title: Lower Incidence of Thrombus Formation With Cryoenergy Versus Radiofrequency Catheter Ablation German ablation registry: Cryoballoon vs. radiofrequency ablation in paroxysmal atrial fibrillation--One-year outcome data. Cryoballoon ablation of pulmonary veins for paroxysmal atrial fibrillation: first results of the North American Arctic Front (STOP AF) pivotal trial. Long-term outcomes after cryoballoon pulmonary vein isolation: results from a prospective study in 605 patients. Cryoballoon Versus Open Irrigated Radiofrequency Ablation in Patients With Paroxysmal Atrial Fibrillation 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. 2012 focused update of the ESC Guidelines for the management of atrial fibrillation: an update of the 2010 ESC Guidelines for the management of atrial fibrillation. Developed with the special contribution of the European Heart Rhythm Association. Cryoballoon versus radiofrequency catheter ablation for paroxysmal atrial fibrillation. Two-Year Follow-Up after Contact Force Sensing Radiofrequency Catheter and Second-Generation Cryoballoon Ablation for Paroxysmal Atrial Fibrillation: A Comparative Single Centre Study Point-by-Point Radiofrequency Ablation Versus the Cryoballoon or a Novel Combined Approach: A Randomized Trial Comparing 3 Methods of Pulmonary Vein Isolation for Paroxysmal Atrial Fibrillation (The Cryo Versus RF Trial). Randomized, Controlled Trial of the Safety and Effectiveness of a Contact Force–Sensing Irrigated Catheter for Ablation of Paroxysmal Atrial Fibrillation: Results of the TactiCath Contact Force Ablation Catheter Study for Atrial Fibrillation (TOCCASTAR) Study Contact-force guided radiofrequency vs. second-generation balloon cryotherapy for pulmonary vein isolation in patients with paroxysmal atrial fibrillation-a prospective evaluation. The COR trial: a randomized study with continuous rhythm monitoring to compare the efficacy of cryoenergy and radiofrequency for pulmonary vein isolation. Results from a multicentre comparison of cryoballoon vs. radiofrequency ablation for paroxysmal atrial fibrillation: is cryoablation more reproducible? Cryoballoon or Radiofrequency Ablation for Paroxysmal Atrial Fibrillation. Circumferential pulmonary vein isolation with the cryoballoon technique results from a prospective 3-center study.
abstract: Background —Radiofrequency ( RF ) catheter ablation is limited by thromboembolic complications . The objective of this study was to compare the incidence and characteristics of thrombi complicating RF and cryoenergy ablation , a novel technology for the catheter-based treatment of arrhythmias . Methods and Results —Ablation  lesions ( n=197 ) were performed in 22 mongrel dogs at right atrial , right ventricular , and left ventricular sites preselected by a r and omized factorial design devised to compare RF ablation with cryocatheter configurations of varying sizes ( 7F and 9F ) , cooling rates ( −1 ° C/s , −5 ° C/s , and −20 ° C/s ) and target temperatures ( −55 ° C and −75 ° C ) . Animals were pretreated with acetylsalicylic acid and received intraprocedural intravenous unfractionated heparin . Seven days after ablation , the incidence of thrombus formation was significantly higher with RF than with cryoablation ( 75.8 % versus 30.1 % , P = 0.0005 ) . In a multiple regression model , RF energy remained an independent predictor of thrombus formation compared with cryoenergy ( OR , 5.6 ; 95 % CI , 1.7 , 18.1;P = 0.0042 ) . Thrombus volume was also significantly greater with RF than with cryoablation ( median , 2.8 versus 0.0 mm3;P < 0.0001 ) . More voluminous thrombi were associated with larger RF lesions , but cryolesion dimensions were not predictive of thrombus size . Conclusions —RF energy is significantly more thrombogenic than cryoenergy , with a higher incidence of thrombus formation and larger thrombus volumes . The extent of hyperthermic tissue injury is positively correlated with thrombus bulk , whereas cryoenergy lesion size does not predict thrombus volume , most likely reflecting intact tissue ultrastructure with endothelial cell preservation BACKGROUND Although radiofrequency ( RF ) ablation has long been the st and ard of care for atrial fibrillation ( AF ) ablation , cryoballoon technology has emerged as a feasible approach with promising results . Prospect i ve multicenter registry data referring to both ablation technologies in AF ablation are lacking so far . OBJECTIVE The purpose of this study was to report data from the German ablation registry with respect to efficacy and safety in pulmonary vein ablation with different energy sources for paroxysmal AF after 1-year follow-up . METHODS A total of 2306 patients with symptomatic paroxysmal AF from the German ablation registry were included in this analysis . The cohort was divided into two groups according to the ablation energy source used : cryoballoon and RF ablation .  MACCE was defined as a combination of death , myocardial infa rct ion , or stroke . RESULTS AF recurrence rate after a single ablation procedure at 1 year follow-up was not significantly different between the two groups ( 45.8 % after cryoablation and 45.4 % after RF ablation , P = .87 ) . Also , the rate of patients without AF recurrence and free of antiarrhythmic drug at 12-month follow-up was similar ( cryoablation 44.2 % and RF 41.4 % , P = .25 ) . MACCE occurred with an incidence of 0.7 % within 500 days after cryoablation and 1.4 % after RF ablation ( P = .30 ) . Persistent phrenic nerve palsy was more common after cryoablation compared to RF ablation ( 1.1 % vs. 0.3 % , P < .05 ) . CONCLUSION AF recurrence rate at 1-year follow-up was similar in RF ablation compared to cryoablation , whereas the spectrum and relevance of complications were significantly different between the two ablation methods . This finding might influence the choice of ablation method offered to the individual paroxysmal AF patient OBJECTIVES This study sought to assess the safety and effectiveness of a novel cryoballoon ablation technology design ed to achieve single-delivery pulmonary vein ( PV ) isolation . BACKGROUND St and ard radiofrequency ablation is effective in eliminating atrial fibrillation ( AF ) but requires multiple lesion delivery at the risk of significant complications . METHODS Patients with documented symptomatic paroxysmal AF and previously failed therapy with ≥ 1 membrane active antiarrhythmic drug underwent 2:1 r and omization to either cryoballoon ablation ( n = 163 ) or drug therapy ( n = 82 ) . A 90-day blanking period allowed for optimization of antiarrhythmic drug therapy and reablation if necessary . Effectiveness of the cryoablation procedure versus drug therapy was determined at 12 months . RESULTS Patients had highly symptomatic AF ( 78 % paroxysmal , 22 % early persistent ) and experienced failure of at least one antiarrhythmic drug . Cryoablation produced acute isolation of three or more PVs in 98.2 % and all four PVs in 97.6 % of patients . PVs isolation was achieved with the balloon catheter alone in 83 % . At 12 months , treatment success was 69.9 % ( 114 of 163 ) of cryoblation patients compared with 7.3 % of antiarrhythmic drug patients ( absolute difference , 62.6 % [ p < 0.001 ] ) . Sixty-five ( 79 % ) drug-treated patients crossed over to cryoablation during 12 months of study follow-up due to recurrent , symptomatic AF , constituting drug treatment failure . There were 7 of the result ing 228 cryoablated patients ( 3.1 % ) with a > 75 % reduction in PV area during 12 months of follow-up . Twenty-nine of 259 procedures ( 11.2 % ) were associated with phrenic nerve palsy as determined by radiographic screening ; 25 of these had resolved by 12 months . Cryoablation patients had significantly improved symptoms at 12 months . CONCLUSIONS The STOP AF trial demonstrated that cryoballoon ablation is a safe and effective alternative to antiarrhythmic medication for the treatment of patients with symptomatic paroxysmal AF , for whom at least one antiarrhythmic drug has failed , with risks within accepted st and ards for ablation therapy . ( A Clinical Study of the A rct ic Front Cryoablation Balloon for the Treatment of Paroxysmal Atrial Fibrillation [ Stop AF ] ; NCT00523978 ) OBJECTIVES The purpose of this study was to investigate long-term outcomes of freedom from atrial fibrillation ( AF ) after pulmonary vein ( PV ) isolation using cryoballoon ablation with balloon-size selection based on individual PV diameters . BACKGROUND Data are lacking on long-term outcomes from cryoablation and on the most effective balloon size . METHODS This was a prospect i ve observational study involving 605 consecutively enrolled patients with symptomatic paroxysmal AF ( n = 579 ) or persistent AF .  Cryoballoon size was based on magnetic resonance imaging and /or conventional angiograms . Patients were followed up every 3 months during the first year after discharge and every 6 months in the second year . After 24 months , follow-up was on an outpatient basis with documented AF episodes recorded . RESULTS The PV isolation was achieved without touch-up in 91.1 % of patients , using the smaller balloon in 26.7 % , the larger balloon in 25.6 % , and both balloons in 47.7 % of patients . Follow-up data for > 12 months ( median 30 months ; interquartile range 18 to 48 months ) were available for 451 patients , 278 ( 61.6 % ) of whom were free of AF recurrence with no need for repeat procedures after the 3-month blanking period . Rates of freedom from AF after 1 , 2 , and 3 repeat procedures ( using cryoballoon or radiofrequency ablation with similar success rates ) were 74.9 % , 76.2 % , and 76.9 % , respectively . Use of the smaller balloons or both balloons produced the highest rates of long-term freedom from AF . Phrenic nerve palsy occurred in 12 patients ( 2 % ) , resolving within 3 to 9 months . CONCLUSIONS Rates of long-term freedom from AF after cryoballoon ablation are similar to those reported for radiofrequency ablation . A choice between balloons may improve outcomes Background — There is a lack of data on the comparative efficacy and procedural safety of open irrigated radiofrequency ( RF ) and cryoballoon catheter ( CB ) ablation for pulmonary vein isolation in patients with paroxysmal atrial fibrillation . Methods and Results — In a prospect i ve , noninferiority study , 315 patients were r and omly assigned to RF ( n=159 ) or CB ( n=156 ) ablation . The primary end point was freedom from atrial arrhythmia with absence of persistent complications . Patients were largely comparable between groups with more vascular disease in the RF group ( 8.2 % versus 2.6 % for CB ; P=0.028 ) . The primary end point at 12 months was achieved by 70.7 % with RF and 73.6 % with CB ( multiple procedure success ) , including 31 redo procedures in each group ( 19.5 % of RF versus 19.9 % of CB ; P=0.933 ) . For the intention-to-treat population , noninferiority of CB was revealed for the predefined inferiority margin ( risk difference , 0.029 ; 95 % confidence interval , −0.074 to 0.132 ; P<0.001 ) . Rates at 6 months were 63.1 % and 64.1 % for the RF and CB groups ( single procedure success ) , and noninferiority was confirmed ( risk difference , 0.010 ; 95 % confidence interval , −0.097 to 0.116 ; P=0.002 ) . Periprocedural complications for the index procedure were more frequent in the CB group ( 5.0 % RF , 12.2 % CB ; P=0.022 ) with a significant difference in phrenic nerve palsies ( 0 % RF , 5.8 % CB ; P=0.002 ) . Conclusion — This large , prospect i ve , r and omized , controlled study demonstrates noninferiority of CB ablation versus RF ablation for treating patients with paroxysmal atrial fibrillation . Clinical Trial Registration — URL : http://www . clinical trials.gov . Unique identifier : NCT00774566 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 ACCF : American College of Cardiology Foundation ACCP : American College of Chest Physicians ACS : acute coronary syndrome ACT : Atrial arrhythmia Conversion Trial ADONIS : American – Australian – African trial with DronedarONe In atrial fibrillation or flutter for the maintenance of Sinus rhythm AF : atrial fibrillation AHA : American Heart Association AND ROMEDA : ANtiarrhythmic trial with DROnedarone in Moderate-to-severe congestive heart failure Evaluating morbidity DecreAse APHRS : Asia Pacific Heart Rhythm Society aPTT : activated partial thromboplastin time ARB : angiotensin-receptor blocker ARISTOTLE : Apixaban for Reduction In STroke and Other ThromboemboLic Events in atrial fibrillation ATHENA : A placebo-controlled , double-blind , parallel arm Trial to assess the efficacy of dronedarone 400 mg b.i.d . for the prevention of cardiovascular Hospitalization or death from any cause in patiENts with Atrial fibrillation/atrial flutter ATRIA : AnTicoagulation and Risk factors In Atrial fibrillation AVERROES : Apixaban VErsus acetylsalicylic acid ( ASA ) to Reduce the Rate Of Embolic Stroke in atrial fibrillation patients who have failed or are unsuitable for vitamin K antagonist treatment AVRO : A prospect i ve , r and omized , double-blind , Active-controlled , superiority study of Vernakalant vs. amiodarone in Recent Onset atrial fibrillation b.i.d : bis in die ( twice daily ) b.p.m . : beats per minute CABANA : Catheter ABlation vs . ANtiarrhythmic drug therapy for Atrial fibrillation CABG : coronary artery bypass graft CAP : Continued Access to Protect AF CHA2DS2-VASc : Congestive heart failure or left ventricular dysfunction Hypertension , Age ≥75 ( doubled ) , Diabetes , Stroke (doubled)-Vascular disease , Age 65–74 , Sex category ( female ) CHADS2 : Congestive heart failure , Hypertension , Age ≥75 , Diabetes , Stroke ( doubled ) CI : confidence interval CRAFT : Controlled R and omized Atrial Fibrillation Trial CrCl : creatinine clearance DAFNE : Dronedarone Atrial FibrillatioN study after Electrical cardioversion DIONYSOS : R and omized Double blind trIal to evaluate efficacy and safety of drOnedarone ( 400 mg b.i.d . ) vs . amiodaroNe ( 600 mg q.d . for 28 daYS , then 200 mg qd thereafter ) for at least 6 mOnths for the maintenance of Sinus rhythm in patients with atrial fibrillation EAST : Early treatment of Atrial fibrillation for Stroke prevention Trial EHRA : European Heart Rhythm Association ECG : electrocardiogram EMA : European Medicines Agency ERATO : Efficacy and safety of dRonedArone for The cOntrol of ventricular rate during atrial fibrillation EURIDIS : EURopean trial In atrial fibrillation or flutter patients receiving Dronedarone for the maIntenance of Sinus rhythm FAST : atrial Fibrillation catheter Ablation vs . Surgical ablation Treatment FDA : Food and Drug Administration Flec-SL : Flecainide Short-Long trial HAS-BLED : Hypertension , Abnormal renal/liver function , Stroke , Bleeding history or predisposition , Labile INR , Elderly , Drugs/alcohol concomitantly HF-PEF : heart failure with preserved ejection fraction HF-REF : heart failure with reduced ejection fraction HR : hazard ratio HRS : Heart Rhythm Society ICH : intracranial haemorrhage INR : international normalized ratio i.v . : intravenous J-RHYTHM : Japanese RHYTHM management trial for atrial fibrillation LAA : left atrial appendage LoE : level of evidence LVEF : left ventricular ejection fraction MANTRA-PAF : Medical ANtiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation NICE : National Institute for Health and Clinical Excellence NOAC : novel oral anticoagulant NSAID : non-steroidal anti-inflammatory drug NYHA : New York Heart Association OAC : oral anticoagulant or oral anticoagulation o.d . : omni die ( every day ) PALLAS : Permanent Atrial fibriLLAtion outcome Study using dronedarone on top of st and ard therapy PCI : percutaneous coronary intervention PREVAIL : Prospect i ve R and omized EVAluation of the LAA closure device In patients with atrial fibrillation v s. Long-term warfarin therapy PROTECT AF : WATCHMAN LAA system for embolic PROTECTion in patients with Atrial Fibrillation PT : prothrombin time RAAFT : Radio frequency Ablation Atrial Fibrillation Trial RE-LY : R and omized Evaluation of Long-term anticoagulant therapY with dabigatran etexilate ROCKET-AF : Rivaroxaban Once daily oral direct factor Xa inhibition Compared with vitamin K antagonism for prevention of stroke and Embolism Trial in atrial fibrillation RRR : relative risk reduction TE : thromboembolism TIA : transient ischaemic attack t.i.d . : ter in die ( three times daily ) TOE : transoesophageal echocardiogram TTR : time in therapeutic range VKA : vitamin K antagonist Guidelines summarize and evaluate all currently available evidence on a particular issue with the aim of assisting physicians in selecting the best management strategy for an individual patient suffering from a given condition , taking into account the impact on BACKGROUND Catheter ablation is an established treatment for atrial fibrillation ( AF ) .  Cryoballoon ablation ( CBA ) has emerged as an alternative to radiofrequency ablation ( RFA ) . However , there are few data comparing these modalities for treatment of paroxysmal AF ( pAF ) in the U.S. POPULATION The purpose of this study was to compare procedural times , safety , and efficacy of CBA against RFA . METHODS A single-center prospect i ve cohort study evaluated patients who underwent catheter ablation for pAF using CBA or RFA between January 1 , 2010 and October 31 , 2013 . Patients with prior ablation and those without rhythm follow-up for at least 3 months were excluded . The primary end point was freedom from AF , atrial flutter , and atrial tachycardia ( FFAF ) > 30 seconds after a 3-month blanking period without requirement for antiarrhythmic drugs . We also compared rates of successful pulmonary vein isolation ( PVI ) , fluoroscopy and procedure times , and major complication rates . RESULTS A total of 201 patients were included ( CBA = 101 , RFA = 100 ) . The rate of successful PVI was 99.3 % in CBA versus 97.4 % in RFA ( P = 0.08 ) . Procedure times were shorter with CBA ( 192.9 ± 44.0 minutes vs 283.7 ± 78.0 minutes , P < 0.001 ) as well as total fluoroscopy times ( 46.0 ± 22.4 minutes vs 73.0 ± 30.1 minutes , P < 0.001 ) . Overall complication rates were equivalent ; however , fewer cardiac perforations occurred with CBA ( 0 % vs 4 % , P = 0.042 ) . The 1-year FFAF rates were 60.3 % for CBA and 61.1 % for RFA ( log rank P = 0.93 ) . CONCLUSION CBA was associated with equivalent 1-year FFAF rate as RFA for pAF . Procedure and fluoroscopy times were shorter for CBA and fewer cardiac perforations occurred Background . There are little comparative data on catheter ablation of paroxysmal atrial fibrillation ( AF ) using the contact force radiofrequency ( CF-RF ) catheter versus the second-generation cryoballoon ( CB2 ) . Methods and results . This is a single center , retrospective , nonr and omized study of 98 patients with symptomatic , drug-refractory paroxysmal AF who underwent their first PVI ablation using either the CB2 ( n = 40 ) or CF-RF ( n = 58 ) . The mean age was 60 years with 63 % men , a mean LA size of 42 mm . The procedure duration ( 74 ± 17 versus 120 ± 49 minutes p < 0.05 ) was shorter for CB2 group ; the fluoroscopy time ( 14 ± 17 versus 16 ± 5 minutes , p = 0.45 ) was similar . Complete PVI was achieved in 96 % of patients with RF-CF and 98 % with CB2 . Phrenic nerve palsies ( 2 transient and 1 persistent ) occurred exclusively in the CB2 group and 1 severe , nonlethal complication ( pericardial tamponade ) occurred in the CF-RF group . At 24-month follow-up , the success rate , defined as freedom from AF/atrial tachycardia ( AT ) after a single procedure without antiarrhythmic drug , was comparable in CF-RF group and CB2 group ( 65.5 % versus 67 % , resp . , log rank p = 0.54 ) . Conclusion . Both the CB2 and the RF-CF ablation appeared safe ; the success rate at 2 years was comparable between both technologies INTRODUCTION Catheter ablation of paroxysmal AF using the Cryoballoon ( CRYO ) has yielded similar success rates to conventional wide encirclement using radiofrequency catheter ablation ( RFCA ) , but r and omized data are lacking . Pilot data suggested a high success rate with a combined approach ( COMBINED ) using wide encirclement with RFCA followed by 2 CRYO applications to each vein . We compared these 3 strategies in a r and omized controlled trial . METHODS AND RESULTS Patients undergoing first time paroxysmal AF ablation were r and omized to RFCA , CRYO , or COMBINED . Patients were followed up at 3 , 6 , and 12 months with 7 days of ambulatory ECG monitoring . Success was defined as freedom from arrhythmia without antiarrhythmic drugs after a single procedure . A total of 237 patients were r and omized . Success at 1 year was achieved in 47 % in the RFCA group , 67 % in the CRYO group , and 76 % in the COMBINED group ( P < 0.001 for RFCA vs. CRYO , P<0.001 for RFCA vs. COMBINED , and P = 0.220 for CRYO vs. COMBINED ) . Procedure time was 211 ( IQR 174 - 256 ) minutes for RFCA compared to 167 ( 136 - 202 ) minutes for CRYO and 278 ( 243 - 327 ) minutes for COMBINED ( P < 0.001 for RFCA vs. COMBINED , RFCA vs. CRYO , and CRYO vs. COMBINED groups ) . CONCLUSIONS Pulmonary vein isolation for paroxysmal AF is faster with CRYO and results in a higher single procedure success rate than conventional point by point RFCA . The COMBINED approach was not superior to CRYO alone Background — Contact force ( CF ) is a major determinant of lesion size and transmurality and has the potential to improve efficacy of atrial fibrillation ablation . This study sought to evaluate the safety and effectiveness of a novel irrigated radiofrequency ablation catheter that measures real-time CF in the treatment of patients with paroxysmal atrial fibrillation . Methods and Results — A total of 300 patients with symptomatic , drug-refractory , paroxysmal atrial fibrillation were enrolled in a prospect i ve , multicenter , r and omized , controlled trial and r and omized to radiofrequency ablation with either a novel CF-sensing catheter or a non-CF catheter ( control ) . The primary effectiveness end point consisted of acute electrical isolation of all pulmonary veins and freedom from recurrent symptomatic atrial arrhythmia off all antiarrhythmic drugs at 12 months . The primary safety end point included device-related serious adverse events . End points were powered to show noninferiority . All pulmonary veins were isolated in both groups . Effectiveness was achieved in 67.8 % and 69.4 % of subjects in the CF and control arms , respectively ( absolute difference , −1.6 % ; lower limit of 1-sided 95 % confidence interval , −10.7 % ; P=0.0073 for noninferiority ) . When the CF arm was stratified into optimal CF ( ≥90 % ablations with ≥10 g ) and nonoptimal CF groups , effectiveness was achieved in 75.9 % versus 58.1 % , respectively ( P=0.018 ) . The primary safety end point occurred in 1.97 % and 1.40 % of CF patients and control subjects , respectively ( absolute difference , 0.57 % ; upper limit of 1-sided 95 % confidence interval , 3.61 % ; P=0.0004 for noninferiority ) . Conclusions — The CF ablation catheter met the primary safety and effectiveness end points . Additionally , optimal CF was associated with improved effectiveness . Clinical Trial Registration — http://www . clinical trials.gov . Unique identifier : NCT01278953 AIMS In the setting of paroxysmal atrial fibrillation ( AF ) , there are no available data comparing the mid-term outcome of patients undergoing pulmonary vein isolation ( PVI ) catheter ablation using contact-force (CF)-guided radiofrequency ( RF ) vs. second-generation balloon cryotherapy . METHODS AND RESULTS Prospect i ve single-centre evaluation , carried out from March 2011 to February 2013 , comparing CF radiofrequency ( Thermocool ( ® ) SmartTouch ™ , Biosense Webster , Inc. ) ( CF group ) with cryoballoon ablation ( A rct ic Front Advance ™ 28 mm cryoballoon , Medtronic , Inc. ) ( CB group ) , in regards to procedural safety and efficacy , as well as recurrence at 12 months . Overall , 150 consecutive patients were enrolled ( 75 in each group ) . The characteristics of patients of both the groups were similar ( 61.2 ± 9.9 years , women 25.3 % , mean AF duration 4.1 ± 4.0 years , mean CHA2DS2-VASc score 1.4 ± 1.3 , mean HAS-BLED 1.4 ± 0.6 ) . Duration of the procedure was significantly lower in the CF group ( 110.7 ± 32.5 vs. 134.5 ± 48.3 min , P = 0.001 ) , with a lower duration of fluoroscopy ( 21.5 ± 8.5 vs. 25.3 ± 9.9 min , P = 0.017 ) and X-ray exposure ( 4748 ± 2411 cGy cm² vs. 7734 ± 5361 cGy cm² , P = 0.001 ) . In contrast , no significant difference was found regarding significant procedural complication ( 2.7 vs. 1.3 % in CF and CB groups , respectively ; P = 0.56 ) , and PVI was eventually achieved in all cases . At 12 months , AF recurrence occurred in 11 patients ( 14.7 % ) in the CB group and in 9 patients ( 12.0 % ) in the CF group ( HR = 1.20 95 % CI 0.50 - 2.90 ; log rank P = 0.682 ) . CONCLUSIONS Our preliminary findings suggest that CF-guided radiofrequency and cryotherapy present very similar performances in the setting of paroxysmal AF catheter ablation BACKGROUND Results from r and omized trials design ed to compare cryoenergy with radiofrequency for pulmonary vein ( PV ) isolation are lacking . OBJECTIVE To compare the efficacy of a simplified strategy for PV cryoablation ( group C ) vs PV isolation with open-irrigated radiofrequency catheters ( group R ) . METHODS Fifty patients with paroxysmal atrial fibrillation ( AF ) and 4 independent PVs received a Reveal XT implantable cardiac monitor and were r and omized to group C or group R. In group C , PV ablation was done with a single A rct ic Front balloon ( 23 or 28 mm ) per patient and two 300-second applications per PV . No further applications were delivered to close residual conduction gaps . In group R , bidirectional PV conduction block was pursued with Lasso and Navistar ThermoCool catheters and the CARTO system . The primary end point was the proportion of patients remaining free from AF recurrences ≥2 minutes without taking antiarrhythmic drugs 12 months after ablation . RESULTS The primary end point was met by 12 ( 48 % ) patients in group C and 25 ( 68 % ) patients in group R ( odds ratio 0.43 ; P = .05 ) . This difference disappeared after adjustment for acute procedural outcome . In patients for whom all 4 PVs were blocked at the end of the procedure , there was no difference between group C and group R in the primary end point ( 67 % vs 68 % ; P = .94 ) . CONCLUSIONS The efficacy of the simplified strategy for PV cryoablation tested in this study is inferior to PV isolation using open-irrigated radiofrequency catheters with electrophysiological and electroanatomical guidance . Complete PV conduction block is critical to the success of AF ablation Aim Cryoballoon ablation ( Cryoballoon ) has emerged as a new alternative for the treatment of  symptomatic drug-refractory atrial fibrillation ( AF ) . Whether the results of Cryoballoon are more reproducible than those of radiofrequency ( RF ) ablation remains to be proved . Methods and results A total of 860 consecutive patients undergoing a first ablation procedure for paroxysmal AF ( 467 treated with RF and 393 treated with Cryoballoon ) were selected from a prospect i ve multicentre survey of AF ablation ( FrenchAF ) .  Radiofrequency and Cryoballoon were compared regarding mid-term efficacy and safety . During a median follow-up of 14 months ( interquartile range 8–23 ) , patients treated with Cryoballoon displayed similar rates of freedom from atrial arrhythmia relapse in centres performing this technique ( 68–80 % at 18 months ) . However , in centres performing RF , a greater heterogeneity in procedural results was observed ( 46–79 % were free from atrial arrhythmia relapse at 18 months ) . On multivariate analysis , Cryoballoon ( HR = 0.47 , 95 % CI 0.35–0.65 , P < 0.001 ) and annual AF ablation caseload ( HR = 0.87 per every 100 AF ablation procedures per year ; 95 % CI 0.80–0.96 , P = 0.003 ) were independent predictors of procedural success . However , on sensitivity analysis , according to the ablation method , annual AF ablation caseload predicted only sinus rhythm maintenance in the subgroup of patients treated with RF . Analysis of interoperator results with Cryoballoon and RF confirmed lower reproducibility of RF , but suggested that besides caseload , other operator-related factors may play a role . Conclusion Cryoballoon seems to be less operator-dependent and more reproducible than RF in the setting of paroxysmal AF ablation 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 , r and omized 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 r and omization ( 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 r and omized 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 Clinical Trials.gov number , NCT01490814 . ) OBJECTIVES The purpose of this study was to investigate the efficacy safety of the novel cryoballoon device ( A rct ic Front , Cryocath , Quebec , Canada ) . BACKGROUND Antral pulmonary vein ( PV ) ablation with radiofrequency energy is widely used as a strategy for catheter ablation of paroxysmal atrial fibrillation ( PAF ) . A novel double lumen cryoballoon catheter was design ed for circumferential pulmonary vein isolation ( PVI ) with the cryoablation technique . METHODS We consecutively enrolled 346 patients with symptomatic , drug refractory paroxysmal ( n = 293 ) or persistent ( n = 53 ) atrial fibrillation ( AF ) . In all patients , PVI of all targeted PVs was the therapeutic aim . The primary end points of this nonr and omized study were : 1 ) acute isolation rate of targeted PV ; and 2 ) first electrocardiogram-documented recurrence of AF . The secondary end point was occurrence of PV stenosis or atrio-esophageal fistula . RESULTS The 1,360 of 1,403 PVs ( 97 % ) were targeted with balloons or balloons in combination with the use of Freezor Max ( Cryocath ) . We found that ablation with the cryoballoon result ed in maintenance of sinus rhythm in 74 % of patients with PAF and 42 % of patients with persistent AF . No PV narrowing occurred . The most frequent complication was right phrenic nerve palsy observed during cryoballoon ablation at the right superior PV . CONCLUSIONS Pulmonary vein isolation with a new cryoballoon technique is feasible . Sinus rhythm can be maintained in the majority of patients with PAF by circumferential PVI using a cryoballoon ablation system . Cryoablation was less effective in patients with persistent AF than in patients with PAF
target: Conclusions Compared with RF ablation , cryoablation present a comparable long-term AF/atrial tachycardial-free survival and procedure-related adverse events .
  Meanwhile , cryoablation markedly shorten the procedure time , nonetheless , with negligible impact on the fluoroscopy time
background: Aims Cryoablation is a promising alternative technique to RF ablation for treating paroxysmal AF with encouraging results .
  However , data about the efficacy and safety comparison between cryoablation and RF ablation is still lacking .