Cryoballoon versus radiofrequency for pulmonary vein re-isolation after a failed initial ablation procedure in patients with paroxysmal atrial fibrillation. Circumferential pulmonary vein isolation with the cryoballoon technique results from a prospective 3-center study. Long-term comparison of cryoballoon and radiofrequency ablation of paroxysmal atrial fibrillation: a propensity score matched analysis. Cryoballoon Versus Open Irrigated Radiofrequency Ablation in Patients With Paroxysmal Atrial Fibrillation Cryoballoon vs. open irrigated radiofrequency ablation for paroxysmal atrial fibrillation: long-term FreezeAF outcomes Early Recurrence After Pulmonary Vein Isolation of Paroxysmal Atrial Fibrillation With Different Ablation Technologies - Prospective Comparison of Radiofrequency vs. Second-Generation Cryoballoon Ablation. EFFICAS II: optimization of catheter contact force improves outcome of pulmonary vein isolation for paroxysmal atrial fibrillation Influence of energy source on early atrial fibrillation recurrences: a comparison of cryoballoon vs. radiofrequency current energy ablation with the endpoint of unexcitability in pulmonary vein isolation 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. Acute and Long-Term Outcomes of Catheter Ablation of Atrial Fibrillation Using the Second-Generation Cryoballoon versus Open-Irrigated Radiofrequency: A Multicenter Experience. Is empirical four pulmonary vein isolation necessary for focally triggered paroxysmal atrial fibrillation? Comparison of selective pulmonary vein isolation versus empirical four pulmonary vein isolation. Cryoballoon versus radiofrequency catheter ablation for paroxysmal atrial fibrillation. Contact-force guided radiofrequency vs. second-generation balloon cryotherapy for pulmonary vein isolation in patients with paroxysmal atrial fibrillation-a prospective evaluation. German ablation registry: Cryoballoon vs. radiofrequency ablation in paroxysmal atrial fibrillation--One-year outcome data. Pulmonary vein isolation using segmental versus electroanatomical circumferential ablation for paroxysmal atrial fibrillation The difference in autonomic denervation and its effect on atrial fibrillation recurrence between the standard segmental and circumferential pulmonary vein isolation techniques. Pericardial effusion in atrial fibrillation ablation: a comparison between cryoballoon and radiofrequency pulmonary vein isolation. Comparison of cryoballoon and radiofrequency ablation of pulmonary veins in 40 patients with paroxysmal atrial fibrillation: a case-control study. Results from a multicentre comparison of cryoballoon vs. radiofrequency ablation for paroxysmal atrial fibrillation: is cryoablation more reproducible? Catheter Ablation for Paroxysmal Atrial Fibrillation: Segmental Pulmonary Vein Ostial Ablation Versus Left Atrial Ablation Cryoballoon vs. radiofrequency contact force ablation for paroxysmal atrial fibrillation: a propensity score analysis Ablation of superior pulmonary veins compared to ablation of all four pulmonary veins:. Differences of two cryoballoon generations: insights from the prospective multicentre, multinational FREEZE Cohort Substudy. Paroxysmal AF catheter ablation with a contact force sensing catheter: results of the prospective, multicenter SMART-AF trial. A randomized trial of circumferential pulmonary vein ablation versus antiarrhythmic drug therapy in paroxysmal atrial fibrillation: the APAF Study. Circumferential pulmonary vein isolation as index procedure for persistent atrial fibrillation: a comparison between radiofrequency catheter ablation and second-generation cryoballoon ablation. Randomized comparison between pulmonary vein antral isolation versus complex fractionated electrogram ablation for paroxysmal atrial fibrillation.
AIM Catheter ablation of paroxysmal atrial fibrillation ( PAF ) is associated with an important risk of early and late recurrence , necessitating repeat ablation procedures . The aim of this prospect i ve r and omized patient-blind study was to compare the efficacy and safety of cryoballoon ( Cryo ) versus radiofrequency ( RF ) ablation of PAF after failed initial RF ablation procedure . METHODS Patients with a history of symptomatic PAF after a previous failed first RF ablation procedure were eligible for this study . Patients were r and omized to Cryo or RF redo ablation . The primary endpoint of the study was recurrence of atrial tachyarrhythmia , including AF and left atrial flutter/tachycardia , after a second ablation procedure at 1 year of follow-up . All patients were implanted with a cardiac monitor ( Reveal XT , Medtronic ) to continuously track the cardiac rhythm . Patients with an AF burden ( AF% ) ≤ 0.5 % were considered AF-free ( Responders ) , while those with an AF% > 0.5 % were classified as patients with AF recurrences ( non-Responders ) . RESULTS Eighty patients with AF recurrences after a first RF pulmonary vein isolation ( PVI ) were r and omized to Cryo ( N = 40 ) or to RF ( N = 40 ) . Electrical potentials were recorded in 77 mapped PVs ( 1.9 ± 0.8 per patient ) in Cryo Group and 72 PVs ( 1.7 ± 0.8 per patient ) in RF Group ( P = 0.62 ) , all of which were targeted . In Cryo group , 68 ( 88 % ) of the 77 PVs were re-isolated using only Cryo technique ; the remaining 9 PVs were re-isolated using RF . In RF group , all 72 PVs were successfully re-isolated ( P = 0.003 vs Cryo ) . By intention-to-treat , 23 ( 58 % ) RF patients were AF-free vs 17 ( 43 % ) Cryo patients on no antiarrhythmic drugs at 1 year ( P = 0.06 ) . Three patients had temporary phrenic nerve paralysis in the Cryo group ; the RF group had no complications . Of the 29 patients who had only Cryo PVI without any RF ablation , 11 ( 38 % ) were AF-free vs 20 ( 59 % ) of the 34 patients who had RF only ( P = 0.021 ) . CONCLUSION When patients require a redo pulmonary vein isolation ablation procedure for recurrent PAF , RF appears to be the preferred energy source relative to Cryo 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 BACKGROUND Although radiofrequency ( RF ) and cryoballoon ( CB ) based technologies for pulmonary vein isolation ( PVI ) have both individually been demonstrated to be effective and safe for the treatment of paroxysmal AF , head-to-head comparisons are lacking . The purpose of this study was to compare the outcome of cryoballoon versus radiofrequency ablation in patients with paroxysmal atrial fibrillation undergoing pulmonary vein isolation . METHODS Out of a prospect i ve registry of 327 patients undergoing PVI , 208 patients ( age 58±11 years , ejection fraction 59±6 % , left atrial size 39±6 mm ) with paroxysmal AF were identified . The presented data set was obtained by 1:1 propensity score matching and contained 142 patients undergoing CB-PVI or RF-PVI in conjunction with a 3D mapping system , respectively . We compared single procedure efficacy of the two methods using a Cox proportional hazards model . RESULTS After a mean follow-up of 28 months and a single procedure , AF recurred in 37 of 71 ( 52 % ) in the CB-PVI group and in 31 of 71 patients ( 44 % ) in the RF-PVI group ( HR [ 95 % CI]=1.19 [ 0.74 , 1.92 ] , p=0.48 ) . Recurrence of AF for PVI using solely the CB was observed in 23 of 51 ( 45 % ) patients and in 23 of 51 ( 45 % ) patients in the corresponding RF-PVI group ( HR [ 95 % CI]=0.93 [ 0.52 , 1.66 ] , p=0.81 ) . Complication rate was not different between the groups . CONCLUSION A propensity score matched comparison between CB-PVI and RF-PVI using a 3D-mapping system for AF ablation showed similar long-term success rates 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 Background Effective treatment of paroxysmal atrial fibrillation ( AF ) is essential for reducing the risk of stroke and heart failure .  Cryoballoon ( CB ) ablation has been developed as an alternative to the use of radiofrequency ( RF ) energy for electrical isolation of the pulmonary veins . Herein , we provide long-term data regarding the efficacy of CB ablation in comparison to RF . Methods FreezeAF was a r and omised non-inferiority study comparing CB ablation with RF ablation for the treatment of patients with drug-refractory paroxysmal AF . Procedural success for the long-term follow-up ( 30 months ) was defined as freedom from AF with an absence of persistent complications . Results Of the 315 patients that were r and omised and received catheter ablation , 292 ( 92.7 % ) completed the 30-month follow-up ( 147 in the RF group and 145 in the CB group ) . The baseline characteristics of the RF and CB groups were similar . Single-procedure success was achieved by 40 % of patients in the RF group and 42 % of the CB group ( p < 0.001 for non-inferiority ) . When including re-do procedures in the analysis , the multiple procedure success rate was 72 % in the RF group and 76 % in the CB group . Conclusion The data provide long-term evidence that CB ablation is non-inferior to RF ablation , with high proportions of patients reporting freedom from AF 30 months after the index procedure . Trial registration Clinical Trials.gov Identifier : NCT00774566 ; first registered October 16 , 2008 ; first patient included October 20 , 2008 BACKGROUND Inflammation plays a prominent role in the etiology of the early recurrence of  atrial fibrillation ( ERAF ) . We prospect ively compared the proportion of ERAF and time-course patterns of biomarkers between radiofrequency ( RF ) and cryoballoon ( CB ) ablation . METHODS AND RESULTS We enrolled 82 consecutive paroxysmal AF patients undergoing pulmonary vein ( PV ) isolation , performed with either a 28-mm 2nd-generation CB and 3-min freeze technique or point-by-point RF ablation .  Each group had 41 patients . In the RF group , all PVs were successfully isolated with 28.9 ± 6.5 min of RF delivery . In the CB group , a mean of 5.3 ± 1.4 applications/patient was delivered . The proportion of ERAF was similar between the groups . The time-course patterns significantly differed between the groups for high-sensitivity C-reactive protein ( hs-CRP ) value ( P=0.006 ) and myocardial injury markers ( P<0.0001 ) . Greater myocardial injury was observed in the CB than in the RF group ( P<0.0001 ) , whereas the peak hs-CRP value was comparable between the groups . The 2-day post-procedure hs-CRP value was the sole factor correlating with ERAF as identified by the multivariable analysis ( hazard ratio 1.697 ; 95 % confidence interval , 1.005 - 2.865 ; P=0.048 ) in the RF , but not the CB group . CONCLUSIONS The proportion of ERAF was comparable after RF and 2nd-generation CB ablation . Despite CB ablation exhibiting greater myocardial injury than RF ablation , the inflammatory responses were comparable between the groups . The inflammatory response extent predicted ERAF post-RF ablation but not post-CB ablation Aims A challenge of pulmonary vein isolation ( PVI ) in catheter ablation for paroxysmal atrial fibrillation ( PAF ) is electrical reconnection of the PV . EFFICAS I showed correlation between contact force ( CF ) parameters and PV durable isolation but no prospect i ve evaluation was made . EFFICAS II was a multicentre study to prospect ively assess the impact of CF guidance for an effective reduction of PVI gaps . Methods and results Pulmonary vein isolation using a radiofrequency ( RF ) ablation catheter with an integrated force sensor ( TactiCath ™ ) was performed in patients with PAF . Operators were provided EFFICAS I-based CF guidelines [ target 20 g , range 10–30 g , minimum 400 g s force-time integral ( FTI ) ] . Conduction gaps were assessed by remapping of PVs after 3 months , and gap rate was compared with EFFICAS I outcome . At follow up , 24 patients had 85 % of PVs remaining isolated , compared with 72 % in EFFICAS I ( P = 0.037 ) in which CF guidelines were not used . The remaining 15 % of gaps correlated to the number of catheter moves at creating the PVI line , quantified as Continuity Index . For PV lines with contiguous lesions and low catheter moves , durable isolation was 81 % in EFFICAS I and 98 % in EFFICAS II ( P = 0.005 ) . At index procedure , the number of lesions was reduced by 15 % in EFFICAS II vs. EFFICAS I. Conclusion The use of CF with the above guidelines and contiguous deployment of RF lesions in EFFICAS II study result ed in more durable PVI in catheter ablation of PAF Introduction Comparative data of early recurrence rates of atrial fibrillation ( ERAF )  following second-generation cryoballoon ( CB-G2 ) and radiofrequency current ( RFC ) ablation for pulmonary vein isolation ( PVI ) in paroxysmal AF ( PAF ) are rare . We r and omized PAF patients into either PVI with CB-G2 ( group 1 ) or PVI with a combined RFC-approach applying contact force ( CF ) with the endpoint of unexcitability ( group 2 ) to investigate ERAF . Methods and results In group 1 ( n = 30 ) , CB-G2-PVI was performed . After CF-PVI in group 2 ( n = 30 ) , bipolar pacing on the ablation line and additional ablation until unexcitability was conducted . Follow-up included 48 h of in-hospital monitoring followed by 5-day Holter ECGs 1 , 2 , 3 , 6 , 12 months postablation to evaluate ERAF . Acute PVI was reached in 100 % of group 2 and in 99 % of group 1 . Shorter procedure duration s ( 98.0 ± 21.9 vs. 114.3 ± 18.7 min , P < 0.05 ) but extended fluoroscopy times ( 15.4 ± 3.9 vs. 10.0 ± 4.3 min , P < 0.05 ) were found in the CB-G2 group . Ten non-severe complications occurred ( 6 vs. 4 in group 1 and 2 , P = 0.73 ) . In group 2 , five patients suffered from ERAF vs. seven patients in group 1 ( P = 0.67 ) . The time until the occurrence of ERAF was shorter in group 2 ( 1 day ( q1-q3 : 1 - 4.5 ) ) when compared with group 1 ( 22 ( q1-q3 : 6 - 54 ) days , P = 0.025 ) . Conclusion ERAF rates were equal among groups ; however , they occurred earlier in the initial phase after RFC ablation when compared with CB-G2 . PVI utilizing cryoablation is associated with shorter procedure duration s but extended fluoroscopy time while being similarly secure 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 st and ard 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 prospect i ve , r and omized , controlled , open , blinded outcome assessment , noninferiority trial comparing cryoballoon- , and RFC-based PVI .  Patients with drug-resistant PAF will be r and omized 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 INTRODUCTION There are limited comparative data on catheter ablation of atrial fibrillation ( CAAF ) using the second-generation cryoballoon ( CB-2 ) versus point-by-point radiofrequency ( RF ) . This study examines the acute/long-term CAAF outcomes using these 2 strategies . METHODS AND RESULTS In this multicenter , retrospective , nonr and omized analysis , procedural and clinical outcomes of 1,196 patients ( 76 % with paroxysmal AF ) undergoing CAAF using CB-2 ( n = 773 ) and open-irrigated , non-force sensing RF ( n = 423 ) were evaluated . Pulmonary vein isolation was achieved in 98 % with CB-2 and 99 % with RF ( P = 0.168 ) . CB-2 was associated with shorter ablation time ( 40 ± 14 min vs. 66 ± 26 min ; P < 0.001 ) and procedure time ( 145 ± 49 minutes vs. 188 ± 42 minutes ; P < 0.001 ) , but greater fluoroscopic utilization ( 29 ± 13 minutes vs. 23 ± 14 minutes ; P < 0.001 ) . While transient ( 7.6 % vs. 0 % ; P < 0.001 ) and persistent ( 1.2 % vs. 0 % ; P = 0.026 ) phrenic nerve palsy occurred exclusively with CB-2 , other adverse event rates were similar between CB-2 ( 1.6 % ) and RF ( 2.6 % ) ; P = 0.207 . However , freedom from AF/atrial flutter/tachycardia at 12 months following a single procedure without antiarrhythmic therapy was greater with CB-2 ( 76.6 % ) versus RF ( 60.4 % ) ; P < 0.001 . While this difference was evident in patients with paroxysmal AF ( P < 0.001 ) , it did not reach significance in those with persistent AF ( P = 0.089 ) . Additionally , CB-2 was associated with reduced long-term need for antiarrhythmic therapy ( 16.7 % vs. 22.0 % ; P = 0.024 ) and repeat ablations ( 14.6 % vs. 24.1 % ; P < 0.001 ) . CONCLUSION In this multicenter , retrospective , nonr and omized study , CAAF using CB-2 coupled with RF as occasionally required was associated with greater freedom from atrial arrhythmias at 12 months following a single procedure without antiarrhythmic therapy when compared to open-irrigated , non-force sensing RF , alone BACKGROUND We question ed whether the empirical four pulmonary vein ( PV ) isolation ( EmPVI ) was necessary in patients with paroxysmal atrial fibrillation ( PAF ) triggered from clearly and reproducibly defined arrhythmogenic PVs . METHODS We compared the selective or ipsilateral isolation of the PVs triggering AF ( SePVI : n = 42 ) and EmPVI ( n = 35 ) in 77 patients ( males 80.5 % , mean age 53.0 + /- 13.4 years ) with PAF who underwent radiofrequency catheter ablation ( RFCA ) .  Arrhythmogenic PVs were identified by the immediate recurrence of AF three consecutive times after cardioverting AF . RESULTS ( 1 ) The duration of the RF energy deliveries ( P < 0.01 ) and total procedure time ( P < 0.01 ) were shorter for the SePVI than the EmPVI . ( 2 ) During a mean follow-up of 38.6 + /- 23.1 months , the AF recurrence rate was 38.1 % in the SePVI group and 25.7 % in the EmPVI group ( P = NS ) . ( 3 ) A redo-ablation was performed in 25 patients , and 81.0 % of the recurrent arrhythmogenic foci were found at a previously ablated PV or ipsilateral PV . ( 4 ) In 15.4 % of the SePVI and 20.0 % of the EmPVI procedures , AF recurred after 32.5 + /- 15.2 months of the redo-ablation . Subsequently , the AF-free rate for each group was 88.1 % ( 37/42 ) in the SePVI group and 91.4 % ( 32/35 ) in the EmPVI group ( P = NS ) . CONCLUSIONS In patients with clearly documented arrhythmogenic PVs , the SePVI of the PV triggering the AF or an ipsilateral PV had a comparable long-term success rate and shorter RF energy delivery and procedure times than the EmPVI 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 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 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 Purpose We tested the hypothesis that electroanatomic pulmonary vein ( PV ) antra encircling for the PV isolation will improve the outcome in treatment of paroxysmal atrial fibrillation ( PAF ) , compared with segmental PV isolation . Methods Fifty-four patients underwent segmental PV isolation ( group 1 ) and 56 patients circumferential PV isolation ( group 2 ) for symptomatic PAF in a r and omized study . Results Following single ablation procedure , at the 48 ± 8 month follow-up , 30 ( 56 % ) and 32 ( 57 % ) patients in groups 1 and 2 remained free of arrhythmia ( P = 0.41 ) . After repeat ablation , 43 ( 80 % ) and 45 ( 80 % ) patients in groups 1 and 2 were free of arrhythmia without antiarrhythmic drugs ( AADs ) ; 48 ( 89 % ) and 51 ( 91 % ) patients in groups 1 and 2 did not have arrhythmia recurrences without or with AADs . Conclusion This study demonstrates no advantage in long-term arrhythmia-free clinical outcome after circumferential PV isolation in patients with frequent PAF AIMS This study examined the difference in autonomic modification ( AM ) and its effect on paroxysmal atrial fibrillation ( PAF ) recurrence between segmental pulmonary vein isolation ( S-PVI ) and circumferential PVI ( C-PVI ) . METHODS AND RESULTS Successful S-PVI or C-PVI with a basket catheter was achieved in 120 consecutive PAF patients . Serial 24 Holter-recordings were obtained before , immediately , and 1 , 3 , 6 , 12 months after the PVI to analyse the heart rate variability ( HRV ) .  Nineteen patients were excluded from analysis because of additional ablation for recurrent PAF after successful PVI . Among the residual 101 patients , 33 had PAF recurrences ( S-PVI = 44.0 % , C-PVI = 21.6 % ) at 1 year of follow-up . The root mean square of successive differences and high-frequency power reflecting parasympathetic nervous activity were significantly lower in patients with and without PAF recurrences after C-PVI and patients without PAF recurrences after S-PVI than patients with PAF recurrences after S-PVI ( P < 0.005 - 0.0001 ) . However , there were no significant differences in any HRV parameters in the immediate aftermath of PVI among the patients without PAF recurrences after S-PVI and those with and without PAF recurrences after C-PVI . CONCLUSION Although additional radiofrequency ablation for AM may be recommended after S-PVI to reduce PAF recurrences , it should be carefully determined after C-PVI AIMS  Atrial fibrillation ( AF ) ablation  is increasingly being performed in electrophysiology laboratories . Pericardial effusion ( PE ) is certainly one of the most frequently observed complications during AF ablation . The aim of our study was to investigate the incidence and outcome of PE following cryothermal energy balloon ablation ( CBA ) in comparison with conventional circumferential pulmonary vein isolation with a focal radiofrequency ( RF ) catheter . METHODS AND RESULTS A total of 133 consecutive patients ( 105 males ) with paroxysmal AF were included in this study . Forty-six patients ( 36 males ) underwent CBA  ( A rct ic Front , Medtronic , USA ) and 87 ( 69 males ) point-by-point RF ablation guided by electroanatomical mapping ( Carto , Biosense Webster , Diamond Bar , CA , USA ) . Ablation was performed under general anaesthesia with both techniques . All patients underwent a 2D transthoracic echocardiogram within 24 h before and after the procedure as routinely performed in our centre . Pericardial effusion was detected in 19 ( 14.2 % ) of 133 patients . Sixteen patients presented mild effusion , one moderate effusion , and two pericardial tamponades . There was no significant difference in the incidence of PE between the cryoballoon and the RF group ( 11 vs. 16 % ) . A longer procedural time , coronary artery disease , and arterial hypertension were found to be independent predictors of PE during AF ablation . CONCLUSION Pericardial effusion occurred in a similar proportion following CBA and RF ablation for AF .  Pericardial effusion was mostly mild and asymptomatic , with benign clinical outcome not requiring additional hospitalization days INTRODUCTION Ablation of pulmonary veins ( PV ) is an established therapeutic option for patients with symptomatic drug-refractory paroxysmal atrial fibrillation ( AF ) .  Radiofrequency ( RF ) is currently the most widespread energy source for PV ablation . Cryothermal energy applied with a cryoballoon technique as an alternative has recently evolved . METHODS AND RESULTS In a case-control setting , we compared 20 patients with paroxysmal AF who underwent their first PV ablation with the cryoballoon technique to 20 matched patients with conventional RF ablation .  In the case of persistent electrical potentials after cryoballoon ablation , it was combined with ablation with a conventional cryocatheter . All patients performed daily event recording for 3 months after ablation procedure . Ablation parameters and success rate after 3 and 6 months were compared . In the cryoballoon group , the overall success rate was 55 % ( 50 % in the cryoballoon only group [ 14 patients ] and 66 % in the combination group [ 6 patients ] ) , as opposed to the RF group with 45 % . AF episode burden was lower after cryoballoon ablation . There was no significant difference between cryoballoon and RF ablation regarding procedure parameters . In the cryoballoon group , 3 phrenic nerve palsies occurred using the 23 mm balloon that resolved spontaneously . CONCLUSION PV ablation with the cryoballoon technique is feasible and seems to have a similar success rate in comparison to RF ablation . Procedure- and fluoroscopy duration are not longer than in conventional RF 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 —Segmental ostial catheter ablation ( SOCA ) to isolate the pulmonary veins ( PVs ) and left atrial catheter ablation ( LACA ) to encircle the PVs both may eliminate paroxysmal atrial fibrillation ( PAF ) .  The relative efficacy of these 2 techniques has not been directly compared . Methods and Results —Of 80 consecutive patients with symptomatic PAF ( age , 52±10 years ) , 40 patients underwent  PV isolation by SOCA and 40 patients underwent LACA to encircle the PVs . During SOCA , ostial PV potentials recorded with a ring catheter were targeted . LACA was performed by encircling the left- and right-sided PVs 1 to 2 cm from the ostia and was guided by an electroanatomic mapping system ; ablation lines also were created in the mitral isthmus and posterior left atrium . The mean procedure and fluoroscopy times were 156±45 and 50±17 minutes for SOCA and 149±33 and 39±12 minutes for LACA , respectively . At 6 months , 67 % of patients who underwent SOCA and 88 % of patients who underwent LACA  were free of symptomatic PAF when not taking antiarrhythmic drug therapy ( P = 0.02 ) . Among the variables of age , sex , duration and frequency of PAF , ejection fraction , left atrial size , structural heart disease , and the ablation technique , only an increased left atrial size and the SOCA  technique were independent predictors of recurrent PAF . The only complication was left atrial flutter in a patient who underwent LACA . Conclusions —In patients undergoing catheter ablation for PAF  , LACA to encircle the PVs is more effective than SOCA Background Radiofrequency and cryoballoon pulmonary vein isolation are common approaches for paroxysmal atrial fibrillation treatment , showing similar results in recent multicenter studies , including heterogeneous tools and protocol s. The aim of this study is to compare prospect ively in a single , high-volume center the outcome of paroxysmal atrial fibrillation ablation performed specifically by second-generation cryoballoon or contact force radiofrequency ablation . Methods Consecutive patients scheduled for paroxysmal atrial fibrillation transcatheter ablation have been included and prospect ively followed up . Aim ing to reduce potential bias deriving from baseline characteristics , a propensity score matching analysis has been performed to analyze safety and efficacy outcomes . Results Out of consecutive patients undergoing atrial fibrillation transcatheter ablation between January 2015 and December 2016 , 46 patients approached by cryoablation  were matched 1 : 1 by propensity score to a similar population treated by last-generation radiofrequency ablation .  Freedom from atrial fibrillation after 12 months ( 76 vs. 78 % , P = 0.804 ) and incidence of complications ( 4 vs. 6 % , P = 0.168 ) did not differ between the two groups . Radiological exposure was higher for the cryoballoon group ( 11 vs. 4 min , P < 0.001 ) , whereas procedural duration did not differ ( P = 0.174 ) . Aim ing to assess the potential impact of a learning curve in patients undergoing cryoablation , the first-third of patients ( n = 15 ) were compared with the remaining , reporting longer radiological exposure ( P < 0.001 ) , but similar safety and efficacy . Conclusion In this propensity score analysis , last-generation cryoballoon and radiofrequency catheters for atrial fibrillation ablation present similar efficacy and safety .  Cryoablation requires longer fluoroscopy exposure compared with radiofrequency , although this is reduced by increased experience INTRODUCTION Isolation of all pulmonary veins ( PV ) is advocated for treatment of paroxysmal atrial fibrillation ( PAF ) . However , the superior PVs are responsible for most AF triggers , whereas the inferior PVs carry the higher risk for ablation-induced ostial stenosis . The aim of this study was to compare a superior PV isolation approach with isolation of all PVs for treatment of PAF . METHODS AND RESULTS Fifty-two patients with PAF were r and omized to either left superior pulmonary vein ( LSPV ) isolation followed by additional isolation of the right superior pulmonary vein ( RSPV ) in case of AF recurrence ( group A , n = 27 ) or isolation of all four PVs followed by a repeat procedure in case of recurrence ( group B , n = 25 ) . At 1-year follow-up , 11 patients ( 41 % ) in group A and 8 patients ( 32 % ) in group B had AF relapse ( P = 0.55 ) . No significant differences in AF relapse were detected between groups at 3 and 12 months ( log rank = 0.36 , P = 0.54 ) and by Cox proportional hazards model analysis ( P = 0.62 ) . Nonsignificant PV stenosis was detected in two patients from group B. Total radiofrequency energy delivery and fluoroscopy and procedure times were lower in group A : 8.9 + /- 1.4 minutes vs 25.6 + /- 3.7 minutes ( P < 0.001 ) , 22.2 + /- 6.8 minutes vs 62 + /- 10.3 minutes ( P < 0.001 ) , and 131.8 + /- 26.5 minutes vs 222.2 + /- 32.3 minutes ( P < 0.001 ) , respectively . CONCLUSION A staged superior PVs isolation approach confers equal success rates but with reduced radiofrequency energy delivery and fluoroscopy and procedure times compared to isolation of all PVs at the initial ablation attempt AIMS Cryoballoon ( CB ) ablation with the second-generation cryoballoon ( CBG2 ) seems to be more effective than its predecessor [ first-generation cryoballoon ( CBG1 ) ] , but phrenic nerve palsies were observed more frequently . The aim of this study was to compare the safety and efficacy of CBG1 and CBG2 in a sub study of the prospect i ve multicentre , multinational FREEZE Cohort Study . METHODS AND RESULTS Periprocedural data were analysed , and a total of 532 patients with paroxysmal atrial fibrillation ( AF ) were examined ( n = 224 for CBG1 and n = 308 for CBG2 ) . Procedure time decreased significantly from 149 to 130 min when comparing CBG1 with CBG2 ( P < 0.0001 ) , and pulmonary vein isolation ( PVI ) was achieved in 97.8 and 97.6 % of PVs with CBG1 and CBG2 ( P = 0.77 ) , respectively . The need for dual-balloon usage within a procedure dropped ( 20.1 vs. 9.0 % , P < 0.001 ) , and the fluoroscopy time was reduced when operating the CBG2 .  Atrial fibrillation recurrence rates until discharge were similar ( 5.0 vs. 5.8 % , P = 0.69 ) . Comparable low rates of major complications were observed with both CBs , and there was a non-significant trend for more phrenic nerve palsies . CONCLUSION Second-generation cryoballoon demonstrated a high rate of acute PVI in a significant faster procedure , which also utilized less radiation exposure and less dual-balloon usage during an average procedure . The safety profile remains favourable with a non-significant trend for more phrenic nerve palsies . If the enhancements lead to a higher clinical benefit has to be determined . The 1-year outcome data from the ongoing FREEZE Cohort Study comparing radiofrequency and CB ablation will shed some light on that issue . CLINICAL TRIALS GOV IDENTIFIER NCT01360008 BACKGROUND Catheter ablation is important for treatment of paroxysmal atrial fibrillation ( PAF ) . Limited animal and human studies suggest a correlation between electrode-tissue contact and radiofrequency lesion generation . OBJECTIVES The study sought to assess the safety and effectiveness of an irrigated , contact force (CF)-sensing catheter in the treatment of drug refractory symptomatic PAF . METHODS A prospect i ve , multicenter , nonr and omized study was conducted . Enrollment criteria included : ≥3 symptomatic episodes of PAF within 6 months of enrollment and failure of ≥1 antiarrhythmic drug ( Class I to IV ) . Ablation included pulmonary vein isolation with confirmed entrance block as procedural endpoint . RESULTS A total of 172 patients were enrolled at 21 sites , where 161 patients had a study catheter inserted and 160 patients underwent radiofrequency application . Procedural-related serious adverse events occurring within 7 days of the procedure included tamponade ( n = 4 ) , pericarditis ( n = 3 ) , heart block ( n = 1 , prior to radiofrequency application ) , and vascular access complications ( n = 4 ) . By Kaplan-Meier analyses , 12-month freedom from atrial fibrillation/atrial flutter/atrial tachycardia recurrence was 72.5 % . The average CF per procedure was 17.9 ± 9.4 g. When the CF employed was between investigator selected working ranges ≥80 % of the time during therapy , outcomes were 4.25 times more likely to be successful ( p = 0.0054 ; 95 % confidence interval : 1.53 to 11.79 ) . CONCLUSIONS The SMART-AF trial demonstrated that this irrigated CF-sensing catheter is safe and effective for the treatment of drug refractory symptomatic PAF , with no unanticipated device-related adverse events . The increased percent of time within investigator-targeted CF ranges correlates with increased freedom from arrhythmia recurrence . Stable CF during radiofrequency application increases the likelihood of 12-month success . ( THERMOCOOL ® SMARTTOUCH ® Catheter for Treatment of Symptomatic Paroxysmal Atrial Fibrillation ; NCT01385202 ) OBJECTIVES We compared ablation strategy with antiarrhythmic drug therapy ( ADT ) in patients with paroxysmal atrial fibrillation ( PAF ) . BACKGROUND Atrial fibrillation ( AF ) ablation strategy is superior to ADT in patients with an initial history of PAF , but its role in patients with a long history of AF as compared with ADT remains a challenge . METHODS One hundred ninety-eight patients ( age , 56 + /- 10 years ) with PAF of 6 + /- 5 years ' duration ( mean AF episodes 3.4/month ) who had failed ADT were r and omized to AF ablation by circumferential pulmonary vein ablation ( CPVA ) or to the maximum tolerable doses of another ADT , which included flecainide , sotalol , and amiodarone . Crossover to CPVA was allowed after 3 months of ADT . RESULTS By Kaplan-Meier analysis , 86 % of patients in the CPVA group and 22 % of those in the ADT group who did not require a second ADT were free from recurrent atrial tachyarrhythmias ( AT ) ( p < 0.001 ) ; a repeat ablation was performed in 9 % of patients in the CPVA group for recurrent AF ( 6 % ) or atrial tachycardia ( 3 % ) . At 1 year , 93 % and 35 % of the CPVA and ADT groups , respectively , were AT-free . Ejection fraction , hypertension , and age independently predicted AF recurrences in the ADT group . Circumferential pulmonary vein ablation was associated with fewer cardiovascular hospitalizations ( p < 0.01 ) . One transient ischemic attack and 1 pericardial effusion occurred in the CPVA group ; side effects of ADT were observed in 23 patients . CONCLUSIONS Circumferential pulmonary vein ablation is more successful than ADT for prevention of PAF with few complications . Atrial fibrillation ablation warrants consideration in selected patients in whom ADT had already failed and maintenance of sinus rhythm is desired . ( A Controlled R and omized Trial of CPVA Versus Antiarrhythmic Drug Therapy in for Paroxysmal AF : APAF/01 ; http:// clinical trials.gov/ct/show ; NCT00340314 ) AIMS To assess the 1 year efficacy of pulmonary vein isolation ( PVI ) as index procedure for persistent atrial fibrillation ( PersAF ) comparing conventional radiofrequency irrigated-tip catheter ablation ( RFCA ) using contact-force technology and ablation using the second-generation cryoballoon ( CB-AdvA ) . METHODS AND RESULTS One hundred consecutive patients ( 74 male , 74 % ; mean age 62.4 ± 9.6 years ) with drug-refractory PersAF undergoing PVI using RFCA and CB-AdvA were enrolled . Follow-up was based on outpatient clinic visits including Holter-electrocardiograms . Recurrence of atrial tachyarrhythmias ( ATas ) was defined as a symptomatic or documented episode > 30 s. Among 100 patients , 50 underwent RFCA whereas 50 CB-AdvA.  Mean procedure and fluoroscopy times were 90.5 ± 41.7 vs. 140.2 ± 46.9 min and 14.5 ± 6.6 vs. 19.8 ± 6.8 min in the CB-Adv and in the RFCA group , respectively ( P < 0.01 ) . At 1 year follow-up , after a 3 months blanking period ( BP ) , freedom from ATas off-drugs after a single procedure was 60 % ( 28/50 patients ) in the CB-Adv and 56 % ( 27/50 patients ) in the RFCA group ( P = 0.71 ) . Multivariate analysis demonstrated that PersAF duration ( P = 0.01 ) and relapses during BP ( P = 0.02 ) were independent predictors of ATa recurrences following the index procedure . CONCLUSION Freedom from ATas following PersAF ablation with RFCA and CB-Adv is comparable at 1 year follow-up after a single procedure . Ablation with the CB-Adv is associated with shorter procedure time and radiation exposure as compared with RFCA . Atrial tachyarrhythmias occurrence during BP and longer time of PersAF seem to be significant predictors of arrhythmia recurrences after the index procedure INTRODUCTION Circumferential pulmonary vein antral isolation ( PVAI ) and atrial complex fractionated electrograms ( CFEs ) are both ablative techniques for the treatment of paroxysmal atrial fibrillation ( PAF ) . However , data on the comparative value of these 2 ablation strategies are very limited . METHODS AND RESULTS We r and omized 118 patients with drug-refractory PAF to receive  PVAI ablation ( n = 60 ) or CFE ablation ( n = 58 ) . For CFE group , spontaneous/induced AF was mapped using vali date d , automated software to guide ablation until all CFE areas were eliminated . For PVAI group , all 4 pulmonary vein antra were electrically isolated as confirmed by circular mapping catheter . Patients with spontaneous/inducible AF after the initial ablation procedure were crossed over to the other arms . After initial ablation procedure , AF persisted/inducible in 24/59 patients ( 41 % ) , and 34/58 patients ( 59 % ) assigned to PVAI and CFE ablation , respectively ( P = 0.05 ) . Then 58 patients underwent PVAI + CFE ablation . After 22.6 ± 6.4 months , PVAI ablation group was more likely than CFE ablation group to achieve control of any AF/atrial tachycardia ( AT ) off drugs ( 43/60 , 72 % vs 33/58 , 57 % , P = 0.075 ) and lower recurrence rate of AT ( 11.9 % vs 34.5 % , P = 0.004 ) . Patients who received CFE ablation alone ( 38 % ) had significantly lower overall success rate to achieve control of AF/AT off drugs compared with patients who received PVAI ablation ( 77 % , P = 0.002 ) alone or PVAI + CFE ablation ( 69 % , P = 0.008 ) due to higher recurrence rate of AT ( 50 % vs 6 % vs 13 % , P < 0.01 ) . CONCLUSIONS CFE ablation in PAF patients was associated with higher occurrence rate of postprocedure AT compared with PVAI ablation , whereby making it less likely to be a sole ablation strategy for PAF patients
Pool analyses indicated that CB ablation was more beneficial in terms of procedural time [ st and ard mean difference = −0.58 ; 95 % confidence interval ( CI ) , −0.85 to −0.30 ] , complications without phrenic nerve injury ( PNI ) [ odds ratio ( OR ) = 0.79 ; 95 % CI , 0.67–0.93 ; I2 = 16 % ] , and recrudescence ( OR = 0.83 ; 95 % CI , 0.70–0.97 ; I2 = 63 % ) for PAF ; however , the total complications of CB was higher than RF .
The subgroup analysis found that , compared with non-contact force radiofrequency ( non-CF-RF ) , both first-generation cryoballoon ( CB1 ) and second-generation cryoballoon ( CB2 ) ablation  could reduce complications with PNI , procedural time , and recrudescence .
However , the safety and efficacy of CB2 was similar to those of CF-RF .
Conclusion Available overall and subgroup data suggested that both CB1 and CB2 were more beneficial than RF ablation , and the main advantages were reflected in comparing them with non-CF-RF .
However , CF-RF and CB2 showed similar clinical benefits
Purpose The present systematic review and meta- analysis aim ed to assess and compare the safety and efficacy of radiofrequency ( RF ) and cryoballoon ( CB ) ablation for paroxysmal atrial fibrillation ( PAF ) .
RF and CB ablation are two frequently used methods for pulmonary vein isolation in PAF , but which is a better choice for PAF remains uncertain .