Comparison of antiarrhythmic drug therapy and radiofrequency catheter ablation in patients with paroxysmal atrial fibrillation: a randomized controlled trial

Atrial Fibrillation in Heart Failure Patients with Preserved or Reduced Ejection Fraction. Prognostic significance of Rhythm control strategy with Catheter Ablation

Introduction

Atrial fibrillation (AF) and heart failure (HF) often coexist with an increase in morbidity and mortality. AF catheter ablation (CA) has proved to be a safe and efficient option for HF patients, but long-term evolution and prognosis remain uncertain. The aim is to assess the efficacy and safety of CA in HF patients with AF, and analyze HF long-term evolution.

Methods

We prospectively analyzed consecutive patients with AF and congestive HF or left ventricular ejection fraction (EF) less than 45%, who underwent CA of AF between 2011 and 2016. We excluded patients who did not complete one year of follow-up.

Results

Seventy-nine patients were included. Mean age was 62.1 years, 72.4% were men, 67.2% had hypertension and 8.6% were diabetics. Mean EF was 49%, left atrial area was 26.5 cm2 and mean CHA2DS2-VASc score was 2. 70.6% were on NYHA FC II-III.The recurrence rate of AF was 60%, and after a second CA the rate decreased to 27.8%. Only persistent AF prior to the procedure was identified as independent predictor of recurrence. There was a significant NYHA FC improvement in the sinus rhythm (SR) group vs those with recurrence (63.6% vs 36.4%; p=0.047). None of the patients in SR were hospitalized, whereas six with recurrence were hospitalized due to HF (0% vs. 18.2%; p = 0.07). The rate of complications was 9.1%.

Conclusions

Catheter ablation of atrial fibrillation in heart failure presents an adequate success rate, improving symptoms and reducing rehospitalizations due to heart failure.

Radiofrequency Ablation Versus Antiarrhythmic Drug Therapy for Atrial Fibrillation: Meta-analysis of Safety and Efficacy

BACKGROUND

Radiofrequency ablation (RFA) and antiarrhythmic drugs (AADs) are the main treatments used for atrial fibrillation (AF). In recent years, a number of articles comparing the 2 treatments have begun to emerge. Though, the influence of follow-up time in the meta-analysis was not considered in these articles. However, more recently, large-scale clinical trial articles have included follow-up with the patients up to 5 years after treatment. Therefore, the aim of this study was to assess the impact of variable follow-up times on the recurrence of AF by observing both the short-term and long-term efficacy and safety of catheter ablation and AADs for the treatment of AF.

METHODS AND RESULTS

The primary investigators of eligible randomized controlled trials were invited to contribute standardized outcome data. Random effect summary estimates were calculated as standardized mean differences and odds ratios with 95% confidence intervals for continuous and binary outcomes. In this study, 9 randomized controlled trials (n = 1542 patients) were included. The rate of recurrence of AF with no limit on follow-up time, >12 months, >18 months, >24 months, >30 months, and approximately 36 months was compared. Furthermore, the gap between the RFA and AAD groups in the recurrence rate of AF was found to decrease inversely to follow-up time. When the follow-up time reached 24 months, the difference between RFA and AAD was relatively stable with an odds ratio of 0.45 (95% confidence interval: 0.32-0.62). Overall, RFA decreased adverse events in the remaining trials; however, AAD performed better in terms of safety and had fewer adverse events with RFA usually causing more serious complications.

CONCLUSION

RFA is more advantageous in terms of recurrence rate of AF than drug therapy. In addition, the analysis suggests that this effect persists during long-term follow-up; however, these benefits appear to decrease with longer follow-up time. Finally, AAD performed better in terms of safety and had fewer adverse events.

Catheter ablation for atrial fibrillation in heart failure with reduced ejection fraction: a systematic review and meta-analysis of randomized controlled trials

Background

Previous randomized controlled trials (RCT)s showed similar outcomes in patients with atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) treated with anti-arrhythmic drugs (AAD) compared to rate control therapy. We sought to evaluate whether catheter ablation is superior to medical therapy in patients with AF and HFrEF.

Methods

We searched electronic databases for all RCTs that compared catheter ablation and medical therapy (with or without use of AAD). We used random-effects models to summarize the studies. The primary end-point was all-cause mortality. Secondary outcomes included heart failure-related hospitalizations and change in left ventricular ejection fraction (LVEF).

Results

We retrieved and summarized 7 randomized controlled trials, enrolling 856 patients (429 in the catheter ablation arm and 427 in the medical therapy arm). Compared with medical therapy (including use of AAD), AF catheter ablation was associated with a significant reduction in mortality (risk ratio 0.50; 95% confidence interval [CI]: 0.34 to 0.74; P = 0.0005) and heart failure-related hospitalizations (risk ratio 0.56; 95% CI: 0.44 to 0.71; P < 0.0001). Furthermore, catheter ablation led to significant improvements in LVEF (weighted mean difference, 7.48; 95% CI: 3.71 to 11.26; P < 0.0001).

Conclusions

Compared to medical therapy, including use of AAD, catheter ablation for AF was associated with a significant reduction in mortality and heart failure-related hospitalizations as well as an improvement in LVEF in patients with HFrEF. Larger trials are needed to confirm whether rhythm control with ablation is superior to rate control in patients with AF and heart failure.

Clinical impact of insulin resistance on pulmonary vein isolation outcome in patients with paroxysmal atrial fibrillation

INTRODUCTION

The relationship between insulin resistance and atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) remains unclear.

METHODS

Drug-refractory 114 paroxysmal AF patients (89 males, 62 ± 8 years) who underwent successful PVI were enrolled. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated and a value of ≥2.5 was defined as insulin resistant. The left atrial volume index (LAVI) was measured using echocardiography before and 1 year after PVI. Tumor necrosis factor-α (TNF-α) and TGF-β1 serum levels were measured before PVI, and the left atrium (LA) conduction velocity was calculated. The patients were divided into two groups (group 1: HOMA-IR < 2.5, n = 81; group 2: HOMA-IR ≥ 2.5, n = 33).

RESULTS

The LAVI between the two groups before PVI did not significantly differ (P > 0.05), nor did TNF-α (7.7 ± 2.0 vs 7.5 ± 1.0 pg/mL; P = 0.149) or TGF-β1 (28.4 ± 12.0 vs 27.6 ± 10.3 ng/mL; P = 0.757). LAVI before and 1 year after PVI in each group did not change. The conduction velocity of group 2 was slower than that of group 1 (0.7 ± 0.1 vs 1.1 ± 0.3 m/s, P < 0.001). Kaplan-Meier analysis showed significantly higher AF recurrence in group 2 than that in group 1 ( P = 0.019). Cox multivariable analysis revealed that insulin resistance was an independent predictor of recurrence (hazard ratio 1.287, P = 0.004).

CONCLUSION

Our results suggest that insulin resistance promotes LA electrical remodeling and might be related to AF recurrence after PVI.

Gains in Paroxysmal Atrial Fibrillation Ablation Using a Standardized Workflow to Optimize Contact Force Technologies

Background

Catheter ablation technology has evolved rapidly in recent years. There is a need to understand the impact of these advances on efficiency, safety, and effectiveness in real-world populations. The objective of this study was to evaluate a standardized workflow that integrates a contact force (CF) catheter and stability module in an attempt to optimize efficiency and clinical outcomes of paroxysmal atrial fibrillation (PAF) ablation, and to compare the outcomes of this workflow with existing ablation technologies at a high-volume center.

Methods

Consecutive ablations for PAF from July 2013 - June 2016 were included. Radiofrequency (RF) ablations were performed with the ThermocoolSF Catheter (SF) through April 2014, after which a change was made to the ThermocoolSmarttouchCatheter (ST)with a standardized workflow. Cryoballoon ablations (CA) were performed with theArctic FrontAdvancebetween July 2013 and March 2016. Systematic collection of 12-month effectiveness data began in July 2014. Prior to that time, only acute outcomes and reablations were captured.

Results

Procedural data for 32 SF, 232 ST, and 59 CA procedures for PAF were available. Mean procedure times were similar across SF and CA, and moderately shorter with ST (p=0.0201). Fluoroscopy times were substantially reduced with ST (p<0.0001). Complication rates were low and similar across all cohorts (p=0.4744), whereas reablation rates were lowest in the ST cohort (p=0.0194).

Conclusions

PAF ablation using integrated CF and catheter stability technology with a systematic ablation workflow maylead to improvements in both procedural efficiency and reablation rates, without compromising patient safety.

Impact of Atrial Fibrillation Ablation on Recurrent Hospitalization: A Nationwide Cohort Study

OBJECTIVES

This study assessed the impact of atrial fibrillation (AF) ablation on hospitalization and antiarrhythmic drug use in the community setting.

BACKGROUND

Despite the widespread increase in the use of catheter ablation to treat AF in the United States, the impact of ablation on arrhythmic, cardiovascular, and noncardiovascular hospitalizations remains unclear.

METHODS

The national prospectively acquired Truven Health MarketScan data set (January 1, 2008 to December 31, 2014) was used to identify patients who underwent first time AF ablation with uninterrupted enrollment for 24 months (12 months pre-ablation and 12 months post-ablation). Multivariate logistic regression was used to determine predictors of hospitalization.

RESULTS

Of 5,238 patients who underwent AF ablation for the first time, 2,720 patients with uninterrupted enrollment were analyzed (age 60 ± 10 years; 29% were women, 79% had hypertension, and 23% had heart failure [HF]). AF ablation was associated with significantly reduced all-cause hospitalization from 1,669 hospitalizations in the year before ablation to 1,034 hospitalizations in the year after ablation, which was driven primarily by a 56% reduction in arrhythmic hospitalization. Nonarrhythmic cardiovascular hospitalizations also declined through a 43% drop off in HF hospitalizations. Noncardiovascular hospitalization rates did not significantly change. Age younger than 55 years (odds ratio [OR]: 1.43; p < 0.001), obstructive sleep apnea (OR: 1.38; p < 0.001), and HF (OR: 1.29; p = 0.024) were multivariate predictors for decreased arrhythmic hospitalization. Rates of antiarrhythmic drug use also significantly declined post-procedure by 37.5% (p < 0.001).

CONCLUSIONS

In this nationwide cohort, AF ablation was associated with significant decreases in arrhythmic and nonarrhythmic cardiovascular hospitalizations, which was driven by reductions in hospitalization for AF and HF.

Is there a difference in rhythm outcome between patients undergoing first line versus second line paroxysmal atrial fibrillation ablation?

BACKGROUND

Catheter ablation of atrial fibrillation (AF) is an established second line therapy for patients with symptomatic paroxysmal AF (PAF) and may be considered as a first line therapy in selected patients who are highly symptomatic, considering patient choice, benefit, and risk, according to recent guidelines. Our study investigated whether a first line vs. second line ablation approach may result in improved sinus rhythm maintenance after ablation.

METHODS

A total of 153 patients undergoing pulmonary vein isolation for PAF were included in the study (age 55±12 years, 29% female). Seventy-nine patients underwent first line AF ablation and 74 patients underwent second line AF ablation after failed antiarrhythmic drug therapy. There was no significant difference in baseline characteristics such as age, history of AF, left atrial size or LVEF between groups. Success was defined as atrial tachyarrhythmia free survival during a 12-month follow-up by means of serial ECG Holter monitoring.

RESULTS

There was no significant difference in cumulative arrhythmia-free survival between those patients who received AF ablation as a first or second line therapy. Single procedure success was 78% in the first line group vs. 81% in the second line group; multiple procedure success was 90 vs. 91%, (n.s.). Complication rate was 1.3% vs. 1.4% (n.s.).

CONCLUSION

Success of AF ablation did not differ between patients who receive ablation as first vs. second line therapy. Based on these data, a trial of AAD therapy before AF ablation may be justified in most patients with symptomatic PAF eligible for rhythm control.

Lesion index: a novel guide in the path of successful pulmonary vein isolation

PURPOSE

Previous studies indicate force time integral (FTI) as a radiofrequency (RF) lesion quality marker, while not considering power supply. Tacticath™ Quartz catheter provides Lesion index (LSI), a lesion quality marker derived by contact force (CF), power supply, and RF time combined. Our aim is to assess LSI and FTI correlation and a LSI-related cutoff of atrial fibrillation (AF) recurrences 12 months after pulmonary vein isolation (PVI).

METHODS

We retrospectively enrolled 37 patients who underwent RF ablation using Tacticath™ Quartz catheter. AF recurrence rate was evaluated 3, 6, and 12 months after PVI procedure.

RESULTS

AF recurrence was detected in 32% of patients. FTI mean value was significantly lower in left superior pulmonary vein (LSPV: 256 ± 86 gs vs 329 ± 117 gs, p = 0.05) and right inferior pulmonary vein (RIPV: 253 ± 128 gs vs 394 ± 123 gs p = 0.006) in patients with AF recurrences; no significant differences were found in right superior pulmonary vein (RSPV) and left inferior pulmonary vein (LIPV). LSI instead was significantly higher for all veins in patients without AF recurrences: LSPV (5.2 ± 0.7 vs 4.6 ± 0.8, p = 0.03), LIPV (5.0 ± 0.8 vs 4.5 ± 0.6, p = 0.04), RSPV (5.5 ± 0.6 vs 5.1 ± 0.6, p = 0.05), and RIPV (5.5 ± 0.7 vs 4.7 ± 0.8, p = 0.006). Receiver operator characteristic curve suggests 5.3 as LSI overall cutoff value predicting freedom from disease at 1-year follow-up.

CONCLUSIONS

Our preliminary data suggest that a LSI mean value higher than 5.3 can be considered a good predictor of AF freedom at 1-year follow-up.

A randomized clinical trial of early invasive intervention for atrial fibrillation (EARLY-AF) - methods and rationale

BACKGROUND

The ideal management of patients with newly diagnosed symptomatic atrial fibrillation (AF) remains unknown. Current practice guidelines recommend a trial of antiarrhythmic drugs (AAD) prior to considering an invasive ablation procedure. However, earlier ablation offers an opportunity to halt the progressive patho-anatomical changes associated with AF, as well as impart other important clinical benefits.

OBJECTIVE

The aim of this study is to determine the optimal initial management strategy for patients with newly diagnosed, symptomatic atrial fibrillation.

METHODS/DESIGN

The EARLY-AF study (ClinicalTrials.govNCT02825979) is a prospective, open label, multicenter, randomized trial with a blinded assessment of outcomes. A total of 298 patients will be randomized in a 1:1 fashion to first-line AAD therapy, or first-line cryoballoon-based pulmonary vein isolation. Patients with symptomatic treatment naïve AF will be included. Arrhythmia outcomes will be assessed by implantable cardiac monitor (ICM). The primary outcome is time to first recurrence of AF, atrial flutter, or atrial tachycardia (AF/AFL/AT) between days 91 and 365 following AAD initiation or AF ablation. Secondary outcomes include arrhythmia burden, quality of life, and healthcare utilization.

DISCUSSION

The EARLY-AF study is a randomized trial designed to evaluate the optimal first management approach for patients with AF. We hypothesize that catheter ablation will be superior to drug therapy in prevention of AF recurrence.

2018 Korean Guideline of Atrial Fibrillation Management

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in the general population. The Korean Heart Rhythm Society organized a Korean AF Management Guideline Committee and analyzed all available studies regarding the management of AF, including studies on Korean patients. This guideline is based on recent data of the Korean population and the recent guidelines of the European Society of Cardiology, European Association for Cardio-Thoracic Surgery, American Heart Association, and Asia Pacific Heart Rhythm Society. Expert consensus or guidelines for the optimal management of Korean patients with AF were achieved after a systematic review with intensive discussion. This article provides general principles for appropriate risk stratification and selection of anticoagulation therapy in Korean patients with AF. This guideline deals with optimal stroke prevention, screening, rate and rhythm control, risk factor management, and integrated management of AF.

Catheter ablation in elderly patients: a review of current studies and pending questions

PURPOSE OF REVIEW

Catheter ablations are established treatment options for cardiac arrhythmias. Despite the fact that they are increasingly performed in elderly patients, publications focusing on procedural safety and success concerning this patient subgroup are sparse. The purpose of this review is to inform about current and upcoming studies regarding catheter ablations in the elderly.

RECENT FINDINGS

The overall pattern of available studies is indistinct because of varying age limits and scant patient populations. Most studies do not identify advanced patient age as a promoting factor for peri-procedural complications and recurrence rates. There are a few upcoming publications with regards to catheter ablations in the elderly, some of which might produce new insight.

SUMMARY

The results at hand might implicate, that in most cases individual patient health could be decisive instead of mere patient age to promise well-tolerated and effective catheter ablation in aged patients. Nevertheless, further studies with larger patient populations are needed to clarify the role of catheter ablation in aged patients.

Resource use and clinical outcomes in patients with atrial fibrillation with ablation versus antiarrhythmic drug treatment

BACKGROUND

The objective of our study was to compare resource use and clinical outcomes among atrial fibrillation (AF) patients who underwent catheter ablation versus antiarrhythmic drug (AAD) treatment.

METHODS

A retrospective cohort design using the Clinical Practice Research Data-Hospital Episode Statistics linkage data from England (2008-2013) was used. Patients undergoing catheter ablation treatment for AF were indexed to the date of first procedure. AAD patients with at least two different AAD drugs were indexed to the first fill of the second AAD. Patients were matched using 1:1 propensity matching. Primary endpoints including inpatient and outpatient visits were compared between ablation and AAD cohorts in the 4 months-1 year period after index. Secondary endpoints including heart failure, stroke, cardioversion, mortality, and a composite outcome were compared for the 4 months-3 years post-index period in the two groups. Cox-proportional hazards models were estimated for clinical outcomes comparison.

RESULTS

A total of 558 patients were matched in the two groups for resource utilization comparison. The average number of cardiovascular (CV)-related outpatient visits in the 4-12 months post-index period were significantly lower in the ablation group versus the AAD group (1.76 vs 3.57, p < .0001). There was no significant difference in all-cause and CV-related inpatient visits and all-cause outpatient visits among the two groups. For secondary endpoints comparison, 615 matched patients in each group emerged. Ablation patients had 38% lower risk of heart failure (hazard ratio [HR] 0.62, p = 0.0318), 50% lower risk of mortality (HR 0.50, p = 0.0082), and 43% lower risk of experiencing a composite outcome (HR 0.57, p = 0.0009) as compared to AAD treatment cohort.

CONCLUSION

AF ablation was associated with significantly lower CV-related outpatient visits, and lower risk of heart failure and mortality versus AAD therapy.

Use of an automaton model to suggest methods for cessation of intractable fibrillatory activity

BACKGROUND

Atrial fibrillation (AF) is the most common heart arrhythmia, and permanent AF is an intractable medical problem. If cessation of permanent AF were possible, via extensive substrate ablation or multisite stimulation, it could significantly improve the public health.

METHOD

A cellular automaton composed of 576 × 576 computerized grid nodes, described in detail previously, was used to test hypotheses concerning the cessation of fibrillatory electrical activity. A refractory period gradient across the grid, and addition of randomly located nonconducting fibers, were utilized as conditions leading to fibrillatory activity. A premature S1-S2 stimulus was applied to one grid corner, resulting in unidirectional conduction block at some locations, followed by rotational activity and random propagation of activation wavelets throughout the grid, none of which terminated spontaneously. Simulated ablation lesions of dimension 20 × 20 grid nodes, imparted at core locations of rotational activity, and multisite electrode stimulation (MES) applied at nodes where recovery of excitability had occurred, were used in attempts to terminate fibrillatory activity. Six impositions of random fiber location were utilized in separate trials.

RESULTS

Simulated ablation lesions eliminated the targeted swirling vortices; however, additional vortices then often appeared at other locations. After ablating approximately one third of the grid area, localized vortices were eliminated, but individual wavelets continued to propagate about longer viable pathways forming at ablation lesions. Thus extensive ablation was unsuccessful in terminating arrhythmia. However, MES applied uniformly throughout the grid, with a coupling interval slightly longer than the maximum refractory period, terminated fibrillatory activity in some trials. More efficaciously, application of MES with a coupling interval half the maximum refractory period of the grid succeeded in capture of activation at all nodes, and when followed by a doubling of the MES coupling interval, resulted in cessation of all fibrillatory activity.

CONCLUSIONS

It is possible to terminate simulated fibrillatory activity in a computerized grid that would otherwise be intractable, using multisite stimulation with a coupling interval related to the maximum refractory period of the substrate. If each MES stimulating electrode could be individually controlled, it would be possible to apply a stimulation pattern mimicking the normal heart activation sequence.

Validating Left Atrial Low Voltage Areas During Atrial Fibrillation and Atrial Flutter Using Multielectrode Automated Electroanatomic Mapping

OBJECTIVES

This study aimed: 1) to determine the voltage correlation between sinus rhythm (SR) and atrial fibrillation (AF)/atrial flutter (AFL) using multielectrode fast automated mapping; 2) to identify a bipolar voltage cutoff for scar and/or low voltage areas (LVAs); and 3) to examine the reproducibility of voltage mapping in AF.

BACKGROUND

It is unclear if bipolar voltage cutoffs should be adjusted depending on the rhythm and/or area being mapped.

METHODS

High-density mapping was performed first in SR and afterward in induced AF/AFL. In some patients, 2 maps were performed during AF. Maps were combined to create a new one. Points of <1 mm difference were analyzed. Correlation was explored with scatterplots and agreement analysis was assessed with Bland-Altman plots. The generalized additive model was also applied.

RESULTS

A total of 2,002 paired-points were obtained. A cutoff of 0.35 mV in AFL predicted a sinus voltage of 0.5 mV (95% confidence interval [CI]: 0.12 to 2.02) and of 0.24 mV in AF (95% CI: 0.11 to 2.18; specificity [SP]: 0.94 and 0.96; sensitivity [SE]: 0.85 and 0.75, respectively). When generalized additive models were used, a cutoff of 0.38 mV was used for AFL for predicting a minimum value of 0.5 mV in SR (95% CI: 0.5 to 1.6; SP: 0.94, SE: 0.88) and of 0.31 mV for AF (95% CI: 0.5 to 1.2; SP: 0.95, SE: 0.82). With regard to AF maps, there was no change in the classification of any left atrial region other than the roof.

CONCLUSIONS

It is possible to establish new cutoffs for AFL and/or AF with acceptable validity in predicting a sinus voltage of <0.5 mV. Multielectrode fast automated mapping in AFL and/or AF seems to be reliable and reproducible when classifying LVAs. These observations have clinical implications for left atrial voltage distribution and in procedures in which scar distribution is used to guide pulmonary vein isolation and/or re-isolation.

Impact of body mass index on the outcome of catheter ablation of atrial fibrillation

Objectives

The association between obesity and atrial fibrillation (AF) is well-established. We aimed to evaluate the impact of index body mass index (BMI) on AF recurrence at 12 months following catheter ablation using propensity-weighted analysis. In addition, periprocedural complications and fluoroscopy details were examined to assess overall safety in relationship to increasing BMI ranges.

Methods

Baseline, periprocedural and follow-up data were collected on consecutive patients scheduled for AF ablation. There were no specific exclusion criteria. Patients were categorised according to baseline BMI in order to assess the outcomes for each category.

Results

Among 3333 patients, 728 (21.8%) were classified as normal (BMI <25.0 kg/m2), 1537 (46.1%) as overweight (BMI 25.5–29.0 kg/m2) and 1068 (32.0%) as obese (BMI ≥30.0 kg/m2). Procedural duration and radiation dose were higher for overweight and obese patients compared with those with a normal BMI (p=0.002 and p<0.001, respectively). An index BMI ≥30 kg/m2 led to a 1.2-fold increased likelihood of experiencing recurrent AF at 12-months follow-up as compared with overweight patients (HR 1.223; 95% CI 1.047 to 1.429; p=0.011), while no significant correlation was found between overweight and normal BMI groups (HR 0.954; 95% CI 0.798 to 1.140; p=0.605) and obese versus normal BMI (HR 1.16; 95% CI 0.965 to 1.412; p=0.112).

Conclusions

Patients with a baseline BMI ≥30 kg/m2 have a higher recurrence rate of AF following catheter ablation and therefore lifestyle modification to target obesity preprocedure should be considered in these patients.

Laser balloon ablation for AF: A systematic review and meta-analysis

INTRODUCTION

The HeartLight laser balloon ablation system was US Food and Drug Administration approved in 2016 for the treatment of paroxysmal atrial fibrillation (AF), but there have been numerous single-center and multicenter studies published reporting its outcomes, in addition to a few randomized trials. We aimed to systematically review and synthesize currently published outcome data on AF ablation using the laser balloon ablation system.

METHODS AND RESULTS

We performed a systematic review and meta-analysis of published studies of AF ablation performed using the laser balloon ablation system. Human studies reporting acute procedural results with a minimum of 6 months follow-up were included. Outcomes of interest included acute and 12-month procedural efficacy, safety, and procedure duration. Aggregated data were analyzed with random effects models, using a Bayesian hierarchical approach. We identified 17 published manuscripts comprising a sample of 1188 patients (mean age 61 years, 80% paroxysmal). At procedure end, 98.8% of targeted pulmonary veins were successfully isolated. The pooled estimate for 12-month freedom from atrial arrhythmia without use of antiarrhythmic drugs for patients with paroxysmal AF was 74.3% (95% confidence interval [CI], 59.9% to 86.4%), and for all AF types combined was 72.9% (65.3% to 79.9%). The most commonly reported procedural complication was phrenic nerve injury (pooled incidence 2.6%; 95% CI, 1.4% to 3.9%), which resolved during follow-up in most cases.

CONCLUSION

Laser balloon ablation is highly effective at achieving pulmonary vein isolation. Although comparisons are mainly indirect, safety and 12-month efficacy compare favorably with those observed using other currently used AF ablation technologies.

Stiff Left Atrial Syndrome; Prospects and Possibilities. Retrospective Analysis and Review of the Literature

OBJECTIVES

Stiff left atrial syndrome is an intriguing clinical phenomena characterized by reduced left atrial compliance, pulmonary venous hypertension and exacerbations of volume overload. We conducted a retrospective review of patients diagnosed with stiff left atrial syndrome at our center.

METHODS

All patients admitted to our hospital with volume overload and pulmonary venous hypertension who were diagnosed with stiff left atrial syndrome based on evidence by echocardiogram and right heart catheterization between July 2011 and July 2013 were included in this retrospective review.

RESULTS

Twentythree patients (mean age 73 ± 11 years, 39% male and 61% female) were diagnosed with stiff left atrial syndrome at our center. Thirty-five percent had persistent while 39% had permanent atrial fibrillation. Mean duration of atrial fibrillation was 7.6 ± 2.1 years. Forty-three percent of patients had long standing hypertension. There was no mitral regurgitation in 39% of patients while 48% had mild mitral regurgitation. On right heart catheterization, mean right atrial pressure was 12.6±4.8 mm of Hg, mean pulmonary arterial pressure was 33±7.2 mm of Hg, mean pulmonary capillary wedge pressure was 24.8± 4.2mm of Hg while peak V waves were seen at mean of 37.8± 5.3 mm of Hg. Mean left atrial volume index was 49.8±17.1 mL/m 2. After the initial diagnosis with a two year follow- up, there were no readmissions in 65% of patients who were on appropriate diuretic therapy and had regular clinical visits. Frequent readmissions were seen in 35% of patients inspite of appropriate diuretic therapy. All-cause mortality rate was 4.3% at two year follow up.

CONCLUSION

In patients with stiff left atrial syndrome, the presence of left atrial dilation, long standing atrial fibrillation and hypertension are the key factors associated with pathogenesis and clinical course. Close follow up and monitoring of volume status is essential to prevent hospital readmissions and improve long term prognosis.

The trend of change in catheter ablation versus antiarrhythmic drugs for the management of atrial fibrillation over time: a meta-analysis and meta-regression

Objective

To evaluate the trend of change in the efficacy and safety of catheter ablation compared with antiarrhythmic drug therapy (ADT) for rhythm control in patients with atrial fibrillation (AF) over time.

Methods

The online databases PubMed and EMBASE were searched for relevant studies. STATA software (version 12.0) was used to perform the meta-analysis and meta-regression.

Results

Fifteen randomized controlled trials including 2249 patients with AF were identified. The pooled results showed that catheter ablation was associated with a 52% reduction in the risk of AF recurrence compared with ADT [risk ratio (RR) = 0.48, 95% confidence interval (CI): 0.40–0.57, I² = 70.7%). Subgroup analyses showed that catheter ablation exhibited less efficacy in studies after 2011 compared to studies before 2011 (RR = 0.61, 95% CI: 0.54–0.68, I² = 9.3% and RR = 0.34, 95% CI: 0.24–0.47, I² = 69.9%, respectively), and the safety outcome showed a 1.08-fold higher incidence of adverse events (14.2% vs. 7.3%; RR = 1.08, 95% CI: 1.04–1.13) in studies after 2011.

Conclusions

Catheter ablation appears to be superior to ADT for rhythm control. However, less efficacy and a higher rate of adverse events were observed in studies after 2011 compared to studies before 2011.

Rotor mapping: black box or very simple? The FIRM approach

Catheter ablation has become the most common therapy in patients with atrial fibrillation (AF). However, despite significant advances in technology and operators' experience, ablation outcomes remain suboptimal, especially in patients with persistent AF. Focal impulse and rotor modulation (FIRM) represents a new technology for mapping and ablation of patient-specific AF sources. This approach is based on the concept of localized sources, which can be understood as organized rotational waves or focal impulses driving disorganized AF. Several studies, mainly single-center case series, have shown an incremental benefit in long-term outcome when adding FIRM-guided ablation to conventional pulmonary vein isolation (PVI). Therefore, the results of ongoing multicenter randomized trials are needed to support this data.

Prognostic significance of atrial fibrillation in acute decompensated heart failure with reduced versus preserved ejection fraction

OBJECTIVE

The prognostic impact of atrial fibrillation (AF) in patients with acute decompensated heart failure (ADHF) has not been fully elucidated yet. Aim of the present study was thus to investigate the association of AF with all-cause mortality in patients with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF).

METHODS

We performed a retrospective single center study and analyzed data of 1286 patients admitted for ADHF. Patients were grouped according to AF status (i.e., "never AF", "history of AF", or "AF on admission") and type of heart failure. Patient and treatment characteristics were extracted by chart review. The primary outcome of all-cause mortality within 3 years following index hospitalization was determined by death registry linkage.

RESULTS

In total, 529 (41.1%), 215 (16.7%), and 542 (42.1%) patients were grouped as "never AF", "history of AF", and "AF on admission", respectively. With regard to type of heart failure, 558 (43.4%) and 728 (56.6%) had HFrEF and HFpEF, respectively. Compared to "never AF", "AF on admission" was associated with increased all-cause mortality in an adjusted Cox regression model [hazard ratio, 1.64 (95% confidence interval 1.32-2.04); P < 0.001]. However, this association remained significant only for patients with HFpEF [2.16 (1.58-2.95)], but not for patients with HFrEF [1.18 (0.85-1.63)] in a subgroup analysis (P for effect modification = 0.020).

CONCLUSIONS

AF is common in the setting of ADHF and is associated with increased all-cause mortality. However, this association remained significant only in patients with HFpEF, but not in patients with HFrEF.

The effects of gender on electrical therapies for the heart: physiology, epidemiology, and access to therapies

The difference between men and women is clear even just by looking at an electrocardiogram: females present higher resting heart rate, a shorter QRS complex length and greater corrected QT interval. The development of these differences from pubertal age onward suggests that sexual hormones play a key role, although their effect is far from being completely understood. Different incidences between sexes have been reported for many arrhythmias, both ventricular and supraventricular, and also for sudden cardiac death. Moreover, arrhythmias are an important issue during pregnancy, both for diagnosis and treatment. Interestingly, cardiovascular structural and electrophysiological remodelling promoted by exercise training enhances this 'gender effect'. Despite all these relevant issues, we lack gender specific recommendations in the current guidelines for electrical therapies for heart rhythm disorders and heart failure. Even more, we continue to see that fewer women are included in clinical trials and are less referred than men for these treatments.

Atrial fibrillation in aging population

With aging, the pathogenesis processes of atrial fibrillation (AF) are heightened. In this article, we review the mechanisms that predispose elderly patients to AF. We also highlight the unique features in diagnosis, stroke prevention, and treatment strategies for the elderly patient with AF.

Different Responses of Left Atrium and Left Atrial Appendage to Radiofrequency Catheter Ablation of Atrial Fibrillation: a Follow Up MRI study

Atrial fibrillation (AF) is known to cause adverse remodeling of left atrium (LA). Radiofrequency catheter ablation (RFCA) of AF is associated with decrease in LA volume. However, the impact of RFCA on left atrial appendage (LAA) volume and hemodynamic function is not fully understood. We analyzed 123 patients who underwent cardiac magnetic resonance imaging (MRI) evaluation before and after RFCA in Korea University Anam Hospital. LA and LAA volume were measured before and after RFCA based on cardiac MRI. Baseline LA volume was 99.5 ± 38.4 cm³ and decreased to 74.6 ± 28.5 cm³ after RFCA (p < 0.001). LA diameter measured with transthoracic echocardiography was also decreased after RFCA (43.3 ± 6.2 mm at baseline and 39.9 ± 5.9 mm at follow up; p < 0.001). However, LAA volume was significantly increased after RFCA (19.4 ± 8.5 cm³ at baseline and 23.7 ± 13.3 cm³ at follow up; p < 0.001). Total ablation time and additional substrate modification was associated with change in LA volume. After RFCA, average LAA velocity measured by transesophageal echocardiography was increased to 51.0 cm/sec from 41.1 cm/sec (p < 0.001). In conclusion, LAA volume was increased after RFCA in contrast to LA volume. Our data raise a concern about worsening hemodynamics of LA and LAA following RFCA and long term clinical significance of enlarged LAA after RFCA needs further evaluation.

Clinical and electrocardiographic characteristics for prediction of new-onset atrial fibrillation in asymptomatic patients with atrial premature complexes

Backgrounds

Identification of precursors of atrial fibrillation (AF) may lead to early detection and prevent associated morbidity and mortality. Atrial premature complexes (APCs) are commonly seen in healthy subjects. However, there was limited data about the clinical and electrocardiographic (ECG) characteristics for prediction of new-onset AF in asymptomatic patients with APCs in the long-term follow up.

Methods

The Kosin University (No. 2014-02-04) 24-h holter monitoring, echocardiography, ECG database were reviewed from 2008 to 2016 to identify new- onset AF in patients with APCs. We analyzed demographic and clinical features and the nature of the APCs by ECG according to new-onset AF in those patients.

Results

Among 652 patients who underwent 24-h holter monitoring, 226 (34.4%) patients had new-onset AF. There was no difference of the baseline characteristics between new-onset AF group and non-AF group. In univariate analysis, hypertension (HTN), renal failure (CRF), high APC burdens, fastest APC running heart rate (HR), minimal HR, left ventricular ejection fraction (LVEF), left atrial volume index, peak mitral flow velocity of the early rapid filling wave and tricuspid regurgitation grade were significantly associated with new-onset AF. In multivariate analysis, higher APCs burden (P = 0.047), higher fastest APCs running HR (P = 0.034) and lower minimal HR (P = 0.025) were independent risk factors for new-onset AF in asymptomatic patients with APCs.

Conclusion

Higher APCs burden, higher fastest APCs running HR and lower minimal HR were associated with new-onset AF in asymptomatic patients with APCs in the long-term follow up.

Obesity is associated with impaired long-term success of pulmonary vein isolation: a plea for risk factor management before ablation

Aims

Obesity is an increasing health problem and is an important risk factor for the development of atrial fibrillation (AF). We investigated the association of body mass index (BMI) on the safety and long-term efficacy of pulmonary vein isolation (PVI) for drug-refractory AF.

Methods

414 consecutive patients who underwent transcatheter PVI for AF between 2003 and 2013 were included. Successful PVI was defined as absence of atrial arrhythmia on Holter monitoring or ECG, without and with antiarrhythmic drugs during follow-up. Obesity was defined as BMI≥30 kg/m².

Results

Mean age was 56±10 years, 316 (76%) were male, 311 (75%) had paroxysmal AF and 111 (27%) were obese. After a mean follow-up of 46±32 months (1590 patient-years), freedom from atrial arrhythmia and antiarrhythmic drugs was significantly lower in patients with obesity compared with non-obese patients (30% vs 46%, respectively, P=0.005, log-rank 0.016). With antiarrhythmic drugs, freedom from atrial arrhythmia was 56% vs 68% (P=0.036). No differences in minor and major adverse events were observed between patients with obesity and non-obese patients (major 6% vs 3%, P=0.105, and minor 5% vs 5%, P=0.512). Sensitivity analyses demonstrated that BMI (as continuous variable) was associated with PVI outcome (HR 1.08, 95% CI 1.02 to 1.14, P=0.012).

Conclusion

Obesity is associated with reduced efficacy of PVI for drug-refractory AF. No relation between obesity and adverse events was found.

Lifestyle Therapy for the Management of Atrial Fibrillation

Atrial fibrillation (AF) is a common arrhythmia associated with increased risk of morbidity and mortality. There is evidence that lifestyle interventions may serve as complementary treatments to reduce AF burden. The objective of this review was to summarize the efficacy of lifestyle interventions for the management of AF. Studies which included patients with systolic heart failure (ejection fraction ≤40%), and those limited to an examination of vigorous physical activity were excluded from our search. Studies were identified through a search of the following databases: MEDLINE, EMBASE, CINAHIL, and PubMed, run from inception through August 2016. All studies were graded for quality using the Oxford Centre for Evidence-based Medicine recommendations. Meta-analyses of the studies were not performed due to the heterogeneity of the studies. From a total of 1,811 publications, 10 articles were identified and included. Selected publications included 1 study on yoga, 2 studies on acupuncture, 3 studies that examined weight loss programs, and 4 studies that evaluated the impact of moderate physical activity. Yoga was associated with less symptomatic AF episodes and improved quality of life. Acupuncture was associated with reduced AF occurrence in patients with persistent and paroxysmal AF. Weight loss was associated with a significant reduction AF burden and symptoms. Moderate exercise resulted in greater arrhythmia free survival and a mean reduction in AF burden. In conclusion, evidence exists to suggest that yoga, weight loss, and moderate exercise are associated with reductions in AF burden and symptoms. Evidence is greatest for weight loss and moderate exercise.

Catheter Ablation versus Antiarrhythmic Drug Therapy for Atrial Fibrillation (CABANA) Trial: Study Rationale and Design

The Catheter Ablation Versus Anti-arrhythmic Drug Therapy for Atrial Fibrillation (CABANA, NCT00911508)(1) trial is testing the hypothesis that the treatment strategy of percutaneous left atrial catheter ablation for the purpose of eliminating atrial fibrillation (AF) is superior to current state-of-the-art pharmacologic therapy. This international 140-center clinical trial was designed to randomize 2200 patients to a strategy of catheter ablation versus state-of-the-art rate or rhythm control drug therapy. Inclusion criteria include: 1) age > 65, or ≤65 with≥ 1 risk factor for stroke, 2) documented AF warranting treatment, and 3) eligibility for both catheter ablation and≥ 2 anti-arrhythmic or≥ 2 rate control drugs. Patients were followed every 3 to 6 months (median 4 years) and underwent repeat trans-telephonic monitoring, Holter monitoring, and CT/MR in a subgroup of patient studies to assess the impact of treatment on AF recurrence and atrial structure.

With 1100 patients in each treatment arm, CABANA is projected to have 90% power for detecting a 30% relative reduction in the primary composite endpoint of total mortality, disabling stroke, serious bleeding, or cardiac arrest. Secondary endpoints include total mortality; mortality or cardiovascular hospitalization; a combination of mortality, stroke, hospitalization for heart failure or acute coronary artery events; cardiovascular death alone; and heart failure death, as well as AF recurrence, quality of life, and cost effectiveness. At a time when AF incidence is rising rapidly, CABANA will provide critical evidence with which to guide therapy and shape health care policy related to AF for years to come.

Cost effectiveness of focal impulse and rotor modulation guided ablation added to pulmonary vein isolation for atrial fibrillation

BACKGROUND

Although ablation with focal impulse and rotor modulation (FIRM), as an adjunct to pulmonary vein isolation (PVI), has been shown to decrease atrial fibrillation (AF) recurrence, cost-effectiveness has not been assessed.

OBJECTIVE

We aimed to evaluate the cost effectiveness of FIRM-guided ablation when added to PVI in a mixed AF population.

METHODS AND RESULTS

We used a Markov model to estimate the costs, quality-adjusted survival, and cost effectiveness of adding FIRM ablation to PVI. AF recurrence rates were based on 3-year data from the CONFIRM trial. Model inputs for event probabilities and utilities were obtained from literature review. Costs were based on Medicare reimbursement, wholesale acquisition costs, and literature review. Three-year total costs FIRM+PVI versus PVI alone were $27,686 versus $26,924. QALYs were 2.338 versus 2.316, respectively, resulting in an incremental cost-effectiveness ratio (ICER) of $34,452 per QALY gained. Most of the cost (65-81%) was related to the index ablation procedure. Lower AF recurrence generated cost offsets of $4,266, primarily due to a reduced need for medications and repeat ablation. Probabilistic sensitivity analysis demonstrated ICER below $100,000/QALY in 74% of simulations.

CONCLUSION

Based on data from the CONFIRM study, the addition of FIRM to PVI does have the potential to be cost-effective due to higher quality-adjusted life years and lower follow-up costs. Value is sensitive to the incremental reduction in AF recurrence, and FIRM may have the greatest economic value in patients with greater AF symptom severity. Results from ongoing randomized trials will provide further clarity.