Why Atrial Fibrillation Ablation Should Be Considered First-Line Therapy for Some Patients

Long-term Patient and Health Service Outcomes of Ablation and Antiarrhythmic Drugs in Atrial Fibrillation: A Comparative Systematic Review

Atrial fibrillation (AF) is a prevalent problem worldwide and a common cause of hospitalization, poor quality of life, and increased mortality. Although several treatments are used, the use of ablation and antiarrhythmic drug therapy has increased in the past decade. However, debate continues on the most suitable option for heart rhythm control in patients. Previous studies have largely focused on short-term outcome effects of these treatments. This systematic review aims to determine the effect of ablation compared to antiarrhythmic drugs for AF on long-term patient and health service outcomes of mortality, hospitalization, and quality of life. Three databases were systematically searched-studies were included if they reported long-term outcomes of more than 12 months comparing the 2 treatments. Title and abstract screening and subsequent full-text screening was done by 2 reviewers. Data were extracted from the final studies identified. The details of the search were recorded according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses report. A total of 2224 records were identified. After removing duplicates and screening the titles and abstracts, 68 records required full-text screening. Finally, 12 papers were included in the analysis. Eight studies reported mortality indicating ablation was superior, 2 studies reported hospitalization with opposing outcomes, and 5 quality of life studies indicating ablation was a better treatment. In studies assessing long-term outcomes, beyond 12 months, following ablation or rhythm control drugs for AF, most found a lower risk of death and greater improvement in quality of life in the ablation group.

Impact of early ablation of atrial fibrillation on long-term outcomes: results from phase II/III of the GLORIA-AF registry

Background

First-line ablation for atrial fibrillation (AF) reduces the risk of recurrent atrial arrhythmias compared to medical therapy. However, the prognostic benefit of early AF ablation remains undetermined. Herein, we aimed to evaluate the effects of early AF ablation compared to medical therapy.

Methods

Using data from phase II/III of the GLORIA-AF registry, we studied patients who were consecutively enrolled with newly diagnosed AF (< 3 months before baseline visit) and an increased risk of stroke (CHA₂DS₂–VASc ≥ 1). At baseline visit, 445 (1.7%) patients were treated with early AF ablation and 25,518 (98.3%) with medical therapy. Outcomes of interest were the composite outcome of all-cause death, stroke and major bleeding, and pre-specified outcomes of all-cause death, cardiovascular (CV) death, non-CV death, stroke and major bleeding.

Results

A total of 25,963 patients (11733 [45.2%] females; median age 71 [IQR 64–78] years; 17424 [67.1%] taking non-vitamin K antagonist oral anticoagulants [NOACs]) were included. Over a follow-up period of 3.0 (IQR 2.3–3.1) years, after adjustment for confounders, early AF ablation was associated with a significant reduction in the composite outcome of all-cause death, stroke and major bleeding (HR 0.50 [95% CI 0.30–0.85]) and all-cause death (HR 0.45 [95% CI 0.23–0.91]). There were no statistical differences between the groups in terms of CV death, non-CV death, stroke and major bleeding. Similar results were obtained in a propensity-score matched analysis of patients with comparable baseline variables.

Conclusions

Early AF ablation in a contemporary prospective cohort of AF patients who were predominantly treated with NOACs was associated with a survival advantage compared to medical therapy alone.

Trial registration

Clinical trial registration: http://www.clinicaltrials.gov. Unique identifiers: NCT01468701, NCT01671007 and NCT01937377.

Graphical abstract

Created with BioRender.com.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00392-022-02022-1.

Effect of Combined Pulmonary Vein and Superior Vena Cava Isolation on the Outcome of Second Catheter Ablation for Paroxysmal Atrial Fibrillation

Recurrence of paroxysmal atrial fibrillation (AF) is partly due to pulmonary vein (PV) reconnection and non-PV foci, especially superior vena cava (SVC). We aimed to investigate the efficacy and safety of empiric SVC isolation plus PV isolation after first failed radiofrequency ablation involving only PV isolation for paroxysmal AF. Procedural and follow-up outcomes of ablation for 144 consecutive paroxysmal AF patients after first failed radiofrequency ablation involving only PV isolation were retrospectively compared between patients undergoing either conventional SVC isolation (additional SVC isolation if SVC-triggered AF or rapid SVC activity was observed; n = 72) or empiric SVC isolation after PV isolation (n = 72). In conventional SVC isolation versus empiric SVC isolation groups: baseline characteristics and proportion of recorded PV electrical potentials were similarly distributed and all pulmonary veins were successfully reisolated; SVC isolation was performed less often (6 [8.3%] vs 70 [97.2%]; p <0.001, respectively); and during 19 ± 10 months follow-up, atrial tachyarrhythmias recurrence-free rate after a second procedure was lower (58.3% vs 77.8%, log rank; p = 0.037). Multivariate regression analysis revealed LA diameter ≥45 mm (odds ratio [OR] = 2.5; 95% confidence interval [CI], 1.4 to 4.6; p = 0.002) as the independent risk factor of atrial tachyarrhythmias recurrence and empiric SVC isolation (OR = 0.47; 95% CI, 0.25 to 0.87; p = 0.016) as the independent protector against atrial tachyarrhythmias recurrence after a second ablation procedure. Empiric SVC isolation plus PV isolation did not increase significantly procedural time or complications. In conclusion, the strategy of empiric SVC isolation plus PV isolation during a second procedure for paroxysmal AF improved atrial tachyarrhythmias recurrence-free rate without increasing procedural time or complications.

Comparing between second-generation cryoballoon vs open-irrigated radiofrequency ablation in elderly patients: Acute and long-term outcomes

Background

Limited comparative data are available regarding catheter ablation (CA) of atrial fibrillation (AF) using second‐generation cryoballoon (CB‐2) vs radiofrequency (RF) ablation in elderly patients (>75‐year‐old).

Hypothesis

CB‐2 ablation may demonstrate different outcomes compared with that using RF ablation for elderly patients with AF.

Method

Elderly patients with symptomatic drug‐refractory AF were included in the study. Pulmonary vein isolation was performed in all patients.

Results

A total of 324 elderly patients were included (RF: 176, CB‐2:148) from September 2016 to April 2019. The CB‐2 was associated with shorter procedure time and left atrial dwell time (112.9 ± 11.1 vs 135.1 ± 9.9 minutes, P < .001; 53.7 ± 8.9 vs 65.1.9 ± 9.0 minutes, P < .001), but marked fluoroscopy utilization (22.1 ± 3.3 vs 18.5 ± 3.6 minutes, P < .001). Complications occurred in 3.3% (CB‐2) and 6.2% (RF) of patients with no significant different (P = .307). The length of stay after ablation was shorter, but the costs were higher in the CB‐2 group (1.94 vs 2.53 days, P < .001 and 91 132.6 ± 3723.5 vs 81 149.4 ± 6824.1 CNY, P < .001) compared to the RF group. Additionally, the rate of early recurrence of atrial arrhythmia was lower in the CB‐2 group (14.2 vs 23.3%, P = .047), but the long‐term success rate was similar between two groups.

Conclusions

CB‐2 is associated with shorter procedure time, left atrial dwell time, and length of stay after ablation, but its costs and fluoroscopy time are greater than the RF group. Moreover, the rate of complications and long‐term success are similar between the two groups.

Use of Light Sensor and Focused Local Atrial Electrogram Recordings for the Monitoring of Thermal Injury to the Esophagus and Lungs During Laser Catheter Ablation of the Posterior Atrial Walls: Preclinical In Vitro Porcine and In Vivo Canine Experimental Studies

During the catheter ablation of atrial fibrillation, thermal damages to the esophagus may have deleterious effects. The use of the SensoLas light sensor (SLLS; LasCor GmbH, Taufkirchen, Germany) and focused local atrial electrograms (LEGs) were tested as means for the assessment of thermal effects on the esophagus during laser catheter ablation. A total of 32 transcatheter in vitro and in vivo 1064-nm laser impacts were aimed at porcine (n = 16) and canine (n = 16) atrial endocardia. Photons scattering through the atrial and esophageal walls were captured by the SLLS, transmitted via an optical fiber to a diode, and converted to power displayed on a monitor. The laser was stopped automatically when the power measurement reached values beyond the preset upper limit. During in vivo laser applications, bipolar LEGs were recorded via the miniature electrodes of the laser catheter. Thermal damage to the esophagus was avoided when the power measurement was limited to 150 μW or less and the diode current was 60 μA or less, regardless of the energy setting used and regardless of the thicknesses of the atrial and esophageal walls. Laser energy applied for eight seconds to 13 seconds (average: 10 seconds) abolished the electrical potentials permanently. In conclusion, the control of laser light via the SLLS and of atrial potential amplitudes in the LEGs can prevent thermal esophageal and lung injury during laser catheter ablation.

Comparison of health-related quality of life in patients with atrial fibrillation treated with catheter ablation or antiarrhythmic drug therapy: a systematic review and meta-analysis protocol

INTRODUCTION

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and causes patients considerable burden; symptoms such as palpitations and dyspnoea are common, leading to frequent emergency room visits. Patients with AF report reduced health-related quality of life (HQOL) compared with the general population; thus, treatments focus on the restoration of sinus rhythm to improve symptoms. Catheter ablation (CA) is a primary treatment strategy to treat AF-related burden in select patient populations; however, repeat procedures are often needed, there is a risk of major complications and the procedure is quite costly in comparison to medical therapy. As the outcomes after CA are mixed, an updated review that synthesises the available literature, on outcomes that matter to patients, is needed so that patients and their healthcare providers can make quality treatment decisions. The purpose of this review protocol is to extend previous findings by systematically analysing randomised controlled trials (RCTs) of CA in patients with AF and using meta-analytic techniques to identify the benefits and risks of CA with respect to HQOL and AF-related symptoms.

METHODS AND ANALYSIS

We will include all RCTs that compare CA with antiarrhythmic drugs, or radiofrequency CA with cryoballoon CA, in patients with paroxysmal or persistent AF. To locate studies we will perform comprehensive electronic database searches from database inception to 4 April 2017, with no language restrictions. We will conduct a quantitative synthesis of the effect of CA on HQOL as well as AF-related symptoms and the number of CA procedures needed for success, using meta-analytic techniques.

ETHICS AND DISSEMINATION

No ethical issues are foreseen and ethical approval is not required given that this is a protocol. The findings of the study will be reported at national and international conferences, and in a peer-reviewed journal using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

TRIAL REGISTRATION NUMBER

In accordance with the guidelines, our systematic review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) on 6 March 2017 and was last updated on 6 March 2017 (registration number CRD42017057427).

PROTOCOL AMENDMENTS

Any protocol amendments will be documented on the International Prospective Register of Systematic Reviews (PROSPERO) and in the final manuscript and indicated as such.

A Simple Porcine Model of Inducible Sustained Atrial Fibrillation

The surgical management of atrial fibrillation (AF) is an evolving field with a history of testing various lesion sets and ablation technologies. Previous animal models of AF require a chronic intervention to make AF reliably inducible. Our objective was to create an acute, reliable, and reproducible porcine model of sustained AF. To accomplish this, 21 adult domestic pigs underwent median sternotomy. Methods to induce AF were then performed sequentially: manual stimulation, rapid pacing (200 beats per minute), and then rapid pacing of 8 beats with a cycle length of 300 milliseconds, followed by an extra stimulus at decreasing cycle lengths. If AF was not induced, burst pacing was performed at a cycle length of 90 milliseconds for 30 seconds. If AF was still not induced, intravenous neostigmine was administered, and the process was repeated. Atrial fibrillation was considered sustained after 1 minute. Attempts at AF induction were successful in 18 (86%) of 21. Atrial fibrillation was induced during manual stimulation in four (19%), during rapid pacing in five (24%), during burst pacing in five (24%), and after the administration of neostigmine in four (19%). Mean (SD) duration of AF was 3.6 (2.6) minutes. Of the 18, 14 (78%) reverted to sinus rhythm spontaneously and 4 (22%) required an antiarrhythmic. This technique of inducing AF can easily be used to evaluate new technologies and lesion sets without the need for creating a chronic animal model.

Ablation as First-Line Therapy for Atrial Fibrillation: Yes

This article addresses the use of catheter ablation (CA) as first-line therapy for atrial fibrillation (AF). CA increases long-term freedom from AF, reduces hospitalizations, and improves quality of life compared with antiarrhythmic drug (AAD) therapy in patients with symptomatic AF who have already failed one AAD. The role of CA as first-line therapy for AF, however, is still controversial. Evidence from randomized controlled trials shows that CA is definitely superior to AADs as first-line therapy for relatively young patients with paroxysmal AF, with comparable complication rates and results consistently reproducible across different institutions, operators, and types of ablation approaches.

Hybrid therapy in the management of atrial fibrillation

Atrial fibrillation is the most common sustained arrhythmia. Because of the sub-optimal outcomes and associated risks of medical therapy as well as the recent advances in non-pharmacologic strategies, a multitude of combined (hybrid) algorithms have been introduced that improve efficacy of standalone therapies while maintaining a high safety profile. Antiarrhythmic administration enhances success rate of electrical cardioversion. Catheter ablation of antiarrhythmic drug-induced typical atrial flutter may prevent recurrent atrial fibrillation. Through simple ablation in the right atrium, suppression of atrial fibrillation may be achieved in patients with previously ineffective antiarrhythmic therapy. Efficacy of complex catheter ablation in the left atrium is improved with antiarrhythmic drugs. Catheter ablation followed by permanent pacemaker implantation is an effective and safe treatment option for selected patients. Additional strategies include pacing therapies such as atrial pacing with permanent pacemakers, preventive pacing algorithms, and/or implantable dual-chamber defibrillators are available. Modern hybrid strategies combining both epicardial and endocardial approaches in order to create a complex set of radiofrequency lesions in the left atrium have demonstrated a high rate of success and warrant further research. Hybrid therapy for atrial fibrillation reviews history of development of non-pharmacological treatment strategies and outlines avenues of ongoing research in this field.

Percutaneous catheter ablation of atrial fibrillation

Atrial fibrillation is the most common arrhythmia and is associated with important morbidity and mortality. Antiarrhythmic therapy is recommended as initial therapy but is associated with modest efficacy and significant side effects. Over the past several years, catheter ablation has been demonstrated to provide effective and safe curative therapy for atrial fibrillation. Future investigations will assess advances in catheter ablation technology and will help to define the precise role of catheter ablation relative to alternative therapies, such as rate-control and antiarrhythmic therapy.

The impact of haemodialysis on the outcomes of catheter ablation in patients with paroxysmal atrial fibrillation

AIMS

The outcomes of catheter ablation (CA) in patients with paroxysmal atrial fibrillation (PAF) who are undergoing haemodialysis (HD) have not been fully elucidated. This study aimed to determine the impact of HD on CA outcome in these patients.

METHODS AND RESULTS

We examined 1364 consecutive PAF patients (mean age, 61 ± 10 years) who underwent CA, including 32 (2.3%) patients undergoing HD. The patients undergoing HD had a significantly lower body mass index (P < 0.0001), higher CHADS2 score (P = 0.006), and higher prevalence of structural heart disease (P < 0.0001), hypertension (P = 0.002), and congestive heart failure (P = 0.02). Echocardiography indicated a larger left atrial diameter (P < 0.0001) and left ventricular diameter (P = 0.0002) in the HD patients. Haemodialysis was a significant predictor of AF recurrence (hazard ratio 2.56; 95% confidence interval 1.56-4.03; P = 0.0004) in the overall population. Sinus rhythm maintenance rates in the HD patients at 1, 3, and 5 years were 42.3, 37.6, and 19.7%, respectively, after the first procedure, and 64.7, 54.9, and 47.1%, respectively, after the final procedure (median, 2; range, 1-2 procedures); these rates were significantly lower than those in the non-HD patients (P < 0.0001). The 5-year survival rate was 78.1% in the HD patients.

CONCLUSION

Haemodialysis was significantly associated with AF recurrence after CA for PAF. However, an ∼50% success rate for sinus rhythm maintenance without antiarrhythmic drug therapy in HD patients suggested that CA could be an option for the treatment of AF.

Efficacy and safety of catheter ablation for long-standing persistent atrial fibrillation in women

OBJECTIVES

It is uncertain whether gender affects the outcomes of catheter ablation (CA) for atrial fibrillation (AF). The objective of the study is to evaluate the efficacy and safety of CA for long-standing persistent AF in women.

METHODS

Between January 2010 and May 2011, 220 consecutive patients (73 females, 33.2%), with long-standing persistent AF who underwent CA were prospectively recruited. Gender-related differences in clinical presentation, periprocedural complications, and outcomes were compared.

RESULTS

Women were less likely to have lone AF than men (27.4% vs 47.6%; P = 0.004). The incidence of rheumatic heart disease was higher in women (19.2% in women vs 1.4% in men; P < 0.001). Women had a lower initial ablation success rate than men (35.6% vs 57.1%; P = 0.003). Hematomas occurred more often in women (6.8% in women vs 0.7% in men; P = 0.027). A Cox regression analysis demonstrated total duration of AF (per month, hazard ratio [HR] 1.003, confidence interval [CI] 1.001-1.006; P = 0.006) and gender (HR 1.663, CI 1.114-2.485; P = 0.013) as the independent predictors for recurrence after the first CA.

CONCLUSIONS

Women and long AF duration were closely related to the recurrence of AF after the first ablation in patients with long-standing persistent AF. Women also had a higher risk of vascular complications.

[Catheter ablation of paroxysmal atrial fibrillation. Optimal approach and result]

The gold standard in ablation of paroxysmal atrial fibrillation (PAF) is radiofrequency (RF) based point by point pulmonary vein isolation (PVI). In the majority of patients with PAF (80 %) PVI can restore stable SR even during long-term follow-up of up to 5 years. However multiple procedures are often required. Cryo-balloon based PVI is an established technique. Safety and efficacy are comparable to RF ablation. Due to the high success rates in patients with PAF and the progression rate to persistent atrial fibrillation (AF) an early intervention is recommended as implemented in the latest guidelines for AF treatment.

Differences in catheter ablation of paroxysmal atrial fibrillation between males and females

BACKGROUND

Catheter ablation (CA) has become a standard treatment for patients with atrial fibrillation (AF). However, gender-related differences associated with CA of paroxysmal AF (PAF) remain unclear.

METHODS

We compared 1124 consecutive patients (mean age, 61 ± 10 years; male, n=864) with PAF scheduled for CA between the genders.

RESULTS

Females were significantly older (p<0.0001), and had a lower body-mass-index (p=0.02), smaller left atrial dimension (LAD; p=0.04), larger LAD indexed by the body-surface-area (LADI; p<0.0001) and better left ventricular ejection fraction (p<0.0001) at baseline. Ischemic heart disease (p=0.007) was more frequent in males, whereas hypertrophic cardiomyopathy (p=0.007) and mitral stenosis (p=0.001) were more frequent in females. More additional procedures were performed to eliminate non-pulmonary vein foci in females than males (p<0.05), but those locations were similar between the genders. The incidence of procedure-related complications was similar between genders (p=0.73). Sinus rhythm was similarly maintained between females and males after the first CA (56.4% vs. 59.3% at 5 years, p=0.24), but was significantly lower in females after the last CA (76.5% vs. 81.3% at 5 years, p=0.007). More females did refuse multiple CA procedures (especially a second one) than males (37.8% in females vs. 27.4% in males, p=0.02). The age (HR, 0.98/y, p=0.01), duration of AF (HR, 1.04/y, p=0.0001), number of failed anti-arrhythmic-drugs (HR, 1.10, p=0.03) and LADI (HR, 1.89 per 10mm/m(2), p=0.001) were significantly associated with AF-recurrence in males, but not in females.

CONCLUSIONS

Specific differences and similarities between the genders were observed in PAF patients undergoing CA.

The incidence and clinical significance of non-isolation of the pulmonary vein carina after encircling ipsilateral pulmonary veins isolation for paroxysmal atrial fibrillation: a pitfall of the double-Lasso technique

AIMS

Encircling ipsilateral pulmonary veins (PVs) isolation (EIPVsI) with the double-Lasso technique has proven to be effective to cure atrial fibrillation (AF). However, in this technique, PV mapping with circular catheters may miss a non-isolation of the PV carina. The purpose of this study was to reveal the incidence and clinical significance of a non-isolation of the PV carina after EIPVsI.

METHODS AND RESULTS

We studied 81 consecutive paroxysmal AF patients (age 61 ± 12 years, 56 men), in whom EIPVsI was successfully performed in one encircling line with the endpoint of the demonstration of bidirectional conduction block between the PVs and left atrium (LA) with the double-Lasso technique. After a successful EIPVsI, pacing from the PV carina was performed and it captured the LA in 17 (21.0%) patients. During a mean follow-up period of 19 ± 13 months, AF recurred in 13 (16.0%) patients. A multivariate Cox proportional analysis revealed that a non-isolation of the PV carina after the EIPVsI was a significant predictor (hazard ratio = 3.91, 95% confidence interval = 1.13-14.16, P = 0.03) of AF recurrence.

CONCLUSIONS

Pulmonary vein mapping with the double-Lasso technique did miss the non-isolation of the PV carina after a successful EIPVsI, which was an independent predictor of AF recurrence after the EIPVsI. Pacing from the PV carina may be required to confirm the electrical isolation of the PV carina after EIPVsI with the double-Lasso technique.

Pulmonary vein isolation for the treatment of drug-refractory atrial fibrillation in adults with congenital heart disease

BACKGROUND

Atrial fibrillation (AF) is a common arrhythmia in adults with congenital heart disease (CHD). Long-term antiarrhythmic therapy (AAT) in these patients has significant shortcomings. The safety and efficacy of pulmonary vein antrum isolation (PVAI) for the treatment of AF in CHD is presently unknown.

HYPOTHESIS

We hypothesized that PVAI for AF in patients with CHD is effective and safe.

METHODS

We reviewed a prospective cohort of 4315 patients (age ≥ 18) undergoing PVAI for drug refractory AF at a single institution and identified 36 consecutive patients with CHD (single ventricle physiology, tetralogy of Fallot, coarctation of the aorta, ventricular septal defects, atrial septal defects (ASD) and cardiomyopathy resulting from anomalous origin of the left main coronary from the pulmonary artery). A second cohort of 355 consecutive patients with noncongenital structural heart disease (NSHD) (coronary artery disease, valvular heart disease, ejection fraction <50%, or prior noncongenital cardiac surgery) undergoing PVAI during the same time period was used as a control. Success was defined as freedom from AF starting two months after PVAI in the absence AAT until the end of follow-up. Partial success was defined as freedom from AF in the presence of AAT until the end of follow-up. Combined success was defined as the sum of success and partial success. We compared the outcomes with the use of propensity-score matching in the overall cohort.

RESULTS

Patients with NSHD were older and had higher prevalence of hypertension (P < .01), diabetes (P < .01) and hyperlipidemia (P < .01). The most common CHD lesion was ASD (61%) and the most common NSHD lesion was valvular heart disease (57%). After one PVAI, success was achieved in 42% and 53% at 300 days in the CHD and NSHD groups respectively. Four-year success was achieved in 27% and 36% in the CHD and NSHD groups, respectively. There were no significant differences in the success rates between patients groups (P= .46), nor were there any differences in left atrial size or changes in ejection fraction after one or two PVAI in the respective groups. Complication rates between the CHD and NSHD groups were similar (15% vs. 11%, P= .42) except for a higher risk of vascular site complications in patients with CHD (8% vs. 1%, P < .05).

CONCLUSION

PVAI is an attractive treatment modality in drug refractory AF in CHD, with combined success rates in excess of 60%. The maintenance of sinus rhythm after PVAI in CHD appears similar to that of NSHD and warrants prospective validation.

Transcatheter closure of atrial septal defect: does age matter?

Atrial septal defect (ASD) is the most common type of common congenital heart disease (CHD) in adults. During the last decade, there has been a remarkable change in the treatment strategy of ASD, shifting the therapeutic gold standard from surgery to transcatheter closure, along with refinements and the evolution of device technology. Reports on the outcome of transcatheter ASD closure have shown an excellent efficacy as well as a low complication rate. However, the procedural details and/or outcomes of this procedure may be influenced by several factors including morphologic characteristics of the defect, co-morbid diseases, as well as individual factors including age and weight of the patient. Because the risk-benefit relationship in both the very young and the elderly subsets of the patients has not been clearly defined yet, closure of an ASD with device may be potentially subtracted from the treatment option in these patient groups. In this article, we will review the basis for device closure in small children and elderly patients with ASD and provide an overview of the frequently encountered problems.

Right-side RF ablation using remote catheter navigation: experimental results in vivo

INTRODUCTION

The close proximity between the interventionalist and patient during catheter-based interventions for cardiac arrhythmia exposes the interventionalist to harmful radiation. A prototype remote catheter navigation system (RCNS) has been developed to reduce occupational dose. The safety, feasibility of this RCNS and a comparison of remote and conventional navigation techniques is investigated in vivo.

METHODS

Seven anatomical locations in the right side of the heart in porcine models were chosen as navigation targets. Using fluoroscopy and electrogram analysis, an experienced electrophysiology interventionalist manipulated a radiofrequency (RF) ablation catheter to each target using the RCNS and conventional navigation. Success rate, navigation time, exposure, exposure time and procedure time was recorded for all anatomical targets. Time to integrate the RCNS with the procedure suite was also measured.

RESULTS

All targets were successfully reached with the RCNS and conventional navigation. No erratic catheter motion was observed with the RCNS whereas 1 operation failure occurred. The anatomical targets were found to have the largest effect on navigation time (P < 0.05), exposure (P < 0.05), and exposure time (P < 0.01), although the navigation method had little to no effect on the metrics. These results suggest that remote navigation procedures can be performed with navigation times comparable to conventional bedside navigation.

CONCLUSION

Remote navigation with the RCNS may present a safe method of reducing occupational dose, while providing comparable navigation time with conventional bedside navigation.

Catheter ablation of atrial fibrillation as first-line therapy--a single-centre experience

AIMS

The aims of the study were (i) to assess the characteristics of patients selected for atrial fibrillation (AF) ablation as first-line therapy, (ii) to identify current clinical criteria for such a strategy, and (iii) to analyse the outcome compared with patients who had failure of antiarrhythmic drug (AAD) therapy prior to ablation.

METHODS AND RESULTS

Consecutive patients undergoing ablation of AF were included in a prospective registry. Serial long-term electrocardiogram monitoring and clinical follow-up were performed after 3, 6, and 12 months. Out of 434 patients, 17% underwent AF catheter ablation as first-line therapy (AAD-), and 83% had undergone at least one AAD trial (AAD+). In AAD- patients, the reasons for this strategy were: (i) patient preference, n= 51 (71%); (ii) contra-indication to AAD, n= 21 (29%). Atrial fibrillation duration prior to ablation was shorter (52 ± 54 vs. 78 ± 81 months, P= 0.005), and the percentage of patients hospitalized for AF (32% vs. 48%, P= 0.01) was lower in AAD- patients. Long-term multiple procedure success rate (78% vs. 64%, P= 0.03) was higher in the AAD- group, and there were less repeat ablations in this group (21% vs. 38%, P= 0.01).

CONCLUSION

Catheter ablation was first-line therapy of AF in a significant number of patients, according either to patient preference or to medical factors, and this had important implications. Ablative therapy was performed at an earlier stage of the disease, and was associated with a significantly higher success rate and with a decreased need for repeat procedures.

Persistence of pulmonary vein isolation after robotic remote-navigated ablation for atrial fibrillation and its relation to clinical outcome

AIMS

A robotic navigation system (RNS, Hansen™) has been developed as an alternative method of performing ablation for atrial fibrillation (AF). Despite the growing application of RNS-guided pulmonary vein isolation (PVI), its consequences and mechanisms of subsequent AF recurrences are unknown. We investigated the acute procedural success and persistence of PVI over time after robotic PVI and its relation to clinical outcome.

METHODS AND RESULTS

Sixty-four patients (60.7 ± 9.8 years, 53 male) with paroxysmal AF underwent robotic circumferential PVI with 3-dimensional left atrial reconstruction (NavX™). A voluntary repeat invasive electrophysiological study was performed 3 months after ablation irrespective of clinical course. Robotic PVI was successful in all patients without complication (fluoroscopy time: 23.5 [12-34], procedure time: 180 [150-225] minutes). Fluoroscopy time demonstrated a gradual decline but was significantly reduced after the 30th patient following the introduction of additional navigation software (34 [29-45] vs 12 [9-17] minutes; P < 0.001). A repeat study at 3 months was performed in 63% of patients and revealed electrical conduction recovery in 43% of all PVs. Restudied patients without AF recurrence (n = 28) showed a significantly lower number of recovered PVs (1 (0-2) vs 2 (2-3); P = 0.006) and a longer LA-PV conduction delay than patients with AF recurrences (n = 12). Persistent block of all PVs was associated with freedom from AF in all patients. At 3 months, 67% of patients were free of AF, while reablation of recovered PVs led to an overall freedom from AF in 81% of patients after 1 year.

CONCLUSION

Robotic PVI for PAF is safe, effective, and requires limited fluoroscopy while yielding comparable success rates to conventional ablation approaches with PV reconduction as a common phenomenon associated with AF recurrences.

Long-term results of catheter ablation in paroxysmal atrial fibrillation: lessons from a 5-year follow-up

BACKGROUND

Paroxysmal atrial fibrillation (AF) naturally progresses toward chronic AF at an estimated rate of 15% to 30% over a 1- to 3-year period. Pulmonary vein (PV) isolation is increasingly performed for the treatment of drug-refractory paroxysmal AF. The long-term data on clinical outcome after circumferential PV isolation are limited.

METHODS AND RESULTS

From 2003 to late 2004, 161 patients (121 men; age, 59.8±9.7 years) with symptomatic paroxysmal AF and normal left ventricular function underwent circumferential PV isolation guided by 3-dimensional mapping and double Lasso technique. Right-sided and left-sided continuous circular lesions encircling the ipsilateral PVs were placed with irrigated radiofrequency energy. The procedure end point was the absence of all PV spikes for at least 30 minutes after PV isolation verified by 2 Lasso catheters placed within the ipsilateral PVs. Sinus rhythm was present in 75 patients (46.6%) after the initial procedure during a median follow-up period of 4.8 years (0.33 to 5.5 years). A second procedure was performed in 66 and a third procedure in 12 patients. Recovered PV isolation conduction was observed in 62 of 66 patients (94.0%) during the second and in 8 of 12 patients (66.7%) during the third procedure. After a median of 1 (1 to 3) procedure, stable sinus rhythm was achieved in 128 of 161 patients (79.5%), whereas clinical improvement occurred in an additional 21 of 161 patients (13.0%) during a median follow-up of 4.6 years (0.33 to 5.5 years). Four patients in stable sinus rhythm died during follow-up. Progression toward chronic AF was observed in 4 patients (2.4%); however, only 2 patients reported symptoms.

CONCLUSION

In patients with paroxysmal AF and normal left ventricular function, circumferential PV isolation results in stable sinus rhythm in the majority of patients, and low incidence of chronic AF was observed after ablation during up to 5 years of follow-up.

Optimizing the management of atrial fibrillation: focus on current guidelines and the impact of new agents on future recommendations

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in everyday clinical practice. It affects ~2.3 million individuals in the United States, and the prevalence is expected to increase ~2.5-fold over the next 40 years. Atrial fibrillation accounts for more than 2 million hospitalizations each year and contributes to nearly 67 000 deaths. Our understanding of the pathophysiology of AF has increased dramatically over the past few decades. Recent treatment guidelines have heightened our awareness of the challenges involved in the treatment of AF and provided useful recommendations for its diagnosis and management. Because AF is usually associated with multiple comorbid conditions, greater emphasis must be placed on individualizing treatment. This review focuses on current treatment guidelines for patients with AF, assessing the benefits and shortcomings of current pharmacologic options and discussing new agents and trials that may provide better opportunities to improve and individualize patient management.

[Atrial fibrillation: practical questions. Who are the best candidates for atrial fibrillation ablation?]

Ablation of paroxysmal AF in symptomatic patients is a clear indication after failure of anti-arrhythmic therapy (class IIa according to the recommendations). Ablation of persistent AF is feasible, as second line after failure of medical treatment, although there is no real consensus on ablative techniques : this procedure is long and complex, exposure to ionizing radiation is important. Regarding ablation of persistent AF, a careful selection of patients and multiple interventions are often necessary to increase the success rate. Standardization of the procedure and better reproducibility of results are essential to increase the indications for ablation in patients with persistent AF. Improvements are expected concerning the operative strategy, the targets of ablation and available tools.

Atrial fibrillation: mechanistic insights and treatment options

Atrial fibrillation (AF) remains the most common clinically encountered arrhythmia. Unlike supraventricular arrhythmias that use a defined mechanism, AF involves a wide spectrum of arrhythmias from lone AF to paroxysmal to chronic AF. AF is an arrhythmia that may develop in several ways. Mechanical remodeling manifests as decreased atrial contractility and increased atrial compliance which leads to a stretch of the atrial myocardium. Atrial remodeling may also increase in atrial fibrosis which can slow conduction velocity and can shorten the refractory period in atria with long-standing AF. It is still unclear whether initiation of AF activates direct inflammatory effects or whether the presence of a pre-existing systemic inflammatory state promotes further persistence of AF. Currently, the patient population undergoing AF ablation has greatly expanded. Patients are older and have larger left atrial size and are more likely to have persistent/permanent AF. It is likely that AF comprises a spectrum of disease with no single mechanism adequate enough to comprehensively explain AF and its variability. The management of patients with AF involves elements of anticoagulation, rate control and rhythm control and such treatment strategies are not necessarily mutually exclusive of each other.

Feasibility and outcome of epicardial pulmonary vein isolation for lone atrial fibrillation using minimal invasive surgery and high intensity focused ultrasound

AIMS

Transvenous pulmonary vein isolation (PVI) is the cornerstone of non-pharmacological rhythm control therapy in symptomatic atrial fibrillation (AF). Success and complications rates are, however, still not optimal. New techniques and energy sources are therefore being developed.

METHODS AND RESULTS

Fifteen patients with lone AF refractory for antiarrhythmic drugs (AADs) underwent PVI by minimal invasive epicardial off-pump monolateral right-sided video-assisted thoracic surgery (VATS) using the UltraCinch with high-intensity focused ultrasound (HIFU). Primary endpoint was successful ablation defined as absence of AF or atrial flutter/tachycardia after 6 months assessed by complaints, 12 lead electrocardiogram, and 96 h Holter monitoring. Secondary endpoints were ablation success at the end of follow-up irrespective of AADs use or re-ablation and complications related to the procedure. Mean age was 47 +/- 10 years and 14 (93%) were male. Eleven (73%) had paroxysmal, and 4 (27%) patients had persistent AF. Median AF history was 5 (1-12) years. At 6 months, six (40%) patients had sinus rhythm after one epicardial PVI (four on AADs). After 1.3 +/- 0.6 years, four (27%) patients had sinus rhythm after one epicardial PVI (two on AADs) and in six (40%) patients endocardial radiofrequency re-ablation was performed, which was successful in three patients (20%). Two patients (13%) were planned for re-ablation. Three others (20%) refused re-ablation. Two major complications occurred (one late tamponade and one bleeding during surgery, necessitating sternotomy).

CONCLUSION

Epicardial PVI using monolateral right-sided VATS with the UltraCinch delivering HIFU is feasible, but is associated with substantial complications. Furthermore, the success rate was low. More research is therefore warranted to assess optimal ablation techniques and energy sources to perform PVI.

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.

[Atrial fibrillation ablation: who comes into consideration?]

Atrial fibrillation ablation is, since the introduction of the guidelines in 2006 and which were updated in 2007, now a standard procedure in many electrophysiological centers. Pulmonary vein isolation has proven itself as a way to eliminate focal triggers. From pathophysiological studies of atrial fibrillation development, it is known that ablation performed early in paroxysmal atrial fibrillation has the highest chance for success. In patients with persistent or permanent atrial fibrillation, success rates are lower and repeat interventions are needed more often. Therefore, continuation of antiarrhythmic drug therapy is often necessary in these patient groups. Thus, the curative use of ablation for atrial fibrillation is only possible with the current techniques for patients with paroxysmal atrial fibrillation.

Complications in the catheter ablation of atrial fibrillation: incidence and management

Radiofrequency catheter ablation is widely performed as an effective treatment for recurrent, drug-resistant atrial fibrillation (AF). Recently, various types of ablation strategies, such as extensive encircling pulmonary vein (PV) isolation, linear ablation and complex fractionated electrogram-guided ablation, have been used to achieve a high efficacy for all types of AF. However, several complications (thromboembolic events, PV stenosis and atrio-esophageal fistula etc) with an incidence of 3.9-6%, have been reported. It is important to understand the incidence, prevention and management of complications in order to develop safe ablation strategies.

Effectiveness of catheter ablation versus antiarrhythmic drug therapy for atrial fibrillation

PURPOSE OF REVIEW

The optimal treatments for atrial fibrillation have long been sought among rhythm control and rate control strategies. Unfortunately, rhythm control strategies with antiarrhythmic drugs have proven to be a disappointment. Catheter ablation techniques, however, have been rapidly advancing and have the potential to offer a permanent cure. Rhythm control with catheter ablation may in fact be a superior treatment modality for atrial fibrillation. The purpose of this review is to examine the evidence in favor of this argument.

RECENT FINDINGS

The dissatisfaction with poorly performing antiarrhythmic drug therapies for the treatment of atrial fibrillation has fueled the development of alternative therapies for rhythm control. Catheter ablation has emerged as a viable, efficacious, and safe alternative. In fact, in head to head comparisons with antiarrhythmic drugs, catheter ablation continues to come out on top with often markedly superior performances. In addition to efficacy and safety, catheter ablation also seems to be a fiscally viable alternative.

SUMMARY

On the basis of the outstanding performance of catheter ablation compared with antiarrhythmic drug therapy, it is not surprising to see its widespread adoption and ever expanding indications.