Contact force sensing for ablation of persistent atrial fibrillation: A randomized, multicenter trial. Randomized, Controlled Trial of the Safety and Effectiveness of a Contact Force–Sensing Irrigated Catheter for Ablation of Paroxysmal Atrial Fibrillation: Results of the TactiCath Contact Force Ablation Catheter Study for Atrial Fibrillation (TOCCASTAR) Study Comparison of robotic and manual persistent AF ablation using catheter contact force sensing: an international multicenter registry study. Comparison of the efficacy between impedance‐guided and contact force‐guided atrial fibrillation ablation using an automated annotation system Comparison of contact force-guided procedure with non-contact force-guided procedure during left atrial mapping and pulmonary vein isolation: impact of contact force on recurrence of atrial fibrillation Use of a contact force-sensing ablation catheter with advanced catheter location significantly reduces fluoroscopy time and radiation dose in catheter ablation of atrial fibrillation. Impact of computed tomography image and contact force technology on catheter ablation for atrial fibrillation. Phased RF ablation in persistent atrial fibrillation. Prospective use of Ablation Index targets improves clinical outcomes following ablation for atrial fibrillation Randomized trial comparing pulmonary vein isolation using the SmartTouch catheter with or without real-time contact force data. Is the knowledge of contact force beneficial in pulmonary vein antrum isolation? Paroxysmal AF catheter ablation with a contact force sensing catheter: results of the prospective, multicenter SMART-AF trial. Real-time contact force sensing for pulmonary vein isolation in the setting of paroxysmal atrial fibrillation: procedural and 1-year results. Pulmonary vein isolation using "contact force" ablation: the effect on dormant conduction and long-term freedom from recurrent atrial fibrillation--a prospective study. Improving procedural and one-year outcome after contact force-guided pulmonary vein isolation: the role of interlesion distance, ablation index, and contact force variability in the 'CLOSE'-protocol. A randomized clinical trial of early invasive intervention for atrial fibrillation (EARLY-AF) - methods and rationale. Two-Year Follow-Up after Contact Force Sensing Radiofrequency Catheter and Second-Generation Cryoballoon Ablation for Paroxysmal Atrial Fibrillation: A Comparative Single Centre Study
BACKGROUND Impact of contact force sensing ( CFS ) on ablation of persistent atrial fibrillation ( PeAF ) is unknown . OBJECTIVE The purpose of the TOUCH AF ( Therapeutic Outcomes Using Contact force H and ling during Ablation of Persistent Atrial Fibrillation ) r and omized trial was to compare CFS-guided ablation to a CFS-blinded strategy . METHODS Patients ( n = 128 ) undergoing first-time ablation for persistent AF were r and omized to a CFS-guided vs CFS-blinded strategy . In the CFS-guided procedure , operators visualized real-time force data . In the blinded procedure , force data were hidden . Wide antral pulmonary vein isolation plus a roof line were performed . Patients were followed at 3 , 6 , 9 , and 12 months with clinical visit , ECG , and 48-hour Holter monitoring . The primary endpoint was cumulative radiofrequency ( RF ) time for all procedures . Atrial arrhythmia > 30 seconds after 3 months was a recurrence . RESULTS PeAF was continuous for 26 weeks ( interquartile range [ IQR ] 13 - 52 ) , and left atrial size was 45 ± 5 mm . Force in the CFS-blinded and CFS-guided arms was 12 g [ IQR 6 - 20 ] and 14 g [ IQR 9 - 20 ] ( P = .10 ) , respectively . Total RF time did not differ between CFS-guided and CFS-blinded groups ( 49 ± 14 min vs 50 ± 20 min , respectively ; P = .70 ) . Single procedure freedom from atrial arrhythmia was 60 % in the CFS-guided arm and 63 % in the CFS-blinded arm off drugs . Lesions with gaps were associated with significantly less force ( 11.4 g [ IQR 6 - 19 ] vs 13.2 g [ IQR 8 - 20 ] , respectively ; P = .0007 ) and less force-time integral ( 174 gs [ IQR 91 - 330 ] vs 210 gs [ IQR 113 - 388 ] , respectively ; P < .001 ) . CONCLUSION CFS-guided ablation result ed in no difference to RF time or 12-month outcome . Lower force/force-time integral was associated with significantly more gaps Background — Contact force ( CF ) is a major determinant of lesion size and transmurality and has the potential to improve efficacy of atrial fibrillation ablation . This study sought to evaluate the safety and effectiveness of a novel irrigated radiofrequency ablation catheter that measures real-time CF in the treatment of patients with paroxysmal atrial fibrillation . Methods and Results — A total of 300 patients with symptomatic , drug-refractory , paroxysmal atrial fibrillation were enrolled in a prospect i ve , multicenter , r and omized , controlled trial and r and omized to radiofrequency ablation with either a novel CF-sensing catheter or a non-CF catheter ( control ) . The primary effectiveness end point consisted of acute electrical isolation of all pulmonary veins and freedom from recurrent symptomatic atrial arrhythmia off all antiarrhythmic drugs at 12 months . The primary safety end point included device-related serious adverse events . End points were powered to show noninferiority . All pulmonary veins were isolated in both groups . Effectiveness was achieved in 67.8 % and 69.4 % of subjects in the CF and control arms , respectively ( absolute difference , −1.6 % ; lower limit of 1-sided 95 % confidence interval , −10.7 % ; P=0.0073 for noninferiority ) . When the CF arm was stratified into optimal CF ( ≥90 % ablations with ≥10 g ) and nonoptimal CF groups , effectiveness was achieved in 75.9 % versus 58.1 % , respectively ( P=0.018 ) . The primary safety end point occurred in 1.97 % and 1.40 % of CF patients and control subjects , respectively ( absolute difference , 0.57 % ; upper limit of 1-sided 95 % confidence interval , 3.61 % ; P=0.0004 for noninferiority ) . Conclusions — The CF ablation catheter met the primary safety and effectiveness end points . Additionally , optimal CF was associated with improved effectiveness . Clinical Trial Registration — http://www . clinical trials.gov . Unique identifier : NCT01278953 BACKGROUND Catheter-based contact force sensing ( CFS ) technology gives detailed information regarding contact between the catheter tip and myocardium . This may result in more effective ablation procedures . The primary objective of this study was comparison of remote robotic navigation ( RRN ) and Manual CFS ablation . The secondary objective was to compare CFS with non-CFS ablation for both navigation modes . METHODS Prospect i ve registries of consecutive cases undergoing their first ablation for persistent atrial fibrillation ( AF ) from six hospitals in the United Kingdom and South Africa were analyzed : 50 Manual/CFS and 50 RRN/CFS cases were included . Historical control non-CFS ablation patients were matched by propensity score , giving a total 200 patient cohort . RESULTS RRN/CFS was associated with improved single procedure 1-year success rates ( 64 % vs 36 % , P = 0.01 ) and shorter fluoroscopy times ( 41 % reduction , P < 0.0005 ) than Manual/CFS ablation , without any difference in procedure times ( P = 0.8 ) . The mean contact force was higher in RRN/CFS than Manual/CFS cases ( 16 [ 15 - 18 g ] vs 13 [ 12 - 15 g ] , respectively , P = 0.003 ) . Compared with non-CFS historical controls , CFS cases had higher 1-year success rates for RRN ( 64 % vs 36 % , P = 0.01 ) , but not Manual ablation ( 36 % vs 38 % , P = 1 ) . Procedure times were reduced for CFS cases ( 20 % , P < 0.005 both navigation modes ) , as were fluoroscopy times ( Manual : 43 % , RRN 83 % , P < 0.005 for both ) . There were no differences in rates of major or minor complications for either comparison ( P > 0.5 ) . CONCLUSIONS A combination of RRN and CFS is associated with improved success rates at 1 year and fluoroscopy times for persistent AF ablation , compared with Manual ablation and non-CFS RRN ablation Abstract Background This study compared the efficacy of catheter ablation of atrial fibrillation ( AF )  between impedance (IMP)‐guided and contact force (CF)‐guided annotation using the automated annotation system ( VisiTag ™ ) . Methods Fifty patients undergoing pulmonary vein isolation ( PVI ) for AF were r and omized to the IMP‐guided or CF‐guided groups . The annotation criteria for VisiTag ™ were a 10 second minimum ablation time and 2 mm maximum catheter movement range . A minimum CF of 10 g was added to the criteria in the CF‐guided group . In the IMP‐guided group , a minimum IMP drop of over 5 Ω was added to the criteria . Results The rates of successful PVI after an initial ablation line were higher in the CF‐guided group ( 80 % vs 48 % , P = .018 ) . Although average CF was similar between two groups , the average force‐time integral ( FTI ) was significantly higher in the CF‐guided group ( 298.3 ± 65 . 2 g·s vs 255.1 ± 38.3 g·s , P = .007 ) . The atrial arrhythmia‐free survival at 1 year demonstrated no difference between the two groups ( 84.0 % in the IMP‐guided group vs 80.0 % in the CF‐guided group , P = .737 ) . If the use of any antiarrhythmic drug beyond the blanking period was considered as a failure , the clinical success rate at 1 year was 52.0 % for the CF‐guided group vs 56.0 % for the IMP‐guided group ( P = .813 ) . Conclusions Atrial fibrillation ablation using an automated annotation system guided by CF improved the success rate of PVI after the initial circumferential ablation . An IMP‐guided annotation combined with catheter stability criteria showed similar clinical outcomes as compared to the CF‐guided annotation Background The aim of this study was to evaluate the impact of contact force ( CF ) visualization on the incidence of low and high CF during left atrial ( LA ) mapping and pulmonary vein isolation ( PVI ) . Methods CF was assessed in 70 patients who underwent PVI .  Three highly experienced operators performed all procedures . The operators were blinded to CF in group A ( 35 patients ) , and CF was displayed in group B ( 35 patients ) . In group B , optimal CF was defined as mean CF between 10 and 39 g , and operators attempted to acquire points and ablate within this range . Results A total of 8401 mapping points were analyzed during LA mapping ( group A : 4104 , group B : 4297 ) . Low CF < 10 g and high CF ≥40 g were noted in a significantly larger number of points in group A ( 37.7 vs. 12.0 % , P < 0.001 ; 11.5 vs. 1.5 % , P < 0.001 ) . At the mitral isthmus and ridge areas , CF was significantly lower ( 7.7 vs. 12.2 g , P < 0.001 ; 5.3 vs. 11.7 g , P < 0.001 ) in group A than in group B. PVI was successfully achieved in all patients . There were significant site-dependent CF differences between the two groups . Optimal CF was achieved in significantly more applications in group B ( P < 0.001 ) . There was no significant difference in atrial fibrillation ( AF ) recurrence rates after a minimum follow-up of 1 year between the two groups in this cohort ( P = 0.24 ) . No significant peri-procedural complications occurred in either group . Conclusions CF visualization can assist in avoiding both low and high CF , which may have the potential to improve lesion formation and patient safety profile . In this study , CF-guided ablation did not affect AF recurrence AIMS The aim of this study was to evaluate the ' real-world ' impact of a novel contact force (CF)-sensing ( SmartTouch ™ , Biosense Webster , Diamond Bar , CA , USA ) catheter coupled with an advanced catheter location ( ACL ) system on fluoroscopy time and fluoroscopy dose during atrial fibrillation ( AF ) ablation . METHODS AND RESULTS This was a retrospective observational cohort study of prospect ively collected data of 1515 consecutive patients undergoing paroxysmal AF ( PAF ) and persistent AF ( PerAF ) ablation at a single institution between 2009 and 2014 . Patients undergoing AF ablation with the SmartTouch catheter and the ACL system ( SmartTouch group , n = 510 ) were compared with those undergoing AF ablation without this technology ( control group , n = 1005 ) . The primary outcomes were total fluoroscopy time ( min ) and fluoroscopy dose as measured by the dose-area product ( mGy cm(2 ) ) . Secondary endpoints included total procedure time , total ablation time , and major cardiac complications ( tamponade , pericardial effusion , and urgent cardiac surgery ) . The SmartTouch group had significantly lower fluoroscopy times ( 9.5 vs. 41 min , P < 0.001 ) , radiation doses ( 1044 vs. 3571 mGy cm(2 ) , P < 0.001 ) , and shorter procedural time ( 195 vs. 240 min , P < 0.001 ) when compared with the control group . This was statistically significant for both PAF and PerAF ablations and for both de novo and redo AF procedures . After a learning curve , a median fluoroscopy time of 3.5 min ( interquartile range 6 ) for all AF ablations was achieved . There was no difference in the rate of cardiac complications ( ∼ 1.5 % ) . CONCLUSION SmartTouch ™ CF-sensing catheter use with ACL ™ during AF ablation significantly reduces fluoroscopy times by 77 % , radiation dose by 71 % , and procedural time by 19 % but does not improve overall safety or the risk of cardiac complications AIM To investigate the impact of using computed tomography ( CT ) and contact force ( CF ) technology on recurrence of atrial tachyarrhythmia after atrial fibrillation ( AF ) ablation . METHODS This non-r and omized study included 2 groups of patients . All patients had symptomatic recurrent paroxysmal or persistent AF and were treated with at least 1 anti arrhythmic medication or intolerant to medication . The first group included 33 patients who underwent circumferential pulmonary veins isolation ( PVI ) for AF during 2012 and 2013 guided by CT image integration ( Cartomerge , Biosense Webster , Diamond Bar , CA , United States ) of left atrium and pulmonary veins into an electroanatomic mapping ( EAM ) system ( CT group ) using st and ard irrigated radiofrequency catheter ( ThermoCool , Carto , Biosense Webster , Diamond Bar , CA , United States ) or irrigated catheter with integrated CF sensor ( Smart Touch , Carto , Biosense Webster , Diamond Bar , CA , United States ) . The second group included immediately preceding 32 patients who had  circumferential PVI by st and ard irrigated catheter ( ThermoCool ) using only EAM ( Carto ) system ( EAM group ) . Linear lesions were performed according to the discretion of operator . RESULTS Sex , age , and persistent AF were not different between groups . PVI was achieved in all patients in both groups . Linear ablations including cavo-tricuspid isthmus and or roof line ablation were not different between groups . Free of atrial tachyarrhythmia during follow-up of 24 mo was significantly higher among CT group compared to EAM group ( 81 % vs 55 % ; respectively ; P = 0.027 ) . When 11 patients from CT group who had ablation using Smart Touch catheter were excluded , the difference between CT group and EAM became non significant ( 73 % vs 55 % ; respectively ; P = 0.16 ) . Sub analysis of CT group showed that patients who had ablation using Smart Touch catheter tend to be more free of atrial tachyarrhythmia compared to patients who had ablation using st and ard irrigated catheter during follow-up ( 100 % vs 73 % ; respectively ; P = 0.07 ) . Major complications ( pericardial effusion , cerebrovascular accident/transient ischemic attack , vascular access injury requiring intervention ) did not occurred in both groups . CONCLUSION These preliminary results suggest that CT image integration and CF technology may reduce the recurrence of atrial tachyarrhythmia after catheter ablation for AF BACKGROUND Persistent and long-st and ing persistent atrial fibrillation ( AF ) often requires extensive and /or repeat radiofrequency ( RF ) ablation procedures . OBJECTIVE The Tailored Treatment of Persistent Atrial Fibrillation ( TTOP-AF ) study assessed the effectiveness and safety of the phased RF system in a r and omized controlled comparison of medical therapy against phased RF ablation for the management of persistent and long-st and ing persistent AF . METHODS Patients who had failed at least 1 antiarrhythmic drug ( AAD ) were r and omized ( 2:1 ) to ablation management ( AM ) or medical management ( MM ) . AM patients were allowed up to 2 ablations . Index and retreatment procedures consisted of pulmonary vein isolation and ablation of complex fractionated atrial electrograms . MM patients received AAD changes and /or cardioversion . The primary end points of the TTOP-AF study included chronic effectiveness and safety at 6 months and acute safety within 7 days of ablation . RESULTS At 6 months , a greater proportion of AM patients achieved effectiveness off AAD ( 77 of 138 [ 55.8 % ] ) compared to MM patients ( 19 of 72 [ 26.4 % ] ) ( P < .0001 ) . Acutely , 92.8 % ( 128/138 ) of the procedures were successful while 12.3 % ( 17/138 ) experienced a serious procedure and /or device-related adverse event . The predefined acute safety end point was not met . The proportion of patients with chronic safety events did not differ significantly between groups . CONCLUSIONS Catheter ablation of persistent/long-st and ing persistent AF with the phased RF ablation system is effective with greater reduction of AF compared with MM . More intense anticoagulation strategies , careful attention to catheter placement relative to the pulmonary vein ostia , and elimination of electrode interaction are expected to reduce the risk of stroke , pulmonary vein stenosis , and asymptomatic cerebral emboli Aims : Late recovery of ablated tissue leading to reconnection of pulmonary veins remains common following radiofrequency catheter ablation for AF . Ablation Index ( AI ) , a novel ablation quality marker , incorporates contact force ( CF ) , time , and power in a weighted formula . We hypothesized that prospect i ve use of our previously published derived AI targets would result in better outcomes when compared to CF‐guided ablation . Methods : Eighty‐nine consecutive drug‐refractory AF patients ( 49 % paroxysmal ) underwent AI‐guided ablation ( AI‐group ) . AI targets were 550 for anterior/roof and 400 for posterior/inferior left atrial segments . Procedural and clinical outcomes of these patients were compared to 89 propensity‐matched controls who underwent CF‐guided ablation ( CF‐group ) . All 178 procedures were otherwise similar , and both groups were followed‐up for 12 months . The last 25 patients from each group underwent analysis of all VisiTags ™ for ablation duration , CF , Force‐Time Integral , and impedance drop . Results : First‐pass pulmonary vein isolation ( PVI ) was more frequent in AI‐group than in CF‐group ( 173 [ 97 % ] vs. 149 [ 84 % ] circles , P < 0.001 ) , and acute PV reconnection was lower ( 11 [ 6 % ] vs. 24 [ 13 % ] circles , P = 0.02 ) . Mean PVI ablation time was similar ( AI‐group : 42 ± 9 vs. CF‐group : 45 ± 14 minutes , P = 0.14 ) . Median impedance drop for AI‐group was significantly higher than in CF‐group ( 13.7 [ 9‐19 ] Ω vs. 8.8 [ 5.2‐13 ] Ω , P < 0.001 ) . Two major complications occurred in CF‐group and none in AI‐group . Atrial tachyarrhythmia recurrence was significantly lower in AI‐group ( 15 of 89 [ 17 % ] ) than in CF‐group ( 33 of 89 [ 37 % ] , P = 0.002 ) . Conclusion : AI‐guided ablation is associated with significant improvements in the incidence of acute PV reconnection and atrial tachyarrhythmia recurrence rate compared to CF‐guided ablation , potentially due to creation of better quality lesions as suggested by greater impedance drop BACKGROUND Contact force ( CF ) information may improve the safety and efficacy of ablation for paroxysmal atrial fibrillation ( PAF ) . OBJECTIVE The purpose of this study was to assess the impact of CF data on ablation for PAF . METHODS Patients undergoing first-time PAF ablation were r and omized at 7 UK centers to ablation with ( CF-on ) or without ( CF-off ) CF data available to the operator , using the same ablation catheter and mapping system . An ablation CF of 5 - 40 g was targeted . Pulmonary vein ( PV ) reconnection was assessed with adenosine at 60 minutes . Follow-up for arrhythmia recurrence was for 1 year with 7-day Holter recordings at 6 and 12 months . RESULTS One hundred seventeen patients were studied ( 59 CF-on , 58 CF-off ) . In the CF-on group , a reduction in acute PV reconnection rates ( 22 % vs 32 % , P = .03 ) but no significant difference in 1-year success rates off antiarrhythmic drugs ( 49 % vs 52 % , P = .9 ) was observed . There was no difference in major complication rates : 2 of 59 ( 3 % ) CF-on , 3 of 58 ( 5 % ) CF-off ( P = .7 ) . Procedural and fluoroscopy times were not significantly different ( P>.5 ) . Overall mean CFs per ablation were not different between groups ( 13.4 [9.1 - 19.6]g CF-on , 13.4 [7.4 - 22.4]g CF-off , P = .5 ) , but a greater proportion of readings in the CF-on group were in the target range ( 80 % vs 68 % , P<.001 ) . CONCLUSION This r and omized multicenter study demonstrated that CF data availability was associated with reduced acute PV reconnection but not improved 1-year success rates , procedural and fluoroscopy times , or complication rates . There was a reduction in extremes of CF , above and below the study target range , suggesting greater CF control during ablation Abstract Objective : To investigate the effect of the operator knowing the real-time contact force ( CF ) on the efficacy of pulmonary vein antrum isolation ( PVAI ) . Methods : Fifty patients with paroxysmal atrial fibrillation ( AF ) or short lasting persistent AF were r and omized to CF guided PVAI ( n = 25 ) or conventional PVAI ( n = 25 ) . In the CF guided group , CF between 10 and 40 g was aim ed at . Efficacy of PVAI was measured as reduction in AF burden ( AFB ) and time to AF recurrence detected by implantable cardiac monitor ( ICM ) , inserted three months before PVAI . Blanking period was three months and follow-up 12 months . Results : All pulmonary veins were isolated in the CF guided group and all but one in the conventional group . Mean CF was 25 g in the CF guided group and 24 g in the conventional group ( p = 0.75 ) . Compared to pre-ablation , median [ IQR ] relative reduction in AFB 3–12 months after ablation was 100 [99–100]% in the CF guided group ( p < 0.001 ) and 99.4 [25–100]% in the conventional group ( p < 0.001 ) , not different between groups ( p = 0.09 ) . Nine patients ( 36 % ) had AF recurrence in the CF guided group and 13 ( 52 % ) in the conventional group ( p = 0.21 , log-rank test ) . CF differed between operators . When adjusted for operator by regression analysis , patients without recurrent AF had lower proportion of ablation time with CF < 10 g than recurrent patients ( p = 0.034 ) . No complications occurred . Conclusions : Operator knowledge of real-time CF had no significant effect on AFB reduction or time to AF recurrence . Larger trials should be done to study benefit of real-time CF 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 ) 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 BACKGROUND Atrial fibrillation ( AF ) recurrence after pulmonary vein isolation ( PVI ) is associated with PV to left atrium reconduction . Effective lesion creation necessitates adequate contact force between the ablation catheter and myocardium . OBJECTIVE The purpose of this study was to study the utility of contact force-guided ablation on immediate and long-term outcomes . METHODS Seventy-five patients with highly symptomatic paroxysmal AF underwent wide circumferential PVI using an irrigated-tip radiofrequency catheter . In 25 patients , ablation was guided by real-time contact force measurements ( CF group ; SmartTouch , Biosense Webster ) . A control group of 50 patients underwent  PVI using a st and ard nonforce sensing catheter ( st and ard group ; ThermoCool , Biosense Webster ) . After PVI , all patients underwent adenosine testing to unmask dormant conduction . Patients were followed up at 3 , 6 , and 12 months and by transtelephonic monitoring as well . RESULTS Dormant conduction was unmasked and subsequently eliminated in 4 PV pairs ( 8 % ; 16 % of patients ) in the CF group and 35 PV pairs ( 35 % ; 52 % of patients ) in the st and ard group ( P = .0004 per PV pair ; P = .0029 per patient ) . The single-procedure , off-antiarrhythmic drug freedom from recurrent atrial arrhythmias at 1 year was 88 % in the CF group vs 66 % in the st and ard group ( P = .047 ) . Procedure duration and fluoroscopy time were significantly longer in the CF group ( P = .0038 and P = .0001 , respectively ) . CONCLUSION The use of real-time contact force guidance results in a significant reduction in the prevalence of dormant conduction with improved long-term freedom from recurrent arrhythmias . The utility of a contact force-guided approach requires evaluation in a long-term prospect i ve r and omized study Aims We have recently shown that a contact force (CF)-guided ablation protocol respecting region-specific criteria of lesion contiguity and lesion depth ( ' CLOSE ' protocol ) is associated with high incidence of acute durable pulmonary vein ( PV ) isolation ( PVI ) and a high single-procedure arrhythmia-free survival at 1 year . In the present study , we compared efficiency , safety , and efficacy of ' CLOSE'-guided PVI to conventional CF-guided PVI ( CONV-CF ) . Methods and results Fifty consecutive paroxysmal atrial fibrillation ( AF ) patients underwent PV encircling using a CF-sensing catheter  targeting an interlesion distance ( ILD ) ≤6 mm and ablation index ( AI ) ≥400 and ≥550 at posterior and anterior wall ( ' CLOSE ' group ) . Results were compared to the last 50 patients undergoing ' CONV-CF ' . All patients underwent adenosine testing after PVI .  Arrhythmia recurrence was defined as any atrial tachyarrhythmia ( ATA ) > 30 s on Holter at 3 , 6 , and 12 months . Clinical characteristics did not differ . Contact force variability was comparable in between both groups ( proportion of applications with intermittent contact 2 % in ' CLOSE ' vs. 1 % in CONV-CF , P = 0.67 ) . In the ' CLOSE ' group , procedure time and radiofrequency ( RF ) time per circle were shorter ( respectively 149 ± 33 min vs. 192 ± 42 min , P < 0.0001 and 18 ± 4 min vs 28 ± 7.5 min , P < 0.0001 ) and incidence of adenosine-proof isolation was higher ( 97 % vs. 82 % , P < 0.001 ) . No complications were observed in the ' CLOSE ' group , one tamponade in the ' CONV-CF ' group . At 12 months , single-procedure freedom from ATA was 94 % in ' CLOSE ' vs. 80 % in ' CONV-CF ' group ( P < 0.05 ) . In both groups , the majority of reconnections at repeat were associated with either ILD > 6 mm and /or AI < 400/550 ( 100 % vs. 83 % , P = 0.99 ) . Conclusion ' CLOSE'-guided PVI improves procedural and 1 year outcome in CF-guided PVI while shortening procedure time . Improvement can not be explained by differences in CF variability and is most likely due to the strict application of criteria for contiguity and ablation index . A r and omized controlled trial is needed to exclude the possible contribution of a learning curve BACKGROUND The ideal management of patients with newly diagnosed symptomatic atrial fibrillation ( AF ) remains unknown . Current practice guidelines recommend a trial of antiarrhythmic drugs ( AAD ) prior to considering an invasive ablation procedure . However , earlier ablation offers an opportunity to halt the progressive patho-anatomical changes associated with AF , as well as impart other important clinical benefits . OBJECTIVE The aim of this study is to determine the optimal initial management strategy for patients with newly diagnosed , symptomatic atrial fibrillation . METHODS / DESIGN The EARLY-AF study ( Clinical Trials.govNCT02825979 ) is a prospect i ve , open label , multicenter , r and omized trial with a blinded assessment of outcomes . A total of 298 patients will be r and omized in a 1:1 fashion to first-line AAD therapy , or first-line cryoballoon-based pulmonary vein isolation .  Patients with symptomatic treatment naïve AF will be included . Arrhythmia outcomes will be assessed by implantable cardiac monitor ( ICM ) . The primary outcome is time to first recurrence of AF , atrial flutter , or atrial tachycardia ( AF/AFL/AT ) between days 91 and 365 following AAD initiation or AF ablation . Secondary outcomes include arrhythmia burden , quality of life , and healthcare utilization . DISCUSSION The EARLY-AF study is a r and omized trial design ed to evaluate the optimal first management approach for patients with AF . We hypothesize that catheter ablation will be superior to drug therapy in prevention of AF recurrence 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
Conclusion Meta- analysis of r and omized data demonstrated that CF guidance does not improve the safety or efficacy of AF ablation , despite initial observational data showing dramatic improvement .
Aims Despite widespread adoption of contact force ( CF ) sensing technology in atrial fibrillation ( AF ) ablation , r and omized data suggests lack of improvement in clinical outcomes .
We aim ed to assess the safety and efficacy of CF-guided vs. non CF-guided AF ablation .