ß 1.92, 95% C.I. 1.3-35 p = 0.02), was an independent predictor of stroke/LAA thrombi. Incidence of stroke after cryoablation is low, with a relative higher prevalence during the first 3 months after CA. Prospective, multicenter long-term registries are needed for a better stroke risk stratification.

Fourth-Generation Cryoablation Based Left Atrial Appendage Isolation for the Treatment of Persistent Atrial Fibrillation: First Case Report.

BACKGROUND Pulmonary vein isolation (PVI) is an effective treatment strategy for patients with paroxysmal atrial fibrillation (AF), yet it is associated with limited success rates in patients with persistent AF (PersAF). The left atrial appendage (LAA) was recently identified as a target of catheter ablation especially in PVI non-responders and LAA-isolation (LAAI) by cryoballoon or radiofrequency was shown to be effective. Recently the fourth-generation cryoballoon (CB4) was introduced to clinical practice. Here we are demonstrating the first case report of CB4-based LAAI followed by LAA-closure in a patient with PersAF. CASE REPORT A 67-year-old male patient presented with symptomatic PersAF and thromboembolism due to LAA-thrombus. After resolving the LAA-thrombus cryoballoon based PVI and empirical LAAI was successfully performed. To prevent further thromboembolism LAA-closure was successfully performed after 6 weeks. On short-term follow-up (12 weeks) the patients stayed in stable sinus rhythm. CONCLUSIONS Fourth-generation cryoballoon based ablation seems to be an effective treatment strategy for LAAI.

Second-Generation Visually Guided Laser Balloon Ablation System for Pulmonary Vein Isolation: Learning Curve, Safety and Efficacy　- The MERLIN Registry.

BACKGROUND: Radiofrequency (RF)-based pulmonary vein isolation (PVI) results in a favorable clinical outcome, although its complexity demands a long learning curve. Balloon-based systems have been developed to possibly solve these limitations. The 2nd-generation laser balloon (LB2) offers optimized features for improved tissue contact and visibility. We determined the safety, efficacy and learning curve of the LB2 for PVI.Methods and Results:A total of 45 consecutive patients (89% persistent AF) were prospectively enrolled and divided into 3 groups (T1, T2, T3) of n=15 patients per group. All patients underwent PVI by 2 operators using the LB2. The operators were experienced in RF and cryothermal procedures, but not in laser ablations. A total of 174/177 PVs (98%) were successfully isolated. The median procedure time significantly declined from 132 (114, 158) to 119 (102, 127) and 91 (86, 105) min in T1-3, respectively (P=0.0009). Similarly, the median fluoroscopy time significantly decreased from T1 to T3 (22 (17, 27) vs. 21 (16, 24) vs. 13 (10, 17) min, respectively, P=0.045). Adverse events occurred in 6.7%, with a trend towards a lower complication rate with increasing experience. CONCLUSIONS: The LB2 was safe and effective for PVI, even for operators without any previous experience in laser balloon-based PVI. Procedure time, left atrial dwelling time and fluoroscopy time decreased after a learning curve of 15 cases.

Mechanism, underlying substrate and predictors of atrial tachycardia following atrial fibrillation ablation using the second-generation cryoballoon.

BACKGROUND: Data regarding atrial tachycardia (AT) following second-generation cryoballoon ablation (CBA) of atrial fibrillation (AF) are limited. AIM: To describe the incidence, mechanisms, and clinical predictors of ATs following CBA. METHODS AND RESULTS: In this retrospective single-center study 238 patients undergoing CBA for treatment of paroxysmal (91/238; 38.2%) or persistent AF were analyzed. During a mean follow-up of 11.9 ± 5.5 months recurrence of AF occurred in 49/238 patients (20.6%) and AT in 27/238 (11.3%). Twenty-six patients with AT and 14 with AF only underwent a redo ablation. The prevailing mechanism of AT was macroreentry [typical atrial flutter (AFL) (n = 10), left atrial macroreentry (n = 14), focal left-AT (n = 2)]. Non-cavotricuspid-isthmus-dependent macroreentry right-AT was mapped and ablated in 3 patients after initial AFL ablation. In a multivariate regression model, persistent type of AF (HR = 3.3; CI = 1.2-9.4), cardiomyopathy (HR = 3.5; CI = 1.5-8.4), treatment with beta-blockers (HR = 0.3; CI = 0.1-0.6), and pulmonary vein-abnormality (HR = 4.6; CI = 2.1-10.4) were independent predictors of AT. Substrate analysis revealed a significantly higher number of low voltage areas in the left atrium in patients with left-AT in comparison to patients with AF recurrence only (2.0; IQR=2.0-4.0 vs. 0.5; IQR = 0.0-2.25; p = 0.005). CONCLUSION: In this study, AT after CBA occurred in 11.3% of patients with macroreentry being the prevalent mechanism. All patients with left-AT presented with low voltage areas in the left atrium, suggesting a more progressive underlying fibrotic disease in these patients.

Catheter Ablation of Ventricular Tachycardia in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia: A Sequential Approach.

Background It has been suggested that endocardial and epicardial ablation of ventricular tachycardia ( VT ) improves outcome in arrhythmogenic right ventricular cardiomyopathy/dysplasia. We investigated our sequential approach for VT ablation in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia in a single center. Methods and Results We included 47 patients (44±16 years) with definite (81%) or borderline (19%) arrhythmogenic right ventricular cardiomyopathy/dysplasia between 1998 and 2016. Our ablation strategy was to target the endocardial substrate. Epicardial ablation was performed in case of acute ablation failure or lack of an endocardial substrate. Single and multiple procedural 1- and 5-year outcome data for the first occurrence of the study end points (sustained VT /ventricular fibrillation, heart transplant, and death after the index procedure, and sustained VT /ventricular fibrillation for multiple procedures) are reported. Eighty-one radiofrequency ablation procedures were performed (mean 1.7 per patient, range 1-4). Forty-five (56%) ablation procedures were performed via an endocardial, 11 (13%) via an epicardial, and 25 (31%) via a combined endo- and epicardial approach. Complete acute success was achieved in 65 (80%) procedures, and partial success in 13 (16%). After a median follow-up of 50.8 (interquartile range, [18.6; 99.2]) months after the index procedure, 17 (36%) patients were free from the primary end point. After multiple procedures, freedom from sustained VT /ventricular fibrillation was 63% (95% CI , 52-75) at 1 year, and 45% (95% CI , 34-61) at 5 years, with 36% of patients receiving only endocardial radiofrequency ablation. A trend (log rank P=0.058) towards an improved outcome using a combined endo-/epicardial approach was observed after multiple procedures. Conclusion Endocardial ablation can be effective in a considerable number of arrhythmogenic right ventricular cardiomyopathy/dysplasia patients with VT , potentially obviating the need for an epicardial approach.

The best of two worlds? Pulmonary vein isolation using a novel radiofrequency ablation catheter incorporating contact force sensing technology and 56-hole porous tip irrigation.

AIMS: This study aimed to evaluate feasibility and safety as well as 1-year clinical outcome of pulmonary vein isolation (PVI) using a unique radiofrequency ablation catheter ("Thermocool SmartTouch SurroundFlow"; STSF) incorporating both, contact force (CF) sensing technology and enhanced tip irrigation with 56 holes, in one device. METHODS: A total of 110 patients suffering from drug-refractory atrial fibrillation underwent wide area circumferential PVI using either the STSF ablation catheter (75 consecutive patients, study group) or a CF catheter with conventional tip irrigation ("Thermocool SmartTouch", 35 consecutive patients, control group). For each ablation lesion, a target CF of ≥ 10-39 g and a force time integral (FTI) of > 400 g s was targeted. RESULTS: Acute PVI was achieved in all patients with target CF obtained in > 85% of ablation points when using either device. Mean procedure time (131.3 ± 33.7 min in the study group vs. 133.0 ± 42.0 min in the control group; p = 0.99), mean fluoroscopy time (14.0 ± 6 vs. 13.5 ± 6.6 min; p = 0.56) and total ablation time were not significantly different (1751.0 ± 394.0 vs. 1604.6 ± 287.8 s; p = 0.2). However, there was a marked reduction in total irrigation fluid delivery by 51.7% (265.52 ± 64.4 vs. 539.6 ± 118.2 ml; p < 0.01). The Kaplan-Meier estimate 12-month arrhythmia-free survival after the index procedure following a 3-month blanking period was 79.9% (95% CI 70.4%, 90.4%) for the study group and 66.7% for the control group (95% CI 50.2%, 88.5%). This finding did not reach statistical significance (p = 0.18). Major complications occurred in 2/75 patients (2.7%; one pericardial tamponade and one transient ischemic attack) in the study group and no patient in the control group (p = 18). CONCLUSION: PVI using the STSF catheter is safe and effective and results in beneficial 1-year clinical outcome. The improved tip irrigation leads to a significant reduction in procedural fluid burden.

Antegrade-transseptal approach for left ventricular tachyarrhythmia in patients with previous Mitraclip implantation.

Aims: Antegrade-transseptal approach to treat left ventricular tachyarrhythmia (LVT) is useful and widespread. Meanwhile, Mitraclip has been recently introduced as an alternative to mitral valve surgery for severe mitral regurgitation, usually coexisting with ventricular arrhythmias. However, data on the antegrade approach for mapping and ablating LVT in these patients are insufficient. We evaluated the feasibility and clinical impact of the antegrade approach for LVT after Mitraclip implantation. Methods and results: We included five patients (all men; age 72.6 ± 10.5 years) with Mitraclip implantation who underwent catheter ablation for LVT and employed the antegrade approach. Post-ablation mitral valve function was systematically evaluated by transthoracic echocardiography. Six procedures with the antegrade approach were performed on the five patients; three of these patients developed electrical storm. The number of implanted Mitraclip was 1 in two patients, 2 in two patients, and 3 in one patient, for a mean duration of 417 ± 324 days before ablation. After 117-day median follow-up, there was no recurrence of electrical storm, but ventricular tachyarrhythmia recurred and required implantable cardioverter defibrillator therapy in one patient (only sporadic anti-tachycardia pacing); two patients died because of reasons other than ventricular arrhythmia. There was no procedure-related injury on the mitral valve immediately and 3 months after ablation. Conclusions: Antegrade ablation of LVT after Mitraclip implantation may be feasible. Non-arrhythmic death during follow-up suggested the need for comprehensive evaluation before and after ablation.

Significant reduction in procedure duration in remote magnetic-guided catheter ablation of atrial fibrillation using the third-generation magnetic navigation system.

PURPOSE: The magnetic navigation system (MNS) has shown to be safe and effective for catheter ablation of atrial fibrillation (AF). However, longer procedure duration as compared to manual catheter ablation may limit its widespread use. This study aimed to assess the impact of the newest generation MNS using an optimized mapping and ablation protocol on the efficacy and safety of remote magnetic catheter (RMC)-guided pulmonary vein isolation (PVI). METHODS: This observational study included 52 patients with symptomatic AF who underwent RMC-guided PVI using the second-generation MNS Niobe II (initial 28 patients, group I) or the third-generation MNS Niobe ES in combination with an optimized mapping and ablation protocol (24 patients, group II). RESULTS: Acute PVI was achieved in 26/28 (93%) patients in group I and 24/24 patients (100%) in group II. Mean procedure time was 263.9 ± 81.9 min in group I and significantly lower in group II (139.7 ± 22.6 min, p < 0.01). Mean fluoroscopy time was 18.8 ± 8.7 min in group I and decreased to 7.9 ± 2.6 in group II (p < 0.01). After a median follow-up of 640.5 days (Q1 460.75; Q3 766.5), 16/24 (67%) patients undergoing RMC-guided PVI in group II remained in stable SR. No periprocedural complications were noted for either group. CONCLUSIONS: Use of the third-generation MNS for RMC-guided PVI is safe, effective, and drastically reduced procedure times.

Three-Year Clinical Outcome After 2nd-Generation Cryoballoon-Based Pulmonary Vein Isolation for the Treatment of Paroxysmal and Persistent Atrial Fibrillation　- A 2-Center Experience.

BACKGROUND: Pulmonary vein isolation (PVI) using the 2nd-generation cryoballoon (CB2) for the treatment of atrial fibrillation (AF) has demonstrated encouraging acute and mid-term results. However, follow-up data on outcomes beyond 1 year are sparse. We investigated the 3-year outcome after PVI using the CB2.Methods and Results:100 patients with paroxysmal (PAF, 70/100 [70%] patients) or persistent AF (pAF, 30/100 [30%] patients) underwent CB2-based PVI in 2 experienced centers in Germany. Freeze-cycle duration was 240 s. After successful PVI a bonus freeze-cycle of the same duration was applied in the first 71 patients but was omitted in the following 29 patients. Phrenic nerve palsy occurred in 3 patients (3%); 2 patients were lost to follow-up. After a median follow-up of 38 (29-50) months, 59/98 (60.2%) patients remained in stable sinus rhythm (PAF: 48/70 (69%), pAF: 11/28 (39%) P=0.0084). In 32/39 (77%) patients with arrhythmia recurrence, a second ablation procedure using radiofrequency energy was conducted. Persistent PVI was noted in 76/125 (61%) PVs. After a mean of 1.37±0.6 procedures and a median follow-up of 35 (25-39) months, 77/98 (78.6%) patients remained in stable sinus rhythm (PAF: 56/70 (80%), pAF: 20/28 (71%), P=0.0276). CONCLUSIONS: CB2-based PVI resulted in a 60.2% single-procedure and a 78.6% multiple-procedure success rate after 3 years. Repeat procedures demonstrated a high rate of durable PVI.

Manual Versus Robotic Catheter Ablation for the Treatment of Atrial Fibrillation: The Man and Machine Trial.

OBJECTIVES: Circumferential pulmonary vein isolation (CPVI) using irrigated radiofrequency is the most frequently used ablation technique for the treatment of atrial fibrillation worldwide. BACKGROUND: To date, no large randomized multicenter trials have evaluated the efficacy and safety of CPVI using robotic navigation (RN) systems compared with the current gold standard of manual ablation (MN). METHODS: In this prospective, international multicenter noninferiority trial, 258 patients with paroxysmal or persistent atrial fibrillation were randomized for CPVI using either RN (RN group, n = 131) or manual ablation (MN group, n = 127). In all patients, CPVI was performed using irrigated radiofrequency ablation in combination with a 3-dimensional mapping system. The primary endpoint was the absence of atrial arrhythmia recurrence on or off antiarrhythmic drugs during a 12-month follow-up period. Secondary endpoints were the evaluation of periprocedural complications and procedural data such as procedure time, fluoroscopy time, and incidence of esophageal injury. RESULTS: Baseline characteristics were comparable between the RN group and MN group. Procedure time was significantly shorter in the MN group (129.3 ± 43.1 min vs. 140.9 ± 36.5 min; p = 0.026). 247 patients completed the 12-month follow-up (RN group, n = 123; MN group, n = 124). Recurrence rate was comparable between the RN and MN groups (n = 29 of 123 [23.6%] vs. 25 of 124 [20.2%]). The incidence of procedure-related major complications did not differ significantly between ablation arms (RN group, n = 8 [6.1%] vs. MN group, n = 6 [4.7%]; p = 0.62). One patient from the RN group developed a fatal atrioesophageal fistula. CONCLUSIONS: This study demonstrated that robotic ablation is noninferior to the current gold standard of manual ablation for CPVI with respect to success and complication rates. Procedure times were significantly longer in the RN group. (Alster Man and Machine: Comparison of Manual and Mechanical Remote Robotic Catheter Ablation for Drug-Refractory Atrial Fibrillation; NCT00982475).

Incidence of Significant Delayed Esophageal Temperature Drop After Cryoballoon-Based Pulmonary Vein Isolation.

BACKGROUND: The second-generation cryoballoon (CB2) has demonstrated superior clinical outcome. Potential procedural complications include esophageal thermal lesions due to excessive esophageal temperature (ET). Safety cut-offs for the ET have previously been published. A safety margin was incorporated due to a delayed esophageal temperature decline even after termination of the CB2 freeze cycle. The extent of these delayed temperature drops requires further systematic evaluation. METHODS AND RESULTS: The study enrolled 29 patients with paroxysmal or shortstanding persistent AF who underwent CB2-based PVI. Freeze cycle duration was 240 seconds. No bonus freeze was applied after successful PVI. The intraluminal ET was continuously measured via a transorally inserted probe (SensiTherm, St. Jude Medical, Inc.). The CB2 temperature and ET were recorded throughout the procedure using a camera setup. The mean number of freeze cycles per patient was 4.3 ± 2. A total of 147 cryoenergy applications were analyzed. A delayed decline in ET of >0.5 °C was recorded following termination of 23.1% of freeze cycles. The maximum drop in delayed ET was 6.4 °C. Excessive esophageal cooling during the freeze cycle exceeding 8.5 °C/min may result in ET ≤10 °C. CONCLUSIONS: Following termination of cryoenergy delivery, the ET may decline an additional 6.4 °C. Proposed ET safety cut-offs during CB2-based PVI need to account for a significant ET drop that may occur even after termination of the individual freeze cycle.

Bonus-freeze: benefit or risk? Two-year outcome and procedural comparison of a "bonus-freeze" and "no bonus-freeze" protocol using the second-generation cryoballoon for pulmonary vein isolation.

BACKGROUND: Second-generation cryoballoon based pulmonary vein isolation has demonstrated encouraging acute and mid-term clinical outcome. Customarily, a bonus-freeze is applied after successful pulmonary vein isolation. OBJECTIVE: To compare the long-term clinical outcome and safety profile of a bonus-freeze and a no bonus-freeze protocol. METHODS: A total of 120 consecutive patients with paroxysmal [95/120 (79 %)] or persistent atrial fibrillation [25/120 (21 %)] underwent CB2-based PVI. Freeze-cycle duration was 240 s. In the first 60 patients a bonus-freeze was applied after successful PVI (group 1), while in the following 60 patients the bonus-freeze was omitted (group 2). RESULTS: Procedure and fluoroscopy times were significantly shorter in group 2 [113.8 ± 32 vs 138.2 ± 29 min (p = 0.03) and 19.2 ± 6 vs 24.3 ± 8 min (p = 0.02)]. No differences in procedural complications were found. During a mean follow-up of 849 ± 74 (group 1) and 848 ± 101 days (group 2, p = 0.13) 69 % of patients (group 1) and 67 % of patients (group 2) remained in stable sinus rhythm without any differences between the groups (p = 0.69). CONCLUSIONS: Freedom from atrial fibrillation after second-generation cryoballoon based pulmonary vein isolation and a follow-up of >2 years is comparable when applying a bonus- and a no bonus-freeze protocol, while procedure and fluoroscopy times are significantly shorter when omitting the bonus-freeze. No differences in periprocedural complications were identified.

Short tip-big difference? First-in-man experience and procedural efficacy of pulmonary vein isolation using the third-generation cryoballoon.

BACKGROUND: The second-generation cryoballoon (CB2) provides effective and durable pulmonary vein isolation (PVI) associated with encouraging clinical outcome data. The novel third-generation cryoballoon (CB3) incorporates a 40 % shorter distal tip. This design change may translate into an increased rate of PVI real-time signal recording, facilitating an individualized ablation strategy using the time to effect (TTE). METHODS AND RESULTS: Thirty consecutive patients with paroxysmal or short-standing persistent atrial fibrillation underwent CB3-based PVI and were compared to 30 patients treated with the CB2. Individual freeze-cycle duration was set to TTE + 120 s for both groups. A total of 118 (CB3) and 119 (CB2) pulmonary veins (PV) were identified and all PVs successfully isolated utilizing the CB3 and CB2, respectively. The real-time PVI visualization rate was 74 % (CB3) and 40 % (CB2; p = 0.001) and the mean freeze-cycle duration 204 ± 88 s (CB3) and 215 ± 90 s (CB2; p = 0.15). Per individual PV, a shorter mean freeze-duration was found for the CB3 and the right superior PVs (188 ± 92 vs. 211 ± 124 s, p = 0.04) and right inferior PVs (192 ± 75 vs. 200 ± 37 s, p = 0.02). No differences were found for the left-sided PVs. CONCLUSIONS: A higher rate of real-time electrical PV recordings is seen using the novel CB3 as compared to CB2, which may facilitate an individualized ablation strategy using the TTE.

Comparison of contact force-guided procedure with non-contact force-guided procedure during left atrial mapping and pulmonary vein isolation: impact of contact force on recurrence of atrial fibrillation.

BACKGROUND: The aim of this study was to evaluate the impact of contact force (CF) visualization on the incidence of low and high CF during left atrial (LA) mapping and pulmonary vein isolation (PVI). METHODS: CF was assessed in 70 patients who underwent PVI. Three highly experienced operators performed all procedures. The operators were blinded to CF in group A (35 patients), and CF was displayed in group B (35 patients). In group B, optimal CF was defined as mean CF between 10 and 39g, and operators attempted to acquire points and ablate within this range. RESULTS: A total of 8401 mapping points were analyzed during LA mapping (group A: 4104, group B: 4297). Low CF <10g and high CF ≥40g were noted in a significantly larger number of points in group A (37.7 vs. 12.0 %, P < 0.001; 11.5 vs. 1.5 %, P < 0.001). At the mitral isthmus and ridge areas, CF was significantly lower (7.7 vs. 12.2g, P < 0.001; 5.3 vs. 11.7g, P < 0.001) in group A than in group B. PVI was successfully achieved in all patients. There were significant site-dependent CF differences between the two groups. Optimal CF was achieved in significantly more applications in group B (P < 0.001). There was no significant difference in atrial fibrillation (AF) recurrence rates after a minimum follow-up of 1 year between the two groups in this cohort (P = 0.24). No significant peri-procedural complications occurred in either group. CONCLUSIONS: CF visualization can assist in avoiding both low and high CF, which may have the potential to improve lesion formation and patient safety profile. In this study, CF-guided ablation did not affect AF recurrence.

Percutaneous, transendocardial injection of bone marrow-derived mononuclear cells in heart failure patients following acute ST-elevation myocardial infarction: ALSTER-Stem Cell trial.

AIMS: Patients with symptomatic heart failure following acute ST-elevation myocardial infarction (STEMI) received transendocardial application of bone marrow-derived mononuclear cells (BMC) to improve left ventricular (LV) function and clinical outcome. METHODS AND RESULTS: Patients (n=12) with LV ejection fraction (EF) <45% and NYHA Class ≥II received NOGA-guided transendocardial injection of BMC into the infarction border zone 17.5±0.8 days following successful interventional revascularisation after STEMI. A matched control group (n=11) was generated from the source data of the previously published LIPSIAbciximab-STEMI trial. Primary and secondary endpoints were derived from comparisons of baseline vs. six-month follow-up cardiac magnetic resonance imaging (CMR) measurements and clinical assessments. Following cell therapy we observed a significant increase of EF (+7.9±1.5%, p=0.001) while the control group showed no change. This effect was driven by a reduction of LV end-systolic volume (ESV) by -27.5±6.5 ml (p=0.001); LV end-diastolic volume (EDV) and scar volu-me remained unchanged. A significant decrease of NYHA Class was found only in the cell therapy group (-0.75 vs. -0.18, p=0.04). Findings were also translated into enhancement of clinical assessments (rehospitalisation for decompensated heart failure, six-minute walk test, NT-proBNP levels). CONCLUSION: The data suggest transendocardial injection of BMC can be used safely in patients with sympto-matic heart failure following acute STEMI. These prospective, preliminary data of a well-characterised, small cohort suggest efficiency compared to routine treatment.