title: Contact force facilitates the achievement of an unexcitable ablation line during pulmonary vein isolation 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. Influence of energy source on early atrial fibrillation recurrences: a comparison of cryoballoon vs. radiofrequency current energy ablation with the endpoint of unexcitability in pulmonary vein isolation Reduction in radiation dose for atrial fibrillation ablation over time: A 12-year single-center experience of 2344 patients. Randomized trial comparing pulmonary vein isolation using the SmartTouch catheter with or without real-time contact force data. Comparison of lesion formation between contact force-guided and non-guided circumferential pulmonary vein isolation: a prospective, randomized study. 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 Randomized comparison of contact force-guided versus conventional circumferential pulmonary vein isolation of atrial fibrillation: prevalence, characteristics, and predictors of electrical reconnections and clinical outcomes Two-Year Follow-Up after Contact Force Sensing Radiofrequency Catheter and Second-Generation Cryoballoon Ablation for Paroxysmal Atrial Fibrillation: A Comparative Single Centre Study Prospective use of Ablation Index targets improves clinical outcomes following ablation for atrial fibrillation Comparison of robotic and manual persistent AF ablation using catheter contact force sensing: an international multicenter registry study. Paroxysmal AF catheter ablation with a contact force sensing catheter: results of the prospective, multicenter SMART-AF trial. Acute pulmonary vein reconnection is a predictor of atrial fibrillation recurrence following pulmonary vein isolation Real-time contact force sensing for pulmonary vein isolation in the setting of paroxysmal atrial fibrillation: procedural and 1-year results. Impact of computed tomography image and contact force technology on catheter ablation for atrial fibrillation. Contact-force guided radiofrequency vs. second-generation balloon cryotherapy for pulmonary vein isolation in patients with paroxysmal atrial fibrillation-a prospective evaluation. Impact of Contact Force Monitoring in Acute Pulmonary Vein Isolation Using an Anatomic Approach. A Randomized Study. Is the knowledge of contact force beneficial in pulmonary vein antrum isolation? Contact force sensing for ablation of persistent atrial fibrillation: A randomized, multicenter trial.
abstract: Aims Contact force ( CF ) catheters provide catheter-tissue contact information to improve outcome of  pulmonary vein isolation ( PVI ) in paroxysmal atrial fibrillation ( PAF ) . We evaluated different target-CF values for achievement of the additional endpoint of an unexcitable ablation line . Methods A total of 106 patients undergoing PVI  were r and omized into three groups ( G ) ( G1 : target-CF 15 g , G2 : target-CF 10 g , G3 : CF concealed from operator ) . The PVI encircling line was divided into predefined sections . Excitable tissue along the PVI-line identified by high output pacing ( 10 V , 2 ms ) was targeted for further ablation . Results Mean average CF was 17.4 ± 4.7 g ( G1 ) vs. 12.3 ± 6.0 g ( G2 ) vs. 11.1 ± 6.5 g ( G 3 ) ( p < 0.001 ) . Primary unexcitable ablation lines were found in 38.6 , 19.4 and 5.7 % ( G1 , G2 , G3 respectively ; G1 vs. G2 p < 0.05 , G1 vs. G3 p < 0.001 , G2 vs. G3 ns ) . Additional radiofrequency (RF)-energy to achieve unexcitability was lowest in G1 ( 3.6 ± 3.1 kJ vs. 8.6 ± 7.2 kJ ( G2 ) and 10.4 ± 6.7 ( G3 ) , p ≤ 0.001 , G2 vs. G3 ns ) with accordingly lowest additional RF applications in G1 ( 3.0 ± 2.6 vs. 7.0 ± 5.4 in G2 and 8.4 ± 4.0 in G3 ; G1 vs. G2 and G3 , p < 0.001 , G 2 vs. G 3 ns ) . Sections along ablation lines with low initial CF were most likely to reveal excitability . Single procedure success was 81.9 vs. 73.5 vs. 71.4 % ( G 1 , 2 and 3 , p = 0.6 ) during 437 ± 254 day follow-up . Conclusion Higher tip-to-tissue CF during PVI facilitates the achievement of an unexcitable ablation line , requiring less additional RF-energy 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 Comparative data of early recurrence rates of atrial fibrillation ( ERAF )  following second-generation cryoballoon ( CB-G2 ) and radiofrequency current ( RFC ) ablation for pulmonary vein isolation ( PVI ) in paroxysmal AF ( PAF ) are rare . We r and omized PAF patients into either PVI with CB-G2 ( group 1 ) or PVI with a combined RFC-approach applying contact force ( CF ) with the endpoint of unexcitability ( group 2 ) to investigate ERAF . Methods and results In group 1 ( n = 30 ) , CB-G2-PVI was performed . After CF-PVI in group 2 ( n = 30 ) , bipolar pacing on the ablation line and additional ablation until unexcitability was conducted . Follow-up included 48 h of in-hospital monitoring followed by 5-day Holter ECGs 1 , 2 , 3 , 6 , 12 months postablation to evaluate ERAF . Acute PVI was reached in 100 % of group 2 and in 99 % of group 1 . Shorter procedure duration s ( 98.0 ± 21.9 vs. 114.3 ± 18.7 min , P < 0.05 ) but extended fluoroscopy times ( 15.4 ± 3.9 vs. 10.0 ± 4.3 min , P < 0.05 ) were found in the CB-G2 group . Ten non-severe complications occurred ( 6 vs. 4 in group 1 and 2 , P = 0.73 ) . In group 2 , five patients suffered from ERAF vs. seven patients in group 1 ( P = 0.67 ) . The time until the occurrence of ERAF was shorter in group 2 ( 1 day ( q1-q3 : 1 - 4.5 ) ) when compared with group 1 ( 22 ( q1-q3 : 6 - 54 ) days , P = 0.025 ) . Conclusion ERAF rates were equal among groups ; however , they occurred earlier in the initial phase after RFC ablation when compared with CB-G2 . PVI utilizing cryoablation is associated with shorter procedure duration s but extended fluoroscopy time while being similarly secure BACKGROUND Pulmonary vein isolation ( PVI ) is a well-established treatment of atrial fibrillation ( AF ) , with contact force (CF)-sensing catheters joining 3-dimensional mapping systems and image integration as technological advancements over the last decade . OBJECTIVE The purpose of this study was to analyze trends in radiation exposure for AF ablation over the last 12 years at our center . METHODS We review ed prospect ively collected data of 2344 consecutive PVI procedures for either paroxysmal or persistent AF between January 2004 and December 2015 . During this period , all cases used 3-dimensional mapping systems , with 8 software and 2 hardware up grade s. Primary endpoints were fluoroscopy time , absorbed dose ( Air Kerma in mGy ) , and effective dose ( mSv ) . RESULTS In total , 1914 patients underwent initial PVI , and 430 patients underwent redo PVI using radiofrequency energy . Fluoroscopy time , and absorbed and effective doses significantly and progressively decreased over the 12-year period for initial PVI as follows : 2004 - 2006 : 61 ± 27 minutes ; 2007 - 2009 : 46 ± 14 minutes , 1365 ± 1369 mGy , 11.3 ± 12.5 mSv ; 2010 - 2012 : 31 ± 11 , 464 ± 339 mGy , 9.0 ± 10.4 mSv ; and 2013 - 2015 : 17 ± 9 minutes , 304 ± 758 mGy , 5.5 ± 6.7 mSv . CF-sensing catheters were used for 357/508 PVI only cases between 2014 and 2015 . Fluoroscopy times ( 11 ± 5 vs 21 ± 8 minutes ; P < .001 ) and absorbed dose ( 200 ± 524 vs 470 ± 1326 mGy ; P = .004 ) were significantly shorter with this catheter . CONCLUSION Radiation exposure has dramatically decreased over the last decade for PVI and is related to operator experience , annual case volume , technology evolution , and more recently CF-sensing catheters . This has significant implication s for both patient and operator long-term risk 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 Contact force ( CF ) monitoring could be useful in accomplishing circumferential pulmonary vein ( PV ) isolation ( CPVI ) for atrial fibrillation ( AF ) . OBJECTIVE The purpose of this study was to compare procedure parameters and outcomes between CF-guided and non-guided CPVI . METHODS Thirty-eight consecutive AF patients ( mean age 60 ± 11 years , 28 paroxysmal AF ) undergoing CPVI were r and omized to non-CF-guided ( n = 19 ) and CF-guided ( n = 19 ) groups .  CPVI was performed with the ThermoCool SmartTouch catheter in both groups . The end-point was bidirectional block between the left atrium ( LA ) and PV . In the CF group , CF was kept between 10 and 20 g during CPVI , whereas in the non-CF group , all CF information was blanked . Radiofrequency energy at 30 W in the anterior and 25 W in the posterior LA wall was applied for 20 - 25 seconds at each point . RESULTS CPVI was successfully accomplished without any major complications in both groups . Mean CF in the non-CF and CF groups were 5.9 ± 4.5 g and 11.1 ± 4.3 g , respectively , for left-side CPVI , and 9.8 ± 6.6 g and 12.1 ± 4.8 g , respectively , for right-side CPVI ( both P < .001 ) . The procedure and fluoroscopy times  for CPVI in the non-CF and CF groups were 96 ± 39 minutes and 59 ± 16 minutes , respectively ( P < .001 ) , and 22 ± 63 seconds and 9 ± 20 seconds ( P = NS ) , respectively . Total number of residual conduction gaps was 6.3 ± 3.0 in the non-CF group and 2.8 ± 1.9 in the CF group ( P < .001 ) . During 6-month follow-up , 84.2 % of patients in the non-CF group and 94.7 % in the CF group were free from any atrial tachyarrhythmias ( P = .34 ) . CONCLUSION CF-guided CPVI  is effective in reducing procedure time and additional touch-up ablation and may improve long-term outcome Background 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 Purpose We prospect ively investigated the differences in pulmonary vein reconnections ( PVRs ) and clinical outcomes between contact force (CF)-guided and conventional circumferential PV isolation ( CPVI ) of atrial fibrillation ( AF ) . Methods One hundred twenty consecutive AF patients ( 63 ± 10 years ; 88 males ) undergoing an initial CPVI were r and omized to ablation with a target CF of 20 g ( CF group ; n = 60 ) or that with operators blinded to the CF information ( blind group ; n = 60 ) . Results The CF group had fewer PVRs ( 0.67 ± 0.91/patient vs. 1.16 ± 1.16/patient ; P = 0.007 ) , a lower incidence of persistent PVRs ( 13.2 vs. 41.2 % ; P < 0.001 ) , and a shorter procedural time for the CPVI ( 50 vs. 56 min ; P = 0.019 ) than the blind group . The mean CF was higher in the CF group than the blind group ( 18.0 vs. 16.1 g ; P < 0.001 ) , with the most significant difference observed along the posterior right-sided PVs ( P-RPVs ) and anterior left-sided PVs ( A-LPVs ) . In logistic regression models , the mean CF was a negative predictor of PVRs along the P-RPVs and A-LPVs in the blind group ( odds ratios , 0.728 and 0.786 ; P < 0.001 and 0.007 ) , while no significant predictor was identified in the CF group or elsewhere in the blind group . In the Kaplan-Meier analysis , the arrhythmia-free survival rate at 12 months was 89.9 % in the CF group and 88.2 % in the blind group , respectively ( P = 0.624 ) . Conclusions CF-guided CPVI can reduce PVRs and the procedural time and be particularly beneficial along regions where a relatively low CF tends to be applied : the P-RPVs and A-LPVs . The comparable clinical outcomes may be due to the learning curve effect obtained by the CF-guided technique and repeated provocation of dormant PV conduction 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 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 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 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 ) Purpose Arrhythmia recurrence following pulmonary vein isolation ( PVI ) occurs predominantly due to the reconnection of previously isolated pulmonary veins ( PVs ) . The prognostic implication s of detection and treatment of acute PV reconnection are not well understood . We aim to examine the prognostic significance of acute PV reconnection on arrhythmia recurrence at 1 year following PVI . Methods This prospect i ve study included 44 patients ( 22 men , 60 ± 7 years ) who underwent index PVI procedure for treatment of atrial fibrillation ( AF ) .  Acute PV reconnection  and /or dormant PV conduction were assessed sequentially in response to a 30-min waiting period , intravenous isoproterenol infusion and /or adenosine . All cases of acute PV reconnection and /or dormant conduction were successfully targeted with additional ablation . Results Freedom from AF at 1 year was 75 % ( 83.3 % in paroxysmal and 65 % in persistent AF , p = ns ) . Acute PV reconnection and /or dormant conduction were evident in 16 of 44 patients ( 36.3 % ) . AF recurrence was documented in eight of 16 patients with , but only in three of 28 patients without acute reconnection ( p = 0.009 ) . Three patients underwent a redo procedure , all from the group of patients with acute PV reconnection . In a multivariate model , acute PV reconnection was a strong independent predictor of arrhythmia recurrence ( hazards ratio [ HR ] , 6.36 ; 95 % confidence interval [ CI ] , 1.12–31.6 ) . Conclusion Identification of acute PV reconnection , even when successfully targeted , is a strong predictor of arrhythmia recurrence following PVI 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 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 AIMS In the setting of paroxysmal atrial fibrillation ( AF ) , there are no available data comparing the mid-term outcome of patients undergoing pulmonary vein isolation ( PVI ) catheter ablation using contact-force (CF)-guided radiofrequency ( RF ) vs. second-generation balloon cryotherapy . METHODS AND RESULTS Prospect i ve single-centre evaluation , carried out from March 2011 to February 2013 , comparing CF radiofrequency ( Thermocool ( ® ) SmartTouch ™ , Biosense Webster , Inc. ) ( CF group ) with cryoballoon ablation ( A rct ic Front Advance ™ 28 mm cryoballoon , Medtronic , Inc. ) ( CB group ) , in regards to procedural safety and efficacy , as well as recurrence at 12 months . Overall , 150 consecutive patients were enrolled ( 75 in each group ) . The characteristics of patients of both the groups were similar ( 61.2 ± 9.9 years , women 25.3 % , mean AF duration 4.1 ± 4.0 years , mean CHA2DS2-VASc score 1.4 ± 1.3 , mean HAS-BLED 1.4 ± 0.6 ) . Duration of the procedure was significantly lower in the CF group ( 110.7 ± 32.5 vs. 134.5 ± 48.3 min , P = 0.001 ) , with a lower duration of fluoroscopy ( 21.5 ± 8.5 vs. 25.3 ± 9.9 min , P = 0.017 ) and X-ray exposure ( 4748 ± 2411 cGy cm² vs. 7734 ± 5361 cGy cm² , P = 0.001 ) . In contrast , no significant difference was found regarding significant procedural complication ( 2.7 vs. 1.3 % in CF and CB groups , respectively ; P = 0.56 ) , and PVI was eventually achieved in all cases . At 12 months , AF recurrence occurred in 11 patients ( 14.7 % ) in the CB group and in 9 patients ( 12.0 % ) in the CF group ( HR = 1.20 95 % CI 0.50 - 2.90 ; log rank P = 0.682 ) . CONCLUSIONS Our preliminary findings suggest that CF-guided radiofrequency and cryotherapy present very similar performances in the setting of paroxysmal AF catheter ablation BACKGROUND The impact of contact force ( CF ) monitoring in pulmonary vein ( PV ) isolation after a circumferential anatomic ablation ( CAA ) is unknown . We analyze the usefulness of CF monitoring in acute PV isolation and procedure parameters using a CAA . METHODS Fifty patients with paroxysmal atrial fibrillation were r and omized into CF-on ( CF > 10 grams ; n = 25 ) or CF-off ( CF blinded ; n = 25 ) groups . We performed a first round of CAA with a ThermoCool ( ® ) SmartTouch ( ® ) catheter blinded to the LASSO ( ® ) catheter ( Biosense Webster , Diamond Bar , CA , USA ) , with radiofrequency ( RF ) lesions tagged with the VisiTag ( ™ ) Module . After the CAA , each PV was review ed with the LASSO ( ® ) catheter recording the segments with gaps . RESULTS All the PVs were isolated with a CAA in 20 patients of the CF-on versus eight of the CF-off ( P = 0.001 ) . Of the 45 segments with gaps in the left PVs , 38 were from the CF-off ( P = 0.0001 ) . Of the eight segments with gaps in the right PVs , seven were from the CF-off ( P = 0.06 ) . The CF in the left PVs was higher in the CF-on ( 16.3 ± 3.2 grams vs 10.5 ± 4.3 grams ; P = 0.0001 ) and similar in the right PVs ( 17.6 ± 3.6 grams vs 15.2 ± 5.3 grams ; P = 0.08 ) . All of the gaps were closed with additional RF LASSO ( ® ) -guided touch-up . Procedure and fluoroscopy times were shorter in the CF-on ( 139 ± 24 minutes vs 157 ± 32 minutes and 20 ± 6 minutes vs 24 ± 7 minutes ; both P = 0.039 ) . At 12 months the patients free of AF recurrence was 84 % CF-on versus 75 % CF-off ( log-rank P = 0.4 ) [ corrected ] . CONCLUSIONS In paroxysmal atrial fibrillation , a CAA guided by CF reduces PV gaps and shortens the procedure parameters at the expense of the left PVs 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 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
target: 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
background: 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 .