Alexander Fürnkranz

The ‘single big cryoballoon’ technique for acute pulmonary vein isolation in patients with paroxysmal atrial fibrillation: a prospective observational single centre study

Aims Cryothermal energy (CTE) ablation via a balloon catheter (Arctic Front, Cryocath™) represents a novel technology for pulmonary vein isolation (PVI). However, balloon-based PVI approaches are associated with phrenic nerve palsy (PNP). We investigated whether ‘single big cryoballoon’-deployed CTE lesions can (i) achieve acute electrical PVI without left atrium (LA) imaging and (ii) avoid PNP in patients with paroxysmal atrial fibrillation (PAF). Methods and results After double transseptal punctures, one Lasso catheter and a big 28 mm cryoballoon catheter using a steerable sheath were inserted into the LA. PV angiography and ostial Lasso recordings from all PVs were obtained. Selective PV angiography was used to evaluate balloon to LA–PV junction contact. CTE ablation lasted 300 s, and the PN was paced during freezing at right-sided PVs. Twenty-seven patients (19 males, mean age: 56 ± 9 years, LA size: 42 ± 5 mm) with PAF (mean duration: 6.6 ± 5.7 years) were included. PVI was achieved in 97/99 PVs (98%). Median (Q1; Q3) procedural, balloon, and fluoroscopy times were 220 min (190; 245), 130 min (90; 170), and 50 min (42; 69), respectively. Three transient PNP occurred after distal PV ablations. No PV stenosis occurred. Total median (Q1; Q3) follow-up time was 271 days (147; 356), and 19 of 27 patients (70%) remained in sinus rhythm (3-month blanking period). Conclusion Using the single big cryoballoon technique, almost all PVs (98%) could be electrically isolated without LA imaging and may reduce the incidence of PNP as long as distal ablation inside the septal PVs is avoided.

Characterization of conduction recovery after pulmonary vein isolation using the “single big cryoballoon” technique

BACKGROUND Pulmonary vein isolation using the cryoballoon technique (CB-PVI) has evolved into a simple and safe alternative for point-by-point radiofrequency ablation. Systematic analysis of conduction recovery occurring after CB-PVI and causing recurrent atrial fibrillation has not yet been performed. OBJECTIVE The purpose of this study was to analyze conduction recovery after PVI using the single big (28-mm) cryoballoon technique. METHODS Twenty-six patients with recurrent atrial tachyarrhythmia after previous CB-PVI underwent repeat ablation. Pulmonary vein (PV) reisolation was performed by antral irrigated radiofrequency ablation using electroanatomic mapping. For analysis of the location of conduction gaps, the ipsilateral LA-PV junction was divided into six equally distributed segments. RESULTS PV reconduction frequently occurred into multiple (>2) PVs (54% patients). Conduction gaps could be abolished by single point ablation in 63% (lateral) and 41% (septal) of patients or by incomplete circular lesions in the remaining patients. A significantly higher number of patients exhibited conduction recovery at inferior segments (85% lateral, 77% septal) compared with superior segments (42% lateral, 31% septal). Furthermore, the ridge between PV ostia and left atrial appendage (LAA) was highly associated with reconduction into lateral PVs (81% of patients). Retrospective analysis of the initial CB-PVI-procedure revealed lower freezing temperatures at superior than inferior PVs as well as sharp catheter angulations with loss of central cryoballoon alignment to reach inferior PVs. CONCLUSION Conduction recovery after CB-PVI occurs at a high incidence at inferior sites around ipsilateral PV ostia and the LAA-PV ridge. Modifications of the technique to ensure optimal balloon-tissue contact at predilection sites may improve long-term success rates.

Luminal esophageal temperature predicts esophageal lesions after second-generation cryoballoon pulmonary vein isolation

BACKGROUND The novel second-generation cryoballoon (CB) facilitates pulmonary vein isolation (PVI) by improved surface cooling. The impact of this redesign on collateral damage is unknown. OBJECTIVE To investigate the incidence of esophageal lesions after PVI using the second-generation CB and the role of luminal esophageal temperature (LET) measurement as a predictor of lesion formation. METHODS Thirty-two consecutive patients underwent PVI using the second-generation 28 mm CB. Target application time was 2 × 240 seconds. Ninety-two percent of the PVs were isolated after 1 cryoenergy application. Complete PVI was achieved in all patients. LET with 3 thermocouples was continuously measured during cryoenergy application. Freezing was interrupted only if weakening/loss of phrenic nerve function or low LET (<5 °C) was observed. RESULTS The lowest measured LET was-12 °C (despite cryoapplication interruption). Postprocedural gastroesophagoscopy was performed after 1-3 days in all patients and showed lesions in 6 of 32 (19%) patients. A minimum LET of≤12 °C predicted esophageal lesions with 100% sensitivity and 92% specificity (area under the receiver-operator characteristic curve 0.97; 95% CI 0.93-1.02; P = .001). Persistent phrenic nerve palsy occurred in 2 (6%) patients during ablation at the right inferior pulmonary vein. Repeat gastroesophagoscopy confirmed healing of lesions after 16 ± 14 days. CONCLUSIONS Second-generation 28 mm CB PVI is associated with significant esophageal cooling, resulting in lesion formation in 19% of the patients. LET measurement accurately predicts lesion formation and may enhance the safety of the novel device.

Cryoballoon ablation of atrial fibrillation.

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. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1427‐1431, December 2010)

Remote Robotic Navigation and Electroanatomical Mapping for Ablation of Atrial Fibrillation — Considerations for Navigation and Impact on Procedural Outcome

Background—Radiofrequency current ablation of atrial fibrillation (AF) requires high technical skills to achieve optimal catheter stability and is associated with an individually high x-ray exposure to both the patient and the operator. To facilitate catheter navigation and to reduce the operators x-ray burden, remote navigation (RN) systems have been developed. Considerations for navigation of a novel remote robotic navigation system in pulmonary vein isolation (PVI) procedures are reported. Methods and Results—In 65 patients with drug-refractory AF (43 paroxysmal, 22 persistent), complete circumferential PVI was performed using RN in conjunction with different electroanatomic mapping systems. Acute complete PVI using exclusively RN was achieved in 95%. The procedure time was 195±40 minutes. The operators x-ray exposure time was reduced by 6±4 minutes (35%) using RN. In 7 of 14 patients with persistent AF, conversion to sinus rhythm was achieved by radiofrequency current ablation. During a median follow-up period of 239 days (range, 184 to 314 days), 47 of 65 patients (73%) remained free of any documented atrial tachyarrhythmia recurrences after a single procedure. The relative proportion of patients remaining free of AF was 76% and 68% for paroxysmal and persistent AF, respectively. Conclusions—PVI using the novel RN system can be performed safely and effectively. One third of the operators fluoroscopy exposure time might be saved using RN. However, the questions of whether the overall fluoroscopy exposure is reduced by RN and whether RN improves PVI procedures needs to be assessed during a comparative trial between man and machine.Background— Radiofrequency current ablation of atrial fibrillation (AF) requires high technical skills to achieve optimal catheter stability and is associated with an individually high x-ray exposure to both the patient and the operator. To facilitate catheter navigation and to reduce the operator’s x-ray burden, remote navigation (RN) systems have been developed. Considerations for navigation of a novel remote robotic navigation system in pulmonary vein isolation (PVI) procedures are reported. Methods and Results— In 65 patients with drug-refractory AF (43 paroxysmal, 22 persistent), complete circumferential PVI was performed using RN in conjunction with different electroanatomic mapping systems. Acute complete PVI using exclusively RN was achieved in 95%. The procedure time was 195±40 minutes. The operator’s x-ray exposure time was reduced by 6±4 minutes (35%) using RN. In 7 of 14 patients with persistent AF, conversion to sinus rhythm was achieved by radiofrequency current ablation. During a median follow-up period of 239 days (range, 184 to 314 days), 47 of 65 patients (73%) remained free of any documented atrial tachyarrhythmia recurrences after a single procedure. The relative proportion of patients remaining free of AF was 76% and 68% for paroxysmal and persistent AF, respectively. Conclusions— PVI using the novel RN system can be performed safely and effectively. One third of the operator’s fluoroscopy exposure time might be saved using RN. However, the questions of whether the overall fluoroscopy exposure is reduced by RN and whether RN improves PVI procedures needs to be assessed during a comparative trial between man and machine. Received August 31, 2008; accepted December 17, 2008. # CLINICAL PERSPECTIVE {#article-title-2}

Cryoballoon Pulmonary Vein Isolation with Real-Time Recordings from the Pulmonary Veins

Introduction: Cryoballoon (CB) ablation represents a novel technology for pulmonary vein isolation (PVI). We investigated feasibility and safety of CB‐PVI, utilizing a novel spiral catheter (SC), thereby obtaining real‐time PV potential registration.

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

Abstract 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.

Cryoballoon temperature predicts acute pulmonary vein isolation

BACKGROUND Cryoballoon pulmonary vein isolation (PVI) currently requires a long cryoballoon application (CBA) time of 240 to 300 seconds, thus repeated ineffective CBA prolongs procedure duration. We hypothesized that cryoballoon temperature (CBT) may be used to discriminate between effective and ineffective CBA during freezing. OBJECTIVE This study sought to evaluate CBT as a predictor of CBA efficiency. METHODS Sixty-six patients with atrial fibrillation underwent PVI using the single big (28 mm) cryoballoon technique. CBT was continuously recorded. After each CBA (300 seconds), a Lasso catheter (Biosense Webster, Inc., Diamond Bar, California) was placed into the target pulmonary vein (PV) to determine whether electrical PV disconnection was present. Only the first CBA at each PV was analyzed to avoid cumulative effects. RESULTS The CBT was lower during CBA at superior compared with inferior PVs. When individual CBAs were grouped according to successful/failed PVI, CBT was lower for those CBAs that resulted in successful PVI at all time points analyzed. To test the performance of CBT to predict failed CBA, receiver-operator curves were constructed. A minimal CBT of ≥ -42°C/ -39°C (superior/inferior PVs) predicted failed PVI with 73%/92% specificity (area under the curve 0.82/0.81); positive predictive value (PPV) 74%/74%. A minimal CBT of < -51°C was invariably associated with PVI. After 120 seconds of freezing, a CBT of ≥ -36°C/ -33°C (superior/inferior PVs) predicted failed PVI with 97%/95% specificity (area under the curve 0.82/0.76); PPV 82%/80%. CONCLUSION Balloon temperature predicts successful target PVI during cryoablation and may serve in the early identification of noneffective balloon applications.

Reduced incidence of esophageal lesions by luminal esophageal temperature–guided second-generation cryoballoon ablation

BACKGROUND An increased incidence of esophageal lesions (EL) after pulmonary vein isolation (PVI) using the second-generation cryoballoon (CB2) has been described. We hypothesized that luminal esophageal temperature (LET)-guided PVI reduces the incidence of EL. OBJECTIVE The aim of this study was to investigate the incidence of EL after LET-guided PVI using the CB2. METHODS Ninety-four consecutive patients underwent CB2-PVI for paroxysmal or persistent atrial fibrillation. Target freezing time was 2 × 240 seconds. LET was continuously measured by a probe with 3 thermocouples. Early freezing interruption was performed when LET reached a prespecified cutoff temperature. A group of 32 patients who underwent CB2-PVI with observational LET measurement served as the control group. Postprocedural esophagoscopy was performed in all patients. RESULTS Compared with observational LET measurement, a strategy of LET-guided CB-PVI significantly reduced the incidence of EL from 18.8% to 3.2% (P = .008). A progressive decline in the incidence of EL was observed with an increasing LET cutoff: 7.1% (2/28 patients, 12°C cutoff) and 1.5% (1/66 patients, 15°C cutoff, P = .005 vs control). Despite early freezing interruption at a single pulmonary vein in 27% (25/94) of patients, complete PVI was achieved in all patients using the 28 mm balloon. Repeat esophagoscopy confirmed healing of EL after 1 week. After a mean of 268 ± 119 days, 87% (76/87) of patients were free of recurrent atrial fibrillation or atrial tachycardia following a 90-days blanking period. CONCLUSION LET-guided CB2-PVI significantly reduced the incidence of thermal EL. Interrupting cryoablation at 15°C LET was associated with the lowest incidence of esophageal injury.

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.