Open-irrigated Catheter Research Articles

Efficacy and safety of catheter ablation of atrioventricular nodal re-entrant tachycardia by means of flexible-tip irrigated catheters.

Irrigated-tip ablation catheters increase safety and efficacy of ablation procedures, but their use in atrioventricular nodal re-entrant tachycardia (AVNRT) ablation has not been systematically evaluated. The aim of this study is to evaluate the safety and efficacy of radiofrequency (RF) catheter ablation of AVNRT by means of the novel flexible-tip open-irrigated catheter FlexAbility™ and a 3D electroanatomic mapping (EAM) system. This is a single-center and single-operator study on 80 patients referred for AVNRT catheter ablation. Outcome included acute and long-term procedural success as well as complications reported over a median follow-up of 19months (interquartile range 6-24months). Acute success was achieved in all 80 patients. One procedure-related major complication, involving the vascular access, occurred. Mean fluoroscopy time was 106 ± 71s. One patient (1.2%) suffered long-term AVNRT recurrence. Five patients (6.2%) underwent ablation for AVNRT combined with ablation for other clinical arrhythmias. Irrigated RF ablation of AVNRT by means of the novel flexible-tip open-irrigated catheter associated to 3D EAM system is effective and safe. Success rates are comparable to those of other techniques. Complication rate is very low.

Outcomes of simultaneous unipolar radiofrequency catheter ablation for intramural septal ventricular tachycardia in nonischemic cardiomyopathy

Radiofrequency (RF) ablation of intramural septal ventricular tachycardia (VT) in patients with nonischemic cardiomyopathy (NICM) is challenging. The purpose of this study was to investigate the outcomes of simultaneous unipolar RF ablation for intramural septal VT in NICM. We included patients with NICM and mid-myocardial septal substrate referred for VT ablation. After failed prolonged sequential unipolar RF lesions, simultaneous unipolar RF was delivered using 2 open-irrigated catheters at the site of earliest activation and/or best entrainment or pace mapping and at an anatomically adjacent/opposite site (up to 40 W for up to 3 minutes; RF energy independently titrated for each catheter to achieve an impedance drop of at least 15% from the baseline values). A total of 6 patients (mean age 62±13 years; mean left ventricular ejection fraction 38%±17%) were included. The clinical VTs were mapped at the anterior interventricular septum in 2 (33%) patients and at the inferior septum in 4 (67%). In all patients, prolonged sequential unipolar RF at the best activation/entrainment/pace-mapping site and at an anatomically opposite/adjacent site failed to eliminate VT. In 3 cases (50%), late VT termination with VT reinducibility was observed after sequential unipolar RF. Simultaneous unipolar ablation was then delivered, resulting in VT elimination and noninducibility in all patients. No procedural complications and no steam pops were observed. After a median follow-up of 20 months (range 13-20 months), 4 patients (67%) remained free of VT recurrence. In patients with NICM and intramural septal VT refractory to conventional RF ablation, simultaneous unipolar RF ablation is a safe and effective alternative ablation approach to improve long-term VT control.

Persistent left superior vena cava as an arrhythmogenic source in atrial fibrillation: results from a multicenter experience.

Persistent left superior vena cava (PLSVC) is one of the most frequently reported congenital anomalies and may be an important source of trigger of atrial fibrillation (AF). This was a multicenter retrospective experience including 28 patients with PLSVC who were referred for catheter ablation for drug-refractory symptomatic AF. Pulmonary vein and PLSVC isolation were performed (3.5-mm open irrigated tip ablation catheter at maximum power of 20W, maximum temperature 43°C with flow rate of 17ml/min). Clinical outcomes such as complications and long-term freedom from AF were measured. The mean age of the population was 61 ± 8years, 21% were females, and AF duration was 60 ± 33months. Sixty-one percent paroxysmal AF (17/28), 25% (7/28) persistent AF, and 14% (4/28) had long-standing persistent AF. There were no major complications that required any intervention. PLSVC isolation was achieved in 96% (27/28). Freedom from AF at 1year without antiarrhythmic drugs was seen in 75% (21/28) of patients. In PLSVC patients with AF, segmental isolation of PLSVC appears to be feasible and safe and can translate into favorable clinical outcomes.

Characteristics of Radiofrequency Catheter Ablation Lesion Formation in Real Time InVivo Using Near Field Ultrasound Imaging.

Visualizing myocardium with near field ultrasound (NFUS) transducers in the tip of the catheter might provide an image of the evolving pathological lesion during energy delivery. Radiofrequency (RF) catheter ablation has been effective in arrhythmia treatment, but no technology has allowed lesion formation to be visualized in real time invivo. RF catheter ablations were performed invivo with the goal to create transmural atrial lesions and large ventricular lesions. RF lesion formation was imaged in real time using M-mode, tissue Doppler, and strain rate information from the NFUS open irrigated RF ablation catheter incorporating 4 ultrasound transducers (1 axial and 3 radial), and growth kinetics were analyzed. Nineteen dogs underwent ablation in the right and left atria (n= 185), right ventricle (n=67), and left ventricle (n= 66). Lesions were echolucent with tissue strain rate by NFUS. Lesion growth frequently progressed from epicardium to endocardium in thin-walled tissue. The half time of lesion growth was 5.5 ± 2.8 s in thin-walled and 9.7 ± 4.3 s in thick-walled tissue. Latency of lesion onset was seen in 57% of lesions ranging from 1 to 63.8 s. Tissue edema (median 25% increased wall thickness) formed immediately upon lesion formation in 83%, and intramyocardial steam was seen in 71% of cases. NFUS was effective in imaging RF catheter ablation lesion formation in real time. It was useful in assessing the dynamics of lesion growth and could visualize impending steam pops. It may be a useful technology to improve both safety and efficacy of RF catheter ablation.

Longer Duration Versus Increasing Power During Radiofrequency Ablation Yields Different Ablation Lesion Characteristics.

The goal of this study was to characterize differences in ablation lesions with varying radiofrequency ablation (RFA) power and time. Increasing power delivery or prolonging duration can improve the efficacy of RFA. However, the extent to which ablation lesion characteristics change, based on varying degrees of power and duration, is unknown. An exvivo model consisting of viable bovine myocardium in a circulating warmed saline bath was used. An open irrigated RFA catheter was positioned with 10 g of force in the perpendicular position, and RFA was delivered at powers of 20, 30, 40, and 50 W and for various time intervals, up to a total of 90 s, at each power. An invivo porcine thigh preparation model was used to perform RFA at 50 W for 5 s and 20 W for 30 s. Lesion volumes were analyzed. Greater power delivery and longer radiofrequency time increased ablation lesion size. However, compared with a proportional change in radiofrequency duration, the same proportional increase in power produced a significantly larger lesion volume (p< 0.01). For invivo models, 50 W/5 s ablation lesions yielded similar volumes but significantly less depth than 20 W/30 s ablation lesions. Peak temperatures were not significantly different at 2 and 4 mm with 50 W/5 s versus 20 W/30 s. Varying power and duration will confer different ablation lesion characteristics that can be tailoredaccording to the substrate/anatomy that is being ablated. This phenomenon has important implications during catheter ablation.

Association of preprocedural cardiac magnetic resonance imaging with outcomes of ventricular tachycardia ablation in patients with idiopathic dilated cardiomyopathy

Knowledge of complex arrhythmogenic substrates can help plan ventricular tachycardia (VT) ablation in patients with idiopathic dilated cardiomyopathy (DCM). The purpose of this study was to assess whether preprocedural late gadolinium enhancement magnetic resonance imaging (LGE-MRI) can improve ablation outcomes in DCM. Consecutive patients (N = 96) with idiopathic DCM underwent VT ablation with open-irrigated catheters (2006-2016). Before 2012, LGE-MRI was not performed at our institution in patients with implanted devices, but it has been performed routinely in all patients after implementation of a new MRI protocol in 2012. We retrospectively compared acute and long-term outcomes of initial VT ablation procedures in patients with (n = 41) and those without (n = 55) preprocedural LGE-MRI. Procedural outcome was classified as successful if VT was not inducible postablation. The 2 groups had a similar mean age and ejection fraction, comorbidities, and frequency of epicardial ablation. Preablation LGE-MRI was independently associated with improved procedural success (63% vs 24%) by logistic regression analysis (adjusted odds ratio [OR] 7.86, P <.001). This result was consistent even when patients with nondiagnostic MRIs due to artifact were included in the imaging group (OR 4.87, P = .005). Preablation imaging was also associated with improved survival free of the composite endpoint of VT recurrence, heart transplantation, or death, which was met by 11 (27%) and 33 (60%) patients in the imaging and no imaging groups, respectively, after median 7.6 months of follow-up (unadjusted log-rank P = .02). However, there was no association with long-term outcomes after adjustment for other covariates. Preprocedural imaging with LGE-MRI may be associated with improved outcomes of VT ablation in DCM.

P340The impact of chronic hemodialysis of catheter ablation using open irrigation catheter in patients with atrial fibrillation

P340The impact of chronic hemodialysis of catheter ablation using open irrigation catheter in patients with atrial fibrillation

P857Comparison of pulmonary vein isolation using a laser balloon and using an open irrigated mapping and ablation catheter (nMARQ)

P857Comparison of pulmonary vein isolation using a laser balloon and using an open irrigated mapping and ablation catheter (nMARQ)

P390Comparison of 8-mm and open irrigated tip catheters for cavotricuspid isthmus atrial flutter ablation: results from the FLIGHT study

P390Comparison of 8-mm and open irrigated tip catheters for cavotricuspid isthmus atrial flutter ablation: results from the FLIGHT study

Evaluation of ablation catheter technology: Comparison between thigh preparation model and an in vivo beating heart

An invivo animal thigh model is the standard technique for evaluation of ablation catheter technologies, including efficacy and safety of ablation. However, the biophysics of ablation in a thigh model may not be similar to a beating heart. The purpose of this study was to compare efficacy and safety of ablation between a thigh preparation model and a beating heart. In 7 swine, radiofrequency ablation using a 3.5-mm open irrigated catheter (ThermoCool Smart Touch) was performed sequentially in a thigh muscle and invivo beating ventricles. Ablation was performed at low (30 W for 40 s) and high (40 W for 60 s) energy settings and at similar contact force. Ablation lesions were scanned in high resolution and measured using electronic calipers. A total of 152 radiofrequency ablation lesions were measured (86 thigh and 66 heart). At low energy, lesion width was greater in the thigh model (12.19 ± 1.8 mm vs 8.99 ± 2.1 mm; P <.001), whereas lesion depth was similar between the thigh and heart (5.71 ± 0.8 mm vs 5.95 ± 1.3 mm, respectively; P=.18). The planar cross-sectional lesion area was greater in the thigh model (thigh 54.8 ± 10.8 mm2 vs heart 43.1 ± 16.1 mm2; P <.001). At the high-energy setting, lesion depth, width, and area were all greater in the thigh model (thigh 91.5 ± 16.8 mm2 vs heart 56.0 ± 15.5 mm2; P <.001). The incidence of steam pop and char formation was similar between the models. The thigh preparation model is a reasonable technique for evaluation of ablation catheter technology; however it often results in overestimation of lesion size, especially at higher energy settings.

Impact of cavotricuspid isthmus morphology in CRYO versus radiofrequency ablation of typical atrial flutter

Objectives. Cryoablation (CRYO) is an alternative to radiofrequency (RF) for catheter ablation of cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL). We aimed to study whether different CTI morphologies had different impacts on procedural success for CRYO and RF. Design. This study randomized 153 patients with CTI-dependent AFL (median age 65 years; range 34–82) to RF or CRYO (78 CRYO; 75 RF). Biplane angiography (RAO 30° and LAO 60°) was done before the ablation procedure and isthmuses were classified as straight (n = 81), concave (n = 43) or pouch-like (n = 29). RF was performed with a 3.5-mm open-irrigated tip catheter and CRYO was performed with a 9 F, 8-mm tip catheter. The ablation endpoint was bidirectional block of CTI. Results. Acute procedural success was achieved in 70/75 patients in the RF group and in 72/78 patients in the CRYO group. With regard to CRYO or RF, acute procedural success rates were similar between the three isthmus types: straight: CRYO (92%) and RF (96%); concave: CRYO (92%) and RF (94%); and pouch-like: CRYO (94%) and RF (85%). There were no significant differences regarding success rate between the different morphologies in the CRYO or the RF group. The CTI was longer in patients with acute failure compared to the patients with acute success (38 ± 7 mm versus 33 ± 6 mm, p = 0.045). Conclusion. The CTI morphology did not influence the acute success rate for either the CRYO or the RF ablation of CTI-dependent AFL. A longer CTI was associated with a lower success rate regardless of energy source.

Preliminary experience with high-density electroanatomical mapping for ablation of atrial fibrillation – Comparison of mini-basket and novel open irrigated magnetic ablation catheter in consecutive patients

BackgroundRecently, a novel electroanatomic mapping system enabling rapid and automatic acquisition of high-resolution maps has been introduced. Previous reports focused on system use in combination with a mini-basket catheter. However, a novel system-specific, magnet-enabled ablation catheter eliminates the need for the mini-basket catheter and can potentially reduce procedure complexity and cost. Here we present our first experience from two consecutive case series using both procedural settings. MethodsIn 14 consecutive patients (67±9years, 5 male) with paroxysmal (n=10) or persistent AF (n=4) undergoing de-novo (n=8) or repeat (n=6) AF ablation, left atrial electroanatomical maps were acquired with a mini-basket and in 22 patients (64±9years, 17 male) with paroxysmal (n=4) or persistent AF (n=18) undergoing de-novo (n=12) or repeat (n=10) AF ablation with the new ablation catheter. ResultsBoth complete (7.9 [IQR 4.5–16.2] vs 18.8 [IQR 12.0–25.5] minutes, p=0.005) and partial maps (3.0 [IQR 2.0–4.6] vs 4.5 [IQR 2.0–6.0] minutes, p=0.014) acquired with mini-basket required significantly shorter mapping time and had higher point density: 8832±4809 vs 4460±3914 (p=0.014) and 2483±1774 vs 1111±1926 data points (p=0.002) in partial maps.However, procedural (201±52 vs 159±29min, p=0.004) and fluoroscopy time (33±11 vs 25±6min, p=0.005) was significantly higher in the mini-basket group. Procedural endpoints and complications rates were similar in both groups. ConclusionThe high-density mapping system can successfully be used with both mini-basket catheters and ablation catheters employed for electro-anatomic reconstruction of the left atrium. While mapping is faster and point density higher with the mini-basket, procedure and fluoroscopy times are longer. The clinical significance of those findings needs to be investigated in future and larger studies.

Influence of catheter orientation on lesion formation in bovine myocardium by using an open-irrigated laser ablation catheter.

Lesion sizes and quality are crucial for successful catheter ablation procedures. We sought to test the influence of catheter orientation towards the endocardial surface on lesion formation in bovine myocardium by using an open-irrigated laser ablation catheter. Continuous wave 1064-nm laser catheter applications at 15W (4.5W/mm²)/30s, (135J/mm²), irrigation flow 30mL/min, were aimed at the left ventricular endocardial surface of bovine myocardium. The catheter was kept in vertical, in slanting (67.5°, 45°, 22.5°), and in flat positions; in flat position, also 60s of radiation times were applied (n = 10, each). Lesions were evaluated morphometrically. Maximum depth of lesion was achieved with the catheter in a vertical orientation. Catheter inclination of <22.5 showed a highly significant decrease of lesion depth from 5.6 ± 1.1 to 3.7 ± 0.5mm (p = 0.0001). In a flat catheter position, laser radiation of 30s achieved the smallest lesions. However, after 60s of radiation, the flat lesions were similar in depth (p = 087) and were larger in width (p = 0.0004) and in volumes (p = 0.0025) as compared to the lesions achieved with the catheter in vertical position after 30s of radiation. Steam-pop with intramural cavitation or tissue vaporization with crater formation did not occur. Longer radiation times can achieve larger lesions regardless of catheter orientation. Catheter orientation is not a major determinant for laser ablation lesion size and quality, and a steerable support may not be needed when using the open-irrigated electrode-laser mapping and ablation (ELMA) catheter RytmoLas.

Long-Term Success of Irrigated Radiofrequency Catheter Ablation of Sustained Ventricular Tachycardia: Post-Approval THERMOCOOL VT Trial

BackgroundRadiofrequency catheter ablation is used to treat recurrent ventricular tachycardia (VT). ObjectivesThis study evaluated long-term safety and effectiveness of radiofrequency catheter ablation using an open-irrigated catheter. MethodsPatients with sustained monomorphic ventricular tachycardia associated with coronary disease were analyzed for cardiovascular-specific adverse events within 7 days of treatment, hospitalization duration, 6-month sustained monomorphic ventricular tachycardia recurrence, quality of life measured by the Hospital Anxiety and Depression Scale, long-term (1-, 2-, and 3-year) survival, symptomatic VT control, and amiodarone use. ResultsOverall, 249 patients, mean age 67.4 years, were enrolled. The cardiovascular-specific adverse events rate was 3.9% (9 of 233) with no strokes. Noninducibility of targeted VT was achieved in 75.9% of patients. Post-ablation median hospitalization was 2 days. At 6 months, 62.0% (114 of 184) of patients had no sustained monomorphic ventricular tachycardia recurrence; the proportion of patients with implantable cardioverter-defibrillator shocks decreased from 81.2% to 26.8% (p < 0.0001); the frequency of VT in implantable cardioverter-defibrillator patients with recurrences was reduced by ≥50% in 63.8% of patients; and the proportion with normal Hospital Anxiety and Depression Scale scores increased from 48.8% to 69.1% (p < 0.001). Patient-reported VT remained steady for 1, 2, and 3 years at 22.7%, 29.8%, and 24.1%, respectively. Amiodarone use and hospitalization decreased from 55% and 77.2% pre-ablation to 23.3% and 30.7%, 18.5% and 36.7%, 17.7% and 31.3% at 1, 2, and 3 years, respectively. ConclusionsRadiofrequency catheter ablation reduced implantable cardioverter-defibrillator shocks and VT episodes and improved quality of life at 6 months. A steady 3-year nonrecurrence rate with reduced amiodarone use and hospitalizations indicate improved long-term outcomes. (NaviStar ThermoCool Catheter for Endocardial RF Ablation in Patients With Ventricular Tachycardia [THERMOCOOL VT]; NCT00412607)

Open-irrigated laser catheter ablation: influence of catheter–tissue contact force on lesion formation

Catheter-tissue contact force (CF) is a major determinant for radiofrequency (RF) ablation lesion size and quality. We sought to test the influence of catheter CF on lesion formation by using an open-irrigated electrode-laser mapping and ablation (ELMA) catheter. With the ELMA catheter in a stable vertical position, continuous wave 1064 nm laser impacts at 15 W (9.5 W/mm(2)), 30 s (285 J/mm(2)), irrigation flow 30 mL/min, were aimed at the endocardial surface of bovine myocardium in heparinized stagnant blood (ACT >350 s) at room temperature (18 °C). Lesions were produced with CFs of 100 g, 10 g, in contact but without pressure, with the catheter tip 2.0 mm, and 5.0 mm away (n = 10, each). Lesions were evaluated morphometrically and were compared by the unpaired t tests. There were no significant differences between volumes of lesions achieved with catheter-tissue CF of 100 g, 10 g, and in contact without pressure: 297 ± 56.0 vs. 300 ± 39 vs. 320 ± 24, respectively (p > 0.05). However, volumes of lesions produced at a distance of 2 mm (95 ± 14 mm(3)) were significantly smaller (p < 0.0001), whereas at a distance of 5.0 mm, no lesions were produced. No steam-pop with crater or thrombus formation occurred. By using an open-irrigated ELMA catheter, catheter-tissue CF is not a determinant for laser ablation lesion size and quality. Maximum sizes of lesions can be achieved with the catheter in intimate endocardial contact without pressure. However, lesions can be produced also at a catheter-tissue distance of 2.0 mm. Noticeably, there is no thrombus formation during laser application with the free floating ELMA catheter in the stagnant blood.

Effects of radiofrequency energy delivered through partially insulated metallic catheter tips on myocardial tissue heating and ablation lesion characteristics.

Cardiac radiofrequency (RF) ablation is typically achieved using symmetric catheter tips, which may result in unintended heating adjacent to targeted tissue. Partial insulation may alter lesion geometry and prevent collateral heating. The purpose of this study was to assess partially insulated focused ablation (PIFA). Partial insulation using thermally conductive materials was applied to a 4-mm or 8-mm nonirrigated catheter and a 3.5-mm open-irrigated catheter. These PIFA tips, or their noninsulated counterparts, were applied to ex vivo viable bovine myocardium. Ablations were delivered at various powers and under temperature control. Potential clinical applicability was evaluated in vivo by targeting porcine epicardium with irrigated PIFA and assessing its protective effects on the pericardium. PIFA catheters exhibited different properties and produced asymmetric lesions compared with corresponding standard ablation catheters. Temperatures at 3- and 5-mm depths were higher for PIFA catheters, with a temperature increase measured at the catheter tip-tissue interface; however, in temperature control ablation, tip-tissue temperature increases did not limit power delivery. Furthermore, temperatures were lower on the insulated surface and were significantly higher on the noninsulated PIFA side. Impedance changes were significantly larger; more steam pops were observed with PIFA but were mitigated by external irrigation, a larger tip electrode, and use of more thermally conductive insulation. In contrast to standard ablation, open-irrigated PIFA created larger asymmetric lesions in vivo over porcine epicardium, without evidence of pericardial injury. PIFA ablation has different characteristics compared with symmetrically conductive ablation. Further research is needed to assess the clinical implications of insulated catheter ablation.

Does diffuse irrigation result in improved radiofrequency catheter ablation? A prospective randomized study of right atrial typical flutter ablation.

Recent developments of open irrigated catheters have sought to create uniform cooling of the entire ablating electrode. The aim of this randomized study was to assess whether the diffuse irrigation of the Coolflex(®) (CF) catheter results in improved short-term procedural benefits in patients undergoing ablation of right atrial typical flutter. Sixty consecutive patients (age 62 ± 13) with typical atrial flutter were prospectively randomized to ablation of the cavotricuspid isthmus (CTI) using either a standard 3.5 mm tip ablation catheter with six distal irrigation channels (6C) (30 patients) or a 4 mm tip fully irrigated ablation catheter (CF) (30 patients). There were no significant differences seen between procedures performed with the diffusely irrigated CF catheter and the standard six-channel irrigated-tip catheter. This concerned the total procedural duration RF duration, fluoroscopic duration, the total amount of irrigation fluid, and the occurrence of steam pop. The use of a diffuse irrigation at the ablation catheter tip does neither facilitate lesion formation nor reduce the amount of irrigation during RF ablation for typical right atrial flutter using recommended flow and power settings.

Low incidence of permanent complications during catheter ablation for atrial fibrillation using open-irrigated catheters: a multicentre registry.

Despite catheter ablation (CA) has become an accepted treatment option for symptomatic, drug-resistant atrial fibrillation (AF), the safety of this procedure continues to be cause for concern. The aim of the present study was to assess the incidence of complications with permanent sequelae of CA for AF using open-irrigated catheters in a contemporary, unselected population of consecutive patients. From 1 January 2011 to 31 December 2011, data from 2167 consecutive patients who underwent CA for AF using an open-irrigated catheter in 29 Italian centres were collected. All the complications occurring to the patient from admission to the 30th post-procedural day were recorded. No procedure-related death was observed. Complications occurred in 81 patients (3.7%): 46 patients (2.1%) suffered vascular access complications; 13 patients (0.6%) cardiac tamponade, successfully drained in all the cases; six patients (0.3%) arterial thromboembolism (four transient ischaemic attack and two ischaemic strokes); five (0.2%) patients conservatively treated pericardial effusion; three patients (0.1%) phrenic nerve paralysis; three patients (0.1%) pericarditis; three patients (0.1%) haemothorax, and two patients (0.1%) other isolated adverse events. At multivariate analysis, only female sex [odds ratio (OR) 2.5, confidence interval (CI): 1.5-3.7, P < 001] and the operator experience (OR 0.5, CI: 0.4-0.7, P < 001) related to the complications. Only five (0.2%) patients developed permanent sequelae from their complications. Catheter ablation for AF with the use of open-irrigated catheters is currently affected by a very low rate of complications leading to permanent sequelae.

Prospective European survey on atrial fibrillation ablation: clinical characteristics of patients and ablation strategies used in different countries.

Atrial fibrillation (AF) ablation is widely adopted. Our aim was to conduct a prospective multicenter survey to verify patients' characteristics, approaches, and technologies adopted across Europe. A total of 35 centers in 12 countries actively participated in the study and 940 patients (median age 60 years) were enrolled. AF was paroxysmal, persistent, and long-lasting persistent in 52.4%, 36%, and 11.6% of patients, respectively; 95.5% of patients were symptomatic and 91.4% were refractory to antiarrhythmic therapy. Redo procedures were performed in 20.9%. Pulmonary vein isolation (PVI) emerged as the cornerstone of ablative therapy and has been performed in 98.7% of procedures, with confirmation of PVI in 92.9% of cases. The ablation of nonparoxysmal AF was not generally limited to isolating the PVs and several adjunctive approaches are adopted, particularly in the case of long-lasting persistent AF. Linear lesions or elimination of complex fractionated atrial electrograms were more frequently added. Circular mapping catheters and imaging techniques were seen to be used in about two-thirds of cases. Radiofrequency energy was delivered through open irrigated catheters in 68% of cases. European centers are largely following the recommendations of the guidelines and the expert consensus documents for AF ablation. AF ablation is mainly performed in relatively young patients with symptomatic drug refractory AF and no or minimal heart disease. Patients with paroxysmal AF are the most frequently treated with a quite uniform ablative approach across Europe. A less standardized approach was observed in nonparoxysmal AF patients.

Does periprocedural anticoagulation management of atrial fibrillation affect the prevalence of silent thromboembolic lesion detected by diffusion cerebral magnetic resonance imaging in patients undergoing radiofrequency atrial fibrillation ablation with open irrigated catheters? Results from a prospective multicenter study

Silent cerebral ischemia (SCI) has been reported in 14% of cases after catheter ablation of atrial fibrillation (AF) with radiofrequency (RF) energy and discontinuation of warfarin before AF ablation procedures. The purpose of this study was to determine whether periprocedural anticoagulation management affects the incidence of SCI after RF ablation using an open irrigated catheter. Consecutive patients undergoing RF ablation for AF without warfarin discontinuation and receiving heparin bolus before transseptal catheterization (group I, n = 146) were compared with a group of patients who had protocol deviation in terms of maintaining the therapeutic preprocedural international normalized ratio (patients with subtherapeutic INR) and/or failure to receive pretransseptal heparin bolus infusion and/or ≥2 consecutive ACT measurements <300 seconds (noncompliant population, group II, n = 134) and with a group of patients undergoing RF ablation with warfarin discontinuation bridged with low molecular weight heparin (group III, n = 148). All patients underwent preablation and postablation (within 48 hours) diffusion magnetic resonance imaging. SCI was detected in 2% of patients (3/146) in group I, 7% (10/134) in group II, and 14% (21/148) in group III (P <.001). "Therapeutic INR" was strongly associated with a lower prevalence of postprocedural silent cerebral ischemia (SCI). Multivariable analysis demonstrated nonparoxysmal AF (odds ratio 3.8, 95% confidence interval 1.5-9.7, P = .005) and noncompliance to protocol (odds ratio 2.8, 95% confidence interval 1.5-5.1, P <.001] to be significant predictors of ischemic events. Strict adherence to an anticoagulation protocol significantly reduces the prevalence of SCI after catheter ablation of AF with RF energy.