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

Left atrial catheter ablation in patients with previously implanted left atrial appendage closure devices

AIMS

Left atrial appendage closure (LAAC) is increasingly used as an alternative to oral anticoagulation (OAC) for stroke prevention in atrial fibrillation (AF) patients. Feasibility and safety of left atrial (LA) catheter ablation (CA) in patients with previously implanted LAAC devices have not been well studied. We report on the feasibility, safety, and efficacy of LA CA in the presence of a previously implanted LAAC device.

METHODS AND RESULTS

In this prospective cohort study consecutive patients that underwent LA CA with a previously implanted Watchman device were included. Periprocedural characteristics and long-term clinical follow-up were evaluated. Twenty-three LA CA procedures were performed in 19/162 AF patients with previously implanted Watchman devices [47% male, age 63.9 ± 6.2 years, CHA2DS2-VASc 4.0 (3.0-5.0); HASBLED 3.0 (2.0-4.0); 63% paroxysmal]. Left atrial CA was performed with irrigated radiofrequency (RF; n = 20, 87%) or phased RF (n = 3, 13%) in a mean of 18 months after LAAC implantation (range 4-80 months). Targets of CA consisted of pulmonary vein isolation (n = 19, 83%), superior vena cava isolation (n = 13, 57%), and additional linear lesions (n = 8, 35%). Procedures were carried out under vitamin K antagonist (VKA; n = 6, 26%), non-VKA OAC (NOAC; n = 8, 35%), or single antiplatelet therapy alone (n = 9, 39%). Left atrial CA was successful without any signs of interference from the device. Procedure-related complications were not observed. During a mean follow-up of 28 months, 11 patients (58%) had AF recurrence.

CONCLUSION

Left atrial CA after LAAC appears to be feasible, effective, and safe in this single centre cohort. Previously implanted Watchman device should not be a reason to relinquish CA in symptomatic AF patients, even in patients on single antiplatelet therapy alone.

Characteristics of Esophageal Injury in Ablation of Atrial Fibrillation Using a High-Power Short-Duration Setting

BACKGROUND

The mechanism of esophageal thermal injury (ETI; esophageal mucosal injury and periesophageal nerve injury leading to gastric hypomotility) remains unknown when using a high-power short-duration (HP-SD) setting. This study sought to evaluate the characteristics of esophageal injuries in atrial fibrillation ablation using a HP-SD setting.

METHODS

After exclusion of 5 patients with their esophagus at the right portion of left atrium and 21 patients with additional ablations such as box isolation and low voltage area ablation in left atrium posterior wall, 271 consecutive patients (62±10 years, 56 women) who underwent pulmonary vein isolation by radiofrequency catheter ablation were analyzed. In the 101 patients, a HP-SD setting at 45 to 50 W with an Ablation Index module was used (HP-SD group). In the remaining 170 patients before introduction of the HP-SD setting, a conventional power setting of 20 to 30 W with contact force monitoring was used (conventional group). We performed esophagogastroduodenoscopy after pulmonary vein isolation in all patients and investigated the incidence and characteristics of ETI.

RESULTS

Although the incidence of ETI was significantly higher in the HP-SD group compared with the conventional group (37% versus 22%, P=0.011), the prevalence of esophageal lesions did not differ between the groups (7% versus 8%). Multivariate logistic regression analysis revealed that the use of the HP-SD setting (odds ratio, 6.09, P<0.001), and the parameters that suggest anatomic proximity surrounding the esophagus, were independent predictors of ETI. However, the majority of ETI in the HP-SD group was gastric hypomotility, and the thermal injury was limited to the shallow layer of the periesophageal wall using the HP-SD setting.

CONCLUSIONS

Although the use of the HP-SD setting was a strong predictor of ETI, it could avoid deeper thermal injuries that reach the esophageal mucosal layer.

Long-term Clinical Outcomes of Radiofrequency Catheter Ablation versus Permanent Pacemaker Implantation in Patients with Tachycardia-Bradycardia Syndrome

BACKGROUND AND OBJECTIVES

Pacemaker (PM) implantation is a well-accepted treatment option for patients with paroxysmal atrial fibrillation (AF) and related tachycardia-bradycardia syndrome (TBS). Data on the long-term clinical outcomes after radiofrequency catheter ablation (RFCA) or PM implantation are sparse.

METHODS

The medical records of 217 patients with TBS were retrospectively assessed. Outcomes in patients who underwent RFCA (n=108, 49.8%) were compared to those with PM implantation (n=109, 50.2%). The clinical outcomes were sinus rhythm maintenance, conversion to persistent AF, additional procedure or crossover, and the composite of cardiovascular hospitalization and death.

RESULTS

During the follow-up period (mean 3.5±2.0 years), the RFCA group, compared to the PM group, showed better sinus rhythm maintenance (adjusted hazard ratio [aHR], 0.27; 95% confidence interval [CI], 0.15-0.46; p=0.002) and less progression to persistent AF (aHR, 0.20; 95% CI, 0.06-0.63; p=0.006). Additional procedure or crossover did not differ significantly between the groups (aHR, 2.07; 95% CI, 0.71-6.06; p=0.185 and aHR, 0.69; 95% CI, 10.8-2.67; p=0.590, respectively). Most RFCA patients (92.6%) did not require pacemaker implantation during long term follow-up period (>3.5 years). The composite endpoint of cardiovascular rehospitalization and death was not significantly different between the groups (aHR, 0.92; 95% CI, 0.50-1.66; p=0.769).

CONCLUSIONS

RFCA is an effective alternative to PM implantation in patients with TBS. In these patients, successful RF ablation of AF is related to a higher rate of sinus rhythm maintenance compared to PM implantation, and the composite outcome of cardiovascular rehospitalization and death is similar.

Does Catheter Ablation Lower the Long-Term Risk of Stroke and Mortality in Patients with Atrial Fibrillation? A Concise Review of the Current State of Knowledge

Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and carries a significant risk of morbidity and mortality. Multiple trials have highlighted the benefit of catheter ablation over medical therapy in restoring sinus rhythm and improving quality of life. Whether it reduces long-term risk of stroke and mortality is still unclear.

We performed a literature search using the PubMed database to review the current state of knowledge regarding the long-term outcomes of stroke and mortality in ablated patients compared to patients who receive medical therapy. Our review mainly consisted of recent randomized controlled trials and large observational studies. 

Results from large observational studies show that catheter ablation significantly reduces the risk of stroke in high-risk patients and mortality compared to medical therapy. However, randomized controlled trials have only demonstrated a mortality benefit in patients with comorbid systolic heart failure. In patients with paroxysmal AF, ablation therapy significantly limits the progression to persistent AF and has a higher efficacy in restoring sinus rhythm. Maintenance of sinus rhythm is the most important factor associated with lower long term risk of stroke and mortality.

Large randomized controlled trials similar to the Catheter Ablation Versus Anti-arrhythmic Drug Therapy for Atrial Fibrillation (CABANA) trial are still needed to clarify whether catheter ablation is superior over medical therapy in improving the long-term outcomes of stroke and mortality.

Real-world outcomes comparison among adults with atrial fibrillation undergoing catheter ablation with a contact force porous tip catheter versus a second-generation cryoballoon catheter: a retrospective analysis of multihospital US database

OBJECTIVE

To compare real-world clinical and economic outcomes among atrial fibrillation (AF) patients undergoing cardiac ablation with the contact force-sensing porous tip THERMOCOOL SMARTTOUCH SF (STSF) catheter versus the Arctic Front Advance Cryoballoon (AFA-CB) catheter.

DESIGN

Retrospective, observational cohort study.

SETTING

Premier Healthcare Database (PHD), between 1 September 2016 and 30 June 2018.

PARTICIPANTS

Patients with AF (≥18 years) were included if they had an index ablation procedure performed using the STSF catheter or AFA-CB catheter at a US hospital that consistently provided inpatient and outpatient data to PHD in the 12-month preindex period. Using 1:1 propensity score matching, patient groups were matched on study covariates.

PRIMARY AND SECONDARY OUTCOME MEASURES

Cost, length of stay (LOS), readmissions, direct current cardioversion (DCCV) and reablation outcomes were compared between matched cohorts of STSF and AFA-CB patients.

RESULTS

A total of 3015 patients with AF met the study criteria, of which 1720 had ablation using the STSF catheter and 1295 had ablation using the AFA-CB catheter. In the propensity-matched sample, patients receiving ablation with the STSF catheter had ~17% lower total costs (US$23 096 vs US$27 682, p≤0.0001) and ~27% lower supply costs (US$10 208 vs US$13 816, p≤0.0001) versus patients receiving ablation with the AFA-CB catheter. A significantly lower likelihood of 4-month to 6-month cardiovascular-related readmission (OR 0.460, 95% CI 0.220 to 0.959) was associated with the STSF catheter versus the AFA-CB catheter. No significant differences in LOS, room and board cost, 4-month to 6-month all-cause and AF-related readmissions, DCCV and reablation were observed among technologies. Sensitivity analysis restricting patient sample by provider ablation volume demonstrated similar results.

CONCLUSION

Lower index ablation total and supply costs were observed among patients with AF undergoing cardiac catheter ablation using the STSF catheter versus the AFA-CB catheter.

Recurrence of Atrial Fibrillation After Catheter Ablation or Antiarrhythmic Drug Therapy in the CABANA Trial

BACKGROUND

The CABANA (Catheter Ablation Versus Antiarrhythmic Drug Therapy for Atrial Fibrillation) trial randomized 2,204 patients with atrial fibrillation (AF) to catheter ablation or drug therapy. Analysis by intention-to-treat showed a nonsignificant 14% relative reduction in the primary outcome of death, disabling stroke, serious bleeding, or cardiac arrest.

OBJECTIVES

The purpose of this study was to assess recurrence of AF in the CABANA trial.

METHODS

The authors prospectively studied CABANA patients using a proprietary electrocardiogram recording monitor for symptom-activated and 24-h AF auto detection. The AF recurrence endpoint was any post-90-day blanking atrial tachyarrhythmias lasting 30 s or longer. Biannual 96-h Holter monitoring was used to assess AF burden. Patients who used the CABANA monitors and provided 90-day post-blanking recordings qualified for this analysis (n = 1,240; 56% of CABANA population). Treatment comparisons were performed using a modified intention-to-treat approach.

RESULTS

Median age of the 1,240 patients was 68 years, 34.4% were women, and AF was paroxysmal in 43.0%. Over 60 months of follow-up, first recurrence of any symptomatic or asymptomatic AF (hazard ratio: 0.52; 95% confidence interval: 0.45 to 0.60; p < 0.001) or first symptomatic-only AF (hazard ratio: 0.49; 95% confidence interval: 0.39 to 0.61; p < 0.001) were both significantly reduced in the catheter ablation group. Baseline Holter AF burden in both treatment groups was 48%. At 12 months, AF burden in ablation patients averaged 6.3%, and in drug-therapy patients, 14.4%. AF burden was significantly less in catheter ablation compared with drug-therapy patients across the 5-year follow-up (p < 0.001). These findings were not sensitive to the baseline pattern of AF.

CONCLUSIONS

Catheter ablation was effective in reducing recurrence of any AF by 48% and symptomatic AF by 51% compared with drug therapy over 5 years of follow-up. Furthermore, AF burden was also significantly reduced in catheter ablation patients, regardless of their baseline AF type. (Catheter Ablation vs Anti-arrhythmic Drug Therapy for Atrial Fibrillation Trial [CABANA]; NCT00911508).

Acute and long-term outcome of redo catheter ablation for recurrent atrial tachycardia and recurrent atrial fibrillation in patients with prior atrial fibrillation ablation

PURPOSE

Organized atrial tachycardia (AT) accounts for a substantial proportion of recurrence after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). We sought to analyze the characteristics and long-term outcome of redo RFCA for recurrent AT compared with those for recurrent AF.

METHODS

We analyzed 133 patients who underwent prior AF ablation and presented for redo RFCA procedure. Documented rhythm at recurrence was AT in 50 patients (37.6%) and AF in 83 patients (62.4%). Redo ablation was conducted using a stepwise approach in all subjects.

RESULTS

Recurrent arrhythmia was more frequently a persistent type in the AT group (70.0% vs. 36.1% in the AT and AF group, respectively, p < 0.001). Fifty mappable ATs were identified in the AT group. Perimitral reentry was most common (19/50), followed by PV-related focal or reentrant tachycardia (16/50). During the redo RFCA, PV reconnection rate and linear ablation rate were similar in the two groups, while the focal target ablation tended to be conducted more frequently in the AF group (26.0% vs. 42.2%, p = 0.060). The AT group showed a higher acute success rate (92.0% vs. 75.9%, p = 0.019) and higher arrhythmia freedom during a mean of 30 months (76.0% vs. 55.4%, p = 0.030), compared with the AF group. The AT group and de novo AF type (paroxysmal) were independent predictors for higher arrhythmia freedom.

CONCLUSIONS

RFCA for recurrent AT following AF ablation showed favorable acute and long-term success rates and was associated with superior procedural outcomes compared with those for recurrent AF.

Electrophysiology's Identity Crisis: What our Clinical Trials Do and Do Not Say About Us

Although it has not always been this way, the impact of large, randomised clinical trials in electrophysiology is limited, at least compared with other disciplines in cardiology. This has been particularly true regarding procedural aspects of our field: successful randomised trials are rare and observational trials are small and typically without a proper active control group. In this article, the authors examine the reasons behind this circumstance, which include underinvestment from funding sources; lack of consensus on procedural endpoints; lack of consensus on techniques; and a therapeutic bias in favour of procedural intervention that stands in the way of investigator equipoise. Together, these factors have created a scientific culture dominated by small-scale, siloed, observational research and unwillingness to collaboratively advance the field with consensus and prospective trials. The authors feel that it is increasingly urgent to improve the scientific basis for clinical practice and explore strategies to accomplish this goal.

The Cryoballoon vs Irrigated Radiofrequency Catheter Ablation (CIRCA-DOSE) Study Results in Context

The Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double Short vs Standard Exposure Duration (CIRCA-DOSE) study was a multicentre, randomised, single-blinded trial that compared contact-force radiofrequency ablation and two different regimens of cryoballoon ablation. All patients received an implantable cardiac monitor for the purpose of continuous rhythm monitoring, with all arrhythmia events undergoing independent adjudication by a committee blinded to treatment allocation. The study demonstrated there were no significant differences between contact-force radiofrequency ablation and cryoballoon ablation with respect to recurrence of any atrial tachyarrhythmia, symptomatic atrial tachyarrhythmia, asymptomatic AF, symptomatic AF or AF burden. While the results of the CIRCA-DOSE study are reviewed here, this article focuses on considerations around the design of the study and places the observed outcomes in context.

Catheter Ablation in the Treatment of Atrial Fibrillation

Catheter ablation (CA) of the pulmonary veins for atrial fibrillation (AF) is growing exponentially and is the most commonly performed electrophysiologic procedure. Initial descriptions focused on CA for paroxysmal AF, and now more recently expanded in application to persistent AF and those with comorbid heart failure. Efforts to improve success have and continue to address issues such as pulmonary vein "reconnection" following ablation through different ablative energy modalities, and the use of a "hybrid" surgical/endocardial combined approach in persistent forms of AF. Technologic advances as well are concurrently seeking to improve safety, particularly regarding the incidence of atrio-esophageal fistula in this seemingly ever-growing ablation population.

Surgical Treatment of Atrial Fibrillation: Cutting Through the Edges

Medical management of atrial fibrillation can be complex, challenging and requiring time to prove its effectiveness; furthermore, the response can be refractory and inconsistent if the underlying pathology is not permanently addressed. Surgical ablation has become a key intervention, and since its first intervention in 1987 (the Cox-maze procedure), the technique has evolved from a conventional open method to a minimally invasive technique whilst retaining excellent outcomes. Furthermore, recent advances in the use of a hybrid approach have been established as satisfactory approach in managing atrial fibrillation with satisfactory outcomes.

This literature review focuses on the evidence behind the surgical success in managing atrial fibrillation throughout the past, present and the future of these surgical interventions.

Long-term safety and effectiveness of paroxysmal atrial fibrillation ablation using a porous tip contact force-sensing catheter from the SMART SF trial

Purpose

The prospective, multicenter SMART SF trial demonstrated the acute safety and effectiveness of the 56-hole porous tip irrigated contact force (CF) catheter for drug-refractory paroxysmal atrial fibrillation (PAF) ablation with a low primary adverse event rate (2.5%), leading to FDA approval of the catheter. Here, we are reporting the long-term effectiveness and safety results that have not yet been reported.

Methods

Ablations were performed using the 56-hole porous tip irrigated CF catheter guided by the 3D mapping system stability module. The primary effectiveness endpoint was freedom from atrial tachyarrhythmia (including atrial fibrillation, atrial tachycardia, and/or atrial flutter), based on electrocardiographic data at 12 months. Atrial tachyarrhythmia recurrence occurring 3 months post procedure, acute procedural failures such as lack of entrance block confirmation of all PVs, and undergoing repeat procedure for atrial fibrillation in the evaluation period (91 to 365 days post the initial ablation procedure) were considered to be effectiveness failures.

Results

Seventy-eight patients (age 64.8 ± 9.7 years; male 52.6%; Caucasian 96.2%) participated in the 12-month effectiveness evaluation. Mean follow-up time was 373.5 ± 45.4 days. The Kaplan-Meier estimate of freedom from 12-month atrial tachyarrhythmia was 74.9%. Two procedure-related pericardial effusion events were reported at 92 and 180 days post procedure. There were no pulmonary vein stenosis complications or deaths reported through the 12-month follow-up period.

Conclusions

The SMART SF 12-month follow-up evaluation corroborates the early safety and effectiveness success previously reported for PAF ablation with STSF.

Prevalence and Factors Associated with Atrial Fibrillation Among Patients with Rheumatic Heart Disease

Introduction

Rheumatic heart disease (RHD) is one of the common causes of atrial fibrillation (AF) is associated with significant morbidity and mortality. There is a lack of data on the prevalence of AF and factors associated with increased risk of AF in patients with RHD from Nepal.

Methods

A total of 120 patients who received care at Nobel Medical College Teaching Hospital from January 2018 to February 2019 with a diagnosis of RHD with AF were enrolled. Demographic information, relevant clinical and laboratory parameters and predisposing conditions for AF were obtained from a structured questionnaire designed.

Results

The prevalence of AF was 120 (36.3%) out of 330 cases of RHD screened. The male to female ratio was 32:88. The mean age was 50.2 (range 22-80) years. Prevalence was slightly more in females (36.9%) as compared to males (34.7 %). The prevalence of AF in patients with predominant mitral stenosis (MS) was 66.6% and less in patients with predominant mitral regurgitation (MR) (16.6%). The prevalence of AF in cases of MS with mitral valve area (MVA) < 1.5 cm2 was 76.2% as compared to 23.7% in cases with MVA > 1.5 cm2. Mitral valve (MV) was the most commonly affected valve (83.3%) followed by the aortic valve (10%). Both mitral and aortic valves were involved in 6.6% of patients. Majority of patients (97.5%) had enlarged left atrium (>40mm), reduced estimated glomerular filtration rate (eGFR) of <90 ml/min (85.8%). Patients of RHD with AF were complicated with decreased left ventricular (LV) systolic function (67.5%), pulmonary artery hypertension (52.5%), left atrial clot (9.1%), stroke (8.3%), and peripheral embolism (2.5%).

Conclusions

AF is a common rhythm disorder in patients with RHD. Prevalence of AF is common in females, increases with age, increasing LA size, increased severity of MS and decreased level of eGFR.

Catheter Ablation Improves Mortality and Other Outcomes in Real-World Patients With Atrial Fibrillation

Background

It is still controversial whether catheter ablation for atrial fibrillation (AF) improves survival and other outcomes in patients with AF. This study evaluated whether ablation reduces death and other events in nationwide real‐world Asian patients with AF.

Methods and Results

From the Korean National Health Insurance Service database, 194 928 adult patients (aged ≥18 years) with newly diagnosed AF were treated with ablation or medical therapy (antiarrhythmic or rate control drugs) between January 1, 2005, and December 1, 2015. Among these patients, this study included 9185 with ablation and 18 770 with medical therapy. The time at risk was counted from the first medical therapy, and ablation was analyzed as a time‐varying covariate. Inverse probability of treatment weighting was used to correct for differences between the groups. After weighting, the 2 cohorts had similar background characteristics. During a median (25th, 75th percentiles) follow‐up of 43 (19, 81) months, ablation of AF was associated with lower incidence and risk of composite outcome, including death, heart failure admission, and stroke/systemic embolism (2.5 and 6.4 per 100 person‐years, respectively; hazard ratio [HR], 0.47; 95% CI, 0.43–0.52; P<0.001), all‐cause death (1.0 and 3.6 per 100 person‐years; HR, 0.41; 95% CI, 0.36–0.47; P<0.001), heart failure admission (0.7 and 1.9 per 100 person‐years; HR, 0.43; 95% CI, 0.37–0.50), and ischemic stroke/systemic embolism (1.1 and 2.8 per 100 person‐years; HR, 0.39; 95% CI, 0.34–0.44) than medical therapy.

Conclusions

Ablation may be associated with lower risk of death, heart failure admission, and ischemic stroke/systemic embolism in real‐world Asian patients with AF.

Meta-Analysis of Catheter Ablation versus Medical Therapy in Patients with Atrial Fibrillation Without Heart Failure

Introduction

Catheter ablation has shown to reduce mortality in patient with atrial fibrillation (AF) and heart failure (HF) with reduced ejection fraction. Its effect on mortality in patients without HF has not been well elucidated.

Methods

Thirteen randomized controlled trials encompassing 3856 patients were selected using PubMed, Embase and the CENTRAL till April 2019. Estimates were reported as random effects risk ratio (RR) with 95% confidence intervals (CI).

Results

Compared with medical therapy, catheter ablation did not reduce the risk of all-cause mortality (RR, 0.86, 95% CI, 0.62-1.19, P=0.36; I2=0), stroke (RR, 0.55, 95% CI, 0.18-1.66, P=0.29; I2=0), need for cardioversion (RR, 0.84, 95% CI, 0.66-1.08, P=0.17; I2=0) or pacemaker (RR, 0.59, 95% CI, 0.34-1.01, P=0.06; I2=0). However, ablation reduced the RR of cardiac hospitalization (0.37, 95% CI, 0.18-0.77, P=0.01; I2=86), and recurrent atrial arrhythmia (0.46, 95% CI, 0.35-0.60, P<0.001; I2=87). There were non-significant differences among treatment groups with respect to major bleeding (RR, 1.89, 95% CI, 0.59-6.08, P=0.29; I2=15), and pulmonary vein stenosis (RR, 3.00, 95% CI, 0.83-10.87, P=0.09; I2=0), but had significantly higher rates of pericardial tamponade (RR, 4.46, 95 % CI, 1.70-11.72, P<0.001; I2=0).

Conclusions

Catheter ablation did not improve survival compared with medical therapy in patients with AF without HF. Catheter ablation reduced cardiac hospitalization and recurrent atrial arrhythmia at the expense of pericardial tamponade.

Significance of early recurrence of atrial fibrillation after catheter ablation: a nationwide Danish cohort study

BACKGROUND

Recurrence of atrial tachyarrhythmias after ablation of atrial fibrillation (AF) is common, although consensus guidelines advise against immediate re-ablation of "early recurrences" (occurring ≤ 90 days after ablation). However, recent studies show early recurrence is associated with "late recurrence" (occurring > 90 days) and question the duration of this "blanking period." We investigated incidence and timing of early recurrence in relation to late recurrence in a large nationwide cohort.

METHODS

From Danish nationwide registers, we included all patients aged 18 and older who underwent first-time ablation for AF between January 2005 and April 2017 and followed them for up to 2 years.

RESULTS

Of the total 7339 patients included (72% male; median age 62 years), 2801 (38%) experienced early recurrence. The odds of late recurrence were 2.34 times higher (95% confidence interval, 2.09-2.63; P < 0.001) given early recurrence, compared with those without early recurrence. In particular, both timing and frequency of early recurrences were associated with a significantly higher odds of late recurrence in a graded relationship: odds ratio (OR) 2.08/4.96/6.25 for early recurrences in the first/second/third month respectively (all P < 0.001); and OR 1.64/2.83/5.14 for those experiencing one/two/more than two episodes respectively (all P < 0.001); compared with those without early recurrence.

CONCLUSION

In patients undergoing first-time ablation for AF, both the frequency and later onset of early recurrence are significantly associated with higher odds of late recurrence. This suggests the arbitrary blanking period should be abandoned in favor of a case-by-case assessment when evaluating candidates for re-ablation.

Safety, Feasibility and Economic Impact of Same-Day Discharge Following Atrial Fibrillation Ablation

BACKGROUND

The widely accepted model for atrial fibrillation (AF) ablation involves overnight hospital stay post-procedure. Day case AF ablation has been carried out at Royal Papworth Hospital (RPH) since early 2017. We evaluated the feasibility, safety and efficacy of day case AF ablation at RPH.

METHOD

This was a retrospective, single-centre study of consecutive AF ablations at RPH between March 2017 and April 2018. Demographic, procedural and outcome data were analysed.

RESULTS

Over the study period, 452 AF ablations were performed in 448 patients. One hundred and twenty-nine (129) (28.5%) were planned day cases; of these 128 were discharged on the same day. Two hundred and eighty-three (283) procedures resulted in at least one night admission. There was no significant difference in age or sex between the groups. Of note, day case procedures were significantly shorter, more likely to commence in the morning and less likely to require general anaesthetic than overnight stays. Patients listed as day cases also had less far to travel. The overall complication rate was 3.3%, with no significant difference between groups. Follow-up data was available for 448 cases (99.1%). Procedural success rates were comparable between groups. The overall cost saving attributable to providing AF ablation as a day case was £67,200 over the 13-month period.

CONCLUSIONS

Day case AF ablation is efficacious and associated with a low event rate, even without strict standardisation of patient selection or procedural protocols, in a high-volume centre. Substantial reduction in health care expenditure can be achieved with more widespread implementation of outpatient AF ablation.

Impact of age on atrial fibrillation recurrence following surgical ablation

OBJECTIVES

The incidence of atrial fibrillation (AF) in patients older than 75 years of age is expected to increase, and its treatment remains challenging. This study evaluated the impact of age on the outcomes of surgical ablation of AF.

METHODS

A retrospective review was performed of patients who underwent the Cox-maze IV procedure at a single institution between 2005 and 2017. The patients were divided into a younger (age <75 years, n = 548) and an elderly cohort (age ≥75 years, n = 148). Rhythm outcomes were assessed at 1 year and annually thereafter. Predictors of first atrial tachyarrhythmia (ATA) recurrence were determined using Fine-Gray regression, allowing for death as the competing risk.

RESULTS

The mean age of the elderly group was 78.5 ± 2.8 years. The majority of patients (423/696, 61%) had nonparoxysmal AF. The elderly patients had a lower body mass index (P < .001) and greater rates of hypertension (P = .011), previous myocardial infarction (P = .017), heart failure (P < .001), and preoperative pacemaker (P = .008). Postoperatively, the elderly group had a greater rate of overall major complications (23% vs 14%, P = .017) and 30-day mortality (6% vs 2%, P = .026). The percent freedom from ATAs and antiarrhythmic drugs was lower in the elderly patients at 3 (69% vs 82%, P = .030) and 4 years (65% vs 79%, P = .043). By competing risk analysis, the incidence of first ATA recurrence was greater in elderly patients (33% vs 20% at 5 years; Gray test, P = .005). On Fine-Gray regression adjusted for clinically relevant covariates, increasing age was identified as a predictor of ATAs recurrence (subdistribution hazard ratio, 1.03; 95% confidence interval, 1.02-1.05, P < .001).

CONCLUSIONS

The efficacy of the Cox-maze IV procedure was worse in elderly patients; however, the majority of patients remained free of ATAs at 5 years. The lower success rate in these greater-risk patients should be considered when deciding to perform surgical ablation.

Cryoballoon ablation for pulmonary vein isolation

Over the past 20 years, multiple studies have demonstrated the superiority of percutaneous catheter-based pulmonary vein isolation (PVI) in the management of atrial fibrillation (AF). Unfortunately, the results of catheter ablation can be limited by arrhythmia recurrence, which is often a result of a failure to achieve durable lesions around the pulmonary vein ostia. In response, significant efforts have been directed toward developing technologies to achieve safer and more durable PVI, including the development of dedicated catheters capable of achieving PVI with a single ablation lesion (eg, the Arctic Front Cryoballoon; Medtronic CryoCath, Pointe-Claire, Canada). The purpose of this review is to discuss the contemporary role of cryoballoon ablation in the invasive management of AF, with a focus on the characteristics that differentiate cryoballoon from radiofrequency ablation.

Health-Related Quality of Life in Patients With Atrial Fibrillation Treated With Catheter Ablation or Antiarrhythmic Drug Therapy: A Systematic Review and Meta-analysis

Background

Catheter ablation (CA) is performed in patients with atrial fibrillation (AF) to reduce symptoms and improve health-related quality of life (HRQL).

Methods

This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated CA of any energy modality compared with antiarrhythmic drugs (AADs) using inverse-variance random-effects models. We searched for RCTs reporting HRQL and AF-related symptoms at 3, 6, 12, 24, 48, and 60 months after treatment as well as the number of repeat ablations.

Results

Of 15,878 records, we included 13 RCTs of CA vs AADs for the analyses of HRQL, 7 RCTs for the analyses of AF-related symptoms, and 13 RCTs for the number of repeat ablations. For the HRQL analyses at 3 months, there were significant increases in both the Physical Component Summary score (3 months' standardized mean difference = 0.58 [0.39-0.78]; P < 0.00001, I ² = 6%, 3 trials, n = 443) and the Mental Component Summary score (3 months' standardized mean difference = 0.57 [0.37-0.77]; P < 0.00001, I ² = 0%, 3 trials, n = 443), favouring CA over AADs. These differences were sustained at 12 months but not >24 months after randomization. Similar results were seen for AF-related symptoms. The number of repeat ablations and success rates after procedure varied considerably across trials.

Conclusions

Evidence from few trials suggests that CA improves physical and mental health and AF-related symptoms in the short term, but these benefits decrease with time. More trials, reporting both HRQL and AF-related symptoms, at consistent time points are needed to assess the effectiveness of CA for the treatment of AF.

Cost Effectiveness Analysis and Payment Policy Recommendation-Population-Based Survey with Big Data Methodology for Readmission Prevention of Patients with Paroxysmal Supraventricular Tachycardia treated with Radiofrequency Catheter Ablation

Recurrence of paroxysmal supraventricular tachycardia (PSVT) has been reported to be lower in patients treated with radiofrequency catheter ablation (RFCA) than in those who are not. Few population-based surveys have stated the cost-effectiveness related to this treatment. We, therefore, performed a nationwide retrospective study using National Health Insurance Research Database (NHIRD) data from 2001–2012 in Taiwan. The incidence of PSVT-related admissions was computed from patients’ first admission for a primary PSVT diagnosis. There were 21,086 patients hospitalized due to first-time PSVT, of whom 13,075 underwent RFCA, with 374 recurrences (2.86%). In contrast, 1751 (21.86%) of the remaining 8011 patients who did not receive RFCA, most of whom had financial concerns, experienced PSVT recurrence. The relative PSVT recurrence risk in those who did not receive RFCA was 7.6 times (95% CI: 6.67–8.33) that of those who did undergo RFCA. In conclusion, the PSVT recurrence rate was much higher in patients who did not receive RFCA at their first admission. Furthermore, RFCA proved cost-effective, with the ratio of the incremental cost-effectiveness ratio (ICER) and gross domestic product (GDP) being only 1.15. To prevent readmission and avoid incremental cost, the authority could provide a financial supplement for every patient so that the procedure is performed, reducing the PSVT-recurrence life-years (disease-specific DALY).

Opposite effect of ablation on early/late-phase thromboembolic incidence in patients with atrial fibrillation: A meta-analysis on more than 100 000 individuals

Background

Atrial fibrillation (AF) is an important risk factor for thromboembolic events, for which catheter ablation represents an effective therapy for rhythm control. Intuitively, ablation may reduce the incidence of thromboembolism, but data is quite limited.

Hypothesis

Catheter ablation was associated with the fewer risk of thromboembolism compared with nonablation in patients with AF.

Methods

A systematic search was performed in PubMed, EMBASE, the Web of Science, and the Cochrane Library from inception to September 2019. Random‐effects model was used to estimate the risk ratios (RR) for the thromboembolic events between the ablation and nonablation groups.

Results

Twenty‐five studies (12 randomized controlled trials and 13 observational studies) with 104 687 participants were included. Pooled analysis suggested that ablation was associated with a 35% lower risk of total thromboembolic events compared to nonablation group (RR = 0.65; 95% CI, 0.51‐0.82; P = .0003). When separated into early‐phase (<30 days) and late‐phase (>30 days) events, ablation was associated with an increased early‐phase thromboembolism (RR = 1.96; 95% CI, 1.35‐2.83; P = .0004) but a decreased late‐phase thromboembolism (RR = 0.75; 95% CI, 0.63‐0.90; P = .002). Subgroup analysis according to different study types found similar results were found in observation studies, but not in RCT studies because the sample size was too small to be conclusive.

Conclusions

In patients with AF, catheter ablation was associated with a fewer risk of overall and late‐phase thromboembolism in comparison with nonablation. However, over the early postoperative period, catheter ablation was associated with the double higher risk of thromboembolic events.

Impact of atrial fibrillation catheter ablation on mortality, stroke, and heart failure hospitalizations: A meta-analysis

BACKGROUND

The impact of atrial fibrillation catheter ablation (AFCA) on hard clinical endpoints remains controversial.

OBJECTIVE

Our aim was to conduct a random-effect model meta-analysis on efficacy data from high-quality large matched database/registry studies and randomized clinical trials. We compared long-term all-cause mortality, stroke, and hospitalization for heart failure in patients undergoing AFCA vs patients treated with medical therapy alone (rhythm and/or rate control medications) in a general AF population.

METHODS AND RESULTS

PubMed/MEDLINE and Embase databases were screened and a total of nine studies were selected (one randomized clinical trial-CABANA-and eight large matched population studies). A total of 241 372 patients (27 711 in the ablation group, 213 661 in the nonablation group) were included. After a median follow-up of 3.5 years, AFCA decreased the risk of mortality (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.54-0.72; I² = 54%; number needed to treat [NNT] = 28), stroke (HR, 0.63; 95% CI, 0.56-0.70; I²  = 23%; NNT = 59) and hospitalization for heart failure (HR, 0.64; 95% CI, 0.51-0.80; I²  = 28%; NNT = 33) compared with AF patients treated with medical therapy alone.

CONCLUSION

Based on the currently available efficacy and effectiveness evidence, AFCA significantly reduces the risk of death, stroke, and hospitalization compared with medical therapy alone.

Automated Noncontact Ultrasound Imaging and Ablation System for the Treatment of Atrial Fibrillation

Background:

Catheter ablation for atrial fibrillation (AF) using point-by-point radiofrequency energy or single-application one-shot balloons is either technically challenging or have limited ability to accommodate variable patient anatomy to achieve acute and durable pulmonary vein (PV) isolation. A novel ablation system employs low intensity collimated ultrasound (LICU)-guided anatomic mapping and robotic ablation to isolate PVs. In this first-in-human, single-center, multioperator trial, VALUE trial (VytronUS Ablation System for Treatment of Paroxysmal Atrial Fibrillation; NCT03639597) in patients with paroxysmal atrial fibrillation, this LICU system was evaluated to determine its safety, effectiveness in PV isolation, and freedom from recurrent atrial arrhythmias.

Methods:

In the enrolled 52 patients with paroxysmal atrial fibrillation, ultrasound M-mode–based left atrial anatomies were successfully created, and ablation was performed under robotic control along an operator-defined lesion path. The LICU system software advanced over the course of the study: the last 13 patients were ablated with enhanced software.

Results:

Acute PV isolation was achieved in 98% of PVs—using LICU-only in 77.3% (153/198) of PVs and requiring touch-up with a standard radiofrequency ablation catheter in 22.7% (45/198) PVs. The touch-up rate decreased to 5.8% (3/52) in patients undergoing LICU-ablation with enhanced software. Freedom from atrial arrhythmia recurrence was 79.6% (39/49 patients) at 12 months or 92.3% (12/13 patients) with the enhanced software. Major adverse events occurred in 3 patients (5.8%): one had transient diaphragmatic paralysis, one vascular access complication, and one had transient ST-segment elevation from air-embolism, without sequelae.

Conclusions:

In this first-in-human study, low- intensity collimated ultrasound-guided anatomic mapping and robotic ablation allows PV isolation with good chronic safety; PV isolation success is improving with device enhancements.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03639597.

Investigation of proper home blood pressure with atrial fibrillation recurrence in patients undergoing radiofrequency catheter ablation

BACKGROUND

Hypertension is an important target for interventions to improve ablation outcome in atrial fibrillation (AF) patients. No studies to date have determined the blood pressure level at which AF is less likely to recur in patients without hypertension.

METHODS

A total of 503 AF patients undergoing radiofrequency catheter ablation (RFCA) (mean age, 59.6±9.6 years; 319 males [63.4%]) were identified for the study cohort and analysis. Patients received a pocket diary to record their home blood pressure (HBP) before RFCA and routine 48-hour Holter-ECGs to evaluate AF recurrence after RFCA.

RESULTS

A total of 383 (76.1%) patients were free of AF recurrence one year after RFCA. Blood pressure (BP), including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP), had different effects on AF recurrence one year after RFCA. A χ2 test showed that when SBP was <110 mmHg, it was associated with a lower AF recurrence in patients with hypertension (P=0.029). AF recurrence decreased (P=0.002) when SBP increased from <110 mmHg to >130 mmHg in patients without hypertension. Regression analysis indicated a significant linear correlation between BP and LAD in all patients.

CONCLUSIONS

SBP should be strictly maintained at 110 mmHg after RFCA to minimize AF recurrence in patients with hypertension. Low SBP might be a risk factor for AF recurrence among patients without hypertension.

High-power, Short-duration Radiofrequency Ablation for the Treatment of AF

High-power, short-duration (HPSD) ablation for the treatment of AF is emerging as an alternative to ablation using conventional ablation generator settings characterised by lower power and longer duration. Although the reported potential advantages of HPSD ablation include less tissue oedema and collateral tissue damage, a reduction in procedural time and superior ablation lesion formation, clinical studies of HPSD ablation validating these observations are limited. One of the main challenges for HPSD ablation has been the inability to adequately assess temperature and lesion formation in real time. Novel catheter designs may improve the accuracy of intra-ablation temperature recording and correspondingly may improve the safety profile of HPSD ablation. Clinical studies of HPSD ablation are on-going and interpretation of the data from these and other studies will be required to ascertain the clinical value of HPSD ablation.

Intermediate term outcome after electrogram guided segmental ostial pulmonary vein isolation using an 8 mm tip catheter for paroxysmal atrial fibrillation

Introduction

Pulmonary vein isolation (PVI) is the most widely used procedure for ablation in patients with paroxysmal atrial fibrillation (AF). Not withstanding recent advancements in this field, including sophisticated three-dimensional (3D) based imaging and advanced ablation catheters with contact force technology, many patients and healthcare systems in developing countries will not afford such an expensive therapeutic procedure. There are no data from India analyzing the efficacy of PVI for PAF using conventional mapping and ablation. In this article, we have summarized the intermediate term outcome following PVI in patients with PAF using electrogram-based mapping and a 8 mm tip ablation catheter.

Method

A total of 42 consecutive patients who underwent PVI for symptomatic PAF not controlled with at least one antiarrhythmic drug were studied in a tertiary care institute from March 2011 to June 2018. Patients with rheumatic AF were excluded. The pulmonary vein (PV) anatomy was assessed by pulmonary angiography during the ablation procedure. Using conventional electrophysiologic mapping, a variable curve Lasso catheter placed in the PVs was used to guide the earliest site of breakthrough. The segmental ostial PVI was performed using a 8 mm tip radiofrequency (RF) ablation catheter. Elimination of all PV ostial potentials and complete entrance block into the PV were considered indicative of complete electrical isolation. Follow-up visits were scheduled at one, three, and six months after the procedure, and every six months thereafter. History, symptom review, clinical examination, and 12-lead ECG were performed at each follow-up.

Results

At pre-discharge, 34 patients (81%) were in sinus rhythm, while eight patients (19%) continued to have atrial fibrillation. The age of the study population was 51.5 ± 11.7 yrs. The mean follow-up duration was 44 ± 21 months (range 6–84 months). The number of PVs isolated included one (five patients, 11.9%), two (20 patients, 47.6%), three (12 patients, 28.6%), and four (five patients, 11.9%). In 42 patients, a total of 101 PVs were isolated. The right superior PV (RSPV) was isolated in 37 patients, the left superior PV (LSPV) was isolated in 39 patients, the left inferior PV (LIPV) was isolated in 14 patients, and the right inferior PV (RIPV) was isolated in six patients. The procedure duration was 125 ± 29 min and the fluoroscopy time was 47 ± 13 min. The number of patients who remained in sinus rhythm at 1, 6, 12, and 24 months were 34 (81%), 32 (76%), 30 (71%), and 26 (62%), respectively. Two patients of these underwent repeat PVI, which was successful, and they had freedom from AF episodes. Complications were rare. One patient had a minor pericardial effusion, and one patient had transient sinus pauses, which were conservatively managed.

Conclusion

Conventional RF ablation using PV potential-based mapping and ablation with 8 mm tip catheters is safe for patients with PAF. The intermediate term outcome is satisfactory and cost-effective in our setting with limited resources.

Predictors of recurrence after pulmonary vein isolation in patients with normal left atrial diameter

BACKGROUND

Enlarged left atrium (LA) is an established predictor of recurrence of atrial fibrillation (AF) after pulmonary vein isolation (PVI), but occasionally recurrences of AF/atrial tachycardia (AT) are experienced in patients with normal left atrial diameter. Therefore, the predictors of AF recurrence and AF triggers were evaluated in patients with normal LA.

METHODS

We enrolled 168 patients with normal LA (<40 mm) who underwent PVI. Various predictors were compared, including age, gender, coronary risk factors, brain natriuretic peptide (BNP), medications, echocardiographic parameters, and procedure parameters, between recurrence and nonrecurrence groups.

RESULTS

The recurrence group consisted of 50 patients (29.8%). A univariate analysis demonstrated that the ratio of females, high BNP levels, severe tricuspid valve regurgitation (TR), and relapses of AF/AT during catheter ablation (CA) were significantly higher in the recurrence group. Multivariate analyses showed that a high BNP, severe TR, and AF/AT relapses during CA were independent factors associated with AF recurrence. During the second CA sessions, nonpulmonary vein (PV) triggers were therapeutic targets in 18 patients (46.2%), which was higher than that previously reported.

CONCLUSION

A high BNP, severe TR and AF/AT relapses during CA may be correlated with AF recurrence after PVI in the patients with normal LA.

Role of inducibility and its dynamic change in the outcome of catheter ablation of atrial fibrillation: a single center prospective study

BACKGROUND

The role of atrial arrhythmia inducibility as an endpoint of catheter ablation of atrial fibrillation (AF) has been a controversial subject in many studies. Our goal is to evaluate the significance of inducibility, the impact of multiple sites or protocols of stimulation or the change in inducibility status in a prospective study including patients with AF undergoing first catheter ablation.

METHODS

We studied 170 consecutive patients with AF (62.9% paroxysmal) undergoing catheter ablation. All patients underwent two separate stimulation protocols before and after the ablation from the coronary sinus ostium and the left atrial appendage: burst pacing at 300, 250, 200 milliseconds (or until refractoriness) for 10 seconds and ramp decrementing from 300 to 200 milliseconds in increments of 10 milliseconds every three beats for 10 seconds. Inducibility was defined as any sustained AF or organized atrial tachycardia (AT) lasting >30 seconds.

RESULTS

We had AF/AT inducibility in 55 patients at baseline compared to 36 following ablation. After a mean of 41, 3 months follow-up, 115 patients were free of AF. Inducibility before or after the ablation or change in inducibility status did not influence AF recurrence. There were no significant differences regarding paroxysmal or persistent patients with AF.

CONCLUSIONS

Non-inducibility of atrial arrhythmia or change in inducibility status following pulmonary vein (PV) isolation and substrate modification are not associated with long-term freedom from recurrent arrhythmia. Therefore, the use of induction of an endpoint in AF ablation is limited.

Comparison of Bayesian and frequentist group-sequential clinical trial designs

BACKGROUND

There is a growing interest in the use of Bayesian adaptive designs in late-phase clinical trials. This includes the use of stopping rules based on Bayesian analyses in which the frequentist type I error rate is controlled as in frequentist group-sequential designs.

METHODS

This paper presents a practical comparison of Bayesian and frequentist group-sequential tests. Focussing on the setting in which data can be summarised by normally distributed test statistics, we evaluate and compare boundary values and operating characteristics.

RESULTS

Although Bayesian and frequentist group-sequential approaches are based on fundamentally different paradigms, in a single arm trial or two-arm comparative trial with a prior distribution specified for the treatment difference, Bayesian and frequentist group-sequential tests can have identical stopping rules if particular critical values with which the posterior probability is compared or particular spending function values are chosen. If the Bayesian critical values at different looks are restricted to be equal, O'Brien and Fleming's design corresponds to a Bayesian design with an exceptionally informative negative prior, Pocock's design to a Bayesian design with a non-informative prior and frequentist designs with a linear alpha spending function are very similar to Bayesian designs with slightly informative priors.This contrasts with the setting of a comparative trial with independent prior distributions specified for treatment effects in different groups. In this case Bayesian and frequentist group-sequential tests cannot have the same stopping rule as the Bayesian stopping rule depends on the observed means in the two groups and not just on their difference. In this setting the Bayesian test can only be guaranteed to control the type I error for a specified range of values of the control group treatment effect.

CONCLUSIONS

Comparison of frequentist and Bayesian designs can encourage careful thought about design parameters and help to ensure appropriate design choices are made.

Biatrial enlargement as a predictor for reablation of atrial fibrillation

Purpose: We aimed to determine whether biatrial enlargement could predict reablation of atrial fibrillation after first ablation. Methods: 519 consecutive patients with drug resistant atrial fibrillation [paroxysmal AF (PAF) 361, non-PAF 158] who underwent catheter ablation in Capital Medical University Xuanwu hospital between 2009 and 2014 were enrolled. Biatrial enlargement (BAE) was diagnosed according to trans-thoracic echocardiography (TTE). Ablation strategies included complete pulmonary vein isolation (PVI) in all patients and additional linear ablation across mitral isthmus, left atrium roof, left atrium bottom and tricuspid isthmus, or electrical cardioversion on the cases that AF could not be terminated by PVI. Anti-arrhythmic drugs or cardioversion were used to control the recurred atrial arrhythmia in patients with recurrence of atrial fibrillation after ablation. Reablation was advised when the drugs were resistant or that patient could not tolerate. Risk factors for reablation were analyzed. Results: After 33.11±21.45months, 170 patients recurred atrial arrhythmia, and reablation were applied in 117 patients. Multivariate Cox regression analysis demonstrated that that biatrial enlargement (BAE, HR 1.755, 95%CI 1.153-2.670, P=0.009) was an independent predictor for reablation and was associated with reablation (Log rank P=0.007). Conclusion: Biatrial enlargement is an independent risk predictor for the reablation in atrial fibrillation patients after first ablation.

Avoiding Urinary Catheterization in Patients Undergoing Atrial Fibrillation Catheter Ablation

Purpose

Indwelling urinary catheters are commonly inserted when administering general anesthesia. However, there are significant risks to routine IUC insertion. We compared urinary and other outcomes in a population of patients undergoing atrial fibrillation (AF) ablation with or without IUC.

Methods

This was a single center, retrospective review of patients undergoing AF ablation. Patients were identified by procedure codes and patient health characteristics and outcome data were manually extracted from electronic health records. The primary composite endpoint was 7-day periprocedural urinary outcomes including cystitis, dysuria, hematuria, urethral damage, or urinary retention.

Results

404 patients were included in the study, 297 with IUC and 107 without IUC. Uncatheterized patients were less likely to have congestive heart failure (CHF) (31.8% vs 43.4%; P = 0.039) and had a shorter procedure length (4.2 vs 4.9 hours; P < 0.001) with less fluid administered (1485 vs 2040 mL; P < 0.001). No urinary complications occurred in the uncatheterized group versus 14 in the catheterized group (P = 0.026). 3 patients in the uncatheterized group developed serious infections versus none in the catheterized group (P = 0.018). There was no incidence of death and no statistically significant difference in readmission in the 30 days after procedure.

Conclusions

There were no urinary complications in 107 patients who received no IUC during AF ablation. Avoiding bladder catheters during AF ablation procedures may lower incidence of adverse urinary complications without adding substantial risk of urinary retention.

Ablation Versus Medical Therapy for Atrial Fibrillation in the Elderly: A Propensity Score-Matched Comparison

Background

Whether ablation therapy reduces the risk of death and embolic events in elderly patients with atrial fibrillation (AF) remains unclear.

Material/Methods

AF patients ≥65 years old receiving either catheter ablation or non-ablation therapy at 2 tertiary and 2 non-tertiary hospitals in Beijing from November 2009 to December 2012 were enrolled. Patients were followed up every 6 months for information on treatment and clinical event occurrence. A propensity score matching algorithm produced comparable 2 groups of patients treated with ablation or non-ablation. Rates of a composite of all-cause death, non-fatal stroke, and peripheral embolism were the primary outcomes. Each composite component and major bleeding were the secondary outcomes.

Results

There were 596 ablated patients and 1144 patients with non-ablation therapy enrolled. Propensity score algorithm matched 347 comparable pairs of patients. Patient characteristics variables were well balanced. During 523.5 and 497.5 patient-years follow-up, respectively, ablation therapy was associated with a significant lower risk of experiencing the primary composite outcome (hazard ratio [HR]=0.40; 95% confidence interval [CI]: 0.19–0.85), all-cause death (HR=0.13 95% CI: 0.04–0.43), and major bleeding (HR=0.23; 95% CI: 0.12–0.67), without apparent heterogeneity by age, sex, and AF type, and for risk score subgroups.

Conclusions

In this propensity-matched elderly sample, ablation therapy was associated with lower risk of composite outcome consisting of all-cause death, non-fatal stroke, and peripheral embolism, and therefore might be an alternative to conservative therapy.

Catheter Ablation Versus Best Medical Therapy in Patients With Persistent Atrial Fibrillation and Congestive Heart Failure

Background:

Optimal treatment of patients with persistent atrial fibrillation (AF) and heart failure (HF) with reduced left ventricular ejection fraction (LVEF) and an indication for internal defibrillator therapy is controversial.

Methods:

Patients with persistent/longstanding persistent AF and LVEF ≤35% were randomly allocated to catheter ablation of AF or best medical therapy (BMT). The primary study end point was the absolute increase in LVEF from baseline at 1 year. Secondary end points included 6-minute walk test, quality-of-life, and NT-proBNP (N-terminal pro-brain natriuretic peptide). Pulmonary vein isolation was the primary ablation approach; BMT comprised rate or rhythm control. All patients were discharged after index hospitalization with a cardioverter-defibrillator or cardiac resynchronization therapy defibrillator implanted. The study was terminated early for futility.

Results:

Of 140 patients (65±8 years, 126 [90%] men) available for the end point analysis, 68 and 72 patients were assigned to ablation and BMT, respectively. At 1 year, LVEF had increased in ablation patients by 8.8% (95% CI, 5.8%–11.9%) and in BMT patients by 7.3% (4.3%–10.3%; P =0.36). Sinus rhythm was recorded on 12-lead electrocardiograms at 1 year in 61/83 ablation patients (73.5%) and 42/84 BMT patients (50%). Device-recorded AF burden at 1 year was 0% or maximally 5% of the time in 28/39 ablation patients (72%) and 16/36 BMT patients (44%). There was no difference in secondary end point outcome between ablation patients and BMT patients.

Conclusions:

The AMICA trial (Atrial Fibrillation Management in Congestive Heart Failure With Ablation) did not reveal any benefit of catheter ablation in patients with AF and advanced HF. This was mainly because of the fact that at 1 year, LVEF increased in ablation patients to a similar extent as in BMT patients. The effect of catheter ablation of AF in patients with HF may be affected by the extent of HF at baseline, with a rather limited ablation benefit in patients with seriously advanced HF.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov . Unique identifier: NCT00652522.

Predictors and Incidence of Atrial Flutter After Catheter Ablation of Atrial Fibrillation

Atrial flutter (AFL) is a common form of arrhythmia recurrence after atrial fibrillation (AF) ablation. We aimed to define (1) the incidence of AFL and (2) the clinical factors associated with cavo-tricuspid isthmus dependent (typical) and atypical AFL, after AF ablation. The retrospective cohort consisted of 1,029 patients that underwent initial radiofrequency AF ablation from May 2005 to December 2013 at a single academic center. Patients with missing follow-up data, history of AFL ablation, and those with undocumented AFL were excluded. Atrial volumes were measured using three-dimensional cardiac computed tomography or magnetic resonance imaging. A total of 607 patients were included in the final cohort (age 59.2 ± 10.6 years, 76.0% men, 58.7% paroxysmal AF). During a median follow-up of 845 days (interquartile range 389 to 1,597 days), 122 (20.1%) patients developed AFL. Of these, 17 had typical AFL, 98 had atypical AFL, and 7 patients had both circuits. In the multivariable Cox regression analysis, only right atrial volume index (hazard ratio [HR] 1.25 per 10 ml/m2, confidence interval [CI] 95% 1.10 to 1.42) was associated with incident typical AFL; whereas persistent AF (HR 1.59, CI 95% 1.06 to 2.40), linear lesions (HR 1.58, CI 95% 1.02 to 2.46) and left atrial volume index (HR 1.17 per 10 ml/m2, CI 95% 1.07 to 1.27) were associated with incident atypical AFL. In conclusion, noninvasive measures of right and left atrial remodeling are strongly associated with incident AFL after AF ablation. Strategies to prevent incident AFL using these measures after index ablation warrant further investigation.

Randomized comparison between dexmedetomidine–remifentanil and midazolam–fentanyl for deep sedation during catheter ablation of atrial fibrillation

Background and objectives

The efficacy of dexmedetomidine for radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) has not been well established. We evaluated the efficacy and safety of sedation using dexmedetomidine with remifentanil compared to conventional sedative agents during RFCA for AF.

Subjects and methods

A total of 240 patients undergoing RFCA for AF were randomized to either the dexmedetomidine (DEX) group (continuous infusion of dexmedetomidine and remifentanil) or the midazolam (MID) group (intermittent injections of midazolam and fentanyl) according to sedative agents. Non-invasive positive pressure ventilation was applied to all patients during the procedure. The primary outcome was patient movement during the procedure resulting in a 3D mapping system discordance, and the secondary outcome was adverse events including respiratory or hemodynamic compromise.

Results

During AF ablation, the incidence of the primary outcome was significantly reduced for the DEX group (18.2% vs. 39.5% in the DEX and the MID groups, respectively, p < 0.001). The frequency of a desaturation event (oxygen saturation < 90%) did not significantly differ between the two groups (6.6% vs. 1.7%, p = 0.056). However, the incidences of hypotension not owing to cardiac tamponade (systolic blood pressure < 80 mmHg, 19.8% vs. 8.4%, p = 0.011) and bradycardia (HR < 50 beats/min: 39.7% vs. 21.8%, p = 0.003) were higher in the DEX group. All efficacy and safety results were consistent within the predefined subgroups.

Conclusion

The combined use of dexmedetomidine and remifentanil provides higher stability sedation during AF ablation, but can lead to more frequent hemodynamic compromise compared to midazolam and fentanyl.

Atrial scar quantification via multi-scale CNN in the graph-cuts framework

•

Propose a fully automatic method for left atrial scar quantification, with promising performance.

•

Formulate a new framework of scar quantification based on surface projection and graph-cuts framework.

•

Propose the multi-scale learning CNN, combined with the random shift training strategy, to learn and predict the graph potentials, which significantly improves the performance of the proposed method, and enables the full automation of the framework.

•

Provide thorough validation and parameter studies for the proposed techniques using fifty-eight clinical images.

Late gadolinium enhancement magnetic resonance imaging (LGE MRI) appears to be a promising alternative for scar assessment in patients with atrial fibrillation (AF). Automating the quantification and analysis of atrial scars can be challenging due to the low image quality. In this work, we propose a fully automated method based on the graph-cuts framework, where the potentials of the graph are learned on a surface mesh of the left atrium (LA) using a multi-scale convolutional neural network (MS-CNN). For validation, we have included fifty-eight images with manual delineations. MS-CNN, which can efficiently incorporate both the local and global texture information of the images, has been shown to evidently improve the segmentation accuracy of the proposed graph-cuts based method. The segmentation could be further improved when the contribution between the t-link and n-link weights of the graph is balanced. The proposed method achieves a mean accuracy of 0.856 ± 0.033 and mean Dice score of 0.702 ± 0.071 for LA scar quantification. Compared to the conventional methods, which are based on the manual delineation of LA for initialization, our method is fully automatic and has demonstrated significantly better Dice score and accuracy (p < 0.01). The method is promising and can be potentially useful in diagnosis and prognosis of AF.

Long-term impact of catheter ablation on arrhythmia burden in low-risk patients with paroxysmal atrial fibrillation: The CLOSE to CURE study

BACKGROUND

Few studies evaluated the impact of catheter ablation (CA) on atrial tachyarrhythmia (ATA) burden in paroxysmal atrial fibrillation (AF).

OBJECTIVE

In the prospective, patient-controlled CLOSE to CURE study, we determined the longer-term impact of optimized CA on ATA burden by using an insertable cardiac monitor (ICM).

METHODS

A total of 105 patients with paroxysmal AF were implanted with an ICM 65 (interquartile range [IQR] 61-78) days before CA. CA consisted of contact force-guided pulmonary vein isolation targeting an intertag distance of ≤6 mm and a region-specific ablation index. The primary end point was reduction in ICM-detected ATA burden; secondary end points were single-procedure freedom from ATA, quality of life, and adverse events.

RESULTS

The mean age was 62 ± 8 years; the median CHA₂DS₂-VASc score was 1 (IQR 1-2); and the median left atrial diameter was 43 (IQR 39-43) mm. After pulmonary vein isolation (1.13 ± 0.39 procedures per patient), median ATA burden decreased from 2.68% (IQR 0.09%-15.02%) at baseline to 0% (IQR 0%-0%) during the first year and to 0% (IQR 0%-0%) during the second year (reduction in ATA burden 100% [IQR 100%-100%]; P < .001). Single-procedure freedom from any ATA was 87% at 1 year and 78% at 2 years. Quality of life improved significantly across all scores. Adverse events occurred in 5 patients (4.8%).

CONCLUSION

CA has become an effective procedure in paroxysmal AF, with a major impact on ICM-detected ATA burden. Whereas conventional survival analysis suggests a progressive decline in efficacy, we observed that burden reduction is maintained at longer follow-up. These data imply that ATA burden is a more optimal end point for assessing ablation efficacy.