title: Neuropsychological Effects of MRI-Detected Brain Lesions After Left Atrial Catheter Ablation for Atrial Fibrillation: Long-Term Results of the MACPAF Study A prospective randomized single-center study on the risk of asymptomatic cerebral lesions comparing irrigated radiofrequency current ablation with the cryoballoon and the laser balloon. Acute and Long-Term Outcomes of Catheter Ablation of Atrial Fibrillation Using the Second-Generation Cryoballoon versus Open-Irrigated Radiofrequency: A Multicenter Experience. Comparison of lesion formation between contact force-guided and non-guided circumferential pulmonary vein isolation: a prospective, randomized study. Cryoballoon Versus Open Irrigated Radiofrequency Ablation in Patients With Paroxysmal Atrial Fibrillation Mesh ablator vs. cryoballoon pulmonary vein ablation of symptomatic paroxysmal atrial fibrillation: results of the MACPAF study. Cryoballoon versus radiofrequency catheter ablation for paroxysmal atrial fibrillation. MEDAFI-Trial (Micro-embolization during ablation of atrial fibrillation): comparison of pulmonary vein isolation using cryoballoon technique vs. radiofrequency energy. Pulmonary venous isolation by antral ablation with a large cryoballoon for treatment of paroxysmal and persistent atrial fibrillation: medium-term outcomes and non-randomised comparison with pulmonary venous isolation by radiofrequency ablation Two-Year Follow-Up after Contact Force Sensing Radiofrequency Catheter and Second-Generation Cryoballoon Ablation for Paroxysmal Atrial Fibrillation: A Comparative Single Centre Study Radiofrequency catheter ablation versus balloon cryoablation of atrial fibrillation: markers of myocardial damage, inflammation, and thrombogenesis Transvenous cryoablation reduces platelet activation during pulmonary vein ablation compared with radiofrequency energy in patients with atrial fibrillation. Long-term comparison of cryoballoon and radiofrequency ablation of paroxysmal atrial fibrillation: a propensity score matched analysis. Early Recurrence After Pulmonary Vein Isolation of Paroxysmal Atrial Fibrillation With Different Ablation Technologies - Prospective Comparison of Radiofrequency vs. Second-Generation Cryoballoon Ablation. Comparison of cryoballoon and radiofrequency ablation of pulmonary veins in 40 patients with paroxysmal atrial fibrillation: a case-control study. Cryoballoon versus radiofrequency for pulmonary vein re-isolation after a failed initial ablation procedure in patients with paroxysmal atrial fibrillation. 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). Cryoballoon versus RF ablation in paroxysmal atrial fibrillation: results from the German Ablation Registry. 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. Real-time contact force sensing for pulmonary vein isolation in the setting of paroxysmal atrial fibrillation: procedural and 1-year results. Contact-force guided radiofrequency vs. second-generation balloon cryotherapy for pulmonary vein isolation in patients with paroxysmal atrial fibrillation-a prospective evaluation. Pericardial effusion in atrial fibrillation ablation: a comparison between cryoballoon and radiofrequency pulmonary vein isolation. The COR trial: a randomized study with continuous rhythm monitoring to compare the efficacy of cryoenergy and radiofrequency for pulmonary vein isolation. Approaches to catheter ablation for persistent atrial fibrillation. Cellular damage, platelet activation, and inflammatory response after pulmonary vein isolation: a randomized study comparing radiofrequency ablation with cryoablation. 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.
abstract: Background — MRI-detected brain lesions are common after  left atrial catheter ablation for symptomatic atrial fibrillation . The clinical relevance of these acute ischemic lesions is not fully understood , but ablation-related cerebral injury could contribute to cognitive dysfunction . Methods and Results — In the prospect i ve Mesh Ablator versus Cryoballoon Pulmonary Vein Ablation of Symptomatic Paroxysmal Atrial Fibrillation ( MACPAF ) study , serial 3-T brain MRIs and neuropsychological assessment were performed to analyze the rate of ablation-related brain lesions and their effect on cognitive function .  Thirty-seven patients with paroxysmal atrial fibrillation ( median age , 63.0 [ interquartile range , 57–68 ] years ; 41 % female ; median CHA2DS2VASc score 2 [ interquartile range , 1–3 ] ) underwent 41 ablation procedures according to study criteria . None of these patients had overt neurological deficits after ablation . High-resolution diffusion-weighted imaging , performed within 48 hours after ablation , showed that new brain lesions ( range , 1–17 ) were present in 16 ( 43.2 % ) patients after 18 ( 43.9 % ) left atrial catheter ablation procedures . Follow-up MRI at 6 months ( median , 6.5 ; interquartile range , 6–7 ) revealed that 7 ( 12.5 % ) of the 56 total acute brain lesions after ablation formed a persistent glial scar in 5 ( 31.3 % ) patients . Large diffusion-weighted imaging lesions and a corresponding fluid-attenuated inversion recovery lesion 48 hours after ablation predicted lesion persistence on 6-month follow-up . Neither persistent brain lesions nor the ablation procedure itself had a significant effect on attention or executive functions , short-term memory , or verbal and nonverbal learning after 6 months . Conclusions — Ablation-related acute ischemic brain lesions persist to some extent but do not cause cognitive impairment 6 months after the ablation procedure . Clinical Trial Registration — URL : http://www . clinical trials.gov . Unique identifier : NCT01061931 BACKGROUND Asymptomatic cerebral lesions ( ACL ) may occur during  atrial fibrillation ( AF ) ablation . We sought to compare the ACL incidence between 3 contemporary technologies : ( 1 ) irrigated radiofrequency current ( RFC ) , ( 2 ) the single big cryoballoon ( CB ) , and ( 3 ) the endoscopic laser-balloon ( LB ) in a prospect i ve r and omized pilot study . METHODS AND RESULTS Ninety-nine patients were treated in 3 groups .  Diffusion weighted MRI was acquired pre- ( n = 20 ) and 24 - 48 h postablation ( n = 99 ) . After ablation , new ACL were detected in 22 % of patients without significant differences between groups ( RFC 8/33 ; CB 6/33 ; LB 8/33 ; P = 0.8 ) . The presence of hypertension was identified as the only independent predictor of ACL by univariate regression analysis . During LB ablation , more ablation lesions ( 140 ± 19 vs 119 ± 18 ; P = 0.007 ) were applied during longer procedures ( 166 ± 36 vs 143 ± 32 min ; P = 0.05 ) in patients with ACL . Univariate analysis revealed that a higher number of ablation lesions predicted ACL ( P = 0.02 ) . CONCLUSION In this prospect i ve , r and omized , single-center pilot study , ablation technology did not influence the occurrence of ACL during AF ablation 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 Contact force ( CF ) monitoring could be useful in accomplishing circumferential pulmonary vein ( PV ) isolation ( CPVI ) for atrial fibrillation ( AF ) . OBJECTIVE The purpose of this study was to compare procedure parameters and outcomes between CF-guided and non-guided CPVI . METHODS Thirty-eight consecutive AF patients ( mean age 60 ± 11 years , 28 paroxysmal AF ) undergoing CPVI were r and omized to non-CF-guided ( n = 19 ) and CF-guided ( n = 19 ) groups .  CPVI was performed with the ThermoCool SmartTouch catheter in both groups . The end-point was bidirectional block between the left atrium ( LA ) and PV . In the CF group , CF was kept between 10 and 20 g during CPVI , whereas in the non-CF group , all CF information was blanked . Radiofrequency energy at 30 W in the anterior and 25 W in the posterior LA wall was applied for 20 - 25 seconds at each point . RESULTS CPVI was successfully accomplished without any major complications in both groups . Mean CF in the non-CF and CF groups were 5.9 ± 4.5 g and 11.1 ± 4.3 g , respectively , for left-side CPVI , and 9.8 ± 6.6 g and 12.1 ± 4.8 g , respectively , for right-side CPVI ( both P < .001 ) . The procedure and fluoroscopy times  for CPVI in the non-CF and CF groups were 96 ± 39 minutes and 59 ± 16 minutes , respectively ( P < .001 ) , and 22 ± 63 seconds and 9 ± 20 seconds ( P = NS ) , respectively . Total number of residual conduction gaps was 6.3 ± 3.0 in the non-CF group and 2.8 ± 1.9 in the CF group ( P < .001 ) . During 6-month follow-up , 84.2 % of patients in the non-CF group and 94.7 % in the CF group were free from any atrial tachyarrhythmias ( P = .34 ) . CONCLUSION CF-guided CPVI  is effective in reducing procedure time and additional touch-up ablation and may improve long-term outcome 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 Catheter ablation of the pulmonary veins ( PVs ) is a promising therapeutic approach for symptomatic atrial fibrillation ( AF ) . The prospect i ve r and omized single-centre study ' Mesh Ablator versus Cryoballoon Pulmonary Vein Ablation of Symptomatic Paroxysmal Atrial Fibrillation ' ( MACPAF ; clinical trials.gov NCT01061931 ) compared the efficacy and safety of two balloon-based PV ablation systems . METHODS AND RESULTS Thirty-two patients underwent PV ablation for symptomatic paroxysmal AF using the A rct ic Front ® or the HD Mesh Ablator ® catheter  according to study protocol . The primary endpoint was complete PV isolation ( PVI ) at the end of the ablation procedure , determined by exit block after achieving entrance block . Long-term follow-up data are not included in this publication . Patients ' mean age was 61.7 ± 8.9 years , 43.2 % were female , and median CHA₂DS₂-VASc score was 2.0 . In the intention-to-treat analysis , the rate of the primary endpoint was 56.5 % in patients r and omized to the A rct ic Front ® and 9.5 % in patients r and omized to the HD Mesh Ablator ® catheter ( P = 0.001 ) . In the per- protocol analysis , complete PVI was achieved in 13 ( 76.5 % ) of 17 A rct ic Front ® patients but in none of the 15 HD Mesh Ablator ® patients ( P < 0.0001 ) . There were one major and two minor complications in each study arm but no clinical ly evident stroke . Post-procedural AF recurrence was detected within hospital stay in two ( 11.8 % ) A rct ic Front ® patients and in seven ( 46.7 % ) HD Mesh Ablator ® patients ( P = 0.049 ) . CONCLUSION The MACPAF study revealed a superiority of the A rct ic Front ® catheter concerning complete PVI . Owing to the insufficient efficacy of the HD Mesh Ablator ® catheter , the safety board decided to stop MACPAF prematurely 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 Cerebral embolism is a possible serious complication during catheter ablation of atrial fibrillation ( AF ) .  The purpose of this prospect i ve pilot study was to analyse the incidence and possible impact of cryo ablation on cerebral lesions and possible differences to radiofrequency ( RF ) ablation during pulmonary vein isolation ( PVI ) . METHODS AND RESULTS Pulmonary vein isolation was performed in 89 patients , either with the cryoballoon technique ( n = 45 ) or with RF ablation ( n = 44 ) .  Phenprocoumon was stopped 3 days before intervention and replaced by subcutaneous low-molecular-weight heparin . During the catheter procedure , an infusion of unfractionated heparin was maintained to achieve an activated clotting time ( ACT ) of > 300 s. Cerebral magnetic resonance imaging scans were performed 1 day before and after PVI , and at 3-month follow-up . Chronic lesions were observed in 11 patients ( 12.3 % ) before PVI without statistically significant difference between the two groups . None of the patients had neurological symptoms during or following the procedure . Seven patients ( 7.9 % ) developed acute lesions 1 day after PVI , without statistically significant difference between the group treated by cryoenergy ( 8.9 % ) and RF ablation ( 6.8 % ) . Patients with acute lesions were significantly older compared with those without acute cerebral lesions . No additional cerebral lesions during follow-up were observed . CONCLUSION A considerable portion of patients with AF but without any neurological symptoms had chronic cerebral lesions before PVI . Additional acute lesions could be added after the procedure . Both ablation techniques showed additional cerebral acute lesions with no neurological symptoms after PVI Background To prevent  atrial fibrillation ( AF ) recurrence after catheter ablation , pulmonary venous isolation ( PVI ) at an antral level is more effective than segmental ostial ablation . Cryoablation around the pulmonary venous ( PV ) ostia for AF therapy is potentially safer compared to radiofrequency ablation ( RFA ) . The aim of this study was to investigate the efficacy of a strategy using a large cryoablation balloon to perform antral cryoablation with ‘ touch-up ’ ostial cryoablation for PVI in patients with paroxysmal and persistent AF . Methods Paroxysmal and persistent AF patients undergoing their first left atrial ablation were recruited . After cryoballoon therapy , each PV was assessed for isolation and if necessary , treated with focal ostial cryoablation until PVI was achieved . Follow-up with Holter monitoring was performed . Clinical outcomes of the cryoablation protocol were compared , with consecutive patients undergoing PVI by RFA . Results 124 consecutive patients underwent cryoablation . 77 % of paroxysmal and 48 % of persistent AF subjects were free from AF at 12 months after a single procedure . Over the same time period , 53 consecutive paroxysmal AF subjects underwent PVI with RFA and at 12 months , 72 % were free from AF at 12 months ( p = NS ) . There were too few persistent AF subjects ( n=8 ) undergoing solely PVI by RFA as a comparison group . Procedural and fluoroscopic times during cryoablation were significantly shorter than RFA . Conclusions PV isolation can be achieved in less than 2 h by a simple cryoablation protocol with excellent results after a single intervention , particularly for paroxysmal AF 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 Summary Background Evidence from animal and human studies suggests that cryoablation might be associated with a lesser inflammatory response and activation of coagulation compared with radiofrequency ablation . The study was aim ed at comparing the effect of cryoballoon and radiofrequency catheter ablation of paroxysmal atrial fibrillation on markers of myocardial damage , inflammation , and activation of coagulation . Methods Forty-one patients received either cryoballoon  ( n = 23 ) or radiofrequency ( n = 18 ) ablation of atrial fibrillation .  We measured troponin I , high-sensitivity CRP , and interleukin 6 at baseline from the cubital vein , and from the right and left atrium before and after ablation , and from the cubital vein the following day . Prothrombin fragments 1 + 2 , soluble P‑selectin , and D‑dimer were measured before and after ablation from both atria . Results We observed higher troponin I release in the cryoballoon than in the radiofrequency group ( 7.01 mcg/l ( interquartile range [ IQR ] : 5.30–9.09 ) vs 2.32 mcg/l ( IQR : 1.45–2.98 ) , p < 0.001 ) . The levels of inflammatory markers ( high-sensitivity CRP and interleukin 6 ) in the two groups were comparable , as were the levels of markers of coagulation activation . Procedure duration , fluoroscopy times , and mid-term success ( 23 months , IQR 7–32 ) of the two groups were also comparable . Conclusions Cryoballoon ablation of atrial fibrillation causes more significant myocardial damage , that is , more extensive ablation lesions , compared with radiofrequency catheter ablation . However , no major differences between these two ablation techniques with regard to the inflammatory response and activation of the coagulation system were observed BACKGROUND Radiofrequency ( RF ) ablation procedures for atrial fibrillation ( AF ) are associated with potential risks of thromboembolism , which may be minimized by the use of cryoablation that preserves the integrity of endocardium . The objective of this study was to compare the thrombogenic potential of transvenous cryoablation versus RF ablation during pulmonary vein ( PV ) isolation . METHODS AND RESULTS Thirty consecutive patients with paroxysmal AF were r and omized to undergo segmental PV isolation procedure using 4-mm tip RF ablation ( n = 15 ) or cryoablation ( CryoCor , San Diego , CA , USA ) ( n = 15 ) . Blood sample s were drawn after sheath insertion ( baseline ) , after transseptal puncture , before ablation ( after heparin administration ) , and after isolation of a superior PV . Activation of coagulation was measured with plasma levels of prothrombin fragment 1 + 2 ( F1 + 2 ) and thrombin-antithrombin III complex ( TAT ) , and platelets by plasma level of beta-thromboglobulin ( beta-TG ) and flow cytometric enumerating of P-selectin (CD62)-positive platelets . In both groups , the plasma level of beta-TG , F1 + 2 , and TAT were elevated after sheath insertion . The percentage changes in plasma level of beta-TG , F1 + 2 , and TAT and CD41/62-positive platelets from baseline after transseptal puncture and before ablation were similar ( P > 0.05 ) . However , the percentage changes in CD62-positive platelets from baseline were significantly higher in patients treated with RF ablation ( 82 + /- 20 % ) than with cryoablation ( 22 + /- 14 % , P = 0.02 ) , although their plasma levels of beta-TG , F1 + 2 , and TAT were not different ( P > 0.05 ) . CONCLUSIONS Significant platelet and coagulation activations were observed during PV ablation procedures , and heparin administration only prevented activation of coagulation but not platelets . Persistent platelets activation was observed during RF energy application , but not during cryoablation 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 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 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 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 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 Catheter ablation is used extensively with curative intention in atrial fibrillation .  Radiofrequency ablation has long been a st and ard of care , while 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 therapy are lacking . METHODS Between January 2007 and August 2011 , a total of 3,775 consecutive patients with symptomatic paroxysmal AF who underwent PV ablation in their respective centers were enrolled . The cohort was divided into 2 groups according to the ablation energy source used : cryoballoon ablation ( group 1 , n = 905 [ 24.0 % ] , median age 63 years , 64.3 % men ) and RF ablation ( group 2 , n = 2870 [ 76.0 % ] , median age 63 years , 62.7 % men ) . Comorbidities and baseline clinical characteristics were similar in both groups . RESULTS Acute success rate was similar in both groups ( 97.5 % in cryo vs 97.6 % in RF ; P = 0.81 ) . Procedure times were similar , ablation and fluoroscopy times were higher in cryoballoon when compared to RF ablation .  Overall complication rate was similar in cryo- ( 4.6 % ) and RF-ablation ( 4.6 % ; P = 1.0 ) . Phrenic nerve palsy was more often in cryo versus RF ablation ( 2.1 % in cryo vs 0.0 % in RF ; P < 0.001 ) . Other complications were more common in RF compared to cryoablation ( 4.6 % in RF vs 2.7 % in cryo ; P < 0.05 ) . CONCLUSION RF ablation is the most widespread ablation method in Germany , but use of cryoballoon increased significantly . Procedure times were similar , but ablation and fluoroscopy times were longer in cryoballoon ablation . No significant differences were found in terms of acute success and overall complication rate 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 The additional benefit of contact force ( CF ) technology during pulmonary vein isolation ( PVI ) for paroxysmal atrial fibrillation ( AF ) to improve mid-term clinical outcome is unclear . METHODS AND RESULTS Eligible patients with symptomatic paroxysmal AF were enrolled in this prospect i ve trial , comparing circular antral catheter ablation ( guided by Carto 3 System , Biosense Webster ) using either a new open-irrigated CF catheter ( SmartTouch Thermocool , Biosense Webster ) ( CF group ) or a non-CF open-irrigated catheter ( EZ Steer Thermocool , Biosense Webster ) ( control group ) . Overall , 30 patients were enrolled in each group , with a st and ardized 12-month follow-up , free of antiarrhythmic therapy . Demographic , cardiovascular and anatomic characteristics were similar in both groups . Though complete PVI was eventually achieved in all cases in both groups , success using an exclusive anatomic approach was 80.0 % in CF group versus 36.7 % in control group ( P < 0.0001 ) . CF use was associated with significant reductions in fluoroscopy exposure ( P < 0.01 ) and radiofrequency time ( P = 0.01 ) . The incidence rates of AF recurrence were 10.5 % ( 95 % CI , 1.38 - 22.4 ) in the CF group , and 35.9 % ( 95 % CI , 12.4 - 59.4 ) in the control group ( log rank test , P = 0.04 ) . After adjustment on potential confounders , the use of CF catheter was found to be associated with a lower AF recurrence ( OR 0.18 , 95 % CI 0.04 - 0.94 , P = 0.04 ) . CONCLUSION Our findings suggest a potential benefit of real-time CF sensing technology , in reducing AF recurrence during the first year after PVI 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 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 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 BACKGROUND Catheter ablation is less successful for persistent atrial fibrillation than for paroxysmal atrial fibrillation . Guidelines suggest that adjuvant substrate modification in addition to pulmonary-vein isolation is required in persistent atrial fibrillation . METHODS We r and omly assigned 589 patients with persistent atrial fibrillation in a 1:4:4 ratio to ablation with pulmonary-vein isolation alone ( 67 patients  ) , pulmonary-vein isolation plus ablation of electrograms showing complex fractionated activity ( 263 patients  ) , or pulmonary-vein isolation plus additional linear ablation across the left atrial roof and mitral valve isthmus ( 259 patients ) . The duration of follow-up was 18 months . The primary end point was freedom from any documented recurrence of atrial fibrillation lasting longer than 30 seconds after a single ablation procedure . RESULTS Procedure time was significantly shorter for pulmonary-vein isolation alone than for the other two procedures ( P<0.001 ) . After 18 months , 59 % of patients assigned to pulmonary-vein isolation alone were free from recurrent atrial fibrillation , as compared with 49 % of patients assigned to pulmonary-vein isolation plus complex electrogram ablation and 46 % of patients assigned to pulmonary-vein isolation plus linear ablation ( P=0.15 ) . There were also no significant differences among the three groups for the secondary end points , including freedom from atrial fibrillation after two ablation procedures and freedom from any atrial arrhythmia . Complications included tamponade ( three patients ) , stroke or transient ischemic attack ( three patients ) , and atrioesophageal fistula ( one patient ) . CONCLUSIONS Among patients with persistent atrial fibrillation , we found no reduction in the rate of recurrent atrial fibrillation when either linear ablation or ablation of complex fractionated electrograms was performed in addition to pulmonary-vein isolation . ( Funded by St. Jude Medical ; Clinical Trials.gov number , NCT01203748 . ) BACKGROUND Experimental data suggest that use of cryoablation in pulmonary vein isolation ( PVI ) is associated with less cell damage and less thrombus formation compared to radiofrequency ( RF ) energy . OBJECTIVE The purpose of this study was to test the hypothesis that cryoablation significantly reduces markers of cell damage , platelet activation , and inflammation in patients undergoing PVI for treatment of atrial fibrillation ( AF ) . METHODS Sixty patients with symptomatic drug-resistant AF ( age 56 ± 9 years , 48 males , 38 with paroxysmal AF ) were r and omly assigned to undergo PVI using either an open irrigated-tip RF catheter or a cryoballoon . Markers of cell damage ( high-sensitive troponin T [ hs-TnT ] , microparticles ) , platelet activation ( platelet reactivity by aggregometry , expression of platelet surface proteins P-selectin and activated glycoprotein [ GP ] IIb/IIIa ) , and inflammatory response ( high-sensitive C-reactive protein [ hs-CRP ] ) were determined before and up to 48 hours after the procedure . RESULTS PVI result ed in a significant rise in hs-TnT , microparticles , markers of platelet activation , and hs-CRP over time , with distinct temporal patterns for each parameter . However , after Bonferroni correction for repeated measurements , no significant differences were noted in these parameters between patients treated with cryoablation or RF energy . Procedural time was significantly shorter in patients treated with cryoballoon ( 177 ± 30 minutes vs 200 ± 46 minutes , P = .03 ) , with no differences in fluoroscopic time , periprocedural complications , or success rate . CONCLUSION Cryoablation and RF energy result in a comparable rise of markers of cell damage , platelet activation and inflammatory response . The data do not support the concept of an improved safety profile for cryoablation in PVI 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 . )
target: 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
background: 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 .