Paroxysmal AF catheter ablation with a contact force sensing catheter: results of the prospective, multicenter SMART-AF trial. 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. 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 Real-time contact force sensing for pulmonary vein isolation in the setting of paroxysmal atrial fibrillation: procedural and 1-year results. Contact force sensing for ablation of persistent atrial fibrillation: A randomized, multicenter trial. Two-Year Follow-Up after Contact Force Sensing Radiofrequency Catheter and Second-Generation Cryoballoon Ablation for Paroxysmal Atrial Fibrillation: A Comparative Single Centre Study Comparison of robotic and manual persistent AF ablation using catheter contact force sensing: an international multicenter registry study. Clinical impact of an open-irrigated radiofrequency catheter with direct force measurement on atrial fibrillation ablation. Pulmonary vein isolation using "contact force" ablation: the effect on dormant conduction and long-term freedom from recurrent atrial fibrillation--a prospective study. Impact of computed tomography image and contact force technology on catheter ablation for atrial fibrillation. Randomized trial comparing pulmonary vein isolation using the SmartTouch catheter with or without real-time contact force data. Optimizing radiofrequency ablation of paroxysmal and persistent atrial fibrillation by direct catheter force measurement-a case-matched comparison in 198 patients. Comparison of the efficacy between impedance‐guided and contact force‐guided atrial fibrillation ablation using an automated annotation system A prospective study on safety of catheter ablation procedures: contact force guided ablation could reduce the risk of cardiac perforation. Phased RF ablation in persistent atrial fibrillation. 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. 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
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 ) 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 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 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 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 . 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 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 BACKGROUND Electrode-tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation ( RFCA ) . OBJECTIVE We assessed the impact of direct catheter force measurement on acute procedural parameters during RFCA of atrial fibrillation ( AF ) . METHODS Fifty consecutive patients ( 28 male ) with paroxysmal AF who underwent their first procedure of circumferential pulmonary vein ( PV ) isolation ( PVI ) were assigned to either RFCA using ( 1 ) a st and ard 3.5-mm open-irrigated-tip catheter or ( 2 ) a catheter with contact force measurement capabilities . Using the endpoint of PVI with entry and exit block , acute procedural parameters were assessed . RESULTS Procedural data showed a remarkable decline in ablation time ( radiofrequency time needed for PVI ) from 50.5 ± 15.9 to 39.0 ± 11.0 minutes ( P = 0.007 ) with a reduction in overall procedure duration from 185 ± 46 to 154 ± 39 minutes ( P = 0.022 ) . In parallel , the total energy delivered could be significantly reduced from 70,926 ± 19,470 to 58,511 ± 14,655 Ws ( P = 0.019 ) . The number of acute PV reconnections declined from 36 % to 12 % ( P = 0.095 ) . CONCLUSIONS The use of contact force sensing technology is able to significantly reduce ablation and procedure times in PVI . In addition , energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact . Procedural efficacy and safety of this new feature have to be evaluated in larger cohorts 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 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 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 BACKGROUND Sufficient electrode-tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation ( RFCA ) . OBJECTIVE We assessed the impact of direct catheter force measurement on acute procedural parameters and outcome of RFCA for paroxysmal and persistent atrial fibrillation ( AF ) . METHODS Ninety-nine consecutive patients ( 70 % men ) with paroxysmal ( 63.6 % ) or persistent AF underwent left atrial RFCA using a 3.5-mm open-irrigated-tip ( OIT ) catheter with contact force measurement capabilities ( group 1 ) . For comparison a case-matched cohort with st and ard OIT catheters was used ( 99 patients ; group 2 ) . Case matching included gender , type of AF , number or RFCA procedures , and type of procedure . RESULTS Procedural data showed a significant decline in radiofrequency ablation time from 52 ± 20 to 44 ± 16 minutes ( P = 0.003 ) with a remarkable mean reduction in overall procedure time of 34 minutes ( P = 0.0001 ; 225.8 ± 53.1 vs 191.9 ± 53.3 minutes ) . In parallel , the total fluoroscopy time could be significantly reduced from 28.5 ± 11.0 to 19.9 ± 9.3 minutes ( P = 0.0001 ) as well as fluoroscopy dose from 74.1 ± 58.0 to 56.7 ± 38.9 Gy/cm(2 ) ( P = 0.016 ) . Periprocedural complications were similar in both groups . CONCLUSIONS The use of contact force sensing technology is able to significantly reduce ablation , procedure , and fluoroscopy times as well as dose in RFCA of AF in a mixed case-matched group of paroxysmal and persistent AF . Energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact . Additionally 12-month outcome data showed increased efficacy . Such time saving and equally safe technology may have a relevant impact on laboratory management and increased cost effectiveness 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 Contact force ( CF ) sensing catheters provide advantages with regard to safety and efficacy . This study aim ed to evaluate if CF catheters reduce cardiac perforations and other major complications and offer equal safety compared to the magnetic navigation system ( MNS ) . METHODS Data from 1.517 ablation procedures from our prospect i ve registry was analyzed . Ablations were performed using either CF guided catheters ( CF group , n=248 ) , non-CF catheters ( NCF group , n=813 ) , or MNS ( n=456 ) . Four subgroups were analyzed : atrial fibrillation ( AF , n=557 ) , supraventricular tachycardia ( SVT , n=715 ) , ventricular tachycardia ( VT , n=190 ) and patients with congenital heart defects ( CHD , n=55 ) . The primary endpoint of this study was incidence of cardiac perforation . Secondary endpoints were major and minor complications within 30 days of the procedure . RESULTS Complications occurred in 11.3 % ( n=172 ) of the procedures . In 2.8 % ( n=43 ) a major complication occurred , 0.9 % ( n=13 ) had a perforation , 8.5 % ( n=129 ) had a minor complication and 2 patients died ( 0.1 % ) . No cardiac perforation occurred in the CF group , which was significantly different from NCF procedures ( 0.0 % vs. 1.6 % ; relative risk 0.76 , 95 % CI 0.74 - 0.79 , P=0.031 ) and equal to MNS ( 0.0 % ) . This was also observed in the AF subgroup ( 0.0 % vs. 3.3 % ; RR 0.67 , 95 % CI 0.63 - 0.72 , P=0.021 ) , and the occurrence of major complications was lower for CF versus NCF procedures ( 2.1 % vs. 7.8 % , P=0.010 ) . CONCLUSIONS CF-guided catheter ablation is superior to NCF with regard to procedural safety and avoidance of cardiac perforation . This difference is due to a reduction of cardiac perforation and major complications in the AF subgroup 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 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 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-
Complication rates , including cardiac tamponade , did not differ between groups .
Compared with the use of other catheters , AF ablation using the CF-sensing ST catheter for AF is associated with improved success rates , shorter procedure and fluoroscopy times and similar safety profile
OBJECTIVES The objective of our review was to systematic ally assess available evidence on the effectiveness , safety and efficiency of a spring sensor-irrigated contact force ( CF ) catheter ( THERMOCOOL SMARTTOUCH Catheter ( ST ) ) for percutaneous ablation of paroxysmal or persistent atrial fibrillation ( AF ) , compared with other ablation catheters , or with the ST with the operator blinded to CF data .
BACKGROUND Emerging evidence suggests improved clinical outcomes of AF ablation using CF-sensing catheters ; however , review s to date have included data from multiple , distinct CF technologies .