Impact of Catheter Ablation for Paroxysmal Atrial Fibrillation in Patients With Sick Sinus Syndrome - Important Role of Non-Pulmonary Vein Foci

Comparison between catheter ablation versus permanent pacemaker implantation as an initial treatment for tachycardia-bradycardia syndrome patients: a prospective, randomized trial

BACKGROUND

Clinical outcomes after catheter ablation (CA) or pacemaker (PM) implantation for the tachycardia-bradycardia syndrome (TBS) has not been evaluated adequately. We tried to compare the efficacy and safety outcomes of CA and PM implantation as an initial treatment option for TBS in paroxysmal atrial fibrillation (AF) patients.

METHODS

Sixty-eight patients with paroxysmal AF and TBS (mean 63.7 years, 63.2% male) were randomized, and received CA (n = 35) or PM (n = 33) as initial treatments. The primary outcomes were unexpected emergency room visits or hospitalizations attributed to cardiovascular causes.

RESULTS

In the intention-to-treatment analysis, the rates of primary outcomes were not significantly different between the two groups at the 2-year follow-up (19.8% vs. 25.9%; hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.25-2.20, P = 0.584), irrespective of whether the results were adjusted for age (HR 1.12, 95% CI 0.34-3.64, P = 0.852). The 2-year rate of recurrent AF was significantly lower in the CA group compared to the PM group (33.9% vs. 56.8%, P = 0.038). Four patients (11.4%) in the CA group finally received PMs after CA owing to recurrent syncope episodes. The rate of major or minor procedure related complications was not significantly different between the two groups.

CONCLUSION

CA had a similar efficacy and safety profile with that of PM and a higher sinus rhythm maintenance rate. CA could be considered as a preferable initial treatment option over PM implantation in patients with paroxysmal AF and TBS.

TRIAL REGISTRATION

KCT0000155.

Catheter Ablation for Paroxysmal Atrial Fibrillation With Sick Sinus Syndrome: Insights From the Kansai Plus Atrial Fibrillation Registry

BACKGROUND

Coexisting sick sinus syndrome (SSS) is associated with both electrical and structural atrial remodelling in patients with atrial fibrillation (AF). Limited data are available concerning catheter ablation (CA) for AF in this condition. This study investigated the efficacy of CA as a curative therapy for AF and SSS in a large-scale prospective multicentre registry.

METHODS

The Kansai Plus Atrial Fibrillation (KPAF) registry enrolled 5,010 consecutive patients who underwent CA for AF; this included 3,133 patients with paroxysmal AF (mean age, 66 years; male, 69.3%; mean CHA₂DS₂-VASc score, 2.05±1.50; SSS, n=315 [tachy-brady syndrome, n=285]). The endpoints included the recurrence of AF with a blanking period of 90 days after CA, and de novo pacemaker implantation during the follow-up period (median duration, 2.93 years).

RESULTS

The AF-free survival did not significantly differ between patients with and those without SSS (n=2,818) after the initial (log-rank p=0.864) and final sessions (log-rank p=0.268). Pacemakers were implanted in 48 patients with SSS, and implantation in this group was significantly associated with AF recurrence, including early recurrence (adjusted odds ratio, 3.57; 95% confidence interval, 1.67-7.64; p=0.002). The remaining 85.3% of patients with SSS did not require pacemaker implantation at 3 years after CA.

CONCLUSIONS

Coexisting SSS did not adversely affect recurrence-free survival after CA for paroxysmal AF. Pacemaker implantation was not required in most patients with SSS, with AF recurrence serving as a strong predictor for this.

Impact of atrial fibrillation ablation on long-term outcomes in patients with tachycardia-bradycardia syndrome

Background

Reports of long-term outcomes after atrial fibrillation (AF) ablation for tachycardia-bradycardia syndrome (TBS) are limited. This study aimed to investigate the impact of radiofrequency catheter ablation (RFCA) on clinical outcomes in patients with TBS.

Methods

Among 1669 patients who underwent AF ablation between January 2010 and April 2020, we retrospectively enrolled 53 patients (62.3% males; age, 67.1 ± 7.0 years) who had been diagnosed with TBS before RFCA for paroxysmal AF (TBS group). After 1:2 propensity score-matching based on age, gender, AF type, and left atrial dimension, 106 patients were assigned to the control group (non-TBS group). The atrial tachyarrhythmia (ATA) recurrence rate and rate of avoidance of permanent pacemaker implantation (PMI) were examined.

Results

During a median follow-up period of 37.7 months, the ATA recurrence rate after a single ablation procedure was significantly higher in the TBS group than in the non-TBS group (51.0% vs. 38.5%; log-rank p = .008); however, the ATA recurrence rate after the final ablation procedure did not significantly differ between groups. In the TBS group, the rate of PMI avoidance after AF ablation was 92.5%. A Cox-regression multivariate analysis revealed that the presence of non-pulmonary vein/superior vena cava premature atrial contractions (odds ratio, 3.38; 95% confidence interval, 1.49-7.66; p = .004) was an independent predictor of ATA recurrence in the TBS group.

Conclusions

Patients with TBS had higher ATA recurrence rates after the first ablation procedure compared to those without TBS. However, ATA recurrence after AF ablation did not necessarily result in PMI for TBS patients.

Impact of the sinus node recovery time after termination of atrial fibrillation during catheter ablation on clinical outcomes in patients with persistent atrial fibrillation

BACKGROUND

Although long sinus arrest is occasionally observed during atrial fibrillation (AF) catheter ablation when the fibrillation was terminated, its meaning and prognosis have not yet been clearly elucidated. We hypothesized that sinus node recovery time (SNRT) after termination of AF (time from termination of AF to the earliest sinus node activation) could reflect the extent of atrial remodeling, influencing the formation of non-pulmonary vein (non-PV) triggers and post-ablation outcomes.

METHOD

The participants were 157 consecutive patients with persistent AF (male: 77.1%, age: 63.3±11.2 years) who underwent catheter ablation. We recorded SNRT after terminating AF by radiofrequency delivery or electrical cardioversion during the first ablation and evaluated the relationships between SNRT and atrial tachyarrhythmia recurrence and between SNRT and non-PV triggers after repeat ablation.

RESULTS

Forty-five patients (28.7%) experienced recurrence of atrial tachyarrhythmias. Patients with recurrence had longer SNRTs (1738 ms vs. 1394 ms, p = 0.012). In the multivariate logistic regression analysis, only SNRT ≥2128ms was a significant independent predictor of clinical AF recurrence (hazard ratio 7.48; 95% confidence interval 2.94-19.00; P<0.001). Kaplan-Meier estimator showed that the recurrence-free rate was significantly lower if ≥ 2128ms (log-rank, p<0.001). Thirty-five patients (77.8%) underwent a second ablation. Although there was no difference in the rate of pulmonary vein reconnections (78.6% vs. 71.4%, p = 0.712), non-PV triggers were observed more frequently in the longer SNRT group (57.1% vs. 14.3%, p = 0.012).

CONCLUSIONS

Patients with a prolonged SNRT had a higher prevalence of AF recurrence after the first ablation and higher inducibility of non-PV triggers. Measuring SNRT might be used for the stratification of patients with persistent AF.

Effect of ganglionated plexi ablation by high-density mapping on long-term suppression of paroxysmal atrial fibrillation - The first clinical survey on ablation of the dorsal right plexusus

Background

Long-term outcomes of suppressing paroxysmal atrial fibrillation (PAF) with additive ganglionated plexus (GP) ablation (GPA) remains unknown.

Objectives

The aim of the study is to assess potential role of additional GPA for PAF suppression.

Methods

This study consisted of 225 patients; 68 (group A: 58 male, aged 60 ± 11 years) underwent pulmonary vein isolation (PVI) alone and 157 (group B: 137 male, aged 61 ± 11 years) GPA followed by PVI. GPA was performed based on the high-density mapping with high-frequency stimulation (HFS) delivered to left atrial (LA) major GP. The latter 85 group B patients (54%) underwent ablation to a posteromedial area within superior vena cava as a part of dorsal right atrial GP (SVC-Ao GP).

Results

In group B, HFS was applied to 126 ± 32 sites, with a median of 47 GP sites (40.0%) being ablated. In patients undergoing an SVC-Ao GPA, HFS and the SVC-Ao GPA were applied at a median of 15 and 4 sites (29.4%), respectively. The PVI with a GPA provided higher PAF suppression than a PVI alone during more than 4 years of follow-up (56.7% vs 38.2%, odds ratio: 0.42, 95% confidence interval: 0.23-0.76, P < .05), but the SVC-Ao GPA did not provide further suppressive effects. Multivariate analyses revealed that tachycardia-bradycardia syndrome and non-PV foci were independent predictors of PAF recurrence after PVI with a GPA (P < .01).

Conclusion

GPA to LA major GP by high-density mapping provides long-term benefits for PAF suppression over 4 years of follow-up, but the effect of an empiric SVC-Ao GPA could not be appreciated, suggesting little effect on suppressing non-PV foci.

Presence of non-pulmonary vein foci in patients with atrial fibrillation undergoing standard ablation of pulmonary vein isolation: Clinical characteristics and long-term ablation outcome

Background

The clinical characteristics of atrial fibrillation (AF) resulting from non-pulmonary vein (PV) triggers remain unknown. This study aimed to evaluate the clinical characteristics of patients with AF caused by non-PV triggers, localization of non-PV foci, clinical differences, and clinical outcomes after catheter ablation in each AF focus.

Methods

A total of 2967 patients who underwent initial catheter ablation for paroxysmal or persistent AF were examined. After PV isolation, all patients underwent high-dose isoproterenol infusion to assess the existence of non-PV foci.

Results

Non-PV foci were identified in 564 patients (19.2%). The localization of successfully ablated non-PV foci in 514 patients were the superior vena cava (SVC: 213 cases), interatrial septum (IAS: 125 cases), coronary sinus (CS: 98 cases), right atrium (RA: 125 cases), left atrium (LA: 114 cases), and unmappable (50 cases). Multivariate analysis revealed that female gender, low body mass index (BMI), non-paroxysmal AF (PAF), and sick sinus syndrome were independent and significant indicators of non-PV foci. In the multivariate analysis of each AF focus, female gender, low BMI, and non-PAF were significant predictors of IAS and CS foci, RA and IAS foci, and CS foci, respectively. In addition, dilatation of the LA was significantly associated with LA foci, whereas RA, LA, IAS, and CS foci were associated with AF recurrence.

Conclusion

These findings could help to identify patients at a higher risk of AF caused by non-PV triggers and clarify the clinical difference according to the localization of non-PV foci.

Cryoballoon pulmonary vein isolation-mediated rise of sinus rate in patients with paroxysmal atrial fibrillation

Background

Modulation of the cardiac autonomic nervous system by pulmonary vein isolation (PVI) influences the sinoatrial nodal rate. Little is known about the causes, maintenance and prognostic value of this phenomenon. We set out to explore the effects of cryoballoon PVI (cryo-PVI) on sinus rate and its significance for clinical outcome.

Methods and results

We evaluated 110 patients with paroxysmal atrial fibrillation (AF), who underwent PVI using a second-generation 28 mm cryoballoon by pre-, peri- and postprocedural heart rate acquisition and analysis of clinical outcome. Ninety-one patients could be included in postinterventional follow-up, indicating that cryo-PVI resulted in a significant rise of sinus rate by 16.5% (+ 9.8 ± 0.9 beats/min, p < 0.001) 1 day post procedure compared to preprocedural acquisition. This effect was more pronounced in patients with initial sinus bradycardia (< 60 beats/min.) compared to patients with faster heart rate. Increase of rate was primarily driven by ablation of the right superior pulmonary vein and for a subset of patients, in whom this could be assessed, persisted ≥ 1 year after the procedure. AF recurrence was neither predicted by the magnitude of the initial rate, nor by the extent of rate change, but postprocedural sinus bradycardia was associated with higher recurrence of AF in the year post PVI.

Conclusions

Cryo-PVI causes a significant rise of sinus rate that is more pronounced in subjects with previous sinus bradycardia. Patient follow-up indicates persistence of this effect and suggests an increased risk of AF recurrence in patients with postprocedural bradycardia.

Graphic abstract

Electronic supplementary material

The online version of this article (10.1007/s00392-020-01659-0) contains supplementary material, which is available to authorized users.

Permanent Pacemaker Implantations after Catheter Ablation in Patients with Atrial Fibrillation Associated with Underlying Sinus Node Dysfunction

BACKGROUND AND OBJECTIVES

The objective of this study was to evaluate the long-term clinical outcomes and the incidence of permanent pacemaker implantation after catheter ablation in patients with of atrial fibrillation (AF) and sinus node dysfunction (SND).

METHODS

Among 3,068 total consecutive patients who underwent AF catheter ablation (AFCA), this study included 222 (9.5%; men 53.2%, 63.7±9.2 years of age, 81.5% paroxysmal AF) with underlying SND and a regular rhythm follow-up. We analyzed the rhythm outcomes, changes in the mean heart rate or heart rate variability, and permanent pacemaker implantation rate.

RESULTS

During 47.5±28.8 months of follow-up, 25 (11.3%) patients received pacemaker implantations due to symptomatic SND. More than half (56.0%, 14/25) underwent a pacemaker implantation within 3 months of the AFCA, and the annual pacemaker implantation rate was 2.0% afterwards. Both the early (68.0% vs. 31.0%, p<0.001) and clinical AF recurrence (68.0% vs. 32.5%, p=0.001) rates and continuous antiarrhythmic drug use after 3 months (44.0% vs. 24.4%, p=0.036) were significantly higher in patients requiring pacemaker implantations than those that did not. An anterior linear ablation (odds ratio [OR], 9.37 [3.03-28.9]; p<0.001) and the E/Em (OR, 1.15 [1.02-1.28]; p=0.018) were independently associated with permanent pacemaker implantations after AFCA in patients with AF and SND.

CONCLUSIONS

After AFCA in patients with AF and SND, 1 of 9 patients needed a pacemaker implantation and half needed implantations within 3 months. The AF recurrence rate was significantly higher in those who required pacemaker implantations after the AFCA.

Ser96Ala genetic variant of the human histidine-rich calcium-binding protein is a genetic predictor of recurrence after catheter ablation in patients with paroxysmal atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) still remains a serious issue. Ca2+ handling has a considerable effect on AF recurrence. The histidine-rich calcium-binding protein (HRC) genetic single nucleotide polymorphism (SNP), rs3745297 (T>G, Ser96Ala), is known to cause a sarcoplasmic reticulum Ca2+ leak. We investigated the association between HRC Ser96Ala and AF recurrence after RFCA in paroxysmal AF (PAF) patients.

METHODS AND RESULTS

We enrolled PAF patients who underwent RFCA (N = 334 for screening and N = 245 for replication) and were genotyped for HRC SNP (rs3745297). The patient age was younger and rate of diabetes and hypertension lower in the PAF patients with Ser96Ala than in those without (TT/TG/GG, 179/120/35; 64±10/60±12/59±13 y, P = 0.001; 18.5/ 9.2/8.6%, P = 0.04 and 66.1/50.0/37.1%, P = 0.001, respectively). During a mean 19 month follow-up, 57 (17.1%) patients suffered from AF recurrences. The rate of an Ser96Ala was significantly higher in patients with AF recurrence than in those without in the screening set (allele frequency model: odds ratio [OR], 1.80; P = 0.006). We also confirmed this significant association in the replication set (OR 1.74; P = 0.03) and combination (P = 0.0008). A multivariate analysis revealed that the AF duration, sinus node dysfunction, and HRC Ser96Ala were independent predictors of an AF recurrence (hazard ratio [HR], 1.04, P = 0.037; HR 2.42, P = 0.018; and HR 2.66, P = 0.007, respectively).

CONCLUSION

HRC SNP Ser96Ala is important as a new genetic marker of AF recurrence after RFCA.

Catheter Ablation of Paroxysmal Atrial Fibrillation Originating from Non-pulmonary Vein Areas

Pulmonary veins (PVs) are a major source of ectopic beats that initiate AF. PV isolation from the left atrium is an effective therapy for the majority of paroxysmal AF. However, investigators have reported that ectopy originating from non-PV areas can also initiate AF. Patients with recurrent AF after persistent PV isolation highlight the need to identify non-PV ectopy. Furthermore, adding non-PV ablation after multiple AF ablation procedures leads to lower AF recurrence and a higher AF cure rate. These findings suggest that non-PV ectopy is important in both the initiation and recurrence of AF. This article summarises current knowledge about the electrophysiological characteristics of non-PV AF, suitable mapping and ablation strategies, and the safety and efficacy of catheter ablation of AF initiated by ectopic foci originating from non-PV areas.

Catheter ablation of paroxysmal atrial fibrillation in patients with sick sinus syndrome

Sick sinus syndrome (SSS) frequently coexists with atrial fibrillation (AF). The results of AF ablation in patients with SSS have not been fully evaluated. We retrospectively investigated 65 patients with paroxysmal AF (PAF) and SSS who underwent AF ablation using either radiofrequency (n = 50) or cryoballoon ablation (n = 15) in our institute. Forty-nine (75.4%) patients had a median of 5.6 (4.8-6.0) s of documented sinus pauses prior to the procedure (42 patients on antiarrhythmic drugs), and were observed when AF terminated in 47 patients. Successful pulmonary vein isolation was achieved in all, and substrate modification was added in 3 patients. Freedom from recurrent atrial arrhythmias after single procedures was 58.7, 45.2, and 38.9% at 1, 2, and 3 years after the initial procedure. During a 23.4 (11.1-40.7) month median follow-up and after 1.4 ± 0.6 sessions, 80.6% of patients were free from arrhythmia recurrence; however, permanent pacemaker implantations were required in 9 (13.8%) patients at a median of 5.3 (2.9-21.0) months after initial procedures. The average heart rate did not significantly differ before or a median of 2.5 (1.2-5.3) months post-procedure (76.7 ± 17.4 vs. 73.5 ± 14.6 bpm, p = 0.90). Multivariate analyses revealed that larger left atrial diameters [odds ratio (OR) 1.21, 95% confidential interval (CI) 1.01-1.45, p = 0.042] were independent predictor of AF recurrence, and SSS type 1 was the sole predictor of pacemaker implantations (OR 10.30, 95% CI 1.38-76.7, p = 0.023), respectively. AF ablation obviated permanent pacemaker implantations in the majority of the patients with SSS and PAF, and SSS type 1 was a sole factor predicting pacemaker implantations.

Usefulness of a Low Resting Heart Rate to Predict Recurrence of Atrial Fibrillation After Catheter Ablation in People ≥65 Years of Age

A low resting heart rate (RHR) is associated with an increased risk of atrial fibrillation (AF), and this is common in older people. Whether a low RHR in older people can predict recurrence of AF after catheter ablation is unclear. A total of 329 consecutive patients ≥65 years of age with paroxysmal AF who underwent index circumferential pulmonary vein isolation were prospectively enrolled. A 10-second standard resting 12-lead electrocardiogram in sinus rhythm was recorded to measure the RR interval, P-wave duration, and PR interval. The RHR was calculated based on the mean RR interval. During a mean follow-up period of 17.0 ± 8.3 months (range, 3 to 32 months), 96 (29.2%) patients developed recurrence of AF. The AF recurrence rate was 46.2%, 32.3%, and 25.4% in patients with an RHR <50, 50 to 59, and ≥60 beats/min, respectively (log-rank test, p = 0.009). Cox regression analysis with adjustment for P-wave duration and the CHADS₂ score showed that an RHR <50 beats/min (hazard ratio [HR] 1.92, 95% confidence interval [CI] 1.12 to 3.28, p = 0.017), advanced interatrial block (HR 1.82, 95% CI 1.09 to 3.04, p = 0.022), and left atrial diameter (HR 1.05, 95% CI 1.00 to 1.09, p = 0.029) were independent predictors of recurrence of AF after catheter ablation. In conclusion, in people ≥65 years of age, an RHR <50 beats/min is an independent predictor of AF recurrence in patients who have undergone catheter ablation for paroxysmal AF.

Impact of Sinus Node Recovery Time after Long-Standing Atrial Fibrillation Termination on the Long-Term Outcome of Catheter Ablation

Atrial electrical and structural remodeling is related to the perpetuation of atrial fibrillation (AF) subsequent to sinus node dysfunction. We investigated the relationship between AF recurrence after catheter ablation and sinus node dysfunction in long-standing persistent AF patients using the sinus node recovery time (SNRT) after defibrillation.Fifty-one consecutive patients who underwent a first ablation for long-standing persistent AF were enrolled. Intracardiac cardioversion was applied before ablation in the absence of any antiarrhythmic drugs, and the power required to defibrillate, number, and SNRT after defibrillation were measured. All patients underwent the same designed radiofrequency catheter ablation procedure.No patient required permanent pacemaker implantation due to sinus dysfunction after the ablation. During the follow-up period of 28.4 months (3.6-43.7), 35 out of 51 patients (69%) experienced an AF recurrence. The AF recurrence was significantly associated with an older age (60 ± 11 versus 52 ± 12 years in the non-recurrence group, P = 0.0196), longer SNRT after defibrillation (1722 [1410-2656] versus 1295 [676-1651] msec, P = 0.0125), and larger left atrial (LA) volume (59 ± 25 versus 41 ± 15 mL, P = 0.0119). There were no significant differences in the AF duration, AF cycle length, and right and total atrial conduction times between the 2 groups. A longer SNRT after defibrillation (adjusted HR 2.13, 95%CI 1.16-3.71, P = 0.0152) and larger LA volume (adjusted HR 1.03, 95%CI 1.01-1.04, P = 0.0054) were independent predictors of AF recurrence after ablation.Assessment of the SNRT after defibrillation may help to predict a successful ablation in patients with long-standing persistent AF.

California study of Ablation (CAABL):early utilization after index hospitalization for non-valvular atrial fibrillation

Background

Catheter ablation (ABL) for non-valvular AF (NVAF) is recommended for symptomatic patients refractory to medical therapy and its success is related to the duration of the arrhythmia prior to intervention.Our aim was to assess the early utilization and the factors that prompted ABL in patients hospitalized for new onset NVAF.

Methods

Using de-identified administrative discharge records for hospitalizations and emergency department (ED) visits, we determined the patients who had a first-time (since 1991) health record diagnosis of AF between2005 - 2011. We linked ambulatory surgery encounters for ABL based on ICD 9 code occurring within two years of initial hospitalization. After excluding other cardiac arrhythmias, atrio-ventricular nodal ablation or pacemaker/defibrillator placement and cardiac valve disease, bivariate comparisons were made with those who did not undergo ABL.

Results

During the study period,3,440 of 424,592 patients (0.81%) hospitalized for new onset NVAF underwent ABL. Parameters significantly (p<0.001) associated with ABL compared tonon-ABL patientsincluded: principal diagnosis of AF (55% vs 25%), age 35-64 yrs (46.1% vs. 22.4%), male (58.9% vs. 48.2%), private insurance (46.6% vs. 21.1%), Caucasian (81.0% vs.71.6%), lower frequency of ED visit < 6 months before index AF hospitalization (10.7% vs. 15.9%), lower severityofillness at time of AF diagnosis (16.5% vs. 35.6%) anda lower prevalence ofmajor comorbidities (p< 0.001).

Conclusions

Ablation has low utilization for treatment of new onset NVAF within two years of diagnosis. Earlier utilization of ABL may reduce health care burden related to NVAF and requires further evaluation.