Cryoballoon or Radiofrequency Ablation for Paroxysmal Atrial Fibrillation.

BACKGROUND: Current guidelines recommend pulmonary-vein isolation by means of catheter ablation as treatment for drug-refractory paroxysmal atrial fibrillation. Radiofrequency ablation is the most common method, and cryoballoon ablation is the second most frequently used technology. METHODS: We conducted a multicenter, randomized trial to determine whether cryoballoon ablation was noninferior to radiofrequency ablation in symptomatic patients with drug-refractory paroxysmal atrial fibrillation. The primary efficacy end point in a time-to-event analysis was the first documented clinical failure (recurrence of atrial fibrillation, occurrence of atrial flutter or atrial tachycardia, use of antiarrhythmic drugs, or repeat ablation) following a 90-day period after the index ablation. The noninferiority margin was prespecified as a hazard ratio of 1.43. The primary safety end point was a composite of death, cerebrovascular events, or serious treatment-related adverse events. RESULTS: A total of 762 patients underwent randomization (378 assigned to cryoballoon ablation and 384 assigned to radiofrequency ablation). The mean duration of follow-up was 1.5 years. The primary efficacy end point occurred in 138 patients in the cryoballoon group and in 143 in the radiofrequency group (1-year Kaplan-Meier event rate estimates, 34.6% and 35.9%, respectively; hazard ratio, 0.96; 95% confidence interval [CI], 0.76 to 1.22; P<0.001 for noninferiority). The primary safety end point occurred in 40 patients in the cryoballoon group and in 51 patients in the radiofrequency group (1-year Kaplan-Meier event rate estimates, 10.2% and 12.8%, respectively; hazard ratio, 0.78; 95% CI, 0.52 to 1.18; P=0.24). CONCLUSIONS: In this randomized trial, cryoballoon ablation was noninferior to radiofrequency ablation with respect to efficacy for the treatment of patients with drug-refractory paroxysmal atrial fibrillation, and there was no significant difference between the two methods with regard to overall safety. (Funded by Medtronic; FIRE AND ICE ClinicalTrials.gov number, NCT01490814.).

Avoiding inappropriate therapy of single-lead implantable cardioverter-defibrillator by using atrial-sensing electrodes.

INTRODUCTION: The single-chamber implantable cardioverter-defibrillator (ICD) can be associated with more frequent inappropriate therapies compared with dual-chamber ICDs, when they are accompanied by a simpler implantation procedure. The aim of this study was to investigate whether the use of a single-lead ICD system with atrial-sensing electrodes results in a reduction of inappropriate ICD therapy. METHODS AND RESULTS: The study population consisted of 212 consecutive patients, who underwent primary prophylactic single-lead ICD implantation at our institute. A ventricular lead with atrial-sensing electrodes was implanted in 77 patients (36%; Group-VDD) and a ventricular lead without atrial-sensing electrodes was implanted in 135 patients (64%; Group-VVI). Procedural and follow-up data were collected in a prospective registry. A higher prevalence of atrial fibrillation was present in Group-VDD. There were no other significant differences in patient baseline characteristics (age, sex, and other comorbidities) or follow-up period between the two groups. The operative parameters including fluoroscopic burden showed no significant differences between Group-VDD and Group-VVI. During a mean follow-up period of 697 ± 392 days, 26 patients (12%) experienced appropriate ICD therapies and 13 patients (6%) suffered inappropriate ICD therapies. The incidence of inappropriate ICD therapies in Group-VDD was significantly lower as compared to that of Group-VVI (1/77 [1%] vs 12/135 [9%]; log-rank, P = 0.028). The incidence of appropriate ICD therapies and the occurrence of device-related complications showed no significant difference between the two groups. CONCLUSION: Single-lead ICD with atrial-sensing electrodes shows a lower incidence of inappropriate ICD therapy compared with the absence of atrial-sensing electrodes, without additional operative burden or increased complications.

Association of left atrial low-voltage area and thromboembolic risk in patients with atrial fibrillation.

Aims: Atrial fibrillation (AF) is associated with thromboembolic events. Currently, the CHA2DS2-VASc score is recommended for thromboembolic risk stratification in non-valvular AF patients. However, recent data suggested a potential role of atrial remodelling on thromboembolism. This study aimed to assess the association between left atrial low-voltage area (LVA) and history of clinical manifest as well as subclinical silent cerebral ischaemia (SCI) in AF patients. Methods and results: Two-hundred patients [64 ± 10.5 years, 75 women (37.5%)] with symptomatic paroxysmal (n = 88, 44%) or persistent AF undergoing pulmonary vein isolation (PVI) were prospectively enrolled. Left atrial LVA (bipolar voltage < 0.5mV) was evaluated by intra-procedural mapping (>300 points per patient) during sinus rhythm. Cerebral delayed-enhancement magnetic resonance imaging was performed after PVI for detection of pre-existing procedural-independent SCI. Over all, 17 patients (8.5%) had previous history of stroke. Pre-existing SCIs were detected in 135 patients (67.5%). Patients with previous stroke (4.0 ± 1.5 vs. 2.1 ± 1.3, P < 0.0001) and pre-existing SCI (2.7 ± 1.3 vs. 1.5 ± 1.4, P < 0.0001) had a significantly higher CHA2DS2-VASc score. LVA was significantly larger in patients with previous stroke (12.5 ± 8.5% vs. 3.4 ± 5.4%, P < 0.0001) as well as pre-existing SCI (5.8 ± 6.9% vs. 0.8 ± 1.7%, P < 0.0001). Multivariate regression analysis revealed that LVA was independently associated with the presence of SCI [hazard ratio (HR) per 1% LVA 1.13 (1.06-1.22), P = 0.0003] and history of stroke [HR per 1% LVA 1.36 (1.19-1.60), P < 0.0001] after adjustment of CHA2DS2-VASc score. Conclusion: Left atrial LVA is associated with history of stroke and SCI in patients with non-valvular AF and might improve thromboembolic risk stratification after confirmation of its predictive value in future studies.

Cryoballoon or radiofrequency ablation for symptomatic paroxysmal atrial fibrillation: reintervention, rehospitalization, and quality-of-life outcomes in the FIRE AND ICE trial.

AIMS: The primary safety and efficacy endpoints of the randomized FIRE AND ICE trial have recently demonstrated non-inferiority of cryoballoon vs. radiofrequency current (RFC) catheter ablation in patients with drug-refractory symptomatic paroxysmal atrial fibrillation (AF). The aim of the current study was to assess outcome parameters that are important for the daily clinical management of patients using key secondary analyses. Specifically, reinterventions, rehospitalizations, and quality-of-life were examined in this randomized trial of cryoballoon vs. RFC catheter ablation. METHODS AND RESULTS: Patients (374 subjects in the cryoballoon group and 376 subjects in the RFC group) were evaluated in the modified intention-to-treat cohort. After the index ablation, log-rank testing over 1000 days of follow-up demonstrated that there were statistically significant differences in favour of cryoballoon ablation with respect to repeat ablations (11.8% cryoballoon vs. 17.6% RFC; P = 0.03), direct-current cardioversions (3.2% cryoballoon vs. 6.4% RFC; P = 0.04), all-cause rehospitalizations (32.6% cryoballoon vs. 41.5% RFC; P = 0.01), and cardiovascular rehospitalizations (23.8% cryoballoon vs. 35.9% RFC; P < 0.01). There were no statistical differences between groups in the quality-of-life surveys (both mental and physical) as measured by the Short Form-12 health survey and the EuroQol five-dimension questionnaire. There was an improvement in both mental and physical quality-of-life in all patients that began at 6 months after the index ablation and was maintained throughout the 30 months of follow-up. CONCLUSION: Patients treated with cryoballoon as opposed to RFC ablation had significantly fewer repeat ablations, direct-current cardioversions, all-cause rehospitalizations, and cardiovascular rehospitalizations during follow-up. Both patient groups improved in quality-of-life scores after AF ablation. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01490814.

Procedural characteristics of pulmonary vein isolation using the novel third-generation cryoballoon.

AIM: A novel third-generation cryoballoon (CB3) to perform pulmonary vein isolation (PVI) has recently been released, featuring a shortened distal balloon tip when compared with the second-generation (CB2), possibly allowing for enhanced intra-ablation pulmonary vein (PV) signal mapping. We aimed to investigate procedural efficacy and safety of the CB3 as compared to the CB2. METHODS AND RESULTS: We studied 472 consecutive patients who underwent CB-PVI for paroxysmal or persistent atrial fibrillation (CB3: 49 patients; CB2: 423 patients). Detailed procedural data and in-hospital complications were registered in a prospective database. Complete PVI using the CB only was achieved in 98% of patients in each group. Single-freeze PVI was observed in 84/88% (CB2/CB3, P = n.s.) of the PVs. Time-to-PVI (TPVI) was 49 ± 32 (CB2) and 45 ± 27 s (CB3) (P = n.s.). Time-to-PVI determination rate was higher in the CB3 group (89.5 vs. 82.6%, P = 0.016). Signal noise due to ice formation on mapping electrodes occurred after 70 ± 46 s using CB3 and did not interfere with TPVI determination. Exchange of the spiral mapping catheter with a guide wire was more frequently required in the CB3 group (8.2 vs. 0.7% patients, P < 0.001). Balloon dislodgement during hockey stick manoeuvres occurred in 6.1% patients of the CB3 group only (P = 0.001). Complication rates were not different between the groups. CONCLUSION: The CB3 offers a higher TPVI determination rate, facilitating dosing schemes based on TPVI, with equally high single-freeze efficacy compared with the CB2. The shortened distal tip of the CB3 requires adaptation of standard catheter manoeuvers to avoid balloon dislodgement.

Filling the gap: interventional occlusion of incompletely ligated left atrial appendages.

AIMS: Patients undergoing heart surgery and with history of atrial fibrillation are often treated with intraoperative left atrial appendage (LAA) ligation. Incomplete LAA ligation is often described and can be associated with thrombo-embolic complications. To describe a case series of percutaneous LAA occlusion in patients previously treated with surgical LAA ligation. METHODS AND RESULTS: Over 179 patients treated with implantation of an LAA-occluder system at our centre, 3 (1.6%) were previously treated with a surgical LAA suture exclusion (2 males, age 74 ± 3 years). Patients 1 and 3 presented a 'hammerhead' LAA morphology with an open neck and were successfully treated with an AGA Cardiac Plug (ACP-St Jude Medical) Device. Patient 2 had a conic monolobar LAA with a small neck, and the occlusion could be performed using a Watchman (Boston Scientific) device. After discharge on dual antiplatelet therapy, all the patients could be switched to single aspirin (ASA) therapy after a 6-week transoesophageal echocardiography control. CONCLUSION: Left atrial appendage occlusion in patient with incomplete surgical ligation using percutaneous LAA occluder devices appears to be feasible, and studies including a larger number of patients are needed.

Incidence and characteristics of phrenic nerve palsy following pulmonary vein isolation with the second-generation as compared with the first-generation cryoballoon in 360 consecutive patients.

AIMS: The second-generation cryoballoon (CB2) with increased surface cooling has recently become available. The aim was to investigate the incidence and characteristics of phrenic nerve palsy (PNP) during pulmonary vein isolation (PVI) using the CB2 as compared with the first-generation balloon (CB1). METHODS AND RESULTS: A total of 360 consecutive patients with atrial fibrillation underwent PVI with the CB1 (106 patients) or the CB2 (254 patients). Right PN function was monitored by continuous stimulation and palpation during septal PV ablation. Persistent PNP (present at discharge) occurred in 2.8 and 1.9% (P = 0.63) of patients, transient PNP (full recovery before discharge) in 5.9 and 3.8% (P = 0.41) of patients in the CB2 and CB1 group, respectively. Phrenic nerve palsy during ablation at the right inferior PV was observed in 0% (CB1) and 4.3% (CB2, P = 0.03) of patients. Using the CB2, a trend of reduced incidence of persistent PNP over quartiles of consecutive patients was observed [4.8% (Q1) vs. 0% (Q4); P = 0.077]. At the culprit PV, PNP occurred after 3.5 ± 2.1 (CB1) and 1.1 ± 0.4 applications (CB2; P = 0.036). Complete recovery of PN function occurred after 29 ± 11 (CB1) and 259 ± 137 days (CB2; P = 0.004). CONCLUSIONS: The rate of transient/persistent PNP associated with the use of the CB2 was 5.9 and 2.8%, respectively. Time to restitution of PN function was longer using the CB2.

High rate of durable pulmonary vein isolation after second-generation cryoballoon ablation: analysis of repeat procedures.

AIMS: Pulmonary vein isolation (PVI) using the first-generation cryoballoon (CB1) was characterized by a high rate of recovered pulmonary vein (PV) conduction along with a typical conduction gap pattern in patients with recurrent atrial tachyarrhythmia (ATa). Second generation (CB2) enables more uniform freezing. However, the rate of chronic PVI and PV conduction gap pattern is unknown. METHODS AND RESULTS: All patients with ATa recurrence undergoing a second procedure after CB2 or (historical) CB1 PVI (28 mm) were enrolled. In all patients, a left atrial three-dimensional electronatomic reconstruction was performed. The rates of chronic PVI and localization of PV conduction gaps were determined and compared between CB1 and CB2. Antral PV re-isolation was performed using irrigated-tip radiofrequency current energy ablation. Of 206 patients (CB2), 18 patients underwent the repeat procedure after 192 (75:245) days. In 6 of 18 (33%) patients, all PVs were electrically isolated whereas in the remaining 12 patients (66%) at least one PV demonstrated PV reconduction. Of 71 PVs [1 left common PV (LCPV)], 55 PVs (77%) were chronically isolated. The right superior PV (RSPV) was characterized by the lowest rate of chronic PVI (RSPV: 56%, LSPV: 76%, RIPV: 83%, LIPV: 94%, LCPV: 100%). Compared with CB1, CB2 ablation resulted in a significantly higher rate of chronic PVI (CB2: 77% vs. CB1: 32%; P < 0.0001) with the greatest improvement along both inferior PVs. CONCLUSION: Second-generation cryoballoon atrial fibrillation ablation is associated with a high rate of durable PVI in patients with ATa recurrence. The RSPV represents the PV with the greatest risk for left atrium-pulmonary vein reconnection.

Association between hospital procedure volume and early complications after pacemaker implantation: results from a large, unselected, contemporary cohort of the German nationwide obligatory external quality assurance programme.

AIMS: Several studies demonstrated an inverse relationship between cardioverter-defibrillator implantation volume and complication rates, suggesting better outcomes for higher volume centres. However, the association of institutional procedural volume with patient outcomes for permanent pacemaker (PPM) implantation remains less known, especially in decentralized implantation systems. METHODS AND RESULTS: We performed retrospective examination of data on patients undergoing PPM from the German obligatory quality assurance programme (2007-12) to evaluate the relationship of hospital PPM volume (categorized into quintiles of their mean annual volume) with risk-adjusted in-hospital surgical complications (composite of pneumothorax, haemothorax, pericardial effusion, or pocket haematoma, all requiring intervention, or device infection) and pacemaker lead dislocation. Overall 430 416 PPM implantations were documented in 1226 hospitals. Systems included dual (72.8%) and single (25.8%) chamber PPM and cardiac resynchronization therapy (CRT) devices (1.1%). Complications included surgical (0.92%), and ventricular (0.99%), and atrial (1.22%) lead dislocation. Despite an increase in relatively complex procedures (dual chamber, CRT), there was a significant decrease in the procedural and fluoroscopy times and complications from lowest to highest implantation volume quintiles (P for trend <0.0001). The greatest difference was observed between the lowest (1-50 implantations/year-reference group) and the second-lowest (51-90 implantations/year) quintile: surgical complications [odds ratio (OR) 0.69; confidence interval (CI) 0.60-0.78], atrial lead dislocations (OR 0.69; CI 0.59-0.80), and ventricular lead dislocations (OR 0.73; CI 0.63-0.84). CONCLUSIONS: Hospital annual PPM volume was directly related to indication-based implantation of relatively more complex PPM and yet inversely with procedural times and rates of early surgical complications and lead dislocations. Thus, our data suggest better performance and lower complications with increasing procedural volume.

How to learn pulmonary vein isolation with a novel ablation device: learning curve effects using the endoscopic ablation system.

INTRODUCTION: Novel ablation devices for pulmonary vein isolation (PVI) need a careful evaluation of its efficacy and safety beyond clinical studies in a real world situation. The endoscopic ablation system (EAS) was recently approved for PVI in Europe. We sought to determine the safety, efficacy, and learning curve effects of EAS-PVI in a large volume single center. METHODS AND RESULTS: Between June 2010 and March 2013, all EAS guided PVI procedures were analyzed and 150 consecutive patients were divided in tertiles (T). Clinical follow-up of 12 months assessed freedom from atrial fibrillation (AF) using 72 hour-Holter ECG recordings. In total, 497 of 583 PVs (85%) were isolated by visual guidance only. In T 2 and T 3, visually guided PVI rates increased from 73% to 91% (P < 0.001). After gap mapping, 96% and 99% of all PVs were isolated in T 1-3, respectively (P = 0.018). Total procedure and fluoroscopy time significantly declined over time. All major periprocedural complications occurred in the first T. In 3 patients (2 in 1st and 1 in 2nd T), phrenic nerve palsy was observed (2%). At 12-months follow-up, 103 of 133 patients (77%) remained in stable sinus rhythm without significant differences between Ts. CONCLUSION: With EAS even first time users may achieve acute PVI in a high number of patients with favorable clinical outcomes after 1 year. Yet, acute procedural efficacy and safety are further improved after passing a learning curve of 50 patients.

Improved 1-year clinical success rate of pulmonary vein isolation with the second-generation cryoballoon in patients with paroxysmal atrial fibrillation.

BACKGROUND: The second-generation cryoballoon (CB2) has recently been introduced featuring improved surface cooling. Increased procedural efficacy of pulmonary vein isolation (PVI) when compared to the first-generation balloon (CB1) has been reported. The aim of the study was to investigate the clinical outcome of cryoballoon PVI after 1 year using the CB2 as compared to the CB1. METHODS AND RESULTS: A total of 105 consecutive patients with paroxysmal atrial fibrillation (AF) were studied. Cryoballoon PVI (28 mm) was performed in 50 patients using the CB1, and in 55 patients using the CB2. Patients were scheduled for 72-hour Holter ECG recording at 3, 6, 9, and 12 months and every 6 months thereafter. The study endpoint was defined as recurrent AF or atrial tachycardia >30 seconds documented after a blanking period of 90 days after the procedure. Complete PVI was achieved in 49/50 (98%) and 55/55 (100%) patients in the CB1 and CB2 group, respectively. After a mean follow-up of 416 ± 75 days, 21 (CB1 group) and 10 (CB2 group) patients reached the study endpoint. Kaplan-Meier estimates of arrhythmia-free survival after a single procedure without AAD therapy after 1 year were 63.9% versus 83.6% (P = 0.008) in the CB1 and CB2 group, respectively. Persistent phrenic nerve palsy with delayed healing occurred in 2 (CB1 group) and 3 (CB2 group) patients. CONCLUSION: Clinical outcome of PVI using the CB2 was significantly improved when compared to the CB1.

Rationale and Design of FIRE AND ICE: A multicenter randomized trial comparing efficacy and safety of pulmonary vein isolation using a cryoballoon versus radiofrequency ablation with 3D-reconstruction.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia imposing substantial morbidity and mortality. Catheter-based pulmonary vein isolation (PVI) using radiofrequency current (RFC) has become a standard treatment for drug-resistant and symptomatic paroxysmal AF (PAF). In recent years, the cryoballoon-based technique is increasingly used as a promising alternative with a short learning curve. METHODS: The FIRE AND ICE trial is a prospective, randomized, controlled, open, blinded outcome assessment, noninferiority trial comparing cryoballoon-, and RFC-based PVI. Patients with drug-resistant PAF will be randomized in a 1:1 matrix in multiple European centers. The primary hypothesis is that cryoballoon ablation is not inferior to RFC ablation using 3-dimensional mapping with respect to clinical efficacy. The primary endpoint is defined as the time to first documented clinical failure, including: (1) recurrence of AF; (2) atrial flutter or atrial tachycardia; (3) prescription of class I or III antiarrhythmic drugs; or (4) re-ablation, whichever comes first, following a blanking period of 3 months after the index ablation procedure. The primary safety endpoint is a composite of death, stroke/transient ischemic attack, cardiac arrhythmias (apart from AF recurrence) causally related to the therapeutic intervention, and procedure-related serious adverse events. CONCLUSION: The FIRE AND ICE trial compares 2 different technologies to perform catheter ablation of PAF with respect to efficacy and safety. It aims at providing objective data to guide selection and usage of ablation catheters in the treatment of AF.

Improved lesion formation using the novel 28 mm cryoballoon in atrial fibrillation ablation: analysis of biomarker release.

AIMS: Recently, a novel second-generation (G2) cryoballoon (CB) was introduced. Comparative analysis of lesion formation in terms of myocardial biomarker release [first-generation CB (G1) vs. G2] has not been studied. To compare myocardial biomarker release using the 28 mm G1 vs. G2 CB. METHODS AND RESULTS: In patients (patients) treated with the simplified single big CB (SBCB) strategy for pulmonary vein isolation (PVI), myocardial biomarkers [troponin T (TnT), creatine kinase, lactic dehydrogenase (LDH)] were measured at 12, 24, and 48 h after PVI. Two groups were defined: Group 1 (G1; freezing time: 300 s), Group 2 (G2; freezing time: 240 s). Mean biomarker peak values were compared. To correct for between-group differences in cumulative freezing time, an index calculated as peak biomarker release divided by cumulative freezing time was calculated. Sixty-six CB PVI procedures (G1: 33 patients, G2: 33 patients) were analysed. Pulmonary vein isolation was achieved in all the patients using the simplified SBCB technique only. Mean freezing time (51 ± 10 vs. 33 ± 6 min, P < 0.01) was significantly shorter in G2. All biomarker levels tended to be higher in G2 vs. G1. The indexed biomarkers values were significantly higher in G2: TnT: 18.8 ± 8.5 vs. 32.3 ± 13.6 pg/L/min (P < 0.01); creatinephosphokinase: 6.7 ± 2.7 vs. 11.7 ± 3.9 U/L/min (P < 0.01); LDH: 5.2 ± 1.0 vs. 9.1 ± 2.7 U/L/min (P < 0.01). On a 6-month follow-up (180 days), G2 revealed a significantly higher success rate (20/33 vs. 28/33; P = 0.027). CONCLUSION: Pulmonary vein isolation using the G2 CB increased the myocardial biomarker release index and is linked to a significantly improved 6 months success rate.

Improved procedural efficacy of pulmonary vein isolation using the novel second-generation cryoballoon.

INTRODUCTION: The cryoballoon technology has the potential to isolate a pulmonary vein (PV) with a single energy application. However, using the first-generation cryoballoon (CB-1G) repeated freezing or additional focal ablation is often necessary. The novel second-generation cryoballoon (CB-2G) features a widened zone of optimal cooling comprising the whole frontal hemisphere. The aim of this study was to investigate the impact of the novel design on procedural efficacy of cryoballoon PV isolation (CB-PVI). METHODS AND RESULTS: Single transseptal CB-PVI using an endoluminal spiral mapping catheter was performed in 60 consecutive patients (CB-1G, 28 mm, 300 seconds application time: 30 patients; CB-2G, 28 mm, 240 seconds application time: 30 patients). When compared to the CB-1G, using the CB-2G increased single-shot PVI rate from 51% to 84% (P < 0.001) and decreased procedure duration (128 ± 27 vs 98 ± 30 minutes; P < 0.001), and fluoroscopy exposure time (19.5 ± 7.4 vs 13.4 ± 5.3 min; P = 0.001). Effective CB-2G PVI could be performed with increased real-time PVI visualization rate (49% vs 76%; P < 0.001). Time to PVI (T(PVI)) was shorter in the CB-2G group (79 ± 60 vs. 52 ± 36 seconds; P = 0.049). Procedure-related complications occurred in 2 patients in the CB-1G group and 1 patient in the CB-2G group. CONCLUSIONS: The CB-2G significantly improved procedural efficacy compared to the CB-1G and provided reliable T(PVI) measurement. T(PVI) may be used to adjust application time and number individually in future studies. Final conclusions regarding the safety profile of the CB-2G requires additional research.

A prospective randomized single-center study on the risk of asymptomatic cerebral lesions comparing irrigated radiofrequency current ablation with the cryoballoon and the laser balloon.

BACKGROUND: Asymptomatic cerebral lesions (ACL) may occur during atrial fibrillation (AF) ablation. We sought to compare the ACL incidence between 3 contemporary technologies: (1) irrigated radiofrequency current (RFC), (2) the single big cryoballoon (CB), and (3) the endoscopic laser-balloon (LB) in a prospective randomized pilot study. METHODS AND RESULTS: Ninety-nine patients were treated in 3 groups. Diffusion weighted MRI was acquired pre- (n = 20) and 24-48 h postablation (n = 99). After ablation, new ACL were detected in 22% of patients without significant differences between groups (RFC 8/33; CB 6/33; LB 8/33; P = 0.8). The presence of hypertension was identified as the only independent predictor of ACL by univariate regression analysis. During LB ablation, more ablation lesions (140 ± 19 vs 119 ± 18; P = 0.007) were applied during longer procedures (166 ± 36 vs 143 ± 32 min; P = 0.05) in patients with ACL. Univariate analysis revealed that a higher number of ablation lesions predicted ACL (P = 0.02). CONCLUSION: In this prospective, randomized, single-center pilot study, ablation technology did not influence the occurrence of ACL during AF ablation.

Two versus one repeat freeze-thaw cycle(s) after cryoballoon pulmonary vein isolation: the alster extra pilot study.

BACKGROUND: Repeated freezing (bonus applications) during cryoballoon pulmonary vein isolation (PVI) has been suggested to improve lesion durability. However, the long-term clinical effects of repeated freezing have not been investigated. METHODS AND RESULTS: A total of 51 patients (pts) with paroxysmal atrial fibrillation (AF) underwent PVI using the single big (28 mm) cryoballoon technique. One (27 pts, group I) or 2 bonus applications (24 pts, group II) were performed at all PVs subsequent to PVI. Clinical follow-up consisted of continuous rhythm monitoring by an implantable cardiac monitor (ICM, 24 pts) and serial 7-day Holter-ECG recording (7DH, 27 pts). The primary endpoint was defined as recurrent AF or atrial tachycardia. Acute PVI of all PVs was obtained in 50/51 pts (98%). The median (Q1;Q3) follow-up duration in this study was 384 (213;638) days. The primary endpoint occurred in 48% (group I, 15 pts ICM, 12 pts 7DH) and 46% (group II, 9 pts ICM, 15 pts 7DH), P = 0.84. Procedure- and fluoroscopy-time for group I versus group II was 193 ± 56 minutes versus 207 ± 27 and 33 ± 13 minutes versus 34 ± 11 minutes, respectively. Right phrenic nerve palsy (PNP) occurred in 3 pts (all group II, time to resolution: 128 ± 112 days). In 2 of these pts, PNP occurred during the second bonus application. CONCLUSION: Application of 2 when compared to 1 freeze-thaw cycle(s) following cryoballoon PVI did not result in improved clinical success but was associated with a higher complication rate.

Ipsilateral pulmonary vein isolation performed by a single continuous circular lesion: role of pulmonary vein mapping during ablation.

AIMS: Complete pulmonary vein isolation (CPVI) can be achieved by continuous circular lesions (CCL) around the ipsilateral pulmonary veins (PVs) guided by a 3D-mapping system. We investigated whether CPVI can be achieved with a single CCL around the isplilateral PVs without recording PV activity during ablation. METHODS AND RESULTS: Fifty patients with atrial fibrillation underwent ablation of CCLs around ipsilateral PVs guided by 3D mapping. One or two Lasso catheters were placed within the PVs. Lasso tracings were hidden to physicians during ablation. After completion of CCLs, Lasso tracings were evaluated. If PV activation was present, conduction gaps (CGs) were identified and ablated with guidance by the local electrogram and the Lasso catheter(s). In 21 patients (42%), CPVI was achieved after ablation of a single CCL around ipsilateral PVs. Pulmonary vein isolation was achieved in 43 patients (86%) in the right-sided PVs and in 21 patients (42%) in the left-sided PVs. In the remaining patients, there were eight CGs in right-sided CCLs and 40 CGs in left-sided CCLs. Conduction gaps along the left CCLs were found at the ridge between the PV ostia and the left atrial appendage in 27 out of 40 CGs (68%). Mean time from the P-wave onset to the earliest PV potential was 112±35 ms in the presence of a CG at the roof, and 166±59 ms in patients with CGs at other locations in left-sided CCLs (P<0.05). CONCLUSION: Complete pulmonary vein isolation is difficult to achieve with a single CCL around ipsilateral PVs without continuous recording of PV activation during ablation.

Cryoballoon ablation of atrial fibrillation.

Pulmonary vein isolation using a cryoballoon has evolved into a relatively simple alternative for point-by-point radiofrequency ablation because this technology theoretically allows for PV isolation with a single application. Recent clinical studies indicate a high efficacy rate of the procedure; however, the incidence of the most common complication-phrenic nerve palsy (PNP)-has been reported in up to 11.2% of cases. Based on the present data, PNP is mainly associated with the use of the smaller 23 mm balloon. Very recently, it became evident that cryoballoon ablation may be associated with PV stenosis. Thus, the use of cryoballoon technology needs to be combined with a strategy aiming for maximal patient safety. The "single big (28 mm) cryoballoon technique" is a straightforward single-device strategy to deploy cryothermal lesions proximal to the PV ostium at the antrum level, thereby reducing the risk of collateral damage. Using this technique the endpoint of complete PV isolation was achieved in 97% of patients in our laboratory. PNP was observed in 4.4% of patients and resolved within 12 months in the majority of cases. In the future, development of an even bigger (32 mm) cryoballoon may further increase procedural safety by reducing the risk of PNP or PV stenosis.

Esophageal endoscopy results after pulmonary vein isolation using the single big cryoballoon technique.

INTRODUCTION: Reversible esophageal thermal lesions after cryoballoon pulmonary vein isolation (CB-PVI) have been reported when using variable balloon sizes. The aim of this study was to investigate (1) the incidence of esophageal thermal lesions, and (2) esophageal temperature changes associated with CB-PVI using the single big cryoballoon technique. METHODS AND RESULTS: Thirty-eight patients with atrial fibrillation underwent successful CB-PVI using only the 28 mm cryoballoon. Luminal esophageal temperature (LET) was continuously monitored by 3 thermocouples. Fluoroscopic distance from cryoballoon to esophagus probe was retrospectively evaluated in RAO 30 degrees and LAO 40 degrees projections. All patients underwent postprocedural esophageal endoscopy. Average minimal LET was lower during freezing at inferior PVs, when compared to superior PVs: 35.4 +/- 0.9 (range: 32.6 to 37.4; RSPV); 31.5 +/- 7.5 (2.5 to 37.6; RIPV); 32.9 +/- 5.2 (8.5 to 36.5; LSPV); and 30.3 +/- 8.4 degrees C (-6 to 36.7 degrees C; LIPV); P = 0.001. We found steep temperature gradients over distance (1) from the cryoballoon center (LETs < 10 degrees C confined to a distance of < 15 mm in both RAO 30 degrees and LAO 40 degrees projections), and (2) along the esophagus long axis, underscoring the need for multiple measurement sites. None of the patients showed esophageal thermal lesions at endoscopy after 3 +/- 1 (range 1-7) days. No AEF occurred during a follow-up of 125 +/- 78 days. CONCLUSION: In a cohort of AF patients treated by the single big cryoballoon technique, CB-PVI was not associated with thermal esophageal lesions.

Unexpected high incidence of esophageal injury following pulmonary vein isolation using robotic navigation.

INTRODUCTION: Robotic navigation (RN) is a novel technology for pulmonary vein isolation (PVI). We investigated the incidence of thermal esophageal injury using RN with commonly used power settings in comparison to manual PVI procedures. methods: Thirty-nine patients underwent circumferential PVI using a 3.5-mm irrigated-tip-catheter. In the manual (n = 25) and the RN(1) group (n = 4) power was limited to 30 W (17 mL/min flow, maximal temperature 43 degrees C, max. 30 sec/spot) at the posterior left atrial (LA) wall. In RN-based procedures, ablation was performed with a contact force of 10-40 g. The operator was blinded to the esophageal temperature (T(eso)). In the RN(2) group ablation power along the posterior LA wall was reduced to 20 W and ablation terminated at T(eso) of 41 degrees C. Endoscopy was carried out 2 days post-ablation. RESULTS: PVI was achieved in all patients. In the manual group no esophageal lesions, minimal lesions, or ulcerations were found in 15 of 25 (60%), 7 of 25 (28%), and 3 of 25 (12%) patients, respectively. All patients in the RN(1) group had an ulceration and one developed esophageal perforation. A covered stent was placed 14 days post-PVI and removed at day 81. In the RN(2) group, only a single minimal lesion was found. CONCLUSIONS: A high incidence of thermal esophageal injury including a perforation was noted following robotic PVI using 30 W along the posterior LA wall. During RN-based PVI procedures esophageal temperature monitoring is advocated. Reduction of ablation power to 20 W and termination of energy delivery at T(eso) of 41 degrees C significantly reduced the risk of esophageal injury.