German ablation registry: Cryoballoon vs. radiofrequency ablation in paroxysmal atrial fibrillation--One-year outcome data. Results from a multicentre comparison of cryoballoon vs. radiofrequency ablation for paroxysmal atrial fibrillation: is cryoablation more reproducible? Transvenous cryoablation reduces platelet activation during pulmonary vein ablation compared with radiofrequency energy in patients with atrial fibrillation. Cryoballoon versus RF ablation in paroxysmal atrial fibrillation: results from the German Ablation Registry. Randomised clinical trial of cryoballoon versus irrigated radio frequency catheter ablation for atrial fibrillation—the effect of double short versus standard exposure cryoablation duration during pulmonary vein isolation (CIRCA-DOSE): methods and rationale 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 Cellular damage, platelet activation, and inflammatory response after pulmonary vein isolation: a randomized study comparing radiofrequency ablation with cryoablation. Comparison of cryoballoon and radiofrequency ablation of pulmonary veins in 40 patients with paroxysmal atrial fibrillation: a case-control study. Cryoballoon ablation of pulmonary veins for paroxysmal atrial fibrillation: first results of the North American Arctic Front (STOP AF) pivotal trial. Cryoballoon vs. open irrigated radiofrequency ablation for paroxysmal atrial fibrillation: long-term FreezeAF outcomes 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. Is the time between first diagnosis of paroxysmal atrial fibrillation and cryoballoon ablation a predictor of efficacy? Pericardial effusion in atrial fibrillation ablation: a comparison between cryoballoon and radiofrequency pulmonary vein isolation. Usefulness of serum uric acid level to predict atrial fibrillation recurrence after cryoballoon-based 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 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 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 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 Introduction Pulmonary vein isolation ( PVI ) is an effective therapy for paroxysmal atrial fibrillation ( AF ) , but it has limitations . The two most significant recent advances have centred on the integration of real-time quantitative assessment of catheter contact force into focal radio frequency ( RF ) ablation catheters and the development of dedicated ablation tools capable of achieving PVI with a single ablation lesion ( A rct ic Front cryoballoon , Medtronic , Minneapolis , MN , USA ) . Although each of these holds promise for improving the clinical success of catheter ablation of AF , there has not been a rigorous comparison of these advanced ablation technologies . Moreover , the optimal duration of cryoablation ( freezing time ) has not been determined . Methods and analysis Patients undergoing an initial PVI procedure for paroxysmal AF will be recruited . Patients will be r and omised 1:1:1 between contact-force irrigated RF ablation , short duration cryoballoon ablation ( 2 min applications ) and st and ard duration cryoballoon ablation ( 4 min applications ) . The primary outcome is time to first documented AF recurrence on implantable loop recorder . With a sample size of 111 per group and a two-sided 0.025 significance level ( to account for the two main comparisons ) , the study will have 80 % power ( using a log-rank test ) to detect a difference of 20 % between contact force RF catheter ablation and either of the two cryoballoon ablation groups . Factoring in a 4 % loss to follow-up , 116 patients per group should be r and omised and followed for a year ( total study population of 348 ) . Ethics and dissemination The study was approved by the University of British Columbia Office of Research ( Services ) Ethics Clinical Research Ethics Board . Results of the study will be su bmi tted for publication in a peer- review ed journal . Trial registration number NCT01913522 ; Pre- 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 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 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 OBJECTIVES This study sought to assess the safety and effectiveness of a novel cryoballoon ablation technology design ed to achieve single-delivery pulmonary vein ( PV ) isolation . BACKGROUND St and ard radiofrequency ablation is effective in eliminating atrial fibrillation ( AF ) but requires multiple lesion delivery at the risk of significant complications . METHODS Patients with documented symptomatic paroxysmal AF and previously failed therapy with ≥ 1 membrane active antiarrhythmic drug underwent 2:1 r and omization to either cryoballoon ablation ( n = 163 ) or drug therapy ( n = 82 ) . A 90-day blanking period allowed for optimization of antiarrhythmic drug therapy and reablation if necessary . Effectiveness of the cryoablation procedure versus drug therapy was determined at 12 months . RESULTS Patients had highly symptomatic AF ( 78 % paroxysmal , 22 % early persistent ) and experienced failure of at least one antiarrhythmic drug . Cryoablation produced acute isolation of three or more PVs in 98.2 % and all four PVs in 97.6 % of patients . PVs isolation was achieved with the balloon catheter alone in 83 % . At 12 months , treatment success was 69.9 % ( 114 of 163 ) of cryoblation patients compared with 7.3 % of antiarrhythmic drug patients ( absolute difference , 62.6 % [ p < 0.001 ] ) . Sixty-five ( 79 % ) drug-treated patients crossed over to cryoablation during 12 months of study follow-up due to recurrent , symptomatic AF , constituting drug treatment failure . There were 7 of the result ing 228 cryoablated patients ( 3.1 % ) with a > 75 % reduction in PV area during 12 months of follow-up . Twenty-nine of 259 procedures ( 11.2 % ) were associated with phrenic nerve palsy as determined by radiographic screening ; 25 of these had resolved by 12 months . Cryoablation patients had significantly improved symptoms at 12 months . CONCLUSIONS The STOP AF trial demonstrated that cryoballoon ablation is a safe and effective alternative to antiarrhythmic medication for the treatment of patients with symptomatic paroxysmal AF , for whom at least one antiarrhythmic drug has failed , with risks within accepted st and ards for ablation therapy . ( A Clinical Study of the A rct ic Front Cryoablation Balloon for the Treatment of Paroxysmal Atrial Fibrillation [ Stop AF ] ; NCT00523978 ) 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 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 Aims Cryoablation is an indicated therapy for the treatment of recurrent atrial fibrillation through pulmonary vein isolation ; however , the optimal time between first diagnosis of atrial fibrillation and cryoablation is still unknown . We aim ed to assess the clinical efficacy and safety of early versus later treatment of patients with paroxysmal atrial fibrillation by cryoablation .  Methods Five hundred and ten patients underwent atrial fibrillation cryoablation and were prospect ively followed for at least 6 months in 43 Italian cardiology centers . The population was divided into two groups according to the time since the first diagnosis of atrial fibrillation until the index cryoablation procedure . An early-treatment group had an elapsed time of 15 months or less from atrial fibrillation diagnosis until cryoablation , and the late-treatment group had an elapsed time of greater than 15 months . During the evaluation , clinical efficacy was defined as atrial fibrillation recurrence outside a l and mark 90-day blanking period , and safety was defined as the reporting of all procedure-related complications . Results In the total cohort , cryoablation was performed after a median of 36 months from the point of the patient diagnosis with drug refractory symptomatic recurrent atrial fibrillation . The early-treatment group was composed of 130 ( 25 % ) patients , whereas the late-treatment group had 380 ( 75 % ) patients . Both cohorts had similar baseline clinical characteristics . Of 510 patients , 22 had a complication related to the procedure with no difference between the two groups . Multivariable analysis showed that the risk of atrial fibrillation recurrence was significantly higher in the late-treatment group ( hazard ratio : 1.77 ; 95 % confidence interval 1.00 - 3.13 ) Conclusion In our multicenter observational examination , cryoablation was well tolerated and effective in the treatment of patients with drug refractory symptomatic paroxysmal atrial fibrillation . Reducing the time between diagnosis and ablation brought about a treatment that had a lower risk of atrial fibrillation recurrence with no change in safety . ( Italian Clinical Service Project : NCT01007474 ) 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 AIMS Catheter-based atrial fibrillation ( AF ) ablation has become an important therapeutic option in AF patients . Although there has been significant improvent in procedural success , post-procedural AF recurrences are continuing to be a major clinical problem . To the best of our knowledge , the impact of pre-procedural serum uric acid ( SUA ) level , as a pro-oxidant and pro-inflammatory marker , on AF recurrence following cryoballoon-based AF ablation has never been studied before . The objective of this study was to establish whether there is a relationship between levels of SUA and recurrence of paroxysmal AF after catheter ablation . METHODS AND RESULTS A total of 363 patients ( mean age 53.5 ± 11.2 years , 52.6 % male ) with symptomatic paroxysmal AF underwent initial cryoablation procedure .  Patients were categorized into quartiles on the basis of their pre-procedural SUA assays and follow-up , and the Kaplan-Meier estimation with a log-rank test was used for the analysis of the influence of SUA on the recurrence of AF . Post-ablation blanking period was observed for 3 months . At a mean follow-up of 19.2 ± 6.1 months , 68 patients ( 18.7 % ) had developed AF recurrence . Atrial fibrillation recurrence rates from the lowest to the highest SUA quartiles were 2.9 , 7.4 , 11.8 , and 77.9 % , respectively ( P < 0.001 ) . On multivariate Cox regression analysis , pre-ablation SUA level ( HR : 1.96 , 95 % CI : 1.49 - 2.59 , P < 0.001 ) , left atrial diameter ( HR : 1.11 , 95 % CI : 1.04 - 1.19 , P = 0.002 ) and early AF recurrence ( HR : 4.34 , 95 % CI : 1.9 - 9.95 , P = 0.001 ) were independent predictors of AF recurrence after cryoablation . Using a cut-off level of 6.37 , the pre-ablation SUA level predicted AF recurrence during follow-up with a sensitivity of 85.7 % and a specificity of 83.7 % . CONCLUSION In this prospect i ve study of patients with paroxysmal AF undergoing cryoablation , increased pre-ablation SUA levels were associated with a higher rate of AF recurrence . Our results support the role of a pre-ablation pro-inflammatory and pro-oxidant environment in the development of AF recurrence after ablation therapy but suggest that other factors are also important
Conclusions Compared with RF ablation , cryoablation present a comparable long-term AF/atrial tachycardial-free survival and procedure-related adverse events .
Meanwhile , cryoablation markedly shorten the procedure time , nonetheless , with negligible impact on the fluoroscopy time
Aims Cryoablation is a promising alternative technique to RF ablation for treating paroxysmal AF with encouraging results .
However , data about the efficacy and safety comparison between cryoablation and RF ablation is still lacking .