Outcome Of Pulmonary Vein Isolation Research Articles

Epicardial adipose tissue and atrial fibrillation: Possible mechanisms, potential therapies, and future directions.

Obesity plays an important role in the pathogenesis of atrial fibrillation (AF). Recently, rather than general fat distribution, epicardial adipose tissue (EAT) gains a growing concern. EAT is the local adipose deposition between myocardium and pericardium. Accumulated evidence revealed several distinguishing characteristics of EAT. It lies contiguously with the myocardium and could infiltration into myocardium, actively secrets cytokines and adipokines mediating inflammation or remodeling, and contains abundant ganglionated plexi. Clinical research also found EAT may be an independent risk factor of AF. Volume or thickness of EAT measured on CT or MRI could be applied as a predictor of presence, severity, and recurrence of AF. Some drugs, like antidiabetic drugs and lipid-lowing drugs, show ability to reduce EAT. Additional surgical ablation of EAT was also proved that it could improve outcome of pulmonary vein isolation for AF. In present review, we summarize recent epidemic, biological, and clinical findings about EAT and its possible role in AF.

P1911The impact of pulmonary vein morphology and orientation on the outcomes of cryoballoon ablation in patients with paroxysmal atrial fibrillation

Abstract Background Circumferential contact of cryoballoon and pulmonary vein (PV) ostium is an important factor for pulmonary vein isolation (PVI). PV ostium shape and orientation can make challenges for PV occlusion. Purpose We aimed to assess the impact of pulmonary vein morphology and orientation on cryoablation outcomes in patients with paroxysmal AF. Material and methods The single-center prospective study included 122 patients (males: 46.7% (57), mean age 57 (53; 62) with drug-refractory paroxysmal AF. The mean AF duration was 4 years (2; 4). A multislice cardiac computed tomography (MSCT) was performed prior to CBA in order to evaluate the PV anatomy (maximal and minimal ostium diameters, ovality of PV ostium, angle of PV orientation in the frontal and axial plane (Figure1)). The presence of typical anatomy (4 separate ostia of PVs) was inclusion criteria. Procedures were performed with 28-mm second generation balloon. A procedural endpoint was the achievement of PVI. Outcomes of PVI were defined as freedom from any AF episodes documented by ECG from the end of blanking period to 12 months. Results PVI was achieved in 97.5% of PVs (476/488). Freedom from AF was 78.7%. Difficult occlusion of right inferior PV was observed in 12 patients and associated with a more horizontal PV orientation in the frontal plane: −15.2±6.20 versus −26.5±6.3°, p<0.001. A total of 11 (9%) patients experienced transient phrenic nerve injury (PNI) during ablation of right superior PV (RSPV). PNI was associated with the maximum and minimum diameter of the RSPV 20.0–24.0 mm (OR=13,2; 95% CI: 3.4–51; p<0.05) and 17.5–20.0 mm (OR=12.5; 95% CI: 4.7–41.9; p<0.05), respectively. Patients with AF recurrence had significantly larger maximum and minimum diameters of left superior PV (LSPV): 18.8 versus 17.5 mm, p=0.048, and 13.4 versus 12.5 mm, p=0.05, respectively. Ovality of PV ostium was larger in the recurrence group: 0.36 versus 0.18, p=0.05. Figure 1. Evaluation of PV orientation Conclusions Evaluation of PV morphology and orientation can be used to predict CBA results. AF recurrence was associated with larger diameters and ovality of LSPV ostium. More horizontal RIPV orientation was associated with difficult PV occlusion. RSPV morphology can affect safety of procedure.

P1920Long-term outcomes of pulmonary vein isolation using second-generation cryoballoon during atrial fibrillation ablation: A single-center large-scale study

Abstract Background Currently available second-generation cryoballoon (CB2) is accepted as an effective and safe tool for pulmonary vein isolation (PVI). Although much more data exists about 1-year outcomes of CB2 ablation, data on long-term outcomes are scarce. Objective: We aimed to assess the long-term outcomes of PVI using CB2 in a large-scale symptomatic AF population at our tertiary referral center. Methods In this non-randomized prospective observational study, a total of 486 patients with paroxysmal (71%) or persistent (29%) AF who underwent index PVI using CB2 at our hospital between January 2013 and June 2017 were enrolled. Atrial tachyarrhythmia (ATa) free survival was defined as absence of AF, atrial flutter or atrial tachycardia recurrence >30 s following 3-months blanking period. Predictors of recurrence were evaluated by univariate and multivariate Cox proportional hazards regression models. Results Acute procedural success rate was 99.8% (1898/1902 PVs). Mean procedural and fluoroscopy time were 64.9±9.2 and 12.1±2.6, respectively. At median 39 (IQR: 26–56) months follow-up, ATa free survival was 78.6% after a single procedure (280/345 [81.2%] for paroxysmal AF vs 102/141 [72.3%] for persistent AF, p=0.019) and 84.4% after a mean 1.48±0.42 ablations.Cox regression analysis showed that left atrium diameter, duration of AF history and early ATa recurrence were found as the independent predictors of late recurrence. PNP was observed in 17 (3.5%) patients. Figure 1 Conclusions Second-generation CB based PVI is effective to maintain sinus rhythm in a significant proportion of paroxysmal and early persistent AF patients with an acceptable complication rates at long-term follow-up.

P1918Comparison of the clinical outcome of pulmonary vein isolation with cryoballoon and radiofrequency ablation for atrial fibrillation with pulmonary vein triggers

Abstract Background Pulmonary vein isolation (PVI) using radiofrequency (RF) or cryoballoon (CB) has been an established treatment for atrial fibrillation. PVI using RF is the most common method with a rather complex technique of a point-by-point tissue heating and navigation of electro-anatomical-guided mapping system, and PVI with CB is also the common method with a relatively simple technique of freezing balloon occlusion. These 2 types of ablation are comparable in terms of the efficacy of the PVI procedure. Purpose The data on the clinical outcome of each AF type with PV triggers has been limited. We compared the outcome of success rate between RF and CB group with respect to each AF type, and further assessed the efficacy of pulmonary vein isolation for AF patients with the origin of only PV. Methods A total of 3402 AF patients (age 64±11; 2463 males) underwent initial PVI from May 2009 to July 2018 (PAF: 67%, non-PAF: 37%). Radiofrequency using irrigation-tip catheter was employed to 1796 patients since May 2009 (RF-PAF: 55%, RF-non-PAF: 45%). Second-generation cryoballoon was employed to other 1606 patients since September 2014 (CB-PAF: 81%, CB-non-PAF: 19%). In CB group, PV touch-up ablation with RF was needed for 113 patients (7%) (CB-PAF: 6%, CB-non-PAF: 13%; p<0.001). After PVI, additional ablation for non-PV foci was undergone after the induction by using isoproterenol infusion and rapid atrial pacing (RF-AF: 34%, CB-AF: 32%; p=0.107). Results In all PAF patients, AF free survival rate was significantly superior in CB group (2-years Kaplan-Meir event rate, CB 83.2%, RF 75.2%; log-rank p<0.001). The percentage of patients with non-PV foci was almost equivalent in both group (CB 30%, RF 31%, p=0.644). And in PAF patients with only PV-foci, AF free survival rate was significantly superior in CB group (2-years Kaplan-Meir event rate, CB 85.0%, RF 78.8%; log-rank p<0.001). On the other hand, in all non-PAF patients, AF free survival rate was almost equivalent in both non-PAF group (2-years Kaplan-Meir event rate, CB 65.5%, RF-non-PAF 70.0%; log-rank p=0.9). The percentage of patients with non-PV foci was almost equivalent in both group (CB 40%, RF 39%, p=0.731), And in non-PAF patients with only PV-foci, AF free survival rate was almost equivalent in both non-PAF group (2-years Kaplan-Meir event rate, CB 69.7%, RF 73.0%; log-rank p=0.376). Conclusions Our study showed better outcome of PVI with CB for PAF patients with PV triggers, and indicated the non-inferiority of PVI with CB for non-PAF patients with PV triggers to PVI with RF.

Catheter Ablation for Atrial Fibrillation in Patients with Hemophilia or von Willebrand Disease

Background Management of atrial fibrillation (AF) is complex in patients with bleeding disorders. Catheter ablation such as pulmonary vein isolation (PVI) has been suggested in cases with bleeding disorders. However, data on safety are missing. This report describes the outcome of PVI in patients with bleeding disorders. Methods A retrospective study in our hemophilia treatment center of patients who underwent a PVI in 2014 to 2018. PVI was done according to local protocol. Clotting factor was given periprocedural. Postprocedural anticoagulation was given for at least 4 weeks, with clotting factor suppletion if needed to maintain factor VIII (FVIII) levels >0.20 IU/mL. Results and Discussion Five patients with hemophilia and one with von Willebrand disease were included. Eight PVIs were performed. Target FVIII levels (>0.80 IU/mL) were met before the procedure. Postprocedural anticoagulation was given: vitamin K antagonist (VKA) or direct oral anticoagulant (DOAC) dabigatran. All patients obtained long-term sinus rhythm, in two patients after a second PVI. However, late recurrent AF occurred in one patient after 42 months. A notable incidence of groin bleeds was observed: two of eight interventions (25%) compared with 0.9% in the general population. Bleeding seemed to be related to agitation, early mobilization, and bridging of VKA with low molecular weight heparin (LMWH). No relevant bleeding was observed when on DOAC therapy. Conclusion PVI seems to be effective in the case of bleeding disorders. To reduce the groin bleeds agitation and early mobilization should be avoided and DOAC is preferred over bridging VKA with LMWH.

Earliest pulmonary vein potential-guided cryoballoon ablation for atrial fibrillation.

No studies have evaluated both the time-to-isolation (TTI) and the sequence of pulmonary vein (PV) potentials in cryoballoon ablation (CBA) for atrial fibrillation (AF). This study aimed to prospectively evaluate the acute results of pulmonary vein isolation (PVI) using a novel CBA technique-the earliest potential (EP) of PV-guided CBA-in paroxysmal AF. We pressed a balloon against the earliest PV potential site during PVI when TTI could not be achieved within 60s (EP-guided CBA group). We compared 32 patients consecutively treated by EP-guided CBA to 32 patients treated without pressing the balloon against the EP site (conventional CBA group). The cryoapplication protocol was the same, except with regard to the pressing of the balloon. All 256 PVs (EP-guided CBA group, 128 PVs; conventional CBA group, 128 PVs) were isolated successfully. The TTI observation rate was similar in both groups. Compared with conventional CBA, EP-guided CBA was associated with a lower non-success rate of TTI ≤ 90s (9% vs. 26%; P = 0.040) and shorter left atrial dwell time (38 ± 9 vs. 46 ± 19min; P = 0.036), total procedure time (76 ± 15 vs. 87 ± 23min; P = 0.043), and fluoroscopy time (23 ± 8 vs. 30 ± 11min; P = 0.006). This novel EP-guided CBA approach may help facilitate the ablation procedure.

Long-term outcomes of pulmonary vein isolation using second-generation cryoballoon during atrial fibrillation ablation.

Currently available second-generation cryoballoon (CB2) is accepted as an effective and safe tool for pulmonary vein isolation (PVI). Although much more data exist about 1-year outcomes of CB2 ablation, data on long-term outcomes are scarce. We aimed to assess the long-term outcomes of PVI using CB2 in a large-scale symptomatic atrial fibrillation (AF) population at our tertiary referral center. In this nonrandomized prospective observational study, a total of 486 patients with paroxysmal (71%) or persistent (29%) AF who underwent index PVI using CB2 at our hospital between January 2013 and June 2017 were enrolled. Atrial tachyarrhythmia (ATa)-free survival was defined as the absence of AF, atrial flutter, or atrial tachycardia recurrence ≥30 s following a 3 months blanking period. Predictors of recurrence were evaluated by univariate and multivariate Cox proportional hazards regression models. Acute procedural success rate was 99.8% (1898/1902 PVs). Mean procedural and fluoroscopy time were 64.9 ± 9.2 and 12.1 ± 2.6, respectively. At median 39 (interquartile range: 26-56) months follow-up, ATa-free survival was 78.6% after a single procedure (280/345 [81.2%] for paroxysmal AF vs. 102/141 [72.3%] for persistent AF, P = .019) and 84.4% after a mean 1.48 ± 0.42 ablations. Cox regression analysis showed that left atrium diameter, duration of AF history, and early ATa recurrence were found as the independent predictors of late recurrence. Phrenic nerve palsy was observed in 17 (3.5%) patients. CB2-based PVI is effective to maintain sinus rhythm in a significant proportion of paroxysmal and persistent AF patients with an acceptable complication rate at long-term follow-up.

Shorter cryoballoon applications times do effect efficacy but result in less phrenic nerve injury: Results of the randomized 123 study.

BackgroundThe second‐generation cryoballoon significantly improves outcome of pulmonary vein isolation (PVI) but may cause more complications than the first generation. Currently, no consensus regarding optimal cryoballoon application time exists. The 123‐study aimed to assess the minimal cryoballoon application duration necessary to achieve PVI (primary endpoint) and the effect of application duration on prevention of phrenic nerve injury (PNI).MethodsPatients <75 years of age with paroxysmal atrial fibrillation, normal PV anatomy, and left atrial size <40 cc/m² or <50 mm were randomized to two applications of different duration: “short,” “medium,” or “long.” A total of 222 patients were enrolled, 74 per group.ResultsDuration per application was 105 (101‐108), 164 (160‐168), and 224 (219‐226) s and isolation was achieved in 79, 89, and 90% (P < 0.001) of the PVs after two applications in groups short, medium, and long, respectively. Only for the left PVs, the success rate of the short group was significantly less compared to the medium‐ and long‐duration groups (P < 0.001). PNI during the procedure occurred in 19 PVs (6.5%) in the medium and in 20 PVs (6.8%) in the long duration groups compared to only five PVs (1.7%) in the short duration group (P < 0.001).ConclusionsShort cryoballoon ablation application times, less than 2 min, did affect the success for the left PVs but not for the right PVs and resulted in less PNI. A PV tailored approach with shorter application times for the right PVs might be advocated.

Clinical impact of insulin resistance on pulmonary vein isolation outcome in patients with paroxysmal atrial fibrillation.

Therelationship between insulin resistance and atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) remains unclear. Drug-refractory 114 paroxysmal AF patients (89 males, 62 ± 8 years) who underwent successful PVI were enrolled. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculatedand a value of ≥2.5 was defined as insulin resistant. The left atrial volume index (LAVI) was measured using echocardiography before and 1 year after PVI. Tumor necrosis factor-α (TNF-α) and TGF-β1 serum levels were measured before PVI, and the left atrium (LA) conduction velocity was calculated. The patients were divided into two groups (group 1: HOMA-IR < 2.5, n = 81; group 2: HOMA-IR ≥ 2.5, n = 33). The LAVI between the two groups before PVI did not significantly differ (P > 0.05), nor did TNF-α (7.7 ± 2.0 vs 7.5 ± 1.0 pg/mL; P = 0.149) or TGF-β1 (28.4 ± 12.0 vs 27.6 ± 10.3 ng/mL; P = 0.757). LAVI before and 1 year after PVI in each group did not change. The conduction velocity of group 2 was slower than that of group 1 (0.7 ± 0.1 vs 1.1 ± 0.3 m/s, P < 0.001). Kaplan-Meier analysis showed significantly higher AF recurrence in group 2 than that in group 1 ( P = 0.019). Cox multivariable analysis revealed that insulin resistance was an independent predictor of recurrence (hazard ratio 1.287, P = 0.004). Our results suggest that insulin resistance promotes LA electrical remodeling and might be related to AF recurrence after PVI.

Improvement in ejection fraction after cryoballoon pulmonary vein isolation for atrial fibrillation in individuals with systolic dysfunction.

Cryoballoon pulmonary vein isolation (PVI) is commonly used for rhythm control of atrial fibrillation (AF). Data are limited examining the outcomes of cryoballoon PVI in patients with systolic dysfunction. We evaluate the impact of cryoballoon PVI in patients with systolic dysfunction. We evaluated a single-center prospective registry of patients undergoing cryoballoon PVI between 8/2011 and 6/2016. Patients with systolic dysfunction (EF < 55%) between the time of AF diagnosis and their cryoballoon PVI procedure were assessed for AF recurrence at 6months and 1year post-procedure, with a 3-month blanking period. Final analysis included 66 patients with systolic dysfunction undergoing cryoballoon PVI. An AF diagnosis for ≥ 1year prior to PVI was present in 62.1% (n = 41), and 53.0% (n = 35) had systolic dysfunction for ≥ 1year pre-procedure. The proportion of AF-free patients at 1year was 51.5%. Of patients with echocardiograms performed at 1year (n = 43), a greater proportion of individuals without AF recurrence had an improvement in EF of ≥ 10% than in those with AF recurrence (54.2% vs. 25.0%, p = 0.039). Of the patients who had systolic dysfunction at the time of the ablation (EF < 55%), there was a significant increase in EF post-procedure (36.5% pre-procedure vs. 48.3% post-procedure, mean change 11.8%, p < 0.001). In patients with systolic dysfunction, cryoballoon PVI provides an acceptable AF recurrence-free rate at 1year. AF recurrence-free individuals were more likely to have improvement in EF. Further evaluation is needed to determine the potential role of early cryoballoon PVI in patients with a new diagnosis of systolic dysfunction and AF.

Single-Procedure Outcomes and Quality-of-Life Improvement 12MonthsPost-Cryoballoon Ablation in Persistent Atrial Fibrillation: Results From the Multicenter CRYO4PERSISTENT AF Trial.

The CRYO4PERSISTENT AF (Cryoballoon Ablation for Early Persistent Atrial Fibrillation) trial aims to report long-term outcomes after a single pulmonary vein isolation (PVI)-only ablation procedure using the second-generation cryoballoon in persistent atrial fibrillation (PerAF) patients. Pulmonary vein isolation is recognized as the cornerstone of atrial fibrillation (AF) ablation, including ablation of PerAF. The CRYO4PERSISTENT AF trial (NCT02213731) is a prospective, multicenter, single-arm trial designed to assess single-procedure outcomes of PVI using the cryoballoon. The primary endpoint was freedom from AF, atrial flutter, or atrial tachycardia≥30 s after a 90-day blanking period. After enrollment, but before ablation, patients without 100% AF burden (18-h Holter monitoring or 3 consecutive electrocardiograms in a time frame≥14 days) were excluded. Patients were followed at 3, 6, and 12 months, with 48-h Holter monitoring at 6 and 12 months. Quality of life and symptoms were evaluated at baseline and 12 months. Arrhythmia recurrence and adverse events were adjudicated by an independent committee. A total of 101 patients (62 ± 11 years of age, 74% men, left ventricular ejection fraction 56 ± 8%, left atrial diameter 43 ± 5 mm) meeting criteria, undergoing cryoballoon-based PVI, with follow-up data, were included. Kaplan-Meier estimate of freedom from AF, atrial flutter, or atrial tachycardia recurrence was 60.7% at 12 months. Compared with baseline, there were significantly fewer patients with arrhythmia-related symptoms at 12 months (16% vs. 92%; p<0.0001). The symptom reduction was supported by significant improvement in 36-Item Short Form Health Survey composite scores and European Heart Rhythm Association score at 12 months. The only device related event was transient phrenic nerve injury in 2 (2%) patients, with resolution pre-discharge. Cryoballoon ablation for treatment of PerAF demonstrated 61% single-procedure success at 12 months post-ablation in addition to significant reduction in arrhythmia-related symptoms and improved quality of life. (Cryoballoon Ablation for Early Persistent Atrial Fibrillation [Cryo4 Persistent AF]; NCT02213731).

Surface ECG and intracardiac spectral measures predict atrial fibrillation recurrence after catheter ablation.

Outcome of patients undergoing catheter ablation of atrial fibrillation (AF) varies widely. We sought to investigate whether parameters derived from the spectral analysis of surface ECG and intracardiac AF electrograms can predict outcome in patients referred for pulmonary vein isolation (PVI). We performed spectral analysis on the surface ECG and intracardiac electrograms from patients referred for AF ablation. After filtering and QRST subtraction, we measured the dominant frequency (DF), regularity index (RI) and the organizational index (OI) of fibrillatory electrograms and determined their value for predicting AF recurrence after ablation. A subjective, blinded prediction based on the surface ECG was also performed. We analyzed data from 153 PVI procedures in 140 patients (67.1% with persistent or longstanding AF). In a multivariable model, DF in the right atrium (RA) and distal coronary sinus (CSd)-to-RA DF gradient predicted AF recurrence (OR, 3.52, P = 0.023 and OR, 0.2, P = 0.034, respectively). DF in RA and CSd to RA DF gradient had a good predictive value for PVI outcome (area under the curve [AUC] of 0.73, P = 0.007 and 0.74, P = 0.007, respectively). These performed better than the subjective predictions of experienced electrophysiologists ( P = 0.2). Higher RA DF, lower CSd to RA DF gradient predicted recurrence after AF ablation. These spectral measures suggest a more remodeled atrial substrate and may provide simple tools for risk stratification or predict the need for additional substrate modification in patients referred for AF ablation.

363Long-term outcome of pulmonary vein isolation versus amiodarone therapy in patients with coexistent persistent atrial fibrillation and congestive heart failure

363Long-term outcome of pulmonary vein isolation versus amiodarone therapy in patients with coexistent persistent atrial fibrillation and congestive heart failure

P3824Effects of grid visualization of ablation lesions on procedure times and outcome of pulmonary vein isolation

P3824Effects of grid visualization of ablation lesions on procedure times and outcome of pulmonary vein isolation

First data on cardiac mapping and outcome of pulmonary vein isolation using a novel ablation catheter with tip mini electrodes

AimsPulmonary vein isolation (PVI) is a standard treatment of atrial fibrillation (AF). AF recurrence after PVI occurs in a substantial number of cases. A novel ablation catheter equipped with mini-electrodes (ME) may facilitate PVI. Our study evaluated outcome after PVI with the ME catheter compared to a standard catheter. MethodsPatients undergoing PVI with the ME catheter were compared to a control group ablated with a standard contact force sensing catheter. Freedom of AF after 12 months was the study endpoint. Additionally, low voltage areas (LVA) <0.5 mV were identified with a circular mapping catheter (CMC) and the ablation catheter in each group. LVA were compared between the maps obtained with the CMC and the ME or standard catheter, respectively. ResultsA total of 110 patients underwent PVI with ME catheter (n = 59) or the standard catheter (n = 51). Procedure duration (117.4 ± 43 vs. 103.1 ± 32.8 min, p = 0.15), radiation dose (1135.6 ± 1125.7 vs. 1078.8 ± 951.4 μGy/m2, p = 0.91), incidence of complications and 12-month success rate (64.4 vs 72.5%, p = 0.36) were not significantly different between the groups. LVA were significantly smaller when obtained with the standard catheter compared to the CMC (14 ± 13 vs. 58.5 ± 22.1 cm2, p < 0.001), while no such difference was seen for mapping with the ME compared to the CMC (37 ± 30.3 vs. 33.4 ± 39 cm2, p = 0.4). ConclusionClinical outcomes are comparable between ME catheter and a standard contact force sensing catheter. Furthermore, better LVA detection points to improved mapping capabilities of the ME catheter.

Variability in pulmonary vein electrophysiology and fibrosis determines arrhythmia susceptibility and dynamics.

Success rates for catheter ablation of persistent atrial fibrillation patients are currently low; however, there is a subset of patients for whom electrical isolation of the pulmonary veins alone is a successful treatment strategy. It is difficult to identify these patients because there are a multitude of factors affecting arrhythmia susceptibility and maintenance, and the individual contributions of these factors are difficult to determine clinically. We hypothesised that the combination of pulmonary vein (PV) electrophysiology and atrial body fibrosis determine driver location and effectiveness of pulmonary vein isolation (PVI). We used bilayer biatrial computer models based on patient geometries to investigate the effects of PV properties and atrial fibrosis on arrhythmia inducibility, maintenance mechanisms, and the outcome of PVI. Short PV action potential duration (APD) increased arrhythmia susceptibility, while longer PV APD was found to be protective. Arrhythmia inducibility increased with slower conduction velocity (CV) at the LA/PV junction, but not for cases with homogeneous CV changes or slower CV at the distal PV. Phase singularity (PS) density in the PV region for cases with PV fibrosis was increased. Arrhythmia dynamics depend on both PV properties and fibrosis distribution, varying from meandering rotors to PV reentry (in cases with baseline or long APD), to stable rotors at regions of high fibrosis density. Measurement of fibrosis and PV properties may indicate patient specific susceptibility to AF initiation and maintenance. PV PS density before PVI was higher for cases in which AF terminated or converted to a macroreentry; thus, high PV PS density may indicate likelihood of PVI success.

The best of two worlds? Pulmonary vein isolation using a novel radiofrequency ablation catheter incorporating contact force sensing technology and 56-hole porous tip irrigation.

This study aimed to evaluate feasibility and safety as well as 1-year clinical outcome of pulmonary vein isolation (PVI) using a unique radiofrequency ablation catheter ("Thermocool SmartTouch SurroundFlow"; STSF) incorporating both, contact force (CF) sensing technology and enhanced tip irrigation with 56 holes, in one device. A total of 110 patients suffering from drug-refractory atrial fibrillation underwent wide area circumferential PVI using either the STSF ablation catheter (75 consecutive patients, study group) or a CF catheter with conventional tip irrigation ("Thermocool SmartTouch", 35 consecutive patients, control group). For each ablation lesion, a target CF of ≥ 10-39g and a force time integral (FTI) of > 400 gs was targeted. Acute PVI was achieved in all patients with target CF obtained in > 85% of ablation points when using either device. Mean procedure time (131.3 ± 33.7min in the study group vs. 133.0 ± 42.0min in the control group; p = 0.99), mean fluoroscopy time (14.0 ± 6 vs. 13.5 ± 6.6min; p = 0.56) and total ablation time were not significantly different (1751.0 ± 394.0 vs. 1604.6 ± 287.8s; p = 0.2). However, there was a marked reduction in total irrigation fluid delivery by 51.7% (265.52 ± 64.4 vs. 539.6 ± 118.2ml; p < 0.01). The Kaplan-Meier estimate 12-month arrhythmia-free survival after the index procedure following a 3-month blanking period was 79.9% (95% CI 70.4%, 90.4%) for the study group and 66.7% for the control group (95% CI 50.2%, 88.5%). This finding did not reach statistical significance (p = 0.18). Major complications occurred in 2/75 patients (2.7%; one pericardial tamponade and one transient ischemic attack) in the study group and no patient in the control group (p = 18). PVI using the STSF catheter is safe and effective and results in beneficial 1-year clinical outcome. The improved tip irrigation leads to a significant reduction in procedural fluid burden.

Long-term outcomes and predictors of recurrence after pulmonary vein isolation with multielectrode ablation catheter in patients with atrial fibrillation.

Despite various techniques used in atrial fibrillation ablation, recurrence of atrial arrhythmias still constitutes a clinical problem. The aim of this study was to document the long-term outcomes of pulmonary vein isolation with a ring-shaped ablation catheter (PVAC). All consecutive patients presenting with paroxysmal or persistent atrial fibrillation (pxAF or perAF, respectively) treated with PVAC (first generation) were enrolled. After standard follow-up during the first year, all patients were contacted for long-term follow-up. In addition to the patient's medical history, 3-day Holter monitoring was performed. Endpoints were atrial fibrillation-related symptoms, ECG documentation of atrial fibrillation or other left atrial arrhythmias and reablation. In total, 125 patients (78% with pxAF) were enrolled. All but two pulmonary veins (0.4% of 485 pulmonary veins) could be successfully isolated. At 12 months, 83% of patients in the pxAF group and 53% of patients in the perAF group were free from symptoms. The mean long-term follow-up was 51 ± 14 months. Regarding long-term efficacy, 56% of patients in the pxAF group and 28% of patients in the perAF group were free from any recurrence at 72 months. Independent predictors of event-free survival were perAF (hazard ratio 2.76, P = 0.001) and the existence of mild valvular disease (hazard ratio 2.69, P = 0.001). No significant complication due to PVAC occurred, especially no ischemic stroke. Long-term follow-up indicated for the first time in such a considerable cohort that pulmonary vein isolation with PVAC is a safe and very efficient method for treating pxAF - despite known microembolism issues. Patients with perAF receive less benefit from PVAC and ablation therapy should be reserved to pxAF. Significantly, even mild valvular disease was an independent predictor of atrial fibrillation recurrence.

Contact force facilitates the achievement of an unexcitable ablation line during pulmonary vein isolation.

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. A total of 106 patients undergoing PVI were randomized into three groups (G) (G1: target-CF 15g, G2: target-CF 10g, 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 (10V, 2ms) was targeted for further ablation. Mean average CF was 17.4 ± 4.7g (G1) vs. 12.3 ± 6.0g (G2) vs. 11.1 ± 6.5g (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 ± 3.1kJ vs. 8.6 ± 7.2kJ (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 3ns). 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 ± 254day follow-up. Higher tip-to-tissue CF during PVI facilitates the achievement of an unexcitable ablation line, requiring less additional RF-energy.

Long-Term Outcome of Pulmonary Vein Isolation With and Without Focal Impulse and Rotor Modulation Mapping: Insights From a Meta-Analysis.

This meta-analysis systematically evaluated the outcome of pulmonary vein isolation (PVI) with and without focal impulse and rotor modulation (FIRM) ablation in patients with atrial fibrillation. Extensive literature search was performed for studies reporting outcomes of PVI alone and PVI+FIRM procedures. For PVI alone, only randomized trials conducted in the past 3 years reporting single-procedure off-antiarrhythmic drugs success rate at ≥12-month follow-up were included. In PVI+FIRM group, all published studies reporting single-procedure off-antiarrhythmic drugs success rate with at least 1-year follow-up were identified. Meta-analytic estimates were derived using DerSimonian and Laird random-effects models, and pooled estimates of success rate (95% confidence interval) were computed. Statistical heterogeneity was assessed using Cochran Q test and I2. Study quality was assessed using Newcastle-Ottawa Scale. Fifteen trials were included, 10 with PVI+FIRM (n=511, nonrandomized prospective design), and 5 with PVI-only trials (n=295, randomized trials). All patients in PVI-only trials had 100% nonparoxysmal atrial fibrillation, except 1 study, and no prior ablations. About 24% of PVI+FIRM population had paroxysmal atrial fibrillation. After 15.9±5.5 (median 12) months follow-up, the off-antiarrhythmic drugs pooled success rate was 50% in FIRM+PVI (95% confidence interval, 28%-72%) and 58% in PVI (95% confidence interval, 46%-71%). Difference in effect size between groups was not statistically significant (P=0.21). No significant heterogeneity (total or within group) was observed in this meta-analysis (negative I2 values considered equal to zero). The overall pooled estimate did not show any therapeutic benefit of PVI+FIRM approach over PVI alone, which suggests the need to reevaluate the clinical use of FIRM ablation in atrial fibrillation.