Sex differences in terms of recurrent atrial fibrillation after catheter ablation according to the history of heart failure: insights from the Kansai Plus Atrial Fibrillation (KPAF) registry

Background

There are significant differences in the prevalence and prognosis of cardiovascular diseases between male and female. We previously reported that catheter ablation (CA) of atrial fibrillation (AF) was less effective in female than male, but whether their history of heart failure influence the recurrence after CA of AF remains still unknown.

Purpose

We sought to clarify sex differences in terms of AF recurrence after RFCA of AF according to the history of heart failure.

Methods

We conducted a large-scale, prospective, multicenter, observational study (Kansai Plus Atrial Fibrillation Registry). We enrolled 5010 consecutive patients who underwent an initial RFCA of AF at 26 centers (64±10 years; 1369 [27.3%] females; non-paroxysmal AF, 35.7%). The median follow-up duration was 2.9 years.

Results

Fourteen % of female had a history of heart failure prior to CA, while 12.8% of male had a history of heart failure at baseline (p=0.29). The 3-year cumulative incidence of AF recurrence after a single procedure was 43.3% in female and 39.0% in male (log rank P=0.0046). In patients with the history of heart failure, AF recurrence rates were 42.2% in female and 45.8% in male (log rank P=0.51). On the other hand, in patients without history of heart failure, more females experienced AF recurrence (female vs. male, 43.5% vs. 38.0%, log rank P=0.001).

The rate of AF recurrence after multiple procedures was higher in female (24.2% vs. 19.6%, log rank P<0.0001). AF recurrence rates were similar between sexes in patients with history of heart failure (female vs. male, 26.0% vs. 26.7%, log rank P=0.86), while AF recurrence rates were higher in female without history of heart failure than those in male (females vs. males, 23.9% vs. 18.5%, log rank P<0.0001).

Conclusion

The Kansai Plus Atrial Fibrillation Registry revealed a distinct sex difference in terms of the AF recurrence after CA of AF. Females had higher recurrence rates compared with males in patients without history of heart failure, while recurrence rates were similar between sexes in patients with history of heart failure.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Research Institute for Production Development in Kyoto, Japan.

Impact of catheter ablation on functional tricuspid regurgitation in patients with atrial fibrillation

Background

Since atrial functional tricuspid regurgitation (AF-TR) is associated with increased heart failure and mortality, the management of AF-TR is clinically important. Atrial fibrillation (AF) plays the main role in AF-TR. However, the effectiveness of catheter ablation (CA) and mechanism of improvement of AF-TR haven't been fully evaluated.

Purpose

We sought to investigate the impact of CA for AF on AF-TR in patients with moderate or more TR.

Methods

We retrospectively investigated consecutive 2685 patients with AF who received CA from February 2004 to December 2019 in Japan. The current study population consisted of 102 patients with moderate or greater TR who underwent CA for AF. The echocardiographic parameters were compared between pre-ablation and post-ablation transthoracic echocardiography (TTE), and the recurrence rate of AF/ atrial tachycardia (AT) was measured.

Results

The mean age was 73.2 years, 53% were women. TR severity and TR jet area significantly improved after CA for AF (TR jet area: 5.8 [3.9–7.6] cm2 to 2.0 [1.1–3.0] cm2, p<0.001). In addition, mitral regurgitation (MR) jet area, left atrial (LA) area, mitral valve diameter, right ventricular (RV) end-diastolic area, right atrial (RA) area, tricuspid valve (TV) diameter decreased after CA (p<0.001, <0.001, <0.001, = 0.02, <0.001, and <0.001, respectively). There was no significant difference between one-year recurrence of AF/AT and TR severity at pre-ablation TTE (moderate 28.6%, moderate to severe 37.2%, and severe 31.6%, p=0.72).

Conclusions

TR severity and jet area improved after CA in patients with AF and moderate or more TR. RV size, RA size, TV diameter also decreased after CA, which may be associated with TR improvement. There was no significant difference between one-year recurrence of AF/AT and TR severity at pre-ablation TTE.

Funding Acknowledgement

Type of funding sources: None.

10-year clinical outcomes after radiofrequency catheter ablation for atrial fibrillation. A single center experience

Background

Radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) is becoming a routine procedure to treat patients with drug-refractory symptomatic AF. However, data regarding very long-term clinical outcomes is limited. The aim of the present study was to evaluate the 10-year clinical outcomes of patients who underwent RFCA for paroxysmal and persistent AF.

Methods

We retrospectively enrolled 503 consecutive patients (mean age 66,9±9,51 years; 71,6% male) who underwent RFCA for drug-refractory symptomatic AF between February 2004 and June 2011. Follow-up information was obtained using medical records and/or telephonic interviews with the patient, relatives and/or referring physicians.

Results

Among 503 patients enrolled in this study, 362 had paroxysmal atrial fibrillation (PAF) and 141 had persistent atrial fibrillation (PeAF) (72% and 28%, respectively). Mean follow-up was 8,84±3,05 years. The 10-year event-free rate for recurrent atrial tachyarrhythmia (AT) after the first procedure was 44,5% (49,4% for PAF vs 31,9% for PeAF; p=0,002 by log-rank test) and 81,9% after the last procedure (87,3% for PAF and 67,9% for PeAF; p≤0,001 by log-rank test). AT recurrence was observed most commonly during the first 12 months of the initial procedure (56%), with only 18% of them occurring after 60 months. Multivariate analysis revealed that persistent AF (hazard ratio=1,366; 95% confidence interval 1,058–1,76; p=0,017) and duration of AF >5 years (hazard ratio=1,357; 95% confidence interval 1,064–1,732; p=0,005) were independent risk factors for AT recurrence. Regarding adverse events, there were 24 (4,8%) hospitalizations for acute decompensated heart failure, 20 (4%) ischemic strokes and 14 (2,8%) bleeding complications requiring hospital admissions. Patients taking oral anticoagulation and antiarrhythmic drugs at the end of the study accounted for 32,8% and 16,7% respectively.

Conclusions

RFCA for AF provided favorable results in terms of arrhythmia event-free survival in long-term follow-up with better results in patients with paroxysmal AF. Persistent AF and long-standing AF (beyond 5 years) were associated with AT recurrence. Despite the large number of patients who discontinued oral anticoagulation, thromboembolic adverse events were rare.

Funding Acknowledgement

Type of funding sources: None.

Sex differences and arrhythmia recurrence after catheter ablation for atrial fibrillation

Background

Several previous studies reported female sex is associated with high recurrence rate of atrial tachyarrhythmia (ATA) after catheter ablation (CA) for atrial fibrillation (AF).

Purpose

We investigated the relationship between sex differences and recurrence rate of ATA after CA for AF in a large single-center database.

Methods

We enrolled consecutive 2033 patients undergoing first time CA for AF in our institution between Feb.2004 and Dec. 2017.

We compared the long-term outcomes between female (N=603) and male (N=1430).

Results

Female patients were older (70.8 vs. 66.3, p<0.0001), and had lower prevalence of persistent AF (23.1% vs. 33.5%, p<0.0001). Also, left atrial dimension was smaller (40.0 vs. 41.1, p=0.0005). and prior antiarrhythmic drug use was more prevalent (38.2% vs. 28.7%, p<0.0001) in female patients.

Ablation method for pulmonary vein isolation (PVI) was radiofrequency catheter ablation in 1634 patients (80.4%) and cryoballoon ablation in 399 (20.6%).

Median follow-up duration was 1342±115 days. The 3-year ATA recurrence rate after first CA was 35.8% overall: 39.9% in female and 34.2% in male (Log-rank P=0.01).

A multivariate analysis revealed that the factors associated with higher ATA recurrence rate were female (p=0.01), persistent AF (p=0.006), and larger left atrial dimension (p=0.007).

Conclusions

Female gender is an independent predictor of arrhythmia recurrence after CA for AF.

Funding Acknowledgement

Type of funding source: None

Predictive factors of recurrent atrial tachyarrhythmia after multiple procedures of radiofrequency catheter ablation for paroxysmal atrial fibrillation: Kansai Plus Atrial Fibrillation Registry (KPAF)

Background

The predictors of arrhythmia recurrence after radiofrequency catheter ablation (RFCA) for paroxysmal atrial fibrillation (PAF) have not yet been fully evaluated.

Purpose

The aim of this study was to develop and validate a risk scoring system to predict the incidence of recurrence of atrial tachyarrhythmia after the final RFCA for PAF.

Methods

The study population consisted of 3223 consecutive patients undergoing first-time RFCA for PAF from November 2011 to March 2014 in 26 cardiovascular centers in Japan who were enrolled in the Kansai Plus Atrial Fibrillation (KPAF) registry. We developed a scoring system in a derivation cohort with 2149 patients and assessed its reproducibility in a validation cohort with 1074 patients. The primary endpoint was recurrent atrial tachyarrhythmia lasting for ≥30 seconds after 91 days post the final ablation.

Results

During a median follow-up period of 3.1 years, 404 (18.8%) patients of the derivation cohort had AF recurrence after the final RFCA. The baseline patient characteristics of the derivation cohort were as follows: mean age 64.7 years, male 1480 (68.9%), mean body mass index (BMI) 23.6 kg/m2, hypertension 1122 (52.2%), prior heart failure 182 (8.5%), diabetes mellitus 203 (9.5%), prior stroke and/or transient ischemic attack 21 (1.0%), prior vascular disease 209 (9.7%), prior valvular disease 105 (4.9%), median CHADS2 score 1.1, median CHA2DS2-VASc score 2.1, mean number of ineffective antiarrhythmic drugs (AAD) 0.80, median duration of history of AF episodes 2.1 years, mean left atrial diameter (LAD) 38.2 mm, mean left ventricular ejection fraction (LVEF) 65.3%, and mean eGFR 68.7 mL/min/1.73m2. There was no significant difference in the baseline characteristics between derivation and validation cohorts. The results of the multivariate logistic regression models identified 5 independent variables of recurrent atrial tachyarrhythmia after the final RFCA: female (odds ratio (OR) = 1.45, p=0.0017), BMI <25 kg/m2 (OR=1.40, p=0.0081), duration of AF history 3 years≤ (OR=1.39, p<0.0034), chronic kidney disease (CKD) (OR=2.1, p=0.005, for stage 2/3CKD, OR=2.6, p=0.018 for stage 4/5 CKD), and LVEF (OR=2.1, p=0.039 for LVEF <50%, OR=1.5, p=0.022 for LVEF 50–60%). The predictive score for each factor was 3 points for CKD stage 4/5, 2 for CKD stage2/3 and LVEF <50%, and 1for the others (11 points in total). The arrhythmia-free rates after the final RCFA in the derivation cohort according to the score were as follows: 0–2 points = 91.7%, 3–4 = 80.7%, 5< = 72.6%, respectively. The similar results were reproduced in the validation cohort (Figure 1).

Conclusion

Our newly developed scoring system, composed of female, BMI, AF duration, CKD, and LVEF, could reproducibly predict arrhythmia recurrence after the final RFCA for PAF.

Funding Acknowledgement

Type of funding source: None

Usefulness of collaboration between mathematical models and cell engineering for elucidating complex disease mechanisms and discover effective drugs

Background

A missense mutation, CACNA1C-E1115K, located in the cardiac L-type calcium channel (LTCC), was recently reported to be associated with diverse arrhythmias. Several studies reported in-vivo and in-vitro modeling of this mutation, but actual mechanism and target drug of this disease has not been clarified due to its complex ion-mechanisms.

Objective

To reveal the mechanism of this diverse arrhythmogenic phenotype using combination of in-vitro and in-silico model.

Methods and results

Cell-Engineering Phase: We generated human induced pluripotent stem cell (hiPSC) from a patient carrying heterozygous CACNA1C-E1115K and differentiated into cardiomyocytes. Spontaneous APs were recorded from spontaneously beating single cardiomyocytes by using the perforated patch-clamp technique.

Mathematical-Modeling Phase: We newly developed ICaL-mutation mathematical model, fitted into experimental data, including its impaired ion selectivity. Furthermore, we installed this mathematical model into hiPSC-CM simulation model.

Collaboration Phase: Mutant in-silico model showed APD prolongation and frequent early afterdepolarization (EAD), which are same as in-vitro model. In-silico model revealed this EAD was mostly related to robust late-mode of sodium current occurred by Na+ overload and suggested that mexiletine is capable of reducing arrhythmia. Afterward, we applicated mexiletine onto hiPSC-CMs mutant model and found mexiletine suppress EADs.

Conclusions

Precise in-silico disease model can elucidate complicated ion currents and contribute predicting result of drug-testing.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists

Sex differences in the predictors of recurrent atrial fibrillation after catheter ablation: insights from the Kansai Plus Atrial Fibrillation (KPAF) registry

Background

The impact of sex differences on the clinical outcomes of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) is controversial. We previously reported that females experienced more frequent AF recurrences than males after the index and last RFCA procedures.

Purpose

To identify the risk factors associated with recurrent AF in females and males after RFCA of AF.

Methods

We conducted a large-scale, prospective, multicenter, observational study (Kansai Plus Atrial Fibrillation Registry). We enrolled 5010 consecutive patients who underwent an initial RFCA of AF at 26 centers (64±10 years; 1369 [27.3%] females; non-paroxysmal AF, 35.7%). The median follow-up duration was 2.9 years.

Results

The incidence of AF recurrences after a single procedure was 43.3% in females and 39.0% in males. After a multivariate adjustment at baseline, the significant predictors of AF recurrence in females after the index RFCA were non-paroxysmal AF (hazard ration [HR],1.59; 95% confidence interval [CI],1.31–1.93, p<0.0001), a history of AF ≥2 years (HR,1.47; 95% CI,1.24–1.74, p<0.0001), coronary artery disease (HR,1.43; 95% CI,1.03–1.98, p=0.0035), and an estimated glomerular filtration rate (eGFR)<60 mL/min/1.73m2 (HR,1.46; 95% CI,1.10–1.95, p=0.0086). On the other hand, significant predictors of AF recurrence in males after the index RFCA were non-paroxysmal AF (HR,1.54; 95% CI,1.37–1.73, p<0.0001), a history of AF ≥2 years (HR,1.40; 95% CI,1.26–1.56, p<0.0001), the number of antiarrhythmic drugs (HR,1.06; 95% CI,1.003–1.13, p=0.040), a left atrial diameter≥40mm (HR,1.13; 95% CI,1.007–1.27, p=0.038), and dilated cardiomyopathy (HR,1.55; 95% CI,1.07–2.26, p=0.021), however, an eGFR<60 mL/min/1.73m2 was not associated with AF recurrence in males (HR, 1.00; 95% CI, 0.88–1.13, p=0.97).

Conclusion

The Kansai Plus Atrial Fibrillation Registry revealed a distinct sex difference in terms of the predictors of recurrent AF after RFCA. Non-Paroxysmal AF and a long history of AF were common risk factors both in females and males. However, renal dysfunction was a significant predictor of AF recurrence in females, while it was not a risk of recurrence in males.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Research Institute for Production Development in Kyoto, Japan.

The impact of catheter ablation for patients with asymptomatic atrial fibrillation: subanalysis of kansai plus atrial fibrillation (kpaf) registry

Background

Catheter ablation (CA) of atrial fibrillation (AF) for symptomatic patients improves the quality of life and prognosis of patients with heart failure. However, the impact of CA for asymptomatic patients is still controversial.

Purpose

We aimed to investigate the clinical outcomes of CA of AF for asymptomatic patients compared to those for symptomatic patients.

Methods

A total of 5,013 patients from the Kansai Plus Atrial Fibrillation (KPAF) Registry who underwent CA were screened. The patients were divided into three groups by type of AF; paroxysmal (PAF), persistent (PEAF) and long standing (LSAF) and the patients in each type of AF were divided into two groups: asymptomatic and symptomatic. The primary endpoint was recurrent supraventricular tachyarrhythmias lasting for more than 30 seconds during follow-up 4 years after CA. The secondary endpoint was a composite of cardiovascular, cerebral, and gastrointestinal events during follow-up 4 years after CA. The incidence of complications related to CA between asymptomatic and symptomatic patients was also evaluated. Kaplan–Meier analysis was employed to estimate the primary and secondary endpoints. The statistical differences in primary and secondary endpoints between asymptomatic and symptomatic patients were evaluated using a log–rank test. The impact of symptom due to AF on the primary and secondary endpoint was evaluated using a Cox hazard analysis. The difference in incidence of complications between asymptomatic and symptomatic patients was evaluated using a chi–square test.

Results

In this study population, PAF was the most frequent at 64.4%, followed by PEAF (22.7%) and LSAF (13.0%). There were some significant differences in the baseline characteristics between asymptomatic and symptomatic patients in each type of AF. The proportion of male was significantly higher in asymptomatic patients than symptomatic patients in PAF (81.2% versus 67.2%, p<0.001) and PEAF (86.4% versus 74.3%, p<0.001). Left atrial diameter was larger in asymptomatic patients than symptomatic patients only in PAF (40±6mm versus 38±6mm, p<0.001). In all types of AF, there was no significant difference in primary endpoint between asymptomatic and symptomatic patients as follows: 37.5% versus 40.6% (p=0.6) in PAF, 45.2% versus 55.1% (p=0.09) in PEAF and 59.3% versus 63.6% (p=1.0) in LSAF. There was also no significant difference in secondary endpoint between asymptomatic and symptomatic patients: 7.1% versus 6.8% (p=0.7) in PAF, 5.4% versus 8.7% (p=0.3) in PEAF and 4.4% versus 5.1% (p=0.5) in LSAF. In a Cox hazard analysis, the symptom did not affect both of the primary and secondary endpoints in each type of AF. In regard to the incidence of complications related to CA, there was no significant difference between asymptomatic and symptomatic patients in each type of AF.

Conclusion

CA of AF for asymptomatic patients can be safe and can lead to equivalent outcomes as well as symptomatic patients.

Funding Acknowledgement

Type of funding source: None

P985The long-term impact of maintaining sinus rhythm on the risk for death or heart failure after catheter ablation for atrial fibrillation in a real world clinical practice

Background

Catheter ablation has been rapidly spread as a first line therapy for atrial fibrillation (AF). A recent randomized trial have shown that AF ablation reduces the risk of death or hospitalization for heart failure (HF). However, the impact of maintained sinus rhythm (SR) on long-term risk of death or HF hospitalization has not been adequately evaluated.

Purpose

To investigate the impact of maintaining SR by AF ablation on long-term risk of all-cause death or HF hospitalization.

Methods

The long-term clinical outcomes were compared between patients with maintained SR and those with recurrent AF using a landmark analysis in which the landmark point was set at 1.5-year after the 1st ablation.

Results

Among consecutive 1467 patients who underwent AF ablation in our institution between February 2004 and December 2017, the study population consisted of 1311 patients after excluding 150 patients because of death or lost to follow-up. Mean age was 67.9±0.3 and paroxysmal AF was 67%. Among 460 patients who had AF recurrence within 1.5 years after the 1st ablation, 328 underwent 2nd ablation. Therefore, at 1.5-year after the 1st AF ablation, 1145 patients had maintained SR rhythm (SR-group), and 166 patients had recurrent AF episodes (AF-group). During 4.7±2.4 years of follow-up, the cumulative 5-year incidence of death or HF beyond 1.5 years after the 1st ablation was 5.1% in SR-group and 15.6% in AF-group (log rank P<0.001). After adjusting for baseline confounders, the lower risk of SR-group relative to AF-group for death or HF was still statistically significant (HR: 2.05, 95% CI: 1.11–3.58, P=0.02).

Risks for a Composite of Death or HF Hazard Ratio (95% CI) Crude HR P value Adjusted HR P value AF recurrence 2.59 (1.43–4.43) 0.002 2.05 (1.11–3.58) 0.02 Age>75 years old 2.55 (1.56–4.10) <0.001 2.32 (1.39–3.81) 0.002 Female 0.85 (0.49–1.43) 0.56 0.73 (0.40–1.25) 0.26 PeAF 1.25 (0.68–2.16) 0.45 0.98 (0.52–1.75) 0.94 LSAF 1.10 (0.46–2.23) 0.82 0.70 (0.28–1.53) 0.39 LVEF>50% 0.27 (0.16–0.48) <0.001 0.57 (0.31–1.09) 0.09 Past history of HF 7.06 (4.18–11.6) <0.001 4.67 (2.51–8.41) <0.001 CKD 4.74 (2.08–9.39) <0.001 2.23 (0.94–4.69) 0.07 AF, Atrial fibrillation; PeAF, Persistent AF; LSAF; Long standing AF; HF, Heart failure; CKD, Chronic kidney disease.

Figure 1

Conclusions

Successfully maintained SR was associated with reduced long-term risk for death or HF hospitalization in real world patients undergoing AF ablation.

P5652Catheter ablation outcome and heart failure hospitalization in atrial fibrillation patients with preserved left ventricular ejection fraction: insights from the Kansai plus atrial fibrillation (KPAF)

Background

Heart failure (HF) is the leading cause of death in patients with atrial fibrillation (AF), and AF is an independent prognostic factor in HF patients with preserved left ventricular ejection fraction (LVEF). Radiofrequency catheter ablation (RFCA) for AF is effective to maintain sinus rhythm.

Purpose

We sought to clarify incidence of HF hospitalization and whether AF ablation outcome influenced incidence of HF hospitalization after the procedures in patients with preserved LVEF.

Methods

We conducted a large-scale, prospective, multicenter, observational study. A total of 4522 consecutive patients with normal LVEF (>/- 50%) who underwent an initial RFCA for AF in 26 centers were enrolled (average age, 64±10 years; non-paroxysmal AF, 33.7%). The median follow-up duration was 2.9 years.

Results

The 3-year cumulative incidence of AF recurrence after a single procedure was 40.3%. Hospitalization for HF was observed in 60 patients (1.3%) and was significantly higher in patients with AF recurrence than those without it (2.63% vs 0.44%, log-rank p<0.001). After adjustment by age ≥65 years, estimated glomerular filtration rate ≤60ml/min, history of HF, and female, all of which were statistically associated with a risk of HF hospitalization, AF recurrence after the index RFCA was an independent predictor of HF hospitalization (hazard ratio; 4.75, 95% confidence interval; 2.59–9.42, p<0.001).

Conclusions

Recurrence after RFCA for AF was a significant risk of HF hospitalization among AF patients with preserved LVEF.

Acknowledgement/Funding

This study was supported by the Research Institute for Production Development in Kyoto, Japan.

P1035Factors associated with quality-of-life improvement after catheter ablation of atrial fibrillation: insights from the Kansai Plus Atrial Fibrillation (KPAF) registry

Background

Improving the quality of life (QoL) is one of the main purposes of catheter ablation (CA) of persistent atrial fibrillation (AF). Factors associated with QoL improvement after CA of AF patients have not been clarified. The Kansai Plus Atrial Fibrillation (KPAF) Registry is a multi-center registry enrolling more than 5,000 consecutive patients undergoing the first radiofrequency catheter ablation of AF.

Purpose

The aim of this study was to investigate the QoL change after AF ablation and its associated factors.

Methods

A total of 2030 patients in whom the QoL score was assessed before and one year after the ablation were enrolled from the KPAF registry (age 64±10 years, 75% male, paroxysmal 66%, CHADS2 score 1.1±1.1). The QoL was evaluated using the AF specific QoL evaluation method (AFQLQ), which scores the patient QoL within a range of 0–98 points.

Results

Overall, catheter ablation showed a significant increase in the AFQLQ score (68±19 vs. 86±13 points, P<0.01). AF recurrence was observed in 372 cases (18%) during a 1-year follow-up period. A multivariate analysis showed that AF recurrence, symptomatic AF, long AF duration, high preprocedural heart rate (>110 bpm) and small left atrial diameter were independent predictors of a QoL improvement defined as a >10% score increase.

Multivariate analysis

Conclusions

CA of AF significantly improved the QoL. AF recurrence was one of the strong factors associated with QoL improvement. Symptomatic AF, long AF duration, high preprocedural heart rate and small left atrial diameter were independent predictors of QoL improvement.

P1029Catheter ablation outcome and heart failure hospitalization in atrial fibrillation patients: insights from the Kansai plus atrial fibrillation (KPAF) registry

Background

Heart failure (HF) is the leading cause of death in patients with atrial fibrillation (AF). Radiofrequency catheter ablation (RFCA) for AF is effective to maintain sinus rhythm.

Purpose

We sought to clarify whether AF ablation outcome influenced incidence of HF hospitalization after the procedures.

Methods

We conducted a large-scale, prospective, multicenter, observational study. A total of 5010 consecutive patients who underwent an initial RFCA for AF in 26 centers were enrolled (average age, 64±10 years; non-paroxysmal AF, 35.6%). The median follow-up duration was 2.9 years.

Results

The 3-year cumulative incidence of AF recurrence after a single procedure was 40.2%. The 3-year incidence of hospitalization for HF was observed in 92 patients (1.8%) and was significantly higher in patients with AF recurrence than those without it (3.3% vs 0.84%, log-rank p<0.001). After adjustment by advanced age,(≥65 years), reduced left ventricular ejection fraction (≤50%), low estimated glomerular filtration rate (≤60ml/min), and history of HF, all of which were statistically associated with a risk of HF hospitalization (p<0.1, respectively), AF recurrence after the index RFCA was an independent predictor of HF hospitalization (hazard ratio [HR]; 3.17, 95% confidence interval [CI]; 2.06–5.04, p<0.001).Even after multiple procedures (1425 re-ablation sessions in 1274 patients [25.4%]), AF recurrence after the last procedure was an independent predictor of HF hospitalization (HR; 2.83, 95% CI; 1.89–4.24, p<0.001).

Conclusions

Among AF patients receiving RFCA, those with AF recurrence were at greater risk of heart failure hospitalization than were patients without AF recurrence. These differences should be noted when treating AF patients in actual clinical practice.

Acknowledgement/Funding

This study was supported by the Research Institute for Production Development in Kyoto, Japan.

P5650Improvement in ejection fraction predicts heart failure after catheter ablation for atrial fibrillation in patients with left ventricular systolic dysfunction: from the KPAF registry

Introduction

The presence of atrial fibrillation (AF) in patients with reduced left ventricular ejection fraction (LVEF) is associated with increased risks of mortality and hospitalization for heart failure (HF). Although prior studies reported that catheter ablation (CA) for AF in low LVEF patients reduced risks of all-cause mortality and HF hospitalization, the predictors of worsening HF after ablation has not been adequately evaluated.

Purpose

The purpose of this study was to investigate the impact of improvement in LVEF after AF ablation on the incidence of subsequent HF hospitalization in patients with low LVEF.

Methods

The Kansai Plus Atrial Fibrillation (KPAF) Registry is a multicenter registry enrolling 5,013 consecutive patients undergoing first-time ablation for AF. The current study population consisted of 1,031 patients with reduced LVEF of <60%. We divided the study population into 3 groups according to LVEF at follow-up; 678 patients (65.8%) with improved LVEF (≥5 U change in LVEF), 288 patients (27.9%) with unchanged LVEF (−5 U ≤ change in LVEF <5 U) and 65 patients (6.3%) with worsened LVEF (<−5 U change in LVEF).

Results

During the median follow-up of 1067 [879–1226] days, patients improved LVEF had lower rate of HF hospitalization, compared with those with unchanged and worsened LVEF (2.1%, 8.0%, and 21.5%, respectively, P<0.0001). Recurrent atrial tachyarrhythmias were documented in 43.5%, 47.2% and 67.7%, respectively (P=0.0008).

Figure 1

Conclusion

Among patients with reduced LVEF undergoing AF ablation, patients with subsequently improved LVEF in association with maintained sinus rhythm had markedly lower risk of HF hospitalization during follow-up as compared with those with unchanged or worsened LVEF.

P1038Device implantation after catheter ablation of paroxysmal atrial fibrillation with coexisting sick sinus syndrome: Insights from the Kansai Plus Atrial Fibrillation (KPAF) study

Background

Sick sinus syndrome (SSS) and atrial fibrillation (AF) frequently coexist and interact to initiate and perpetuate each other. Several retrospective or small cohort studies have suggested that successful catheter ablation of AF may help to waive device implantations in patients with paroxysmal AF plus SSS, however, no prospective large studies are so far available on this scenario.

Purpose

We aimed to elucidate the device implantation-free survival after catheter ablation of paroxysmal AF with coexisting SSS in a prospective large-scale registry. We also determined the risk factors for device implantations after catheter ablation of paroxysmal AF.

Methods

The Kansai Plus Atrial Fibrillation (KPAF) study is a multi-center prospective registry that enrolled 5,019 consecutive patients that underwent an initial pulmonary vein isolation-based radiofrequency catheter ablation of AF. This study was comprised of 3,226 patients with paroxysmal AF registered in the KPAF study (age, 64.8±10.5 years old; female, n=999 [31.0%]; left atrial diameter [LAD], 37.5±8.0 mm; left ventricular ejection fraction [LVEF], 65.3±8.4%, CHADS2 score, 1.09±1.05). The atrial tachyarrhythmia-free and device-free survivals after catheter ablation were compared between patients with SSS (n=368; tachy-brady syndrome, 88%) and without SSS (control; n=2,858).

Results

The atrial tachyarrhythmia-free survival was almost identical between the two groups both after the first ablation session (Fig.1A) and after the last procedure with an average of 1.3±0.5 sessions. At baseline, the devices had already been implanted in 53 (14.4%) SSS and 36 (1.3%) control patients. In the remaining patients, devices were newly implanted in 54 (17.1%) SSS and 62 (2.2%) control patients during the follow-up of 3 years after the catheter ablation (Figure 1B). In the SSS group, devices were implanted predominantly within 6 months after the catheter ablation, and atrial tachyarrhythmia recurrence preceded the device implantation in 48 (89%) patients. Multivariate predictors of device implantations after the paroxysmal AF ablation included: SSS (hazard ratio [HR] 6.85, 95% confidence interval [CI] 4.61–10.19, p<0.001), an age>75 years old (HR 1.69, 95% CI 1.08–2.64, p=0.019), a female gender (HR 2.16, 95% CI 1.44–3.24, p<0.001), the LAD (mm) (HR 1.05, 95% CI 1.02–1.08, p=0.006), and the LVEF (%) (95% CI 0.96, 95% CI 0.94–0.98, p<0.001).

Figure 1

Conclusions

Device implantations could be waived in >80% of patients with SSS at 3 years of follow-up after the catheter ablation of paroxysmal AF in this real world all comer prospective registry. In addition to coexisting SSS, predictors of device implantations after paroxysmal AF ablation included: the elderly, a female gender, a large LA, and a reduced LVEF.

Acknowledgement/Funding

None

Identification of the five essential histidine residues for peptidylglycine monooxygenase

Peptidylglycine monooxygenase (PGM) is a copper-containing monooxygenase that plays a key role in the peptide C-terminal alpha-amidation. Comparative analysis of the amino acid sequences of rat, human, bovine and frog PGMs revealed that ten histidines (residues 107, 108, 172, 235, 242, 244, 279, 364, 366 and 367 in rat PGM) are conserved among the four species. We introduced site-directed mutations to the ten histidines of rat PGM and found that the mutation of His- 107-->Ala, His-108-->Ala, His-172-->Ala, His-242-->Arg or His-244-->Ala abolished the enzyme activity. The five mutant proteins lacking the enzyme activity bound to a substrate, Phe-Gly-Phe-Gly, as did the wild type PGM. These results along with available evidence indicate that the five histidine residues (His-107, 108, 172, 242 and 244) are essential for PGM activity, acting as copper ligands.