Use Of Contact Force Research Articles

Abstract 12390: Differences in the Impact of Use of Contact Force Sensing Catheters on Subsequent Rates of Pulmonary Vein Reconnection Detected Between Men and Women During Repeat Ablation of Atrial Fibrillation

Background: Radiofrequency catheter ablation (CA) is an effective treatment for atrial fibrillation (AF). Contact force (CF) sensing catheters permit tissue contact monitoring that may lead to durable pulmonary vein (PV) isolation. Objective: To assess the impact of CF-sensing catheters on PV reconnection rates at repeat AF ablation and whether there are sex-based differences. Methods: We conducted a retrospective study of patients who underwent repeat AF ablation after index PV isolation between 2010 and 2022. Patients were divided into 2 groups: Group 1 (non-CF sensing catheters) and Group 2 (CF-sensing catheters). Results: One hundred sixty-one patients were included in the study (76 in Group 1 and 85 in Group 2, 32% female, 70 ± 10 years old). Initial use of CF-sensing catheters at index ablation was associated with a lower PV reconnection rate at repeat ablation (60% for Group 2 vs 87% for Group 1; P = 0.001). There were no significant differences in locations of PV reconnection between Group 1 and Group 2. When stratified by sex, there were significantly lower rates of PV reconnection in male patients with use of CF-sensing catheters (92% for Group 1 vs 67% for Group 2; p=0.001) but not for female patients (71% for Group 1 vs 50% for Group 2; p=0.23). On multivariable logistic regression analysis, use of CF-sensing catheters at index ablation (adjusted odds ratio [aOR]: 0.28, 95% CI: 0.12 to 0.65; p=0.003) and female sex (aOR: 0.38, 95% CI: 0.17 to 0.86; p=0.02) were associated with significantly lower rates of PV reconnection found at repeat ablation. Conclusion: Use of CF sensing catheters reduced PV reconnection rate found at repeat AF ablation. Females have lower rates of PV reconnection identified at repeat ablation which suggest that non-PV triggers may be a more common cause of recurrent AF, thereby blunting the impact of CF-sensing catheters on reducing recurrent AF in females.

Incremental value of maximum voltage and activation-guided ablation for cavotricuspid isthmus-dependent atrial flutter

Abstract Funding Acknowledgements Type of funding sources: None. Radiofrequency (RF) catheter ablation is an effective method for treatment of typical cavo-tricuspid isthmus (CTI) dependent atrial flutter. However, despite the widespread use of contact force irrigated catheter, 11% of patients don’t achieve a first-pass CTI block, requiring additional RF applications or additional line during the same or a second procedure. From an anatomical point of view, CTI is composed of discrete bundles of muscle with intervening connective tissue, suggesting that its conduction proprieties are dependent of the anatomic architecture of the bundles. The maximum voltage-guided (MGV) ablation technique targets high-voltage electrograms along CTI to ablate the functionally active anatomic muscle bundle, without drawing a complete anatomic line. [1;2] Purpose The aim of this study was to evaluate the efficacy of maximum voltage and activation-guided ablation (MVG/LAT) for CTI atrial flutter in real-world setting. Methods This was a prospective observational study in which all patients undergoing CTI atrial flutter ablation at the Electrophysiology Laboratory of our Department from 01/2021 to 10/2022 were recruited. Patients who were undergoing the ablation procedure after having already made an unsuccessful attempt of the same were excluded from the study. Substrate and activation mapping of CTI, both during flutter and during pacing from the proximal coronary sinus (CSp), was performed in all patients, identifying the earliest activated high-voltage channels, without the use of fluoroscopy, using the Smart-Touch SF catheter (CARTO 3, V7, Biosense Webster). High-voltage channels were validate also during lateral RA pacing. CTI ablation was performed only in channels with high voltage and early activation (W 45, AI 500). Bidirectional CTI block were validate by differential atrial pacing maneuvers and activation mapping during pacing from CSp. Results Procedural data of 39 patients were evaluated (mean age 68±13 years; men 92.6%; mean right atrium volume 149 mL). The mean number of points taken per map per patient was 1151. Bipolar thresholds were customized (0.5-2.5 mV) with the aim of better visualizing high-voltage channels. In 20/39(51.2%) patients ablation was performed during atrial flutter, in 19/39(48.8%) during pacing from proximal CS. In 19/39(48.8%) patients high-voltage channels were not detected at the central isthmus line (6 o'clock, LAO). The median number of RF applications to achieve bidirectional block of the CTI were 6 (1-20) in all patients (p=NS) (Figure 1,2). During a mean follow-up of 260 days (90-531) no recurrences were documented in any patient. Conclusions MVG/LAT-guided ablation, targeting selectively conductive muscle fibers, decreases the number of RF applications and improves efficacy, mostly in patients with challenging anatomies.

Radiofrequency ablation for treatment of atrial fibrillation with the use of intracardiac echocardiography versus without intracardiac echocardiography: A meta-analysis of observational and randomized studies.

Intracardiac echocardiography (ICE) provides superior quality images and can monitor catheter location within the heart continuously. Given the limited evidence, we conducted the meta-analysis to evaluate outcomes with ICE in radiofrequency (RF) ablation of atrial fibrillation (AF). PubMed/MEDLINE, Embase, and Cochrane were searched for studies reporting RF ablation for treatment of AF with the use of ICE versus without ICE and 12 studies were included. Sensitivity analyses limiting studies to ablation with the use of contact force (CF) catheters were conducted and subgroup analyses were performed according to the published year. In main analyses, RF ablation with ICE for treatment of AF was associated with significant reduction in total X-ray time (mean difference [MD], -9.80; 95% confidence interval [CI], -15.57 to -4.04; I2 = 99%; p < .01), total procedure time (MD, -17.65; 95% CI, -30.22 to -5.09; I2 = 89%; p < .01), and complications (relative risk [RR], 0.90; 95% CI, 0.87-0.92; I2 = 20%; p < .01) versus without ICE. The ICE-guided group tended to decrease total absorbed X-ray dose (standardized mean difference, -0.91; 95% CI, -1.86 to 0.04; I2 = 96%; p = .06). Freedom from arrhythmia (RR, 1.06; 95% CI, 0.98-1.14; I2 = 0%; p = .13) was comparable between the two groups. In patients with AF, ICE-guided RF ablation is correlated with significant reductions in total X-ray time, total procedure time, and complications versus ablation without ICE. Total absorbed X-ray dose tends to reduce in the ICE group and freedom from arrhythmia is comparable between the two groups.

Independent factors of low radiation dose during atrial fibrillation ablation with cryoballoon or radiofrequency: Results from the “Go for zero fluoroscopy” registry

AbstractAimsAtrial fibrillation (AF) catheter ablation is a common procedure requiring in most cases the use of fluoroscopy. We aimed to evaluate the factors associated with a lower dose of fluoroscopy used during AF ablation with cryoballoon or radiofrequency.MethodsIn this prospective European registry, centers were requested to provide procedural characteristics of consecutive AF ablation cases. Lower doses of fluoroscopy were defined as those with dose‐area‐product (DAP) under the median dose used in the radiofrequency and the cryoballoon ablation groups.ResultsA total of 638 AF ablation procedures were collected (n = 492 for radiofrequency and n = 146 for cryoballoon ablation groups) in 25 centers. The median [IQR] DAP were 926 [349;2092] and 1516 [418;3408] cGy*cm2 in the radiofrequency and cryoballoon groups, respectively. Main factors associated with lower DAP in cryoballoon ablation group were electrophysiology dedicated laboratory (OR 6.04, 95%CI 1.16–31.54; P = .03) and frequent dosimetry report (OR 21.39, 95%CI 5.43–98.54; P = .03). Main factors associated with lower DAP in the radiofrequency ablation group were the use of a chest dosimeter (OR 12.57, 95% CI 2.88‐54.90; P = .01), biplane X‐ray equipment (OR 3.12, 95%CI 1.89‐5.16; P &lt; .01), university hospital (OR 2.10, 95%CI 1.35‐3.25; P = .01), electrophysiology dedicated laboratory (OR 2.45, 95%CI 1.48‐4.05; P &lt; .01) and use of contact force enabled catheter (OR 22.60, 95%CI 6.82‐74.88; P &lt; .01).ConclusionThis real‐life study of fluoroscopy use during AF ablation provides new data about current practices across European countries. Technological advances and quality of the fluoroscopic environment were the main factors associated with lower radiation dose during AF ablation.

Simple periprocedural precautions to reduce Doppler microembolic signals during AF ablation

BackgroundDoppler microembolic signals (MES) occur during atrial fibrillation ablation despite of permanent flushed transseptal sheaths, frequent controls of periprocedural coagulation status and the use of irrigated ablation cathetersPurposeTo investigate the number and type of MES depending on the procedure time, prespecified procedure steps, the activated clotting time (ACT) during the ablation procedure and the catheter contact force.MethodsIn a prospective trial, 53 consecutive atrial fibrillation patients underwent pulmonary vein isolation by super-irrigated “point-by-point” ablation. All patients underwent a periinterventional, continuous transcranial Doppler examination (TCD) of the bilateral middle cerebral arteries during the complete ablation procedure.ResultsAn average of 686±226 microembolic signals were detected by permanent transcranial Doppler. Thereby, 569±208 signals were differentiated as gaseous and 117±31 as solid MES. The number of MES with regard to defined procedure steps were as follows: gaseous: [transseptal puncture, 26 ± 28; sheath flushing, 24±12; catheter change, 21±11; angiography, 101±28; mapping, 9±9; ablation, 439±192; protamine administration, 0±0]; solid: [transseptal puncture, 8±8; sheath flushing, 9±5; catheter replacement, 6±6; angiography, not measurable; mapping, 2±5; ablation, 41±22; protamine administration, 0±0]. Significantly less MES occurred with shorter procedure time, higher ACT and the use of tissue contact force monitoring.ConclusionThe current study demonstrates that during atrial fibrillation ablation using irrigated, “point-by-point” RF ablation, masses of microembolic signals are detected in transcranial ultrasound especially in the period of RF current application. The number of MES depends on the total procedure time and the reached ACT during ablation. The use of contact force monitoring might reduce MES during RF ablation.

Esophago-pericardial fistula after catheter ablation of atrial fibrillation: A review.

Much have been reported about esophago-left atrium fistula. However, esophago-mediastinal fistula, not reaching the left atrium, has not been studied as a different clinical entity, with different management. We review and discuss the literature of esophago-mediastinum fistula after catheter ablation for atrial fibrillation with emphasis on the following points: the timing of its occurrence after ablation; the mechanisms and localization of the fistula; and its natural history. We showed that esophageal stenting was associated with a better outcome in patients with esophagus-mediastinal fistula, introduced the concept of left atrial wall weakening during ablation, and suggest a possible role of contact force use in fistula formation.

P968Impact of contact force sensing catheters on fluoroscopy time in left-sided atrial procedures

Abstract Funding Acknowledgements None. OnBehalf Go for Zero Fluoroscopy Project investigators Background Contact force sensing catheters provide electrophysiologists with direct feedback and therefore improve safety and help to generate more effective lesions. The use of contact force may also reduce fluoroscopy and procedure times. Purpose The aim of this study was to systematically evaluate the impact of using contact force sensing catheters (CFSCs) on fluoroscopy times and procedure times in left-sided atrial procedures. Methods In this multinational, multicenter study, data from 622 left-sided procedures (142 without and 480 with CFSCs) of 25 participating European centers were prospectively collected with a structured questionnaire. Examinations comprised 393 pulmonary vein isolations (PVIs, group 1[G1]), 122 PVIs with linear lesions (group 2[G2]), 65 left-sided accessory pathway ablations (group 3 [G3]) and 42 ablations for left atrial tachycardia (group 4 [G4]). Fluoroscopy and procedure times were compared with respect to the use of CFSCs, procedure type, and level of operator experience as possible confounders. A Mann-Whitney U-test was applied for comparison, and a p-value &amp;lt;0.05 was considered statistically significant. Results With the use of CFSCs, fluoroscopy time was significantly reduced when performing pulmonary vein isolations (G1 median [IQR]: 19 [11.0-33.7] vs. 7.2 [4.0-13.0] min., p &amp;lt; 0.001, G2: 45.3 [34.9-61.8] vs. 7.3 [5.0-14.0], p &amp;lt; 0.001, respectively). For groups G3 and G4, no difference could be detected. Procedure times were shortened for pulmonary vein isolations with additional lesions only (G4: 210 [180-240] vs. 153 [127-200] min., p &amp;lt; 0.001). When assessing the effect of operator experience, all left-sided atrial procedures were combined. Significantly shorter fluoroscopy times with contact force were found at all career levels (early career &amp;lt; 5 years: median -6 min., p = 0.024, mid-career 5-15 years: -15 min., p &amp;lt; 0.001, mentor status with experience &amp;gt; 15 years: -6.5 min., p &amp;lt; 0.001). The use of contact force proved to be especially beneficial in reducing fluoroscopy time in operators performing one to 19 procedures per month (1-9: median -15.8 min., p &amp;lt; 0.001, 10-19: -15.9 min., p &amp;lt; 0.001), whereas it lost its statistical significance when more than 20 procedures per month were performed (20-39: - 3.2 min., p = 0.100, &amp;gt;40: -1.5 min., p = 0.346). Conclusion Contact force sensing catheters can help to reduce fluoroscopy times, especially when performing pulmonary vein isolations. This effect could be demonstrated for all career levels. However, it diminished with the operator"s caseload. A shortening of procedure time was found for PVIs with additional linear lesions.

P1033Cryo-ablation vs radiofrequency ablation: is there a difference between the two technologies - A single centre analysis of the sites pulmonary vein reconnection

Abstract Funding Acknowledgements Nil Introduction Pulmonary vein isolation (PVI) remains the most common initial ablation strategy for management of atrial fibrillation (AF). The two main methods of creating these lesions include cryo-ablation or radiofrequency ablation (RFA). In both methods, gaps in the encircled lesions have the potential to cause recurrences of AF. The aim of this analysis was to determine whether there is a difference in the number of gap lesions when comparing cryoablation to RFA. Methods A retrospective single tertiary centre analysis was performed in 1152 patients who had an AF ablation between January 2015 to June 2019. Patients who required a redo-PVI were included for analysis (n = 155). Demographic (gender, age), clinical (BMI, type of AF, hypertension, DM, left atrial volume) and procedural (PVI method, fluoroscopy time, procedural time) data was collected. For the redo cases, the number of gap lesions by region were analysed by looking at electromechanical maps to determine where the most common gaps occurred for both technologies Results A total of 155 redo procedures (Cryo-RF, n= 46, RF-RF, n = 109) were analysed. There was no statistically significant difference or linear correlation between being obese and number of gaps in the cryo-RF or RF-RF group (R = -0.042, p = 0.351, R = 0.153, p = 0.110 respectively). The total number of gaps in the in the Cryo-RF group = 232 and RF-RF group = 564. There was no significant difference between the two groups (p = 0.963). There was no significant difference or correlation between the use of contact force and the number of gaps in the RFA group (p = 0.644, R = -0.045). Conclusion Each of these PVI technologies have previously been found to be effective in treating AF. Avoiding gaps during PVI remains challenging. This retrospective analysis has demonstrated that overall there is no difference in the number of gap lesions that occur after using either of these current ablation technologies. Cryo-RF vs RF-RF: group comparison CRYO-RF (n = 46) RF-RF (n = 109) P Value Male (%) 28 (60.1) 80 (73) 0.197 Age at 2nd procedure (mean +/- SD) 61.5 +/- 8.9 59.8 +/- 11.6 0.008 Time between procedures (days - mean +/- SD) 497.5 +/- 228.2 1007.7 +/- 924.8 &amp;lt;0.001 Obese (%) 17 (37) 58 (53) 0.073 LA volume (ml/m2 - mean +/- SD) 59.6 +/- 23 57 +/- 26 0.996 Contact force used in index procedure (%) 68 (62) 0.644 Total number of gaps 232 564 0.963 Table representing difference between and significance level for Cryo-RF and RF-RF groups.

P2862Complementary use of contact force and local catheter impedance during RF ablation reduces ablation time in an in vivo swine model

Abstract Catheter-tissue coupling is crucial for effective delivery of radiofrequency (RF) energy during catheter ablation. Force sensing catheters provide a metric of mechanical tissue contact and catheter stability, while local impedance has been shown to provide sensitive information on real-time tissue heating. The complementary use of force and local impedance during RF ablation procedures could provide an advantage over the use of one metric alone. This study evaluates a prototype ablation catheter that measures both contact force (CF) using inductive sensors and local catheter impedance (LI) using only catheter electrodes. The complementary nature was assessed with discrete lesions in vitro and an intercaval line in vivo. A force-sensing catheter with LI was evaluated in explanted swine hearts (n=14) in an in vivo swine model (n=9, 50–70kg) using investigational electroanatomical mapping software. In vitro, discrete lesions were created in ventricular tissue at a range of forces (0–40g) controlled externally. RF energy was applied at a range of powers (20W, 30W, and 40W), durations (10s-60s), and catheter orientations (0°, 45°, and 90°). Lesions were stained with TTC and measured. LI drop relative to baseline during RF in the bench studies was used to inform the in vivo study. In a separate subset of animals in vivo, an intercaval line was created in three experimental groups: LI blinded, 20Ω ΔLI, and 30Ω ΔLI. CF was maintained between 15 and 25g in all groups. All ablations were performed with a power of 30W. In the LI blinded group, all lesions were delivered for 30s. In the 20Ω ΔLI group, the investigator ablated until a 20Ω drop or 30 seconds was achieved. Likewise, in the 30Ω ΔLI, the investigator ablated until a 30Ω drop or 30 seconds was achieved. In vitro, 137 discrete ventricular lesions were created. LI drop during ablation correlated strongly with lesion depth using a monoexponential fit (R=0.84) while force time integral (FTI) did not correlate as strongly (R=0.56). In the intercaval LI blinded group, starting LI ranged from 126–163Ω with a median of 138Ω. LI drops ranged from 13Ω-44Ω, with a median of 26Ω. In the 20Ω ΔLI group, starting LI ranged from 137–211Ω with a median of 161Ω and LI drop ranged from 7Ω-35Ω, with a median of 22Ω. In the 30Ω ΔLI group, starting LI ranged from 130–256Ω with a median of 171Ω and LI drop ranged from 20Ω-52Ω, with a median of 31Ω. Notably, RF time for the LI blinded group was 13±0.1 minutes while RF time in the 20Ω ΔLI group was 6.4±1.9 minutes and 7.5±0.7 minutes in the 30Ω ΔLI group. A catheter incorporating CF-sensing and LI capabilities provides a powerful tool for RF ablation. Bench studies demonstrate a strong correlation between LI drop and lesion dimensions, which guided the use of LI in vivo. In vivo, the confirmation of stable mechanical contact and viewing of real-time LI drops enabled a significant reduction in RF time while creating a continuous intercaval line. Acknowledgement/Funding This study was funded by Boston Scientific.

Comparison of high‐power short‐duration (HPSD) ablation of atrial fibrillation using a contact force‐sensing catheter and conventional technique: Initial results

Atrial fibrillation (AFib) ablation is alternative treatment to drugs. Literature suggests that use of contact force (CF) catheter with higher power for short periods is effective and safe. Retrospectively analyzed 76 patients undergoing the first ablation. Third five patients-group A: 27 (77%) paroxysmal AFib (PAFib) and 8 (23%) persistent AFib (PersAFib) who underwent ablation at the power of 30 W-17 mL/minute flow with a CF of 10-30 g for 30 seconds. Fourty one patients-group B: 28 (68.3%) PAFib and 13 (31.70%) PersAFib underwent ablation using 45 W on posterior wall with CF of 8/15 g, as well as 50-W anterior wall with CF of 10/20 g-35 mL/minute flow for 6 seconds. Pulmonary vein isolation in both groups and ablated. For patients not in the sinus, we performed cardioversion before ablation. No complications. Group A: Left atrial time 110 ± 29 minutes, total 148 ± 33.6 minutes, radiofrequency time (RF) 4558 ± 1998 seconds, X-ray 8.5 ± 3.5 minutes, and elevation of esophageal temperature (ET) in 26 (74.3%). group B: Left atrial time 70.7 ± 18.5 minutes ( P < .00001), total 106 ± 23 minutes ( P < .00001), RF 1909 ± 675.8 seconds ( P < .00001), X-ray 8.8 ± 6.6 minutes ( P = .221) and elevation of ET in 21 (51.20% - P = .0578). In 6 and 12 months follow-up, we had 9 (25.71%) and 11 (31.42%) recurrences in group A and 5 (12.19%) and 7 (17.07%) in group B ( P = .231 at 6 and P = .14 at 12 months), respectively. HPSD was safe, useful, and efficient compared with CT, and reduced procedural time and total RF time. HPSD may reduce esophageal injury because of lower heating rate and it may reduce the recurrence of atrial tachyarrythmias.

Usefulness of Electroanatomical Mapping with Contact Force Monitoring for Accessory Pathways Ablation in Pediatric Population.

The current approach for catheter ablation (CA) of accessory pathways (AP) includes the use of standard catheters under fluoroscopic visualization. We hypothesize that use of contact force (CF) irrigated tip catheters might increase procedural safety in pediatric patients compared to standard irrigated tip catheters, by decreasing the number of radiofrequency (RF) pulses required to obtain AP elimination. Seventy-one pediatric patients (13.7 ± 2.5years, 45 male) with ventricular pre-excitation were enrolled in the study. CA was performed with a standard irrigated tip catheter up to June 2013 in 41 patients (Group S) and with a CF sensing irrigated tip catheter later on in 30 patients (Group CF). In the Group CF, RF was applied with a minimal CF of 5g; CF > 35g was avoided. Group CF procedures required less fluoroscopy (6.8 ± 4.8min), compared to Group S (12.2 ± 10.8min, p = 0.007). The number of RF pulses was smaller in Group CF compared to Group S (2.5 ± 2.0 vs 5.5 ± 1.9, p < 0.01). The mean CF during the effective RF pulse was 18 ± 7.7g, force-time integral was 1040.7 ± 955.9gs, Ablation Index was 513.0 ± 214.2. The procedure was acutely successful in 70 patients; at 12months follow-up 2 patients had AP recurrence, one for each group. No major complications were reported. The use of CF irrigated tip catheters was associated with a smaller number of RF pulses and less fluoroscopy, as compared to mapping and ablation with standard irrigated tip catheters.

3D Mapping for PVI- Geometry, Image Integration and Incorporation of Contact Force Into Work Flow.

Catheter ablation of atrial fibrillation has evolved enormously thanks to rapid improvement of modern mapping technologies, progress in catheter development and current possibilities for reduction of radiation exposure. Pulmonary vein isolation is thereby the cornerstone in this interventional treatment. Increased precision of catheter localization by modern three-dimensional mapping systems, faster and better processing of local electrograms and their immediate color-based visualization make it possible to treat even challenging arrhythmias very effectively. The commonly used three-dimensional mapping systems CARTO 3 (Biosense Webster, Irvine, Ca.) and Ensite Precision (St. Jude Medical, St. Paul, Min) differ in construction and principles of the underlying mapping technology. In this review article, we aim to emphasize the most important aspects of possibilities that make both systems so valuable for interventional treatment of atrial fibrillation. We present a modern workflow, that unites three-dimensional LA mapping with collecting relevant local information, image integration for refining the map and beneficial use of contact force based ablation approach.

P370Impact of intraprocedural electrical cardioversion and the use of contact force sensing catheters on atrial fibrillation recurrences after pulmonary vein isolation: a single centre experience

P370Impact of intraprocedural electrical cardioversion and the use of contact force sensing catheters on atrial fibrillation recurrences after pulmonary vein isolation: a single centre experience

Atrial fibrillation patients with isolated pulmonary veins: Is sinus rhythm achievable?

The cornerstone of atrial fibrillation (AF) ablation is isolation of the pulmonary veins (PVs). Patients with recurrent AF undergoing repeat ablation usually have PV reconnection (PVr). The ablation strategy and outcome of patients undergoing repeat ablation who have persistent isolation of all PVs (PVi) at the time of repeat ablation is unknown. We studied consecutive patients with recurrent AF undergoing repeat ablation and compared patients with PVi to those with PVr. One hundred fifty-two patients underwent repeat ablation, and of these, 25 patients (16.4%) had PVi. Patients with PVi underwent ablation targeting any isoproterenol induced AF triggers, atrial substrate, or inducible atrial tachycardias or flutters. Patients with PVi compared to PVr were more likely to have a history of persistent AF (64% vs. 26%; P < 0.0001), obesity (BMI 30.4 vs. 28.2; P = 0.05), and prior use of contact force sensing catheters (28% vs. 0.8%, P < 0.0001). After a mean follow-up of 19 ± 15 months, 56% of PVi patients remained in sinus rhythm compared to 76.3% of PVr patients (P = 0.036). In a multivariable model, PVi patients and those with cardiomyopathy had a higher risk of recurrent atrial tachyarrhythmias (HR = 3.6 95%, CI 1.6-8.3, P = 0.002 and HR = 6.2, 95% CI 2.3-16.3, P < 0.0001, respectively). In patients who have all PVs isolated at the time of the redo AF ablation, a strategy of targeting non-PV AF triggers and inducible flutters can still lead to AF freedom in more than half of patients. Patients with PVr, however, have a better long-term outcome.

GW27-e0198 A Meta-Analysis of the Comparative Efficacy and Safety of Ablation for Atrial Fibrillation With the Use of Contact Force Sensing Catheter and second-generation Cryoballoon

This meta-analysis aimed to compare the efficacy and safety of the CF-sensing catheter and second-generation cryoballoon (CB) ablation in treating AF. The randomized controlled trials (RCTs) or controlled clinical trials (CCTs) comparing the ablation for AF using a CF-sensing catheter or second-

56-11: The impact of simple protocol changes in improving safety of Catheter Ablation for Atrial Fibrillation: experience from a tertiary centre in England

Introduction: Historically, AF ablation (AFA) has been associated with a significant risk of complications. While there have been several recent advances aimed at improving success rates, little data exist on ways to improve procedural safety. Methods: In 2011, we put into place simple processes aimed to make AFA safer, including mandating use of vascular ultrasound to guide femoral vein access, avoiding use of bridging heparin peri-procedure, and using contact force sensing catheters for AFA. Electronic Patient Record System was used to prospectively capture procedural data and clinical events on follow up. The incidence of complications in 561 consecutive AFAs performed from 2011-2013 (Group 1) was compared with 327 consecutive AFAs between 2009-2011 (Group 2). In addition, follow up data were evaluated for the 406 consecutive first time AFA patients amongst Group 1, including 267 (65.7%) paroxysmal AF (PAF), and 139 (34.2%) persistent AF (PeAF). 95% cases were performed using contact force sensing RF catheters with Carto mapping. Results: The two groups were similar in baseline characteristics. The incidence of major and minor complications in Group 1 was significantly lower than in Group 2, Table 1, P = 0.02. 1/561 complication required vascular or surgical intervention in Group 1 as compared to 4/327 in Group 2, P = 0.04. Follow up was available for 400/406 (98.5%) first time AFAs over a mean of 20 ± 10 months. Clinical success for PAF was 55% after single procedure and 86% after a mean 1.3 (1-4) procedures and for PeAF was 42% after single procedure and 74% after a mean 1.4 (1-3) procedures. 60 (15%) of the patients were on antiarrhythmic drugs at last follow up, compared to 279/400 (70%) at time of AFA. Conclusions: With mandated use of ultrasound to guide vascular access, predominant use of contact force sensing catheters and by avoiding bridging therapy, complication rates for AFA have decreased markedly, in particular those needing surgical intervention.

GW26-e4736 A Meta-Analysis of the Comparative Efficacy and Safety of Ablation for Paroxysmal Atrial Fibrillation With and Without the Use of Contact Force Sensing Catheter

GW26-e4736 A Meta-Analysis of the Comparative Efficacy and Safety of Ablation for Paroxysmal Atrial Fibrillation With and Without the Use of Contact Force Sensing Catheter

Use of contact force sensing technology during radiofrequency ablation reduces recurrence of atrial fibrillation: A systematic review and meta-analysis

The suboptimal outcomes of atrial fibrillation (AF) ablation have been attributed to lack of transmural lesions during pulmonary vein isolation. The advent of contact force (CF) sensing technology enables real-time assessment of the applied force at the catheter-tissue interface and increases the chances of transmural lesions. We sought to perform a meta-analysis of data from eligible studies to delineate the true impact of CF technology. Database searches through April 2015 identified 9 eligible studies (enrolling 1148 patients). The relative risk of AF recurrence at follow-up was used as the primary end point and assessed with random-effects meta-analysis. Radiofrequency (RF) duration, total procedure length, and fluoroscopy exposure were assessed as secondary outcomes using weighted mean difference with the random-effects model. Compared with standard technology, the use of CF technology showed a 37% reduction (relative risk 0.63; 95% confidence interval 0.44-0.91; P = .01) in AF recurrence at a median follow-up of 12 months and a 7.3-minute reduction (95% confidence interval -14.05 to -0.55; P = .03) in RF use during ablation. There was no significant difference in total procedure length and fluoroscopy exposure between the 2 groups. In conclusion, this meta-analysis shows that the use of CF technology decreases AF recurrence at a median follow-up of 12 months and also led to decreased use of RF during ablation. There was no difference in total procedure length and fluoroscopy exposure.

PALPATION OF INTRA-CARDIAC BLOOD FLOW, PRESSURE, CONTACT FORCE AND MOTOR REACTION TIME OF SUBJECTS USING A NOVEL HAPTIC FEEDBACK SYSTEM

SMART AF showed that consistent contact during ablation improves pulmonary vein (PV) isolation but use of contact force (CF) displays led to a 2.5% risk of tamponade and required procedural, ablation, fluoroscopy times of 3.7 +/- 1.4 h, 2.0 +/- 1 h and 41.5 +/- 26 min. When the HRS Consensus

30 * Use of a contact force sensing catheter with advanced catheter location significantly reduces fluoroscopy time and radiation dose in catheter ablation of atrial fibrillation

Background: The aim of this study was to evaluate the ‘real-world’ impact of a novel contact force-sensing catheter (SmartTouch, Biosense Webster, USA) coupled with an advanced catheter location system (ACL) which essentially allows visualisation of the catheter shaft and hence orientation. The impact of this technology on procedure time, fluoroscopy time and fluoroscopy dose was assessed for cathter ablation of atrial fibrillation (AF). Methods: This was an observational cohort study of prospectively collected data for 1441 consecutive patients undergoing paroxysmal (PAF) and persistent AF (PerAF) ablation at a single institution between 2009 and 2014. All procedures involved pulmonary vein isolation, with additional targeting of fractionated potentials and/or linear ablation for persistent AF. Patients undergoing AF ablation with the SmartTouch catheter and ACL (SmartTouch group, n=510) were compared to those undergoing AF ablation without this technology (Control group, n=1005). The primary outcomes were fluoroscopy time (min) and fluoroscopy dose as measured by dose area product (mGycm2). Secondary endpoints included procedure time, total ablation time, and major cardiac complications (focusing on sequelae of cardiac perforation i.e. tamponade). Results: The SmartTouch group had significantly lower fluoroscopy times (9.5 min vs. 41 min, p<0.001), radiation doses (1044 mGycm2 vs. 3571 mGycm2, P<0.001) and shorter procedure time (195min vs. 240min, P<0.001) compared to Controls. This was statistically significant across all sub-groups including both PAF and PerAF ablations and for both de novo and redo AF procedures. To examine whether fluoroscopy times were already reducing due to other technology advancements, the 500 cases were compared before and after the introduction of SmartTouch/ACL. This showed thatfluoroscopy times were already decreasing at a rate of approximately 4-19% per year (P<0.001) before SmartTouch/ACL was introduced. However, after the introduction of the technology, there was a significant 37% reduction in fluoroscopy time in the first 100 SmartTouch procedures (P<0.001) followed by a further 35% reduction in the next 100 consecutive cases (P<0.001), followed by a further 46% decrease in the next 100 cases (P<0.001). Thereafter, the rate of fluoroscopy reduction did not change significantly and fluoroscopy time plateaued with a median fluoroscopy times of 3.5 min (IQR 6) for the final 200 procedures. There was no difference in the rate of cardiac tamponade which was static at approximately 1.5% each year in the study period. Conclusion: Use of SmartTouch contact force sensing catheters with ACL during catheter ablation of AF significantly reduces fluoroscopy times by 77%, radiation dose by 71% and procedural time by 19%, but does not improve overall safety in terms of the risk of tamponade.