Radiofrequency Catheter Ablation for Atrial Fibrillation Patients on Hemodialysis (From the Kansai Plus Atrial Fibrillation Registry)　― Clinical Impact of Early Recurrence ―

Abstract

Background: Catheter ablation (CA) for atrial fibrillation (AF) in patients on hemodialysis (HD) is reported to have a high risk of late recurrence (LR). However, the relationship between early recurrence (ER) within a 90-day blanking period after CA in AF patients and LR in HD patients remains unclear.

Methods and Results: Of the 5,010 patients in the Kansai Plus Atrial Fibrillation Registry, 5,009 were included in the present study. Of these patients, 4,942 were not on HD (non-HD group) and 67 were on HD (HD group). HD was an independent risk factor for LR after the initial CA (adjusted hazard ratio 1.6; 95% confidence interval 1.1–2.2; P=0.01). In patients with ER, the rate of sinus rhythm maintenance at 3 years after the initial CA was significantly lower in the HD than non-HD group (11.4% vs. 35.4%, respectively; log-rank P=0.004). However, in patients without ER, there was no significant difference in the rate of sinus rhythm maintenance at 3 years between the HD and non-HD groups (67.7% vs. 74.5%, respectively; log-rank P=0.62).

Conclusions: ER in HD patients was a strong risk factor for LR. However, even HD patients could expect a good outcome without ER after the initial CA.

The incidence and prevalence of atrial fibrillation (AF) in patients on hemodialysis (HD) are reported to be higher than in the general population.¹ However, it is reported that patients on HD are more likely to experience AF recurrence after catheter ablation (CA) than AF patients not on HD (non-HD).^2–6 Furthermore, early recurrence (ER) within a 90-day blanking period after CA is reported to be a risk factor for late recurrence (LR),^7–9 but, to the best of our knowledge, there have been no reports on the association between ER and LR in HD patients. Therefore, we decided to use data from the Kansai Plus Atrial Fibrillation (KPAF) Registry, a large-scale prospective multicenter observational study, to examine AF ablation outcomes and the association between ER and LR in HD patients.

Methods

Study Population

The KPAF Registry is a physician-initiated, non-company sponsored, all-case registration, multicenter study of radiofrequency CA for AF in Japan that includes 2 prospective randomized trials (the UNmasking Dormant Electrical Reconduction by Adenosine TriPhosphate [UNDER-ATP] trial¹⁰ and the Efficacy of Antiarrhythmic Drugs Short-Term Use After Catheter Ablation for Atrial Fibrillation [EAST-AF] trial¹¹), and 1 observational trial (NCT01477983). Patients were recruited to the KPAF Registry from 26 cardiovascular centers in Japan between November 2011 and March 2014. In all, 5,010 consecutive patients who underwent CA for the first time for any type of AF were enrolled in the KPAF Registry.^12–14 The study protocol was approved by institutional review boards at each of the participating centers and the study complied with the Declaration of Helsinki. Written informed consent was obtained from all patients. The median follow-up period was 2.92 years, and the follow-up rate was 97.7%.

Of the 5,010 patients in the KPAF Registry, 5,009 were included in the present study after excluding one participant without any information on HD status. Of the 5,009 patients in the present study, 4,942 patients were not on HD (non-HD group; 99%) and 67 patients were on HD (HD group; 1%).

Ablation Procedure

Vaughan Williams Class I or III antiarrhythmic drugs (AADs) were primarily discontinued 5 half-lives before the ablation procedure, except amiodarone, for which discontinuation was encouraged at least 1 month before the procedure. Pulmonary vein isolation (PVI) was performed with the use of at least 1 circular catheter after a successful trans-septal puncture. Intravenous heparin was continuously administered to maintain the activated clotting time between 250 and 350 s. The standard PVI method used by participating centers in the present study was an extensive encircling PVI, broadly isolating the ipsilateral superior and inferior pulmonary veins (PVs) simultaneously, mostly with the use of double circular catheters. An irrigation catheter was used in most patients in combination with a 3-dimensional (3D) mapping system (CARTO [Biosense Webster Inc., Diamond Bar, CA, USA] or Ensite NavX [St. Jude Medical, St. Paul, MN, USA]). Radiofrequency energy was applied to the ipsilateral PV antrum with minimal anatomical gaps at the ablation points. The electrophysiological endpoint of PVI was bidirectional conduction block between the left atrium (LA) and PVs. We tried to ablate non-PV atrial premature contractions (APCs), including those from the superior vena cava, if they triggered AF or frequently appeared during continuous intravenous infusion of isoproterenol. The decision to perform additional ablation was left up to the operator and/or attending physician.

Definitions and the Primary Endpoint

Paroxysmal AF (PAF) was defined as AF that spontaneously terminated or terminated under AADs within 7 days of onset. Persistent AF was defined as AF lasting for more than 7 days and up to 1 year. Long-standing AF was defined as AF lasting for more than 1 year. In the present study, persistent and long-standing AF were classified as non-PAF. ER was defined as atrial tachyarrhythmia (AT) lasting for 30 s during a blanking period of 90 days after ablation. The primary endpoint in the present study was LR, defined as recurrent ATs occurring after the 90-day postablation blanking period. The definition of recurrent AT was AT lasting for 30 s or requiring a repeat ablation, hospital admission, or the unscheduled use of Vaughan Williams Class I or III AADs.

Follow-up

Patients were scheduled to receive regular follow-up at the outpatient clinics of the centers where the index ablation was performed at 3, 6, 12, 24, and 36 months. A 12-lead electrocardiogram (ECG) was obtained at every visit. One-channel ECGs were recorded for 2 weeks, twice daily, when patients had symptoms suggestive of an arrhythmia in the hospital, at hospital discharge, and at 6 and 12 months using an ambulatory electrogram recorder (HCG-801; Omron Healthcare Co., Ltd., Osaka, Japan). The outpatient physician performed 24-h Holter monitoring at 6 and 12 months, and it was performed as needed for >1 year after the ablation. Experienced clinical research coordinators from the study management center (Research Institute for Production Development, Kyoto, Japan) checked 10% of the input data and viewed the hospital charts and records.

Statistical Analysis

Data are presented as values and percentages, the mean±SD, or as the median and interquartile range. Categorical variables were compared using χ² tests or Fisher’s exact test; continuous variables were compared using Student’s t-test or the Wilcoxon rank-sum test depending on their distribution. The AT event-free rate after a 90-day blanking period in the non-HD and HD groups was estimated by the Kaplan-Meier method, and the significance of differences was assessed using log-rank tests. The same evaluation was performed in the 2 groups with and without ERs. Hazard ratios (HRs) and 95% confidence interval (CIs) for the primary endpoint were analyzed using Cox proportional hazards regression models adjusting for the following clinical factors potentially related to LR from previous studies: age (≥75 or <75 years), female sex, AF evolution time (≥24 or <24 months), history of sleep-disordered breathing, AF type (PAF or non-PAF), history of hypertension, history of diabetes, history of heart failure, decreased left ventricular ejection fraction (<50% or ≥50%), LA dilation (LA diameter >40 or ≤40 mm), ER within a 90-day blanking period, and HD.^{6,9,12,15–18} Patients who died or were lost to follow-up were censored on the date they died or the date of last contact.

All statistical analyses were performed using EZR software (Saitama Medical Center, Jichi Medical University, Saitama, Japan),¹⁹ which is a graphical user interface for R (R Foundation for Statistical Computing Vienna, Austria). More precisely, EZR is a modified version of R commander designed to add statistical functions frequently used in biostatistics. P<0.05 was considered statistically significant, and all tests were 2-tailed.

Results

Baseline Clinical Characteristics

Baseline characteristics of the non-HD and HD groups are presented in Table 1. In the non-HD and HD groups, 2,092 (42.3%) and 35 (52.2%) patients had ERs, respectively, with no significant difference between the 2 groups (P=0.11). Statistically significant differences were observed between the 2 groups in age, body mass index, non-PAF, female sex, history of heart failure, hypertension, diabetes, vascular disease, CHADS₂ score, CHA₂D₂-VASc score, representative parameters of transthoracic echocardiography (left ventricular end-diastolic diameter, left ventricular ejection fraction, and left atrial diameter), and representative blood sampling data (hemoglobin, creatinine, creatinine clearance, and B-type natriuretic peptide).

Table 1.

Baseline Characteristics of Patients With and Without HD

	Non-HD (n=4,942)	HD (n=67)	P value
Age (years)	64.3±10.4	66.9±7.7	0.04
Body mass index (kg/m2)	24.0±3.5	21.7±3.2	<0.001
Non-PAF	1,774 (35.9)	13 (19.4)	0.005
Female sex	1,343 (27.2)	26 (38.8)	0.04
Duration of AF (years)	2.1 [0.6–5.6]	1.2 [0.3–4.5]	0.25
Sleep-disordered breathing	187 (3.9)	2 (3.2)	1.0
History of heart failure	644 (13.0)	17 (25.4)	0.006
Hypertension	2,588 (52.3)	46 (68.7)	0.009
Diabetes	698 (14.1)	21 (31.3)	<0.001
Ischemic stroke	379 (7.7)	5 (7.5)	1.0
Vascular disease	442 (9.0)	16 (24.2)	<0.001
CHADS2 score	1.1±1.1	1.6±1.3	<0.001
CHA2D2-VASc score	2.0±1.5	2.8±1.7	<0.001
Early recurrence	2,092 (42.3)	35 (52.2)	0.11
Re-ablation	1,251 (25.3)	23 (34.3)	0.12
Total no. procedures	1.3±0.5	1.4±0.6	0.06
Transthoracic echocardiography
LVDD (mm)	47.1±5.6	49.1±6.6	0.004
LVEF (%)	63.4±9.4	60.9±13.4	0.03
LAD (mm)	40.0±6.7	42.2±6.7	0.008
Blood sampling data
Hemoglobin (mg/dL)	14.2±1.5	11.8±1.6	<0.001
Creatinine (mg/dL)	0.9±0.3	6.7±2.3	<0.001
CCr (mL/min/1.73 m2)	82.1±28.7	10.1±12.2	<0.001
BNP (pg/mL)	177.0±380.7	725.8±1,210.7	<0.001
Medications
Oral anticoagulation	4,750 (96.1)	64 (95.5)	0.75
Class I/III AAD	1,618 (32.7)	20 (29.9)	0.70
Amiodarone	102 (2.1)	4 (6.0)	0.05
ACEI/ARB	1,928 (39.0)	23 (34.3)	0.45
β-blocker	1,794 (36.3)	30 (44.8)	0.16

Unless indicated otherwise, data are given as the mean±SD, median [interquartile range], or n (%). AAD, anti-arrhythmic drug; ACEI, angiotensin-converting enzyme inhibitor; AF, atrial fibrillation; ARB, angiotensin II receptor blocker; BNP, B-type natriuretic peptide; CCr, creatinine clearance; HD, hemodialysis; LAD, left atrial diameter; LVDD, left ventricular end-diastolic diameter; LVEF, left ventricular ejection fraction; PAF, paroxysmal atrial fibrillation.

Ablation Procedure Characteristics and Complications

Procedural characteristics during the initial and second ablation procedures are presented in Table 2. The rate of PVI failure during the initial ablation was significantly higher in the HD than non-HD group (6.1% and 1.5%, respectively; P=0.02). There were no differences between the 2 groups for additional ablation procedures other than a PVI. In patients who underwent a second ablation procedure, there was no significant difference in the rate of PV reconnections or the site of the reconnected PVs and rate of a non-PV ablation between the HD and non-HD groups.

Table 2.

Procedural Characteristics During the Initial and Second Ablation Procedures in the Groups With and Without HD

	Non-HD	HD	P value
First ablation procedure
No. patients	4,942	67
3-D mapping system	4,927 (99.7)	67 (100.0)	1.0
Irrigation catheter	4,530 (93.2)	61 (95.3)	0.80
PVI failure	71 (1.5)	4 (6.1)	0.02
Total procedure time (min)	193.1±64.0	186.3±52.4	0.41
Additional ablations
CTI ablation	3,408 (69.9)	50 (75.8)	0.35
SVC isolation	669 (13.7)	4 (6.1)	0.07
CFAE ablation	520 (10.7)	3 (4.5)	0.15
Left atrial roof line	968 (19.9)	14 (21.2)	0.76
Mitral isthmus line	321 (6.6)	3 (4.5)	0.80
Non-PV foci ablation	150 (3.1)	1 (1.5)	0.72
Second ablation procedure
No. patients	1,251	23
PV reconnection	996 (81.8)	21 (95.5)	0.16
Reconnection site
LSPV	603 (49.5)	15 (68.2)	0.09
LIPV	500 (41.1)	13 (59.1)	0.12
RSPV	601 (49.3)	12 (54.5)	0.67
RIPV	572 (47.0)	13 (59.1)	0.29
Non-PV foci ablation	101 (8.3)	0 (0)	0.25

Unless indicated otherwise, data are given as the mean±SD or n (%). CFAE, continuous fractionated atrial electrogram; CTI, cavotricuspid isthmus; HD, hemodialysis; LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; pulmonary PV, pulmonary vein; PVI, pulmonary vein isolation; RIPV, right inferior pulmonary vein; RSPV, right superior pulmonary vein; SVC, superior vena cava.

The complications following the initial ablation procedure are presented in Table 3. The incidence of cardiac tamponade was significantly higher in the HD than non-HD group (4.5% and 1.0%, respectively; P=0.03), but there were no significant differences between the 2 groups in the incidence of other complications (mortality, heart failure, stroke, hematoma).

Table 3.

Procedural Complications During the Initial Ablation Procedure According to HD Status

	Non-HD (n=4,942)	HD (n=67)	P value
Death	4 (0.1)	0 (0)	1.0
Cardiac tamponade	47 (1.0)	3 (4.5)	0.03
Pericarditis	29 (0.6)	0 (0)	1.0
Stroke	6 (0.1)	0 (0)	1.0
Transient ischemic attack	5 (0.1)	0 (0)	1.0
Systemic embolism	2 (0.04)	0 (0)	1.0
Myocardial ischemia	9 (0.2)	0 (0)	1.0
In-hospital heart failure	17 (0.3)	0 (0)	1.0
Respiratory failure	5 (0.1)	0 (0)	1.0
Atrial-esophageal fistula	1 (0.02)	0 (0)	1.0
Sepsis	3 (0.06)	0 (0)	1.0
Phrenic nerve injury	9 (0.2)	0 (0)	1.0
Gastric motility of pyloric spasm	14 (0.3)	1 (1.5)	0.18
Hematoma, surgery/transfusion	14 (0.3)	1 (1.5)	0.18
Pseudoaneurysm, surgery	5 (0.1)	0 (0)	1.0
Arteriovenous fistula, surgery	2 (0.04)	0 (0)	1.0
Pacemaker implantation	10 (0.2)	0 (0)	1.0
Pneumothorax	2 (0.04)	0 (0)	1.0
Contrast allergy	5 (0.1)	0 (0)	1.0
Transfusion	15 (0.3)	1 (1.5)	0.19

Unless indicated otherwise, data are given as n (%). HD, hemodialysis.

Sinus Rhythm Maintenance After CA

The rate of sinus rhythm (SR) maintenance after the initial CA in the non-HD and HD groups is shown in Figure 1A. The rate of SR maintenance 3 years after the ablation was significantly lower in the HD than non-HD group (36.9% vs. 57.9%, respectively; log-rank P=0.001). Among patients in the non-HD group, the rate of SR maintenance was significantly lower in those with than without ER (35.4% vs. 74.5%, respectively; log-rank P<0.001; Figure 1B). Similarly, the rate of SR maintenance among patients in the HD group was significantly lower in those with than without ER (11.4% vs. 67.7%, respectively; log-rank P<0.001; Figure 1C). In the presence of ER, the rate of SR maintenance was significantly lower in the HD than non-HD group (11.4% vs. 35.4%, respectively; log-rank P=0.004; Figure 2A), whereas in the absence of ER there was no statistically significant difference between the 2 groups (67.7% vs. 74.5%, respectively; log-rank P=0.62; Figure 2B). In addition, the HD group tended to have a lower rate of SR maintenance after the last ablation than the non-HD group, although the difference did not reach statistical significance (64.3% vs. 76.4%, respectively; log-rank P=0.05; Figure 3).

Figure 1.

Event-free survival from the primary endpoint of recurrent atrial tachyarrhythmias following a blanking period of 90 days from the initial ablation: (A) all patients, comparing patients on hemodialysis (HD) with non-HD patients; (B) non-HD patients with and without early recurrence (ER) within the 90-day blanking period after catheter ablation; and (C) HD patients with and without ER.

Figure 2.

Event-free survival from the primary endpoint of recurrent atrial tachyarrhythmias following a blanking period of 90 days from the initial ablation: (A) patients with early recurrence (ER) within the 90-day blanking period after catheter ablation, comparing patients on hemodialysis (HD) with non-HD patients; and (B) non-HD vs. HD patients without ER.

Figure 3.

Event-free survival from the primary endpoint of recurrent atrial tachyarrhythmias following a blanking period of 90 days from the last ablation comparing patients on hemodialysis (HD) with non-HD patients.

Risk Factors for LR After a Single Ablation Procedure

The 3-year cumulative incidence of AF recurrence after a single procedure was significantly higher in the HD than non-HD group (63.1% vs. 42.1%, respectively; P=0.001) and the adjusted HR for the HD relative to non-HD group for LR was 1.6 (95% CI 1.1–2.2; P=0.01; Table 4). The adjusted HRs for LR in the HD without ER, non-HD with ER, and HD with ER groups relative to the non-HD without ER group were 1.0 (95% CI 0.4–2.2; P=0.95), 3.6 (95% CI 3.3–4.0; P<0.0001), and 6.5 (95% CI 4.4–9.6; P<0.0001), respectively (Table 5). The same analysis was attempted in a population excluding the 75 patients in whom a PVI was unsuccessful (71 in the non-HD group, 4 in the HD group), with similar results obtained to those presented in Table 5 (see Supplementary Table). It was found that HD patients with ER often had recurrent AF late beyond the 90-day blanking period, and that in patients without ER, the prognosis was comparable to that in non-HD patients.

Table 4.

HRs and 95% CIs for Late Recurrence of Atrial Tachyarrhythmia Following Catheter Ablation for AF in the HD Relative to Non-HD Group

No. (%) patients with eventA	Crude HR (95% CI)	P value	Adjusted HR (95% CI)	P value
38 (63.1)	1.7 (1.2–2.3)	0.001	1.6 (1.1–2.2)	0.01

^ACumulative 3-year incidence of late recurrence of atrial fibrillation. AF, atrial fibrillation; CI, confidence interval; HD, hemodialysis; HR, hazard ratio.

Table 5.

HRs and 95% CIs for Late Recurrence of Atrial Tachyarrhythmia Following Catheter Ablation for AF According to HD and ER Status

	Crude HR (95% CI)	P value	Adjusted HR (95% CI)	P value
Non-HD without ER (n=2,850)	Reference		Reference
HD without ER (n=32)	1.1 (0.5–2.3)	0.68	1.0 (0.4–2.2)	0.95
Non-HD with ER (n=2,092)	3.8 (3.5–4.2)	<0.0001	3.6 (3.3–4.0)	<0.0001
HD with ER (n=35)	6.6 (4.6–9.6)	<0.0001	6.5 (4.4–9.6)	<0.0001

ER, early recurrence. Other abbreviations as in Table 4.

Discussion

Main Findings

HD patients had a significantly higher recurrence rate after the initial CA for AF than non-HD patients. Moreover, ER after the initial CA in HD patients was a strong risk factor for LR. Conversely, in the absence of ER, the outcomes were comparable between HD and non-HD patients.

AF Management in HD Patients

The incidence and prevalence of AF in HD patients are reported to be higher than in the general population.¹ When AF occurs in HD patients, the risk of a thrombosis arises and the difficulties in continuing HD due to hypotension during tachycardias can be observed, which also decrease the quality of life.^20,21 However, anticoagulation therapy in HD patients with AF is generally not recommended²² because of the high risk of bleeding complications associated with anticoagulation.²⁰ The use of anticoagulation in HD patients is limited, usually with warfarin in patients with a mechanical valve or perioperatively during CA for AF. In addition, AADs that are not metabolized in the kidney must be selected. For those reasons, the management of AF in HD patients is not easy. Therefore, CA has been expected to be a useful therapeutic modality. However, there are many reports of poor outcomes with ablation in HD patients.^2–6 In the present study, as in previous studies, the rate of SR maintenance after the initial CA session was significantly lower in HD than non-HD patients. However, there was no statistically significant difference in the rate of SR maintenance after the final session between the 2 groups. Furthermore, with the exception of cardiac tamponade, there was no difference in the incidence of other serious complications, such as mortality or stroke, between the 2 groups. Considering both efficacy and safety, CA as a treatment option for the management of AF in HD patients appears to be reasonable and CA should not be excluded simply because the patient is on HD.

ER After AF Ablation in HD Patients and Its Clinical Significance

It has been reported that ER within a 90-day blanking period after CA does not necessarily lead directly to a treatment failure with CA for AF because ER could be caused by transient inflammation of the myocardium, edema, ischemia, or abnormal automaticity due to autonomic hyperactivity.²³ Therefore, it is recommended that a blanking period of 90 days is used after CA when reporting efficacy outcomes.²⁴ However, it is well known that ER is a strong risk factor for LR.^9,25 The present study revealed that ER was a stronger risk factor for LR in HD compared with non-HD patients. Conversely, this study also found that the outcomes in the group without ER were as good as those in the non-HD group. That is, the 90-day blanking period could be considered the key to determining the success of AF ablation in the late phase after CA in HD patients. To the best of our knowledge, this is the first study reporting an association between ER and LR after CA for AF in HD patients.

It has been reported that LA dilatation, activation of the renin-angiotensin-aldosterone system, intravascular volume depletion, and an electrolyte shift after dialysis can result in the development AF and poor outcomes after CA in HD patients.^26,27 In the present study, the diameter of the left atrium on transthoracic echocardiography was indeed significantly larger in HD than non-HD patients, despite the higher rate of PAF in HD patients. It has also been reported that in HD patients, PAF is more likely to occur on a HD day, especially during HD²⁷ and the dynamic changes in intravascular volume and electrolytes due to HD are thought to increase the likelihood of APCs triggering AF.²⁷ Some studies have reported that even if there is a PV reconnection after AF ablation, there are cases in which ER and LR do not occur.^28,29 However, it was speculated that in HD patients even a single reconnection of the PVs could lead to AF recurrence, and AF recurrence within the blanking period (i.e., ER) may predict further future recurrence.

Importance of PVI as a CA Strategy in HD Patients

It is possible that APCs associated not only with a PV origin, but also non-PV foci are prevalent during HD. In the present study, the success rate of PVI was significantly lower in HD than non-HD patients during the first procedure, and the rate of CA of non-PV foci was the same. In the case of a second procedure, the rate of a PV reconnection was very high in both the HD and non-HD groups, with no significant difference between them. Moreover, there was no difference in added non-PV foci ablation. Thus, APCs with a PV origin seemed to be the main cause of recurrence in patients with and without HD. Furthermore, there was no statistically significant difference between the HD and non-HD groups in terms of the overall outcome after the final session, when the PVI was considered to be generally complete. These results suggest that treating APCs with a PV origin (i.e., a PVI) is the first, most important step, even in HD patients. There have been recent reports of better outcomes with cryoballoon vs. radiofrequency ablation in HD patients.^26,30 It is possible that the durability of the PVI in cryoablation, a specialized treatment for PVI, may be superior to that of radiofrequency ablation.³¹ These results suggest a reliable PVI is still essential for a successful ablation, even in HD patients.

A reliable PVI with new technologies, such as contact force catheters, using a high-resolution 3D mapping system, and balloon ablation may help further improve ablation outcomes in HD patients in the future.

Clinical Implications

Because the results of multiple CA sessions are not much worse than those in non-HD patients, we believe that AF ablation should be attempted in HD patients under adequate indication (under adequate dry-weight control on HD) without hesitation. Although the durability of the PVI is important for non-HD patients, it is even more important for HD patients. In addition, close observation should be paid to bleeding complications (especially cardiac tamponade). A 90-day blanking period should be monitored for recurrence (e.g., by ECG monitoring during HD) and, if there is no ER, a good outcome can be expected. Conversely, if ER occurs, the patient should be followed up with care because of a very high risk of LR, and repeat ablation sessions should be performed when LR is present.

Study Limitations

This study has some limitations. Although the study population was large, the number of HD patients was still small, and baseline patient characteristics differed between the HD and non-HD groups. This study used standard non-invasive follow-up methods, not insertable cardiac monitors (ICMs), because the implantation of an ICM for post-CA monitoring purposes is not covered by insurance in Japan. Therefore, detecting AF recurrence after CA, particularly in cases with asymptomatic AF, was difficult. Moreover, it was possible that the type of follow-up differed between the HD and non-HD groups; the HD group underwent ECG, blood pressure, and peripheral capillary oxygen saturation monitoring for several hours during HD, and the AF detection rate may have been higher in this group than in the non-HD group. Finally, technical advances in recent years (e.g., the development of contact force-sensing catheters and balloon ablation technologies such as the cryoballoon, hot balloon, and laser balloon) may have led to increased PVI durability, which may have improved the CA results.

Conclusions

After the initial CA for AF, the risk of recurrence was higher in HD than non-HD patients. Furthermore, ER was a strong risk factor for LR after the initial CA for AF in HD patients. However, the same good outcome after the initial CA could be expected in HD patients as in non-HD patients if there was no ER.

Acknowledgment

The authors thank Mr. John Martin for his linguistic assistance with the manuscript.

Sources of Funding

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

Disclosures

C.I. and K.O. are members of Circulation Journal’s Editorial Team. The remaining authors have no conflicts of interest to declare.

IRB Information

The study protocol was approved on May 13, 2017, by a suitably constituted Ethics Committee of Tenri Hospital (No. 429), and the conformed to the provisions of the Declaration of Helsinki.

Supplementary Files

Please find supplementary file(s);

https://doi.org/10.1253/circj.CJ-23-0671

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