Clinical Outcomes Of Catheter Ablation Research Articles

Circulation: Arrhythmia and Electrophysiology Editors’ Picks

<i>Circulation: Arrhythmia and Electrophysiology</i> Editors’ Picks

Impact of Image Integration on Catheter Ablation for Atrial Fibrillation Using Three‐Dimensional Electroanatomic Mapping: A Meta‐Analysis

Studies comparing the procedural and clinical outcomes of catheter ablation for atrial fibrillation (AF) guided by CartoMerge and that by Carto have achieved mixed results (Carto, Biosense Webster, Diamond Bar, CA, USA). We collected these studies and conducted a meta-analysis to determine whether CartoMerge results in better procedural and clinical outcomes. Three randomized controlled trials and two controlled observational studies were collected for analysis. The clinical and procedural outcomes of interest were AF recurrence after catheter ablation, major complications, procedure durations, and fluoroscopy time. Meta-analysis was performed using RevMan 5.0.18 software (The Cochrane Collaboration, Copenhagen, Denmark) and pooled estimates of effect were reported as risk ratios with 95% confidence intervals (CI). The overall results of this meta-analysis indicate that catheter ablation for AF guided by CartoMerge is insignificantly associated with a decreased risk of recurrences (RR = 0.76; 95% CI: 0.55-1.04; P = 0.09) and major complications (RR = 0.73; 95% CI: 0.37-1.45; P = 0.37) compared with that by Carto. The image integration using CartoMerge guiding catheter ablation for AF does not improve the main clinical outcomes significantly compared with that by Carto in centers with experienced operators.

Clinical Outcome of Catheter Ablation in Patients With Nonparoxysmal Atrial Fibrillation

Background— Catheter ablation of atrial fibrillation (AF) became an effective therapy for patients with drug-refractory AF, and the indications have broadened to include nonparoxysmal AF patients. However, data about the long-term effectiveness of ablation in patients with nonparoxysmal AF are lacking. The aim of the present study was to investigate the long-term outcomes of catheter ablation in patients with nonparoxysmal AF. Methods and Results— A total of 88 nonparoxysmal AF patients who received a stepwise catheter ablation (isolation of the pulmonary veins plus substrate modification) from 2006 to 2008 were enrolled. Freedom of recurrence was defined as the absence of atrial arrhythmias without using any antiarrhythmic agents after the catheter ablation. There were 63 patients (71.6%) with recurrences (47 patients with AF and 16 patients with atrial flutter/atrial tachycardia) after the initial procedure during a median follow-up period of 36.8 months. A CHADS 2 score of ≥3 and the left atrial (LA) diameter were significant predictors of recurrences in the multivariable analysis. Of the patients with CHADS 2 scores of ≥3 and an LA dimension ≥44 mm, all had recurrences within 1 year after the initial procedure. The overall recurrence-free rate could increase to 47.7% after the second procedure and 51.1% after the third procedure. Conclusions— The long-term recurrence-free rate of ablation in nonparoxysmal AF was only 28.4% after a single procedure, and multiple procedures were necessary to raise the recurrence-free rate. The CHADS 2 score and LA dimension may help us to identify patients who will have recurrences after catheter ablations of nonparoxysmal AF.

Clinical Significance of Inducibility Test of Atrial Fibrillation after Termination of Chronic, Persistent Atrial Fibrillation during Stepwise Approach

Background and Purpose: Atrial fibrillation (AF) termination has been used as the endpoint of catheter ablation of longstanding persistent AF (LPAF). A value of an inducibility testing after achieving AF termination as predicting clinical outcome of catheter ablation of AF is unclear. Methods: In 170 patients with LPAF (>1 year) underwent stepwise approach (pulmonary vein isolation, multiple linear ablations, defragmentation, and bidirectional block of cavotricuspid isthmus), inducibility was tested by rapid atrial pacing after AF terminated. Results: Of 170 patients, induced AF (>5 minutes) in 61 patients (group 1), induced atrial tachycardia (AT) (>10 minutes) (group 2) in 72 and no induction of AF and AT (group 3) in 37. During 39±21 months of follow up, AF recurrence rate in group 1 (n=29, 48%) was similar to that in group 2 (n=34, 35%), however, higher than that in group 3 (n=10, 27%, p<0.05). Conclusion: Noninducibility of AF and AT after termination of LPAF during biatrial ablation led to a better outcome during the follow-up period.

Pathophysiologic Characteristics and Clinical Outcomes of Catheter Ablation in Patients with Atrial Fibrillation Associated with Diabetes

Pathophysiologic Characteristics and Clinical Outcomes of Catheter Ablation in Patients with Atrial Fibrillation Associated with Diabetes

A shock in time saves ablation?

This editorial refers to ‘Atrial defibrillation threshold as a novel predictor of clinical outcome of catheter ablation for persistent atrial fibrillation’ by Y. Komatsu et al ., on page 213. Atrial fibrillation (AF) is the most common sustained arrhythmia encountered in clinical practice and is associated with substantial mortality and morbidity due to stroke and heart failure. In the last 10 years, catheter-based AF ablation aiming at isolation of arrhythmogenic pulmonary venous triggers and atrial substrate of AF has evolved as an important treatment option for patients with paroxysmal AF because of its high efficacy and reasonable safety. In fact, AF recurrence-free survival during 12-month follow-up after a single ablation procedure has been reported to be as high as 85%.1 In a recent meta-analysis of 63 studies by Calkins et al ., major complications of AF ablation, including pulmonary vein stenosis, cardiac tamponade, pericardial effusion, peri-procedural stroke, and periprocedural transient ischaemic attack, occurred …

Atrial Substrate Properties and Outcome of Catheter Ablation in Patients With Paroxysmal Atrial Fibrillation Associated With Diabetes Mellitus or Impaired Fasting Glucose

Diabetes mellitus has been reported to be an independent risk factor of atrial fibrillation (AF). The present study investigated the atrial substrate properties and clinical outcome of catheter ablation in patients with paroxysmal AF and abnormal glucose metabolism. A total of 228 patients with paroxysmal AF who had undergone catheter ablation for the first time were enrolled. An abnormal glucose metabolism (n = 65) was defined as diabetes mellitus or an impaired fasting glucose. We analyzed the clinical and electrophysiologic characteristics in, and the clinical outcome of, patients with AF with and without an abnormal glucose metabolism. The right atrial (107.2 ± 15.4 vs 96.0 ± 16.5 ms, p < 0.001) and left atrial (108.4 ± 22.3 vs 94.0 ± 17.5 ms, p < 0.001) total activation times were significantly longer in the patients with AF and an abnormal glucose metabolism than in those without an abnormal metabolism. Furthermore, the right atrial (1.46 ± 0.61 vs 2.00 ± 0.70 mV, p < 0.001) and left atrial (1.48 ± 0.74 vs 2.05 ± 0.78 mV, p < 0.001) bipolar voltages were significantly lower in those with AF and an abnormal glucose metabolism than in those without. The AF recurrence rate was also greater in the patients with an abnormal glucose metabolism (18.5% vs 8.0%, p = 0.022) than in those without. The follow-up duration was 18.8 ± 6.4 months. In conclusion, an abnormal glucose metabolism affects the biatrial substrate properties with an intra-atrial conduction delay, decreased voltage, and greater recurrence rate after catheter ablation.

Atrial defibrillation threshold as a novel predictor of clinical outcome of catheter ablation for persistent atrial fibrillation

Catheter ablation for persistent atrial fibrillation (AF) is currently performed with different procedural endpoints. When AF did not terminate during ablation procedure, electrical cardioversion was performed at different defibrillation threshold (DFT) according to AF characteristics and atrial electrophysiologic substrates. We sought to evaluate the impact of atrial DFT after catheter ablation for persistent AF on clinical outcome. We studied 128 patients with persistent AF (age 63±9 years, 106 men). After completion of circumferential pulmonary vein isolation, the left atrial substrate ablation was performed until AF terminated or all identified complex fractionated electrograms were eliminated. If AF did not terminate during ablation, an internal cardioversion protocol was started at 5J and was increased incrementally in 5 J steps until successful cardioversion was accomplished. Procedural AF termination was achieved in 50 patients (Group A). Atrial fibrillation was terminated by cardioversion with DFT≤10 J in 47 patients (Group B) and with DFT>10 J in 31 patients (Group C). At 14±7 follow-up months after 1.3±0.5 sessions, 47 (94%) Group A patients, 42 (89%) Group B patients, and 14 (45%) Group C patients remained in sinus rhythm. In multivariate analysis of Group B and Group C, DFT (hazard ratio 5.54, P<0.001) and AF duration (hazard ratio 3.74, P=0.011) were independent predictors of recurrent arrhythmia. When AF does not terminate after the completion of predetermined stepwise ablation, further extensive ablation to terminate AF might be unnecessary if the AF can be successfully terminated by electrical cardioversion at low DFT.

Atrial flutter catheter ablation in adult patients with repaired tetralogy of Fallot: mechanisms and outcomes of percutaneous catheter ablation in a consecutive series

Prior investigators note successful ablation of both typical cavotricuspid isthmus-dependent and scar-related macroreentrant right atrial flutters (AFL) in adult patients with repaired tetralogy of Fallot (TOF). However, an analysis of the mechanisms (including a description of a uniform approach to diagnose such mechanisms), and clinical outcomes of catheter ablation in a consecutive series of adult patients with AFL late after surgical TOF repair has not been previously reported. Background clinical data and follow-up were evaluated in a consecutive series of TOF patients evaluated from September 2001 to June 2008. We report a prevalence of sustained, symptomatic AFL in patients with repaired TOF equal to 20% (28/140 patients), and of recurrent, drug-refractory and/or severely symptomatic AFL to be 11% (16/140 patients). The AFLs manifested variable cycle lengths ranging from 215 to 525 ms. Underlying mechanisms were: (1) cavotricuspid (CTI)-dependent, counterclockwise atrial flutter (n=8 patients); (2) non-CTI-dependent macroreentrant scar-related AFL (n=6 patients); and (3) both CTI- and non-CTI-dependent macroreentrant AFL (n=2 patients). Recurrent arrhythmias occurred in six patients, five of whom were successfully treated with repeat ablation. After a mean follow-up of 23 months, 15 of 16 patients were alive and free of sustained AFL. AFL late after surgical TOF repair occurs in 20% of such patients. In more than half of these patients, the AFLs are drug-refractory and/or severely symptomatic. Despite the presence of congenital heart disease treated with prior cardiac surgery and AFLs with variable atrial cycle lengths, the CTI-dependent mechanism underlies approximately half of the sustained, symptomatic AFLs.

Clinical Predictors of Termination and Clinical Outcome of Catheter Ablation for Persistent Atrial Fibrillation

Clinical Predictors of Termination and Clinical Outcome of Catheter Ablation for Persistent Atrial Fibrillation

Clinical Predictors of Termination and Clinical Outcome of Catheter Ablation for Persistent Atrial Fibrillation

This study evaluated the role of pre-procedural clinical variables to predict procedural and clinical outcomes of catheter ablation in patients with long-lasting persistent atrial fibrillation (AF). Catheter ablation of persistent AF remains a challenging task. Catheter ablation was performed in 90 patients (76 men, age 57 +/- 11 years) with long-lasting persistent AF. The history of AF, echocardiographic parameters, presence of structural heart disease, and surface electrocardiogram (ECG) AF cycle length (CL) were assessed before ablation and analyzed with respect to procedural termination and clinical outcome. Mean follow-up was 28 +/- 4 months. Persistent AF was terminated in 76 of 90 patients (84%) by ablation. The duration of continuous AF was shorter (p < 0.0001), the surface ECG AFCL was longer (p < 0.0001), and the left atrium was smaller (p < 0.01) in patients in whom AF was terminated by catheter ablation. The surface ECG AFCL was the only independent predictor of AF termination (p < 0.01). Maintenance of sinus rhythm was associated with a shorter duration of continuous AF (p < 0.0001), a longer surface ECG AFCL (p < 0.001), and a smaller left atrium (p < 0.05) compared with those with recurrent arrhythmia. In multivariate analysis, the surface ECG AFCL and the AF duration predicted clinical success of persistent AF ablation (p < 0.01 and p < 0.05, respectively). The surface ECG AFCL is a clinically useful pre-ablation tool for predicting patients in whom sinus rhythm can be restored by catheter ablation. The duration of continuous AF and the surface ECG AFCL are predictive of maintenance of sinus rhythm.

Clinical Outcomes of Catheter Substrate Ablation for High-Risk Patients With Atrial Fibrillation

The purpose of this study was to determine the long-term clinical outcomes of catheter ablation of atrial fibrillation (AF) substrate for high-risk patients with AF. The benefits of catheter ablation for high-risk AF patients with respect to mortality and stroke reductions remain unclear. We performed AF substrate ablation guided by complex fractionated atrial electrogram (CFAE) mapping in 674 high-risk AF patients. The clinical end points were sinus rhythm (SR), death, stroke, or bleeding. Of these 674 patients, 635 were available for follow-up and made up the study cohort. The patients were relatively old (mean age 67 +/- 12 years) and 129 had an ejection fraction (EF) <40%. After the mean follow-up period of 836 +/- 605 days, 517 were in SR (81.4%). There were 15 deaths among the patients who stayed in SR compared with 14 deaths among those who remained in AF (5-year survival rate, 92% vs. 64%, respectively; p < 0.0001). SR was the most important independent favorable parameter for survival (hazard ratio 0.14, 95% confidence interval 0.06 to 0.36, p < 0.0001), whereas old age was unfavorable. Warfarin therapy was discontinued in 434 of the 517 patients in SR post-ablation (84%) whose annual stroke rate was only 0.4% compared with 2% in those with continuing warfarin treatment (p = 0.004). CFAE-targeted ablation of AF is effective in maintaining SR in selected high-risk AF patients and might allow patients to stop warfarin therapy. SR after AF ablation is a marker of relatively low mortality and stroke risk. Our findings support conducting further randomized studies to determine whether AF ablation is associated with mortality and/or stroke reduction.

The Impact of CT Image Integration into an Electroanatomic Mapping System on Clinical Outcomes of Catheter Ablation of Atrial Fibrillation

A detailed appreciation of left atrial/pulmonary vein (LA/PV) anatomy may be important in improving the safety and success of catheter ablation (CA) for atrial fibrillation (AF). The aim of this nonrandomized study was to determine the impact of computerized tomography (CT) image integration into a 3-dimensional (3D) mapping system on the clinical outcome of patients undergoing CA for AF. Ninety-four patients (age: 56 +/- 10 years) with AF (paroxysmal 46, persistent 48) underwent wide encirclement of ipsilateral PV pairs using irrigated radiofrequency ablation with the endpoint of electrical isolation. Ablation was guided by 3D mapping alone (electroanatomic 24, noncontact 23) in 47 (3DM group) patients and by CT image integration (Cartomerge) in 47 (CT group). In persistent AF, a combination of linear ablation and targeted ablation of complex fractionated electrograms was also performed. Successful PV electrical isolation did not differ between the two groups. A significant reduction in fluoroscopy times was demonstrated in the CT group (49 +/- 27 minutes vs 3DM group 62 +/- 26 minutes, P = 0.03). Arrhythmia recurrence was reduced in the CT group (32% vs 51% in the 3DM group, P < 0.01). In 30 symptomatic patients (12 CT and 18 3DM), repeat procedures for AF (13 in 3DM and 5 CT, P < or = 0.10) and AT (5 in 3DM and 7 CT, P = NS) were performed. Overall success on 7-day monitor off antiarrhythmic drugs was achieved in 60% in the 3DM group when compared with 83% in the CT group (P < 0.05) at a follow-up of 25 +/- 5 weeks. CA for AF guided by CT integration was associated with reduced fluoroscopy times, arrhythmia recurrence, and increased restoration of sinus rhythm. Improved visualization of complex LA geometries might improve the safety and success of CA for AF.

Outcomes of radiofrequency catheter ablation of atrioventricular reciprocating tachycardia in patients with congenital heart disease

Objectives Assessment of clinical outcomes of catheter ablation of atrioventricular reciprocating tachycardias in patients with congenital heart disease (CHD). Background Atrioventricular reciprocating tachycardias occur in patients with CHD and may be poorly tolerated. Methods Retrospective review of all 105 such ablations in 83 patients performed between 03/90 and 02/02 at one institution. Results The dominant arrhythmia mechanism was accessory pathway (70 patients, 84%), and the most common indications were drug-refractory tachycardia, life-threatening arrhythmia, and elective presurgical ablation. Congenital heart disease diagnoses were diverse, with one third of patients having Ebstein’s anomaly. Twenty patients (24%) had catheter access limited by prior surgeries or occluded vascular access. Of 109 accessory pathways (APs), 74 (68%) were manifestly preexcited, and 71 (65%) were located on the right atrioventricular groove. Fourteen patients (20%) had multiple pathways. There were 2 major complications (1 death, 1 hemorrhage), and 3 minor complications (5.5% of procedures). Acute success rate was 80% per procedure, 82% for left- and 70% for right-sided APs. Acute success rates for patients with Ebstein’s anomaly were similar to patients with other CHD diagnoses, but Ebstein’s patients were more likely to have recurrence. At 44 ± 35 months follow-up, successful ablation was achieved in 59% of procedures and 68% of patients, with 19 patients (23%) undergoing one or more repeat ablations. Conclusions Compared to patients with normal cardiac anatomy, patients with CHD of all varieties have lower rates of acute and long-term success for ablation for atrioventricular reciprocating tachycardias.