Long-term Efficacy Of Catheter Ablation Research Articles

The effect of amiodarone given periprocedurally on the effectiveness of catheter ablation in patients with persistent atrial fibrillation refractory to cardioversion

Abstract Background Rhythm control strategy in patients with persistent atrial fibrillation refractory to electrical cardioversion (AF-REC) poses an important clinical problem. Little is known about the effect of amiodarone therapy given periprocedurally with catheter ablation on maintaining sinus rhythm in this group of patients. Purpose This study aimed to determine whether initial amiodarone therapy introduced prior to AF ablation and continued for one month after the procedure affects the long-term effectiveness of the rhythm control strategy in patients with AF-REC. Methods We conducted a retrospective case-control study of medical records of AF-REC patients treated periprocedurally with amiodarone in addition to pulmonary vein isolation. Data on comorbidities, transthoracic echocardiogram results, and short- and long-term effectiveness of ablation was extracted. Patients were followed up in the out patient clinic with the use of a 72-hour Holter monitoring and telephone interviews. AF recurrence was defined as ≥ 30s episode of atrial tachyarrhythmia. Results The analysis comprised 56 patients: 37 in the amiodarone and 19 in the control group; 12 women, mean age 57 years, mean follow-up of 39.5 months. Amiodarone was discontinued after 1 month at the most after the ablation in all of the patients. The primary endpoint (AF-free survival) was achieved in 17 (45,9%) pts in the amiodarone group and 3 (15,8%) pts in the control group (p=0.026). On multivariable analysis, amiodarone therapy was the only variable correlating with the primary endpoint: OR 6.8 (95% CI: 1.4 - 33.9), p=0.019. Conversion of AF from persistent to paroxysmal or no AF in the follow-up was achieved in 32 pts (86,5%) in the amiodarone group and 9 pts (47,4%) in the control group: OR 8.0 (95% CI: 2.1 - 30.0), p=0.002. Patients in the amiodarone group experienced a borderline better increase of left ventricular ejection fraction: ∆ 5.2% (95% CI: -0.1 - 10.5), p= 0.054. Conclusion Periprocedural use of amiodarone in patients ablated due to persistent atrial fibrillation refractory to electrical cardioversion may lead to significantly better long-term efficacy of catheter ablation in this group of patients.

Procedural Feasibility and Long-Term Efficacy of Catheter Ablation of Atypical Atrial Flutters in a Wide Spectrum of Heart Diseases: An Updated Clinical Overview.

Atypical atrial flutters (AAFL) are difficult-to-manage atrial arrhythmias, yet potentially amenable to effective radiofrequency catheter ablation (CA). However, data on CA feasibility are only sparingly reported in the literature in different clinical settings, such as AAFL related to surgical correction of congenital heart disease. The aim of this review was to provide an overview of the clinical settings in which AAFL may occur to help the cardiac electrophysiologist in the prediction of the tachycardia circuit location before CA. Moreover, the role and proper implementation of cutting-edge technologies in this setting were investigated as well as which procedural and clinical factors are associated with long-term failure to maintain sinus rhythm (SR) to find out which patients may, or may not, benefit from this procedure. Not only different surgical and non-surgical scenarios are associated with peculiar anatomical location of AAFL, but we also found that CA of AAFL is generally feasible. The success rate may be as low as 50% in surgically corrected congenital heart disease (CHD) patients but up to about 90% on average after pulmonary vein isolation (PVI) or in patients without structural heart disease. Over the years, the progressive implementation of three-dimensional mapping systems and high-density mapping tools has also proved helpful for ablation of these macro-reentrant circuits. However, the long-term maintenance of SR may still be suboptimal due to the progressive electroanatomic atrial remodeling occurring after cardiac surgery or other interventional procedures, thus limiting the likelihood of successful ablation in specific clinical settings.

Combination of pulmonary vein isolation and left atrial appendage closure for non-valvular atrial fibrillation

Atrial fibrillation might occur up to 2% of the general population, with a lifetime risk of 24% in persons > 40 years of age. Catheter ablation is increasingly being used to treat drug-refractory atrial fibrillation. The long-term efficacy of catheter ablation is disappointing, with success rates about 50%. Stroke is one of the major complications of atrial fibrillation because of atrial thrombus formation. The overall annual stroke risk is 5% in patients with atrial fibrillation, increasing up to 15% in high-risk patients. The left atrial appendage was the source of thrombi in >90% of the patients with non-valvular atrial fibrillation. Anticoagulation should be given to prevent thromboembolic events. However, anticoagulant therapy has several disadvantages, such as (major) bleedings, interactions with some dietary components and other medications, and a narrow therapeutic range. In addition, patients with atrial fibrillation, especially the elderly, have low compliance. Exclusion of the left atrial appendage from the systemic circulation could be an alternative. Thus, the combination of the left atrial appendage closure with the isolation of the pulmonary veins appears to be a rational method for the treatment of atrial fibrillation. This approach eliminates the need for anticoagulants and reduces the risk of stroke.

Novel mechanisms in the initiation and maintenance of atrial fibrillation: tailored individual treatment

Atrial fibrillation affects approximately three percent of the adults. Ablation strategies targeting the isolation of the pulmonary veins are the up-to-date cornerstones for atrial fibrillation ablations. However, a one-year success rate of repeated interventions is not more than 70%. Long-term efficacy of catheter ablation is presumably limited by electrical and structural remodeling of the atria, which results in a progressive increase in the duration of atrial fibrillation to become sustained. The potential pathophysiological importance of the epicardial adipose tissue, atrial fibrosis, autonomic nervous system and arrhythmogenic foci are documented by several studies. Increased volume, inflammation induced transformation to fibrosis and myocardial infiltration of atrial subepicardial fat in obese patients result in higher risk of atrial fibrillation development. Changes in atrial autonomic innervation under some conditions including regular physical exercise strongly promote arrhythmogenesis via the mechanism of enhanced triggered activity or abbreviated atrial refractoriness. Individualized management of possible trigger and substrate mechanisms are proposed to provide a novel basis for the effective treatment of atrial fibrillation. Pro-fibrotic signalling pathways can be inhibited by the suppression of renin-angiotensin-aldosterone system. Neuromodulation strategies include renal sympathetic denervation and ganglionic plexi ablation. Anticoagulation therapy has also been shown to reduce the burden of abnormal atrial remodeling. Possible novel catheter ablation techniques are used for right or left atrial linear lesions, scar homogenization and catheter ablation of complex fractionated atrial electrograms, rotors or ectopic foci. Beside these new management strategies, clinical consideration of factors of particular risks as obesity, hyperlipidaemia, hypertension, diabetes and obstructive sleep apnoe are also essential. Orv Hetil. 2018; 159(28): 1135-1145.

Long-term efficacy of catheter ablation as first-line therapy for paroxysmal atrial fibrillation: 5-year outcome in a randomised clinical trial

ObjectiveThe Medical ANtiarrhythmic Treatment or Radiofrequency Ablation in Paroxysmal Atrial Fibrillation (MANTRA-PAF) trial compared radiofrequency catheter ablation (RFA) with antiarrhythmic drug therapy (AAD) as first-line treatment for paroxysmal atrial fibrillation...

Long-term efficacy of catheter ablation for paroxysmal atrial fibrillation in patients with Brugada syndrome and an implantable cardioverter-defibrillator to prevent inappropriate shock therapy

In patients with an implantable cardioverter-defibrillator (ICD) and Brugada syndrome (BrS), the long-term efficacy of catheter ablation for preventing inappropriate shock therapy due to paroxysmal atrial fibrillation (PAF) has not been elucidated. To evaluate the efficacy of atrial fibrillation (AF) ablation for PAF for prevention of inappropriate ICD therapy over a longer follow-up period. We enrolled 76 men with BrS and an ICD, with a mean age of 46.2 ± 16.5 years. Twenty-one patients had AF (19 had PAF, 1 had persistent AF, and 1 had longstanding persistent AF). Fourteen patients with PAF underwent pulmonary vein isolation (PVI) and received follow-up electrophysiological study (EPS) 6 months after the first PVI. If necessary, ablation was performed. Over a mean follow-up period of 3.3 ± 1.4 years after the repeat session, 13 of the 14 patients (92.9%) had no recurrence of AF. Six patients with PAF without inappropriate ICD therapy before PVI had no recurrence of AF and no inappropriate therapy during follow-up. Among the 8 patients who had inappropriate therapy because of PAF before PVI, 1 patient who had recurrent AF underwent another ablation session. After this final session, there were no recurrences of AF and no inappropriate therapy (mean follow-up period 3.1± 1.2 years). Catheter ablation is effective in patients with BrS and an ICD, and prevents inappropriate ICD therapy owing to PAF; thus, catheter ablation is an appropriate first-line therapy for PAF among such patients.

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Weerasooriya et al (J Am Coll Cardiol 2011;57:160–166, PMID 21211687) evaluated the long-term efficacy of catheter ablation of atrial fibrillation (AF). One hundred patients undergoing first AF ablation (63% paroxysmal; 3.5 ± 1.4 prior ineffective antiarrhythmic agents) were followed for 5 years. Complete success was defined as absence of any AF or atrial tachycardia recurrence (clinical or by 24-hour Holter monitoring) lasting ≥30 seconds. Arrhythmia-free survival rates after a single catheter ablation procedure were 40%, 37%, and 29% at 1, 2, and 5 years, respectively, with most recurrences over the first 6 months.

Impact of variant pulmonary vein anatomy and image integration on long-term outcome after catheter ablation for atrial fibrillation

To investigate the impact of variant pulmonary vein (PV) anatomy and the use of three-dimensional image integration (3D-II) on long-term efficacy of catheter ablation for atrial fibrillation (AF). Consecutive procedures from 2002 to 2007 were analysed from a prospective database. All patients underwent wide area circumferential ablation, with linear lesions added and complex fractionated electrograms targeted for persistent AF. Imaging was segmented on Carto to assess PV anatomy. Three hundred and fifty patients underwent 1.9 ± 0.9 procedures. The mean age was 57 ± 11 years, 73% males, and 55% paroxysmal AF. Freedom from AF/atrial tachycardia was 42% for paroxysmal AF and 20% for persistent AF at 3.1 years after the first procedure, or 86 and 66%, respectively, at 2.5 years after the last procedure. The Kaplan-Meier analysis showed a trend towards improved single-procedure efficacy with 3D-II (8.9% difference, P = 0.087) and a reduction in the number of procedures per patient from 2.1 ± 1.1 to 1.8 ± 0.9 (P < 0.0001). The use of 3D-II improved single-procedure efficacy with Carto (13.3% difference, P = 0.018), but not with Ensite NavX. Variant PV anatomy was identified in 28% and was associated with a lower single-procedure efficacy (10.0% difference, P = 0.024) but with no effect on final outcome. Multivariate analysis confirmed the impact of 3D-II [hazard ratio (HR) for recurrence of AF 0.67, P = 0.020] and variant PV anatomy (HR 1.37, P = 0.044). The use of 3D-II improves single-procedure efficacy of PV isolation for AF. Variant PV anatomy was associated with a lower single-procedure success rate.

Atrial Flutter after Heart Transplantation: Mechanism and Catheter Ablation

Background Atrial flutter is a frequent arrhythmia after heart transplantation, but little is known about its mechanism and treatment. We report the results of an electrophysiologic study in patients with atrial flutter after orthotopic heart transplantation, describing its mechanism and demonstrating the acute and long-term efficacy of catheter ablation for treating this arrhythmia. Methods We included 14 patients with symptomatic atrial flutter after orthotopic heart transplantation. All of them underwent an electrophysiologic study to determine the mechanism of the arrhythmia and catheter ablation when possible. Results Counterclockwise right atrial circuit around the tricuspid annulus involving the cavotricuspid isthmus was demonstrated in 13 patients (86%). Catheter ablation of the isthmus was performed with good acute results in all but 1. During a mean follow-up of 24 ± 17 months, recurrent atrial flutter was documented in 3 patients and atrial fibrillation in 2. In another patient, we demonstrated a left atrial origin. Conclusions The most common mechanism of atrial flutter in heart transplant recipients is a counterclockwise circuit around the tricuspid annulus involving the cavotricuspid isthmus. Catheter ablation of the isthmus between tricuspid annulus and posterior atrial suture line represents an effective treatment in these patients. This condition may be avoided by changing the surgical technique to a bicaval anastomosis.

136 Long term efficacy of catheter ablation for AF: impact of additional targeting of fractionated electrograms

Introduction Published long term follow-up data for catheter ablation (CA) of AF is scarce. Although many centres perform ablation of complex fractionated electrograms (CFE) in addition to pulmonary vein isolation (PVI), evidence for this is conflicting. We sought to investigate long term efficacy of CA for AF and the impact of ablating CFE in addition to PVI and linear lesions in persistent AF (PeAF). Methods Consecutive cases from 2002 to 2007 at St Bartholomew9s Hospital were analysed. All patients underwent wide area circumferential ablation with confirmation of electrical isolation. For PeAF linear lesions were added at the roof and mitral isthmus, with additional targeting of CFE from 2005. Data were collected in a prospective database. Attempts were made to contact all patients for follow-up in September 2009. Failure was defined as documented recurrence of AF or other atrial tachyarrhythmia (AT) lasting ≥30 s. As repeated procedures for patients with recurrence of AF/AT can distort patterns of late recurrence, this was analysed following the first cluster of procedures defined as when the patient first emerged from their 3 month blanking period free of AF/AT (or failure accepted), that is, when AF was first successfully eliminated whether after one CA or several. Results Two hundred eighty-five patients underwent 530 procedures. Mean age was 57±11 years, 75% male, 20% had structural heart disease and 53% paroxysmal AF. Left atrial diameter was 4.3±0.8 cm and 17% had left ventricular systolic dysfunction. Mean number of procedures was 1.9 per patient (1.7 for PAF and 2.0 for PeAF). Procedural complications included stroke or TIA in 0.6% (all of which resolved) and pericardial effusions which were drained without sequelae in 1.7%. There were no peri-procedural deaths. Of 285 patients, 270 were contacted for follow-up. During 3.3 (2.4 to 7.5) years from the first procedure, there were seven deaths (unrelated to their ablation or AF) and three strokes or TIA (0.3% per year). Freedom from AF/AT at 2.7 (0.2 to 7.4) years after the last procedure was 86% for PAF and 68% for PeAF. Most recurrence occurred in the first year, with late recurrence >3 years occurring in 3/100 years of follow-up. Kaplan–Meier analysis showed that CFE ablation improved outcome for PeAF after the first cluster of procedures (p=0.04), with a trend towards improved final outcome (p=0.13). Conclusion Long term freedom from AF is achievable in the majority of patients with PAF and PeAF with low rates of late recurrence. Rates of periprocedural complications are low, and late adverse events including stroke are few. Targeting CFE in addition to PVI and linear lesions improves outcome for PeAF.

Long-term efficacy of catheter ablation for atrial fibrillation: impact of additional targeting of fractionated electrograms

ObjectivesTo investigate long-term efficacy of catheter ablation for atrial fibrillation (AF) and the impact of ablating complex or fractionated electrograms (CFEs) in addition to pulmonary vein isolation and linear lesions...

Effectiveness of Catheter Ablation of Ventricular Tachycardia in Elderly Patients With Structural Heart Disease

The implantable cardioverter-defibrillator (ICD) is a well-recognized means of providing effective treatment for patients with ventricular tachycardia (VT) and structural heart disease. However, the benefits of these devices in patients with limited life-expectancy have been questioned. Moreover, the long-term efficacy of catheter ablation of VT in this setting is unknown. This study involved 33 consecutive patients aged over 75 years with structural heart disease who underwent catheter ablation of VT. We investigated the efficacy of the procedure and its complications, and evaluated patient outcomes during follow-up. The patients' mean age at the time of the procedure was 79.7 (3.7) years. Twenty-seven had ischemic heart disease and 6 had dilated cardiomyopathy. Their mean left ventricular ejection fraction (LVEF) was 35.9 (8.9%). Ablation of clinical VT was successful in 28 patients (84.8%). There were no statistically significant differences in the efficacy of ablation between patients with post-infarction scars (88.9%) and those with dilated cardiomyopathy (66.7%; P=.17). An ICD was implanted after the procedure in 4 patients. Complications associated with the procedure occurred in only 3 patients. Twenty patients were contacted later, after a mean follow-up period of 38.5 (27.7) months. Nine (mean age, 82.2 [4.6] years) were still alive and reported a good quality of life, without recurrent arrhythmias. Catheter ablation of VT in elderly patients with structural heart disease appeared to be effective and relatively safe. It could provide an alternative to ICD implantation in this patient group.

Is verapamil a double-edged sword in rate control of paroxysmal atrial fibrillation?

Over the last decade, remarkable progress has been made in the field of atrial fibrillation (AF) pathophysiology and management. There is no doubt that radiofrequency catheter ablation therapy improves the quality of life and left ventricular function in patients with symptomatic AF by improving the maintenance of sinus rhythm. 1 A new antiarrhythmic agent, dronedarone, was recently shown to reduce the composite outcome of cardiovascular hospitalization and death in patients with AF. 2 Moreover, novel approaches such as the dominant frequency (DF) analysis of atrial electrograms have offered clinicians a better insight into the pathogenesis of AF. 3 Despite these advancements, longterm maintenance of sinus rhythm is challenging, and persistent or permanent AF still develops in many patients. In these cases, control of the ventricular rate has an essential role in alleviating the symptoms and preventing the development of tachycardia-induced cardiomyopathy. Spectral analysis of atrial recordings increasingly has been used to detect areas with high atrial activation rate during AF. The main benefit of frequency domain analysis is that it can be applied to the complex electrograms of AF more easily than time domain measurements. 3 Experimental and clinical studies indicate that the DF sites within the pulmonary veins (PV) have an important role in the initiation and maintenance of paroxysmal AF. 4,5 Furthermore, it has been postulated that DF mapping can be used to guide rapid identification of extrapulmonary sites that drive AF. 6 In this issue, Kushiyama et al 7 report the results of a study that evaluated the effects of verapamil on regional distribution of DFs in the PVs and atria in 43 patients undergoing catheter ablation of paroxysmal AF. They found that the highest DF was localized in the PVs and showed that there was a substantial PV-to-atria DF gradient at baseline. These findings are in agreement with previous studies indicating that the PVs are the main drivers of paroxysmal AF. 4,5 It is well established that beta-blockers, calcium channel antagonists, and digitalis slow ventricular rate, but much fewer data are available on their effect on atrial arrhythmogenesis. Verapamil is a nondihydropyridine calcium channel antagonist with potent negative chronodropic and dromodropic effects. Due to its use-dependent dromodropic action, verapamil is highly effective in controlling rapid ventricular rate in AF, but has less effect on atrioventricular (AV) nodal conduction at a normal rate. Kushiyama et al 7 showed that verapamil caused variable changes in the PV excitation. The maximum PV DF increased in 65% of the patients and decreased in the remaining 35%. In contrast, verapamil consistently increased the DFs in all of the atrial recording sites. As a result of these tissue-specific effects, verapamil eliminated the PV-to-atria DF gradient. According to the investigators, this is attributable to regional heterogeneities of action potential morphology and ionic currents responsible for the repolarization (e.g., I CaL ) in the PV myocardial muscle sleeves and atria rather than to a reflex increase in sympathetic tone in response to a reduction in blood pressure. Prior studies indicate that the extrapulmonary DF areas and the absence of the PV-to-atria frequency gradient can be used to identify additional ablation targets. For example, Lin et al 6 have shown that the DF shifts to the right atrium when AF is initiated in the superior vena cava. Sanders et al 5 reported that termination of permanent AF requires ablation of extrapulmonary high-frequency sites in addition to PV isolation. Hence, it is tempting to speculate that ablation of the verapamil-induced atrial high-frequency areas may improve the long-term efficacy of catheter ablation of paroxysmal AF. The results of Kushiyama et al 7 are also important with regard to rate control of AF because they raise the possibility that verapamil may provoke paroxysmal AF by creating new high-frequency sources in the atria. In keeping with this, verapamil facilitated the induction of sustained AF. That is, in all of the 6 patients with no inducible AF at baseline, sustained AF was easily induced after verapamil by burst pacing from the coronary sinus. These findings are consistent with experimental data indicating that verapamil promotes maintenance of AF by shortening the atrial refractory period and AF cycle length and enhancing reentrant activity in the atria. 8 In lieu of these data, the usefulness of verapamil for ventricular rate control in patients with paroxysmal AF may be limited by its profibrillatory effect in

Implantable Monitors – Recent Developments

For many years implantable cardiac monitors have proved to be helpful diagnostic tools for illuminating mechanisms of syncopes and documenting symptomatic arrhythmias in selected patients. With an increasing number of patients being treated interventionally for atrial fibrillation (AF), continuous rhythm monitoring with implantable devices can help to address several unsolved questions in this field, such as the true AF burden after an ablation procedure, the percentage of completely asymptomatic recidives and the long-term efficacy of catheter ablation, and can thereby influence the timing for discontinuation of antiarrhythmic drug treatment or even oral anticoagulation. The recently published Reveal® XT Performance Trial (XPECT) quantified the performance of the first implantable cardiac monitor with dedicated AF detection capabilities. In this validation study the AF detection algorithm was proved to deliver reliable detection of the presence or absence of AF. In addition, the AF burden could be reliably assessed and quantified. In the future, continuous monitoring strategies may be helpful to overcome the shortcomings of non-continuous monitoring and may be able to better document AF recurrence, identify the type of recurrence and document the burden of AF.

P6-32: Prediction of long-term efficacy of catheter ablation by signal-averaged electrocardiogram and 24-hour holter electrocardiogram in arrhythmogenic right ventricular cardiomyopathy patients with sustained ventricular tachycardia

P6-32: Prediction of long-term efficacy of catheter ablation by signal-averaged electrocardiogram and 24-hour holter electrocardiogram in arrhythmogenic right ventricular cardiomyopathy patients with sustained ventricular tachycardia

Catheter ablation of ventricular tachycardia in 136 patients with coronary artery disease: Results and long-term follow-up

Objectives. This study attempted to determine the feasibility and long-term efficacy of catheter ablation by means of either radiofrequency or direct current energy in a selected group of patients with coronary artery disease.Background. Catheter ablation of ventricular tachycardia has proved to be highly effective in patients with idiopathic and bundle branch reentrant ventricular tachycardia. In patients with coronary artery disease and recurrent sustained ventricular tachycardia resistant to medical antiarrhythmic management, the value of catheter ablation has not yet been established.Methods. One hundred thirty-six patients with coronary artery disease and one configuration of monomorphic sustained ventricular tachycardia underwent radiofrequency (72 patients) or direct current catheter ablation (64 patients). The mapping procedure to localize an adequate site for ablation included pace mapping during sinus rhythm, endocardial activation mapping, identification of isolated mid-diastolic potentials and pacing interventions during ventricular tachycardia.Results. Primary success was achieved in 102 (75%) of 136 patients (74% of 72 undergoing radiofrequency and 77% of 64 with direct current ablation). Complications were noted in 12% of patients. During a mean (± SD) follow-up period of 24 ± 13 months (range 3 to 68), ventricular tachycardia recurred in 16% of patients.Conclusions. Catheter ablation of ventricular tachycardia in coronary artery disease is feasible in patients with one configuration of monomorphic sustained ventricular tachycardia. There is no significant difference with respect to the type of energy applied. The follow-up data show that in a selected group of patients with coronary artery disease, catheter ablation offers a therapy alternative.