Matching Ablation Endpoints to Long-Term Outcome: The Prospective Multicenter Italian Ventricular Tachycardia Ablation Registry.

BACKGROUND: Multicenter ventricular tachycardia (VT) ablation studies have shown poorer outcomes compared with single-center experiences. This difference could be related to heterogeneous mapping and ablation strategies. OBJECTIVES: This study evaluated a homogenous simplified catheter ablation strategy for different substrates and compared the results with those of a single referral center. METHODS: This was a multicenter prospective VT ablation registry of patients with the following 4 causes of VT: previous myocardial infarction; previous myocarditis; arrhythmogenic right ventricular dysplasia; or idiopathic dilated cardiomyopathy. The procedural protocol included precise mapping and ablation steps with the combined endpoint of late potential (LP) abolition and noninducibility of VT. The long-term primary efficacy endpoint was freedom from VT. RESULTS: A total of 309 patients were enrolled. LPs were present in 70% of patients and were abolished in 83%. At the end of the procedure 74% of LPs were noninducible. The primary combined endpoint of LP abolition and noninducibility was achieved in 64% of patients with LPs at baseline. Freedom from VT at 12 months was observed in 67% of patients. In the overall study group, VT inducibility was the only predictor of freedom from VT (P = 0.013). In patients with LPs, the VT recurrence rate was lower both for patients with complete LP abolition (P = 0.040) and for patients meeting the composite endpoint (P = 0.035). CONCLUSIONS: A standardized VT mapping and ablation technique reproduced the procedural outcomes of a single referral center in a multicenter prospective study. LP abolition and noninducibility were effective in reducing VT recurrences in patients with 4 causes of cardiomyopathy. (Ventricular Tachycardia Ablation Registry; NCT03649022).

Lesion Index-guided workflow for the treatment of paroxysmal atrial fibrillation is safe and effective - Final results from the LSI Workflow Study.

Background: Pulmonary vein isolation (PVI) ablation is a standard therapy for paroxysmal atrial fibrillation (PAF). Lesion Index (LSI) is a metric to guide radiofrequency (RF) ablation using the TactiCath Ablation Catheter, Sensor Enabled with the EnSite Cardiac Mapping System (Abbott). Objective: This study (NCT-03906461) was designed to capture best practices using LSI-guided catheter ablation to treat PAF subjects in a real-world setting. Methods: This prospective single-arm observational study enrolled 143 PAF subjects in the United States, Europe, and Japan undergoing de novo PVI with RF ablation. PVI lesions were assigned to 10 anatomically defined segments. Mean LSIs achieved for all lesions were analyzed. Follow-up was conducted between 3-6 months and 12 months after the procedure. Results: Pulmonary veins were isolated in all subjects. The mean achieved LSI was 4.9, with lower values in Europe (4.4) and Japan (4.5) than the United States (5.5). First-pass success, defined as no gaps requiring touch-up ablation after 20 minutes post isolation, was achieved in 76.2% of subjects. Use of high LSI (≥5) resulted in shorter procedure, RF, and fluoroscopy times and fewer touch-up ablations compared to low LSI (<5). At 12 months, 99.3% of subjects were free from procedure- or device-related serious adverse events and 95.7% (112/117) (35.0% on antiarrhythmic drugs) were free from recurrence and/or a repeat ablation procedure for atrial fibrillation / atrial flutter / atrial tachycardia. Conclusion: LSI-guided ablation strategies proved safe and effective despite differences in LSI workflows. Use of high LSI values resulted in shorter procedure, RF, and fluoroscopy times and fewer touch-up ablations compared to low LSI.

[Appropriateness in Cardiology: a statement of the ANMCO Veneto Region]. / L'appropriatezza prescrittiva in Cardiologia: documento dell'ANMCO Regione Veneto.

Inappropriate tests are responsible for longer waiting lists, higher economical costs for the National Health System and major clinical risks due to radiation exposure from prescription abuse of diagnostic testing. Clinical inappropriateness frequently derives from poor knowledge of guidelines, "defensive medicine" approach and/or repeat requests of patients and family members. About one third of non-invasive imaging tests are considered inappropriate.In order to define the most appropriate instruments for the follow-up of the most common cardiovascular diseases with the highest risk of inappropriateness, all the cardiologists of the Veneto Region (Italy), along with the local chapters of the main national cardiology societies and general practitioners have been involved by the Regional Section of the Italian Association of Hospital Cardiologists (ANMCO) in several scientific meetings on the following topics: hypertension, chronic ischemic heart disease, valvular heart disease, heart failure, and atrial fibrillation. This has led to the present document where: (i) the most appropriate clinical and diagnostic strategies are taken into account, and (ii) the most robust scientific evidence is provided for the regulatory commission of the Veneto Region Health Service to identify inappropriateness, prescription unsuitability, and economical sustainability.

Left atrial model reconstruction in atrial fibrillation ablation: reliability of new mapping and complex impedance systems.

AIMS: The effectiveness of atrial fibrillation (AF) ablation relies on detailed knowledge of the anatomy of the left atrium (LA) and pulmonary veins (PVs). It is common to combine computed tomography/magnetic resonance (CT/MR) with imaging by electroanatomical (EA) mapping systems. The aim of this study was to evaluate the accuracy of LA anatomical reconstruction by 'One Model' and 'VeriSense' tools (Ensite Velocity 3.0, St Jude Medical), compared with CT/MR imaging. METHODS AND RESULTS: Seventy-two patients with AF underwent pre-procedural imaging (97% CT-scan, 3% MR imaging) and transcatheter ablation of PVs. Operators were blinded to CT/MR imaging. Electrical Coupling Index (ECI) was used to recognize venous structures when the circular catheter could not. The LA 'One Model' map was obtained without complications; all 124 main left PVs and 144 main right PVs were detected. Nine of 9 intermediate right PVs and 30 of 30 early branches were detected, whereas 1 of the 27 early branches on the right inferior PVs was missed. Comparison between LA intervein distances measured on the roof (RO) and the posterior wall (PW) showed a high correspondence between the EA model and CT/MR imaging (RO CT/MR imaging vs. EA: 32 ± 7 vs. 32 ± 7 mm; PW CT/MR imaging vs. EA: 36 ± 6 vs. 36 ± 7 mm). The EA model yielded slightly larger PV ostia diameters, owing to the distortion caused by catheter pressure. CONCLUSIONS: Recent 3D mapping tools allow outstanding anatomical rendering and are key in complex ablation procedure set-up. This study shows that 3D anatomical reconstruction of LA, PVs, and their variable branches is not only safe and fast but also accurate and reliable.

Ablation of perimitral flutter following catheter ablation of atrial fibrillation: impact on outcomes from a randomized study (PROPOSE).

INTRODUCTION: Patients with previous ablation for atrial fibrillation (AF) may experience recurrence of perimitral flutter (PMFL). These arrhythmias are usually triggered from sources that may also induce AF. This study aims at determining whether ablation of triggers or completing mitral valve isthmus (MVI) block prevents more arrhythmia recurrences. METHODS AND RESULTS: Sixty-five patients with recurrent PMFL after initial ablation of long standing persistent AF were included in this study. Thirty-two patients were randomized to MVI ablation only (Group 1) and 33 were randomized to cardioversion and repeat pulmonary vein (PV) isolation plus ablation of non-PV triggers (Group 2). MVI bidirectional block was achieved in all but 1 patient from Group 1. In Group 2, reconnection of 17 PVs was detected in 14 patients (42%). With isoproterenol challenge, 44 non-PV trigger sites were identified in 28 patients (85%, 1.57 sites per patient). At 18-month follow-up, 27 patients (84%) from Group 1 had recurrent atrial tachyarrhythmias, of whom 15 remained on antiarrhythmic drug (AAD); however, 28 patients from Group 2 (85%, P < 0.0001 vs Group 1) were free from arrhythmia off AAD. The ablation strategy used in Group 2 was associated with a lower risk of recurrence (hazard ratio = 0.10, 95% CI 0.04-0.28, P < 0.001) and an improved arrhythmia-free survival (log rank P < 0.0001). CONCLUSION: In patients presenting with PMFL after ablation for longstanding persistent AF, MVI block had limited impact on arrhythmia recurrence. On the other hand, elimination of all PV and non-PV triggers achieved higher freedom from atrial arrhythmias at follow-up.

Left atrial appendage: an underrecognized trigger site of atrial fibrillation.

BACKGROUND: Together with pulmonary veins, many extrapulmonary vein areas may be the source of initiation and maintenance of atrial fibrillation. The left atrial appendage (LAA) is an underestimated site of initiation of atrial fibrillation. Here, we report the prevalence of triggers from the LAA and the best strategy for successful ablation. METHODS AND RESULTS: Nine hundred eighty-seven consecutive patients (29% paroxysmal, 71% nonparoxysmal) undergoing redo catheter ablation for atrial fibrillation were enrolled. Two hundred sixty-six patients (27%) showed firing from the LAA and became the study population. In 86 of 987 patients (8.7%; 5 paroxysmal, 81 nonparoxysmal), the LAA was found to be the only source of arrhythmia with no pulmonary veins or other extrapulmonary vein site reconnection. Ablation was performed either with focal lesion (n=56; group 2) or to achieve LAA isolation by placement of the circular catheter at the ostium of the LAA guided by intracardiac echocardiography (167 patients; group 3). In the remaining patients, LAA firing was not ablated (n=43; group 1). At the 12+/-3-month follow-up, 32 patients (74%) in group 1 had recurrence compared with 38 (68%) in group 2 and 25 (15%) in group 3 (P<0.001). CONCLUSIONS: The LAA appears to be responsible for arrhythmias in 27% of patients presenting for repeat procedures. Isolation of the LAA could achieve freedom from atrial fibrillation in patients presenting for a repeat procedure when arrhythmias initiating from this structure are demonstrated.

Periprocedural stroke and management of major bleeding complications in patients undergoing catheter ablation of atrial fibrillation: the impact of periprocedural therapeutic international normalized ratio.

BACKGROUND: Catheter ablation of atrial fibrillation is associated with the potential risk of periprocedural stroke, which can range between 1% and 5%. We developed a prospective database to evaluate the prevalence of stroke over time and to assess whether the periprocedural anticoagulation strategy and use of open irrigation ablation catheter have resulted in a reduction of this complication. METHODS AND RESULTS: We collected data from 9 centers performing the same ablation procedure with the same anticoagulation protocol. We divided the patients into 3 groups: ablation with an 8-mm catheter off warfarin (group 1), ablation with an open irrigated catheter off warfarin (group 2), and ablation with an open irrigated catheter on warfarin (group 3). Outcome data on stroke/transient ischemic attack and bleeding complications during and early after the procedures were collected. Of 6454 consecutive patients in the study, 2488 were in group 1, 1348 were in group 2, and 2618 were in group 3. Periprocedural stroke/transient ischemic attack occurred in 27 patients (1.1%) in group 1 and 12 patients (0.9%) in group 2. Despite a higher prevalence of nonparoxysmal atrial fibrillation and more patients with CHADS2 (congestive heart failure, hypertension, age >75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score >2, no stroke/transient ischemic attack was reported in group 3. Complications among groups 1, 2, and 3, including major bleeding (10 [0.4%], 11 [0.8%], and 10 [0.4%], respectively; P>0.05) and pericardial effusion (11 [0.4%], 11 [0.8%], and 12 [0.5%]; P>0.05), were equally distributed. CONCLUSIONS: The combination of an open irrigation ablation catheter and periprocedural therapeutic anticoagulation with warfarin may reduce the risk of periprocedural stroke without increasing the risk of pericardial effusion or other bleeding complications.

The risk of thromboembolism and need for oral anticoagulation after successful atrial fibrillation ablation.

OBJECTIVES: The aim of this multicenter study was to evaluate the safety of discontinuing oral anticoagulation therapy (OAT) after apparently successful pulmonary vein isolation. BACKGROUND: Atrial fibrillation (AF) is associated with an increased risk of thromboembolic events (TE) and often requires OAT. Pulmonary vein isolation is considered an effective treatment for AF. METHODS: We studied 3,355 patients, of whom 2,692 (79% male, mean age 57 +/- 11 years) discontinued OAT 3 to 6 months after ablation (Off-OAT group) and 663 (70% male, mean age 59 +/- 11 years) remained on OAT after this period (On-OAT group). CHADS(2) (congestive heart failure, hypertension, age [75 years and older], diabetes mellitus, and a history of stroke or transient ischemic attack) risk scores of 1 and > or =2 were recorded in 723 (27%) and 347 (13%) Off-OAT group patients and in 261 (39%) and 247 (37%) On-OAT group patients, respectively. RESULTS: During follow-up (mean 28 +/- 13 months vs. 24 +/- 15 months), 2 (0.07%) Off-OAT group patients and 3 (0.45%) On-OAT group patients had an ischemic stroke (p = 0.06). No other thromboembolic events occurred. No Off-OAT group patient with a CHADS(2) risk score of > or =2 had an ischemic stroke. A major hemorrhage was observed in 1 (0.04%) Off-OAT group patient and 13 (2%) On-OAT group patients (p < 0.0001). CONCLUSIONS: In this nonrandomized study, the risk-benefit ratio favored the suspension of OAT after successful AF ablation even in patients at moderate-high risk of TE. This conclusion needs to be confirmed by future large randomized trials.

Impact of systematic isolation of superior vena cava in addition to pulmonary vein antrum isolation on the outcome of paroxysmal, persistent, and permanent atrial fibrillation ablation: results from a randomized study.

BACKGROUND: Pulmonary veins (PVs) have been shown to represent the most frequent sites of ectopic beats initiating paroxysmal atrial fibrillation (AF). However, additional non-PV triggers, arising from different areas, have been reported as well. One of the most common non-PV sites described is the superior vena cava. AIMS: The purpose of the study was to investigate the impact resulting from the systematic isolation of the superior vena cava (SVCI) in addition to pulmonary vein antrum isolation (PVAI) on the outcome of paroxysmal, persistent, and permanent AF ablation. METHODS: A total of 320 consecutive patients who had been referred to our center in order to undergo a first attempt of AF ablation were randomized into 2 groups. Group I (160 patients) underwent PVAI only; Group II (160 patients) underwent PVAI and SVCI. RESULTS: AF was paroxysmal in 134 (46%), persistent in 75 (23%), and permanent in 111 (31%) of said patients. SVCI was performed on 134 of the 160 patients (84%) in Group II. SVC isolation was not performed on the remaining 26 patients either because of phrenic nerve capture or the lack of SVC potentials. Comparison of the outcome data between the 2 groups, after a follow-up of 12 months, revealed a significant difference in total procedural success solely with patients manifesting paroxysmal atrial fibrillation (56/73 [77%] Group I vs. 55/61 [90%] Group II; P = 0.04; OR 2.78). CONCLUSIONS: In our study, the strategy of the empiric SVCI in addition to PVAI has improved the outcome of AF ablation solely in patients manifesting paroxysmal AF.

A randomized controlled trial of the efficacy and safety of electroanatomic circumferential pulmonary vein ablation supplemented by ablation of complex fractionated atrial electrograms versus potential-guided pulmonary vein antrum isolation guided by intracardiac ultrasound.

BACKGROUND: The study was conducted to compare relative safety and efficacy of pulmonary vein antrum isolation (PVAI) using intracardiac echocardiographic guidance and circumferential pulmonary vein ablation (CPVA) for atrial fibrillation (AF) using radiofrequency energy. METHODS AND RESULTS: Sixty patients (81% men; 81% paroxysmal; age, 56+/-8 years) failing 2+/-1 antiarrhythmic drugs were randomly assigned to undergo CPVA (n=30) or PVAI (n=30) at 5 centers between December 2004 and October 2007. CPVA patients had circular lesions placed at least 1 cm outside of the veins. Ipsilateral veins were ablated en block with the end point of disappearance of potentials within the circular lesion. Left atrial roof line and mitral isthmus line were ablated without verification of block. For patients in AF postablation or with AF induced with programmed stimulation, complex fractionated electrograms were mapped and ablated to the end point of AF termination or disappearance of complex fractionated electrograms. PVAI did not include complex fractionated electrogram ablation. Esophageal temperature was monitored and kept within 2 degrees C of baseline or under 39 degrees C. Success was defined as absence of atrial tachyarrhythmias (AF/AT) off antiarrhythmic drugs. There was no difference between CPVA and PVAI regarding to baseline variables, catheter used, duration of the procedure, or RF delivery. Fluoroscopy time was longer with PVAI (54+/-17 minutes versus 77+/-18 minutes, P=0.0001). No significant complications occurred in either arm. PVAI was more likely to achieve control of AF/AT off antiarrhythmic drugs (57% versus 27%, P=0.02) at 2+/-1 years of follow-up. CONCLUSIONS: A single PVAI procedure is more likely to result in freedom from AF/AT off antiarrhythmic drugs than CPVA supplemented by complex fractionated electrogram ablation in select patients.

Atrial fibrillation ablation strategies for paroxysmal patients: randomized comparison between different techniques.

BACKGROUND: Whether different ablation strategies affect paroxysmal atrial fibrillation (AF) long-term freedom from AF/atrial tachyarrhythmia is unclear. We sought to compare the effect of 3 different ablation approaches on the long-term success in patients with paroxysmal AF. METHODS AND RESULTS: One hundred three consecutive patients with paroxysmal AF scheduled for ablation and presenting in the electrophysiology laboratory in AF were selected for this study. Patients were randomized to pulmonary vein antrum isolation (PVAI; n=35) versus biatrial ablation of the complex fractionated atrial electrograms (CFAEs; n=34) versus PVAI followed by CFAEs (n=34). Patients were given event recorders and followed up at 3, 6, 9, 12, and 15 months postablation. There was no statistical significant difference between the groups in term of sex, age, AF duration, left atrial size, and ejection fraction. At 1 year follow-up, freedom from AF/atrial tachyarrhythmia was documented in 89% of patients in the PVAI group, 91% in the PVAI plus CFAEs group, and 23% in the CFAEs group (P<0.001) after a single procedure and with antiarrhythmic drugs. CONCLUSIONS: No difference in terms of success rate was seen between PVAI alone and PVAI associated with defragmentation. CFAEs ablation alone had the smallest impact on AF recurrences at 1-year follow-up. These results suggest that antral isolation is sufficient to treat most patients with paroxysmal AF.

Impact of type of atrial fibrillation and repeat catheter ablation on long-term freedom from atrial fibrillation: results from a multicenter study.

BACKGROUND/OBJECTIVE: The purpose of this prospective multicenter study was to compare results of catheter ablation in patients with paroxysmal atrial fibrillation (PAF) and those with nonparoxysmal atrial fibrillation (NPAF). The impact and the role of repeat catheter ablation were assessed in patients with recurrence. METHODS/RESULTS: One thousand four hundred four patients underwent catheter ablation for atrial fibrillation (AF) performed by 12 operators at four institutions using a single technique guided by intracardiac echocardiography. Of these patients, 728 had PAF and 676 had NPAF. Among the NPAF patients, 293 had persistent AF and 383 had long-standing persistent AF. Patients with NPAF had a higher incidence of hypertension and/or structural heart disease (64.8% vs 48.5%, P = .003) and a lower mean left ventricular ejection fraction (53.3% +/- 8.7% vs 55.7 +/- 6.5%, P <.001). All patients underwent antral isolation of all four pulmonary veins and the superior vena cava. At mean follow-up of 57 +/- 17 months, 565 of 728 patients with PAF and 454 of 676 patients with NPAF (77.6% vs 67.2%, P <.001) had freedom from AF after a single ablation procedure. For arrhythmia recurrences, 74.2% (121/163) patients with PAF and 74.8% (166/222) with NPAF underwent repeat ablation, after which 92.4% patients with PAF and 84.0% patients with NPAF remained free from AF. CONCLUSION: Pulmonary vein antrum isolation guided by intracardiac echocardiography results in significant freedom from AF, even when performed by multiple operators in different centers. At least moderate efficacy can be achieved in patients with NPAF, although the success rate is lower than in patients with PAF. Considerably higher success can be achieved in both groups with repeat ablation.

Visually-guided balloon catheter ablation of atrial fibrillation: experimental feasibility and first-in-human multicenter clinical outcome.

BACKGROUND: Electric isolation of the pulmonary veins (PVs) can successfully treat patients with paroxysmal atrial fibrillation. However, it remains technically challenging to identify the left atrial-PV junction and sequentially position the ablation catheter in a point-by-point contiguous fashion to isolate the PVs. In this study, a novel endoscopic ablation system was used to directly visualize and ablate tissue at the left atrial-PV junction with laser energy. METHODS AND RESULTS: This study consisted of 2 phases: a short-term (n=9) and long-term (n=11) canine experimental validation phase and a multicenter clinical feasibility phase (n=30 paroxysmal atrial fibrillation patients). After transseptal puncture, the balloon-based endoscopic ablation system was advanced to each PV ostium, and arcs of laser energy (90 degrees to 360 degrees ) were projected onto the target left atrial-PV junction. Electric PV isolation was defined with a circular multielectrode catheter. In the short-term preclinical experimental phase, 15 of 17 targeted PVs (88%) were successfully isolated. Pathological examination revealed well-demarcated circumferential lesions with minimal endothelial disruption. In the long-term experiments, 9 of 10 targeted veins (90%) remained persistently isolated (at 4 to 8 weeks). In the clinical phase, 105 of 116 PVs (91%) were successfully isolated. After a single procedure, the 12-month drug-free rate of freedom from atrial fibrillation was 60% (18 of 30 patients). There were no significant PV stenoses, but adverse events included 1 episode of cardiac tamponade, 1 stroke without residual defect, and 1 asymptomatic phrenic nerve palsy. CONCLUSIONS: This study establishes the feasibility of a novel paradigm for AF ablation: direct visualization to guide catheter ablation of the left atrial-PV junction.

Novel ICE-guided registration strategy for integration of electroanatomical mapping with three-dimensional CT/MR images to guide catheter ablation of atrial fibrillation.

INTRODUCTION: Image integration is used in AF ablation procedures. To maximize the efficacy of image integration, it is essential to obtain good alignment between the electroanatomical map and the 3D image of the heart. In the present study, we compared an ICE-guided landmark registration with an ICE-guided focused endocardial surface registration. METHODS AND RESULTS: In 20 patients, registration was based on posterior landmarks acquired under ICE guidance (group A); in another 20 matched patients, a new ICE-guided focused endocardial surface registration technique was used (group B). In these latter patients, a single landmark was acquired in the inferior part of the LIPV, and several surface points were recorded in the posterior area of the left PV antrum and around the antra of the right PVs. The mean ablation point-to-CT image distance was calculated in both groups. In group A, the mean landmark point-to-CT image distance was also calculated after adding the surface registration. The mean landmark point-to-CT image distance was 4.62 +/- 1.65 mm and increased to 7.66 +/- 2.44 mm when surface registration was added. The ablation point-to-CT image distance was significantly shorter in group B (1.73 +/- 0.29 mm vs 3 +/- 0.99 mm; P < 0.001). CONCLUSIONS: This ICE-guided focused endocardial surface registration seems to be superior to landmark registration in achieving a better alignment between the CT/MR image and the electroanatomical map. The concurrent use of standard surface registration may result in rotation of the atrial chamber.

Pulmonary-vein isolation for atrial fibrillation in patients with heart failure.

BACKGROUND: Pulmonary-vein isolation is increasingly being used to treat atrial fibrillation in patients with heart failure. METHODS: In this prospective, multicenter clinical trial, we randomly assigned patients with symptomatic, drug-resistant atrial fibrillation, an ejection fraction of 40% or less, and New York Heart Association class II or III heart failure to undergo either pulmonary-vein isolation or atrioventricular-node ablation with biventricular pacing. All patients completed the Minnesota Living with Heart Failure questionnaire (scores range from 0 to 105, with a higher score indicating a worse quality of life) and underwent echocardiography and a 6-minute walk test (the composite primary end point). Over a 6-month period, patients were monitored for both symptomatic and asymptomatic episodes of atrial fibrillation. RESULTS: In all, 41 patients underwent pulmonary-vein isolation, and 40 underwent atrioventricular-node ablation with biventricular pacing; none were lost to follow-up at 6 months. The composite primary end point favored the group that underwent pulmonary-vein isolation, with an improved questionnaire score at 6 months (60, vs. 82 in the group that underwent atrioventricular-node ablation with biventricular pacing; P<0.001), a longer 6-minute-walk distance (340 m vs. 297 m, P<0.001), and a higher ejection fraction (35% vs. 28%, P<0.001). In the group that underwent pulmonary-vein isolation, 88% of patients receiving antiarrhythmic drugs and 71% of those not receiving such drugs were free of atrial fibrillation at 6 months. In the group that underwent pulmonary-vein isolation, pulmonary-vein stenosis developed in two patients, pericardial effusion in one, and pulmonary edema in another; in the group that underwent atrioventricular-node ablation with biventricular pacing, lead dislodgment was found in one patient and pneumothorax in another. CONCLUSIONS: Pulmonary-vein isolation was superior to atrioventricular-node ablation with biventricular pacing in patients with heart failure who had drug-refractory atrial fibrillation. (ClinicalTrials.gov number, NCT00599976.)

Role of transoesophageal echocardiography in evaluating the effect of catheter ablation of atrial fibrillation on anatomy and function of the pulmonary veins.

AIMS: Radiofrequency ablation (ABL) of pulmonary veins (PVs) is an effective treatment of atrial fibrillation (AF). The aim of this study was to evaluate the possible morphological and functional consequences of this procedure on PV during a 12-month follow-up. METHODS AND RESULTS: Ninety-six patients underwent transoesophageal echocardiography (TEE) before ABL, and 48 h, 3, and 12 months later. The peak velocity, mean velocity, mean/peak flow velocity, and diameter of each vein were measured at every follow-up examination. All patients also underwent multidimensional computer tomography (MCT) 3 months after ABL. At the first control, a 5% reduction in PV diameters and an increase in the peak velocity, mean velocity, and mean/peak velocity (34.3, 42.2, and 6.9, respectively: P < 0.000) of their Doppler flow were observed. Later follow-up examinations revealed no further significant increase in PV narrowing or flow velocities. MCT showed PV stenoses (>50%) in four PVs, while TEE showed a >100% increase over basal values in flow velocities and a plateau configuration of the pulsed-wave Doppler spectrum. CONCLUSION: ABL of AF reduces the diameter and increases the flow velocities of PV. However, critical stenosis is rare and can be diagnosed by TEE through a marked change in the velocities and in the configuration of the Doppler flow.

Efficacy, safety, and outcome of atrial fibrillation ablation in septuagenarians.

AIMS: Catheter ablation is an effective treatment for atrial fibrillation (AF). The outcome of AF ablation in septuagenarians is not clear. Our aim was to evaluate success rate, outcome, and complication rate of AF ablation in septuagenarians. METHODS AND RESULTS: We collected data from 174 consecutive patients over 75 years of age who underwent AF ablation from 2001 to 2006. AF was paroxysmal in 55%. High-risk CHADS score (>or=2) was present in 65% of the population. Over a mean follow-up of 20 +/- 14 months, 127 (73%) maintained sinus rhythm (SR) with a single procedure, whereas 47 patients had recurrence of AF. Twenty of them had a second ablation, successful in 16 (80%). Major acute complications included one CVA and one hemothorax (2/194 [1.0%]). During the follow-up, three patients had a CVA within the first 6 weeks after ablation. Warfarin was discontinued in 138 out 143 patients (96%) who maintained SR without AADs with no embolic event occurring over a mean follow-up of 16 +/- 12 months. CONCLUSION: AF ablation is a safe and effective treatment for AF in septuagenarians.

Clinical predictors and relationship between early and late atrial tachyarrhythmias after pulmonary vein antrum isolation.

BACKGROUND: Several studies have reported early (EAT) and late (LAT) atrial tachyarrhythmias following atrial fibrillation (AF) ablation, but the factors associated with them and their clinical significance are not well known. OBJECTIVE: The purpose of this study was to investigate the predictors and the relationship between EAT and LAT after AF ablation. METHODS: A total of 1298 patients with paroxysmal (54%), persistent (18%), or permanent (28%) AF underwent intracardiac echocardiography-guided pulmonary vein antrum isolation and were followed for 41 +/- 10 months. EAT and LAT were defined as an episode of AF or atrial flutter/tachycardia lasting longer than 1 minute that occurred within the first 3 months of ablation and after 3 months postablation, respectively. RESULTS: After a single ablation procedure, EAT developed in 514 (40%) patients and LAT in 292 (22%) patients. At a multivariable analysis, longer AF duration (odds ratio [OR] 1.03), history of hypertension (OR 1.32), left atrial enlargement (OR 1.55), permanent AF (OR 1.72), and lack of superior vena cava isolation (OR 1.60) were significantly associated with EAT. Independent predictors of LAT were longer AF duration (OR 1.03), history of hypertension (OR 1.65), persistent (OR 2.17) or permanent AF (OR 2.28), and occurrence of EAT (OR 30.62). The risk of LAT was inversely related to the time to first EAT occurrence (OR 20, 54, and 1,052 in first, second, and third month, respectively). Notably, 49% of patients with EAT did not experience LAT. CONCLUSION: EAT strongly predict LAT. However, EAT did not automatically mean ablation failure. Delaying redo procedure may be appropriate during the first 2 months after ablation. Longer AF duration, hypertension, and nonparoxysmal AF are independent predictors of EAT and LAT.

Role of anticoagulation therapy after pulmonary vein antrum isolation for atrial fibrillation treatment.

BACKGROUND: Atrial fibrillation (AF) increases the risk of atrioembolic stroke. However, the role of anticoagulation therapy (OAT) in preventing cerebrovascular accidents (CVA) after intracardiac echocardiography-guided pulmonary vein antrum isolation (ICE-PVAI) is still unclear. In the present study, we evaluated the incidence of CVA following the interruption of OAT 3 months after ICE-PVAI. METHODS: Between September 2002 and March 2004, 85 consecutive patients (72 men, mean age 62 +/- 7 years) underwent ICE-PVAI for symptomatic drug-refractory AF. Heart disease was present in 61 patients (72%) (left ventricular ejection fraction = 58 +/- 6%, LA diameter 44 +/- 6 mm). Eighty-five consecutive patients who underwent electrical cardioversion (EC) for AF, matched for age, sex and heart disease, served as a control group. After 3 months, OAT was stopped unless one of the following conditions was observed: (i) AF-recurrence; (ii) severe pulmonary vein stenosis; (iii) non-good atrial contractility on transesophageal echocardiography; or (iv) other indications for OAT. RESULTS: In the study group, OAT was stopped after 3 months in 77 patients (90%) and no CVA occurred during the remaining follow-up (15 +/- 7 months). In the control group, 1 month after EC, OAT was stopped by the referring physician in 29 patients (34%). A stroke occurred in five patients (6%) (P = 0.09; mean P = 0.059) during follow-up. In two of these (2%), the stroke was fatal. CONCLUSIONS: Stopping OAT 3 months after ICE-PVAI seems to be safe in patients without AF recurrences after the first 3 months following ablation. Further randomized-controlled studies are needed to confirm these preliminary data.

Anatomic location of pulmonary vein electrical disconnection with balloon-based catheter ablation.

INTRODUCTION: Balloon-based catheters are an emerging technology in catheter ablation for atrial fibrillation, which aim to achieve consistent and rapid ablation encirclement of pulmonary veins (PVs). Recent emphasis has been placed on achieving more proximal electrical isolation within the PV-left atrial (LA) junction. We sought to evaluate the precise anatomic level of PV electrical disconnection with current design balloon-based catheters. METHODS AND RESULTS: Thirteen patients with drug-refractory paroxysmal atrial fibrillation undergoing balloon catheter ablation with the endoscopic laser system (CardioFocus) or the high frequency-focused ultrasound system (ProRhythm) underwent electroanatomic mapping (EAM) of the left atrium. Intracardiac echocardiographic (ICE) imaging was used for visualization of the position of the balloon catheter during energy delivery. Detailed point analysis of the location of electrical disconnection was then documented on EAM and with ICE. Successful electrical isolation was achieved in all 52 PVs. Despite ICE imaging confirming balloon catheter position at the antrum of the PVs, the location of electrical disconnection was demonstrated to be at or near the tubular ostium of the PVs on EAM and on ICE in all patients. CONCLUSION: Current generation balloon-based catheter ablation achieves electrical isolation distal in the LA-PV junction. This may limit the results of such systems in treating nonparoxysmal forms of atrial fibrillation.