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

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.

Importance of the relative epicardial connection locations and right-sided pulmonary vein isolation line for successful pulmonary vein isolation.

INTRODUCTION: The presence of an epicardial connection (EC) decreases the success rate of pulmonary vein isolation (PVI); however, the effect of designing isolation lines has not been evaluated. We sought to clarify the effects of designing an anterior line for right-sided PVI considering the presence and location of the EC. METHODS: Seventy-four consecutive patients who underwent initial catheter ablation for atrial fibrillation were retrospectively included in this study. The presence of the EC was determined by the left atrial (LA) activation map during right atrial pacing, and patients were divided into EC-positive (n = 23, 31%) and EC-negative (n = 51, 69%) groups. EC-positive patients were further subdivided based on the EC location: on-the-line group, (EC on the PVI line, n = 11); inside-line group (EC on the pulmonary vein [PV] side, n = 10); and outside-line group (EC on the LA side, n = 2). The PVI parameters were compared among the three groups. RESULTS: The success rates of the first-pass isolation were comparable between the EC-negative and EC-positive groups (70.6% vs. 60.9%, ns), but the success rate was significantly higher in the on-the-line group than in the inside-line group (91% vs. 20%, p = 0.002). First-pass isolation was successful in both patients in the outside-line group. Additional carina ablation was required only in the inside-line group. CONCLUSIONS: The association between the EC site and the right-sided PV anterior isolation line affected the success rate of first-pass isolation. For successful right-sided PVI, it is important to consider the EC site when designing the PVI line.

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.

Long-term prognosis of patients undergoing radiofrequency catheter ablation for atrial fibrillation: comparison between heart failure subtypes based on left ventricular ejection fraction.

AIMS: Heart failure (HF) prognosis has been reported similar in patients with preserved vs. reduced left ventricular ejection fraction (LVEF). This study compared the long-term prognosis of HF patients undergoing radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF). METHODS AND RESULTS: Among 5010 patients undergoing RFCA in Kansai Plus AF registry, 656 patients (13.1%) with a documented history of HF were enrolled in the study before RFCA. The primary endpoint was a composite of all-cause death, HF hospitalization, and stroke or systemic embolism. Patients with reduced (<40%), mid-range (40-49%), and preserved (≥50%) LVEF were 98 (14.9%), 107 (16.3%), and 451 (68.8%) patients, respectively. The prevalence of ischaemic heart disease and cardiomyopathies was higher among patients with reduced as compared with preserved LVEF (27.6% vs. 10.0%, P < 0.05 and 36.7% vs. 15.3%, P < 0.05, respectively). The median follow-up period was 2.9 years. The 3-year cumulative risk for the primary endpoint was higher in patients with reduced LVEF (32.7%) compared to those with mid-range (11.7%) or preserved (11.6%) LVEF (P < 0.001). Reduced LVEF was the most significant independent risk factor for primary endpoint (hazard ratio, 2.83; 95% confidence interval 1.74-4.61, P < 0.001). The 3-year arrhythmia recurrence rate was similar among the groups (48.2%, 42.8%, and 47.3%, respectively, P = 0.75). CONCLUSION: This study raises hypothesis that patients with HFrEF and AF had approximately three times higher risk for a composite of all-cause death, HF hospitalization, and stroke or systemic embolism after AF ablation compared with patients with HFmrEF or HFpEF.

Efficacy of left atrial posterior wall isolation guided by lesion size prediction module for non-paroxysmal atrial fibrillation.

AIMS: The efficacy of left atrial posterior wall isolation (PWI) is controversial. Lesion durability may be a major cause of arrhythmia recurrence. The use of the lesion size prediction module improves lesion durability. This study aimed to compare the clinical outcomes of pulmonary vein isolation (PVI) alone and PWI in addition to PVI (PVI + PWI) in patients with non-paroxysmal atrial fibrillation (AF) using a lesion size prediction module. METHODS AND RESULTS: This study is a sub-analysis of the recently published prospective multicentre observational study called ALCOHOL-AF (association of alcohol consumption with outcome of catheter ablation of AF). In this sub-analysis, patients with non-paroxysmal AF in whom PVI alone or PVI + PWI was performed using the lesion size prediction module were included. Freedom from atrial tachyarrhythmia was compared between PVI alone and PVI + PWI groups using propensity score analyses. Of the 3474 patients registered in the ALCOHOL-AF study, 572 patients (age 65.6 ± 10.1 years, male 77.4%, longstanding persistent AF 25.5%) were included in this sub-analysis. We selected 212 patients treated with PVI alone and 212 treated with PVI + PWI using one-to-one propensity score matching. During the follow-up period, atrial tachyarrhythmia recurrence was documented in 92 (43.4%) and 50 (23.6%) patients in the PVI alone and PVI + PWI groups, respectively. Freedom from atrial tachyarrhythmia recurrence without anti-arrhythmic drugs after a single procedure was significantly higher in PVI + PWI than in PVI alone groups (hazard ratio: 0.452, 95% confidence interval: 0.308-0.664, P < 0.001). CONCLUSION: In this hypothesis-generating study, lesion size prediction module-guided PVI + PWI was associated with better clinical outcomes than PVI alone in patients with persistent or longstanding persistent AF.

Comparison of Cryoballoon and Contact Force-Sensing Radiofrequency Ablation for Persistent Atrial Fibrillation in Clinical Practice.

BACKGROUND: Outcomes of cryoballoon ablation for persistent atrial fibrillation (AF) are unclear, especially in Japanese patients, so the effectiveness and safety of cryoballoon ablation in clinical practice were retrospectively compared with those of contact force-sensing radiofrequency (CFRF) ablation including the high-power protocol.Methods and Results:Consecutive patients with persistent AF were reviewed, and 253 and 265 patients who underwent cryoballoon and CFRF ablation, respectively, were enrolled. The primary endpoint was atrial arrhythmia recurrence. The secondary endpoints were periprocedural complications and repeat ablation. The rate of additional left atrial (LA) ablation after pulmonary vein isolation (PVI) was similar between groups (68.8% cryoballoon vs. 74.0% CFRF, P=0.19). Freedom from atrial arrhythmia recurrence was comparable between groups over a follow-up of 25.5±12.5 months (72.3% cryoballoon vs. 69.8% CFRF; adjusted hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.59-1.21, P=0.36). Outcomes were similar in the subgroups of PVI alone and PVI plus additional LA ablation. LA posterior wall isolation, absence of defragmentation, and low creatine clearance, but not catheter selection, were associated with the primary endpoint. Periprocedural complications (adjusted HR 0.73, 95% CI 0.34-1.54, P=0.41) and repeat ablation (adjusted HR 1.11, 95% CI 0.71-1.74, P=0.64) were similar for both procedures. CONCLUSIONS: Cryoballoon ablation for persistent AF in Japanese clinical practice had acceptable outcomes comparable to those of advanced CFRF ablation.

Mechanism of improvement in atrial functional mitral regurgitation after catheter ablation for atrial fibrillation: Three-dimensional analysis using multislice computed tomography.

BACKGROUND: Several factors associated with atrial functional mitral regurgitation development have been reported; however, geometric changes in the mitral apparatus after catheter ablation for atrial fibrillation have not been sufficiently investigated. This study aimed to clarify what determines improvements in atrial functional mitral regurgitation after sinus rhythm restoration in patients who underwent catheter ablation for atrial fibrillation by using multislice computed tomography. METHODS: We analysed volumetric multislice computed tomography images of 44 atrial fibrillation patients with significant atrial functional mitral regurgitation (moderate or worse) before and after catheter ablation. We measured the three-dimensional geometry of the mitral apparatus including the mitral annular area and interpapillary muscle distance. We calculated the differences before and after catheter ablation (Δmitral annular area, Δinterpapillary muscle distance) and assessed mitral regurgitation severity based on the mitral regurgitant jet area and its changes before and after catheter ablation (Δjet area) using transthoracic echocardiography. RESULTS: After catheter ablation, the jet area was significantly decreased. The left ventricular ejection fraction was significantly increased and the left ventricular volume had a decreasing trend. The Δjet area was significantly correlated with the Δinterpapillary muscle distance (r = .43; p = .004). The Δinterpapillary muscle distance was the strongest determinant of improvements in atrial functional mitral regurgitation severity (p = .026). CONCLUSIONS: Decreased interpapillary muscle distance was strongly associated with improvements in atrial functional mitral regurgitation. Amelioration of left ventricular dysfunction by sinus rhythm restoration might be related to improvements in atrial functional mitral regurgitation after catheter ablation.

Efficacy and Safety of SATAKE HotBalloon® Catheter for Treatment of Paroxysmal Atrial Fibrillation　- A Post-Marketing Surveillance Study.

BACKGROUND: SATAKE HotBalloon®catheter (HBC) is a radiofrequency balloon catheter for the treatment of atrial fibrillation (AF), and was approved for use in Japan to treat drug-resistant paroxysmal AF in 2015. Post-marketing surveillance study was conducted by Toray Industries, Inc. to evaluate the efficacy and safety of HBC treatment in patients with paroxysmal AF in a real-world setting. This study is the first nation-wide survey of HBC treatment for paroxysmal AF in clinical practice in Japan.Methods and Results:This was a single-arm, multicenter observational study with an observation period of 48 weeks after ablation. Pulmonary vein isolation and AF non-recurrence rates were evaluated and adverse events (AEs) were observed at 46 sites in Japan. An AF event was defined as recurrence of AF or re-ablation from 12 to 48 weeks after ablation. The success rate of pulmonary vein isolation was 99.0% (486/491) for patients with AF. The cumulative AF non-recurrence rate was 94.1% at 24 weeks and 87.8% at 48 weeks. AEs were found to occur 21.5% (114/530), and ablation-related AEs were found to occur 2.6% (14/530) during the study period, with the most common being pericardial effusion (0.8%, 4/530). CONCLUSIONS: This study demonstrates the efficacy and safety of HBC ablation in Japanese patients with recurrent symptomatic paroxysmal AF refractory to antiarrhythmic therapy.

Incidence and Characteristics of Coronary Artery Spasms Related to Atrial Fibrillation Ablation Procedures　- Large-Scale Multicenter Analysis.

BACKGROUND: Coronary artery spasms (CASs), which can cause angina attacks and sudden death, have been recently reported during catheter ablation. The aim of the present study was to report the incidence, characteristics, and prognosis of CASs related to atrial fibrillation (AF) ablation procedures.Methods and Results:The AF ablation records of 22,232 patients treated in 15 Japanese hospitals were reviewed. CASs associated with AF ablation occurred in 42 of 22,232 patients (0.19%). CASs occurred during ablation energy applications in 21 patients (50%). CASs also occurred before ablation in 9 patients (21%) and after ablation in 12 patients (29%). The initial change in the electrocardiogram was ST-segment elevation in the inferior leads in 33 patients (79%). Emergency coronary angiography revealed coronary artery stenosis and occlusions, which were relieved by nitrate administration. No air bubbles were observed. A comparison of the incidence of CASs during pulmonary vein isolation between the different ablation energy sources revealed a significantly higher incidence with cryoballoon ablation (11/3,288; 0.34%) than with radiofrequency catheter, hot balloon, or laser balloon ablation (8/18,596 [0.04%], 0/237 [0%], and 0/111 [0%], respectively; P<0.001). CASs most often occurred during ablation of the left superior pulmonary vein. All patients recovered without sequelae. CONCLUSIONS: CASs related to AF ablation are rare, but should be considered as a dangerous complication that can occur anytime during the periprocedural period.

Open-Label Randomized Trial Comparing Oral Anticoagulation With and Without Single Antiplatelet Therapy in Patients With Atrial Fibrillation and Stable Coronary Artery Disease Beyond 1 Year After Coronary Stent Implantation.

BACKGROUND: Despite recommendations in the guidelines and consensus documents, there has been no randomized controlled trial evaluating oral anticoagulation (OAC) alone without antiplatelet therapy (APT) in patients with atrial fibrillation and stable coronary artery disease beyond 1 year after coronary stenting. METHODS: This study was a prospective, multicenter, open-label, noninferiority trial comparing OAC alone to combined OAC and single APT among patients with atrial fibrillation beyond 1 year after stenting in a 1:1 randomization fashion. The primary end point was a composite of all-cause death, myocardial infarction, stroke, or systemic embolism. The major secondary end point was a composite of the primary end point or major bleeding according to the International Society on Thrombosis and Haemostasis classification. Although the trial was designed to enroll 2000 patients during 12 months, enrollment was prematurely terminated after enrolling 696 patients in 38 months. RESULTS: Mean age was 75.0±7.6 years, and 85.2% of patients were men. OAC was warfarin in 75.2% and direct oral anticoagulants in 24.8% of patients. The mean CHADS2 score was 2.5±1.2. During a median follow-up interval of 2.5 years, the primary end point occurred in 54 patients (15.7%) in the OAC-alone group and in 47 patients (13.6%) in the combined OAC and APT group (hazard ratio, 1.16; 95% CI, 0.79-1.72; P=0.20 for noninferiority, P=0.45 for superiority). The major secondary end point occurred in 67 patients (19.5%) in the OAC-alone group and in 67 patients (19.4%) in the combined OAC and APT group (hazard ratio, 0.99; 95% CI, 0.71-1.39; P=0.016 for noninferiority, P=0.96 for superiority). Myocardial infarction occurred in 8 (2.3%) and 4 (1.2%) patients, whereas stroke or systemic embolism occurred in 13 (3.8%) and 19 (5.5%) patients, respectively. Major bleeding occurred in 27 (7.8%) and 36 (10.4%) patients, respectively. CONCLUSIONS: This randomized trial did not establish noninferiority of OAC alone to combined OAC and APT in patients with atrial fibrillation and stable coronary artery disease beyond 1 year after stenting. Because patient enrollment was prematurely terminated, the study was underpowered and inconclusive. Future larger studies are required to establish the optimal antithrombotic regimen in this population. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01962545.

Comparison of dragging ablation and point-by-point ablation with a laser balloon on linear lesion formation.

INTRODUCTION: Lesion size and continuity in dragging laser balloon (LB) ablation, which may enable fast and durable pulmonary vein isolation for atrial fibrillation, are unknown. We evaluated the differences in size and continuity of linear lesions formed by dragging ablation and conventional point-by-point ablation using an LB in vitro model. METHODS AND RESULTS: Chicken muscles were cauterized using the first-generation LB in dragging and point-by-point fashion. Dragging ablation was manually performed with different dragging speeds (0.5-2°/s) using an overlap ratio of the beginning and last site during one application at 12 W/20 s and 8.5 W/30 s. Point-by-point ablation was performed with 25% and 50% overlap ratios at six energy settings (5.5 W/30 s to 12 W/20 s). Lesion depth, width, and continuity were compared. Lesion continuity was assessed by the surface and deep visible gap degree categorized from 1 (perfect) to 3 (poor). Twenty lesions were evaluated for each ablation protocol. Lesion depth and width in dragging ablation at high power (12 W) were comparable with most measurements in point-by-point ablation. Lesion depth and width were smaller at faster-dragging speed and lower power (8.5 W) in dragging ablation. The surface visible gap degree was better in dragging ablation at all dragging speeds than a 25% overlapped point-by-point ablation (p < .001). CONCLUSION: Dragging LB ablation at high power provides deep and continuous linear lesion formation comparable with that of point-by-point LB ablation. However, lesion depth and width depending on the dragging speed and power.

Sex differences in atrial fibrillation ablation outcomes: insights from a large-scale multicentre registry.

AIM: The impact of sex differences on the clinical outcomes of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) is controversial. We investigated the sex differences regarding the efficacy and clinical outcomes of RFCA of AF. METHODS AND RESULTS: We conducted a large-scale, prospective, multicentre, observational study (Kansai Plus Atrial Fibrillation Registry). We enrolled 5010 consecutive patients who underwent an initial RFCA of AF at 26 centres (64 ± 10 years; non-paroxysmal AF, 35.7%). The median follow-up duration was 2.9 years. Female patients (n = 1369, 27.3%) were older (female vs. male, 68 ± 9 vs. 63 ± 11 years, P < 0.0001) with a lower prevalence of non-paroxysmal AF (27.1% vs. 38.9%, P < 0.0001). Fewer females experienced time-dependent pulmonary vein (PV) reconnections and more females received a non-PV foci ablation than males in the index RFCA. The 3-year cumulative incidence of AF recurrences in the multivariate analysis after single procedures was significantly higher in females than males (43.3% vs. 39.0%, log rank P = 0.0046). Females remained an independent predictor of AF recurrence (hazard ratio 1.24; 95% confidence interval 1.12-1.38, P < 0.0001). The AF recurrence rates after multiple procedures were also higher in females, but fewer females experienced PV reconnections during second sessions. More females experienced de novo pacemaker implantations during the long-term follow-up. Females were associated with a higher risk of heart failure hospitalizations and major bleeding after RFCA in the multivariate analysis. CONCLUSIONS: Females experienced more frequent AF recurrences probably due to non-PV arrhythmogenicity and de novo pacemaker implantations than males during the long-term follow-up after RFCA of AF.

Efficacy of Antiarrhythmic Drugs Short-Term Use After Catheter Ablation for Atrial Fibrillation (EAST-AF) trial.

AIMS: Substantial portion of early arrhythmia recurrence after catheter ablation for atrial fibrillation (AF) is considered to be due to irritability in left atrium (LA) from the ablation procedure. We sought to evaluate whether 90-day use of antiarrhythmic drug (AAD) following AF ablation could reduce the incidence of early arrhythmia recurrence and thereby promote reverse remodelling of LA, leading to improved long-term clinical outcomes. METHODS AND RESULTS: A total of 2038 patients who had undergone radiofrequency catheter ablation for paroxysmal, persistent, or long-lasting AF were randomly assigned to either 90-day use of Vaughan Williams class I or III AAD (1016 patients) or control (1022 patients) group. The primary endpoint was recurrent atrial tachyarrhythmias lasting for >30 s or those requiring repeat ablation, hospital admission, or usage of class I or III AAD at 1 year, following the treatment period of 90 days post ablation. Patients assigned to AAD were associated with significantly higher event-free rate from recurrent atrial tachyarrhythmias when compared with the control group during the treatment period of 90 days [59.0 and 52.1%, respectively; adjusted hazard ratio (HR) 0.84; 95% confidence interval (CI) 0.73-0.96; P = 0.01]. However, there was no significant difference in the 1-year event-free rates from the primary endpoint between the groups (69.5 and 67.8%, respectively; adjusted HR 0.93; 95% CI 0.79-1.09; P = 0.38). CONCLUSION: Short-term use of AAD for 90 days following AF ablation reduced the incidence of recurrent atrial tachyarrhythmias during the treatment period, but it did not lead to improved clinical outcomes at the later phase.

Adenosine triphosphate-guided pulmonary vein isolation for atrial fibrillation: the UNmasking Dormant Electrical Reconduction by Adenosine TriPhosphate (UNDER-ATP) trial.

AIMS: Most of recurrent atrial tachyarrhythmias after pulmonary vein isolation (PVI) for atrial fibrillation (AF) are due to reconnection of PVs. The aim of the present study was to evaluate whether elimination of adenosine triphosphate (ATP)-induced dormant PV conduction by additional energy applications during the first ablation procedure could reduce the incidence of recurrent atrial tachyarrhythmias. METHODS AND RESULTS: We randomly assigned 2113 patients with paroxysmal, persistent, or long-lasting AF to either ATP-guided PVI (1112 patients) or conventional PVI (1001 patients). The primary endpoint was recurrent atrial tachyarrhythmias lasting for >30 s or those requiring repeat ablation, hospital admission, or usage of Vaughan Williams class I or III antiarrhythmic drugs at 1 year with the blanking period of 90 days post ablation. Among patients assigned to ATP-guided PVI, 0.4 mg/kg body weight of ATP provoked dormant PV conduction in 307 patients (27.6%). Additional radiofrequency energy applications successfully eliminated dormant conduction in 302 patients (98.4%). At 1 year, 68.7% of patients in the ATP-guided PVI group and 67.1% of patients in the conventional PVI group were free from the primary endpoint, with no significant difference (adjusted hazard ratio [HR] 0.89; 95% confidence interval [CI] 0.74-1.09; P = 0.25). The results were consistent across all the prespecified subgroups. Also, there was no significant difference in the 1-year event-free rates from repeat ablation for any atrial tachyarrhythmia between the groups (adjusted HR 0.83; 95% CI 0.65-1.08; P = 0.16). CONCLUSION: In the catheter ablation for AF, we found no significant reduction in the 1-year incidence of recurrent atrial tachyarrhythmias by ATP-guided PVI compared with conventional PVI.

Late re-conduction sites in the second session after pulmonary vein isolation using adenosine provocation for atrial fibrillation.

AIMS: Intravenous adenosine triphosphate (ATP) administration could reveal dormant conduction (DC) gaps on the ablation line of a pulmonary vein isolation (PVI). We compared the ATP-provoked DC sites in the initial PVI with the PV re-conduction sites in the second session in patients with paroxysmal atrial fibrillation (AF). METHODS AND RESULTS: We conducted a multicenter, observational study from a prospective registry undergoing AF ablation. A total of 110 consecutive drug-refractory paroxysmal AF patients were enroled in this study. Dormant conduction was detected by an ATP provocation of up to 40 mg during a continuous isoproterenol infusion (0.5-2 µg/min). The DC sites at each of the right and left PVs were precisely determined by using double spiral catheters under the guidance of a three-dimensional constructed anatomical mapping system. In the initial session, DC was observed in 35 patients (31.8%, 1.3 gaps/patient), and the sites of the DC were commonly observed in the carina region (43.5%). Atrial fibrillation recurrence was confirmed in 33 patients (30.0%) during follow-up (27.1 months), and a second session was performed in 24 of 33 patients (70.6%). In the second session, the re-conduction sites were also commonly observed in the carina region (59.5%). CONCLUSION: The carina region was still a dominant re-conduction site even after the elimination of any ATP-provoked DC in the index procedure.

The impact of haemodialysis on the outcomes of catheter ablation in patients with paroxysmal atrial fibrillation.

AIMS: The outcomes of catheter ablation (CA) in patients with paroxysmal atrial fibrillation (PAF) who are undergoing haemodialysis (HD) have not been fully elucidated. This study aimed to determine the impact of HD on CA outcome in these patients. METHODS AND RESULTS: We examined 1364 consecutive PAF patients (mean age, 61 ± 10 years) who underwent CA, including 32 (2.3%) patients undergoing HD. The patients undergoing HD had a significantly lower body mass index (P < 0.0001), higher CHADS2 score (P = 0.006), and higher prevalence of structural heart disease (P < 0.0001), hypertension (P = 0.002), and congestive heart failure (P = 0.02). Echocardiography indicated a larger left atrial diameter (P < 0.0001) and left ventricular diameter (P = 0.0002) in the HD patients. Haemodialysis was a significant predictor of AF recurrence (hazard ratio 2.56; 95% confidence interval 1.56-4.03; P = 0.0004) in the overall population. Sinus rhythm maintenance rates in the HD patients at 1, 3, and 5 years were 42.3, 37.6, and 19.7%, respectively, after the first procedure, and 64.7, 54.9, and 47.1%, respectively, after the final procedure (median, 2; range, 1-2 procedures); these rates were significantly lower than those in the non-HD patients (P < 0.0001). The 5-year survival rate was 78.1% in the HD patients. CONCLUSION: Haemodialysis was significantly associated with AF recurrence after CA for PAF. However, an ∼50% success rate for sinus rhythm maintenance without antiarrhythmic drug therapy in HD patients suggested that CA could be an option for the treatment of AF.

Association of HFA-PEFF score with clinical outcomes after catheter ablation for atrial fibrillation.

BACKGROUND: The Heart Failure Association Pretest assessment, echocardiography and natriuretic peptide, functional testing and final aetiology (HFA-PEFF) score has been developed for diagnosing heart failure with preserved ejection fraction (HFpEF), which is frequently associated with atrial fibrillation (AF). We aimed to investigate whether preprocedural HFA-PEFF score could be used to predict clinical outcomes in patients with AF who underwent catheter ablation (CA). METHODS: Overall, 1679 patients with AF who underwent primary CA (71±10 years, 1218 males (72.5%), median follow-up duration 3.3 years) from July 2011 to December 2019 were included in this retrospective study. HFpEF was defined as an HFA-PEFF score ≥5. The primary study outcome was 5-year major adverse cardiovascular and cerebrovascular events (MACCE), which is a composite of all-cause death, hospitalisation for heart failure (HF) and hospitalisation for stroke. RESULTS: The prevalence of HFpEF was 32.3%, but only 7.7% were diagnosed with HF at the time of CHADS2 scoring. Five-year MACCE occurred in 77 patients (4.6%). The cumulative 5-year incidence of MACCE was significantly higher in the HFpEF group than in the non-HFpEF group (11.2% vs 4.8% at 5 years, p<0.001). In the multivariable analysis, HFpEF by the HFA-PEFF score was associated with MACCE (adjusted HR 1.65, 95% CI 1.02 to 2.65, p=0.041). CONCLUSIONS: Early detection of HFpEF using the HFA-PEFF score may have clinical applications in guiding therapeutic decision-making and improving prognosis by preventing HF and stroke in patients with AF undergoing CA.

Characteristics of two different cryoballoon systems for treatment of paroxysmal atrial fibrillation: study protocol for a multicenter randomized controlled trial (CONTRAST-CRYO Trial).

BACKGROUND: Single-shot pulmonary vein isolation (PVI) utilizing cryothermal energy is an effective and safe treatment for atrial fibrillation (AF) patients. A novel cryoballoon system, POLARx™, has been recently introduced. The aim of this study was to compare the efficacy, safety, and biophysical parameters of PVI between the novel cryoballoon system, POLARx™, and the standard cryoballoon system, Arctic Front Advance Pro™ (AFA-Pro), in patients with paroxysmal AF. METHODS: The CONTRAST-CRYO trial is a prospective, multicenter, open-label, randomized controlled study performed at seven large cardiac centers. This study was approved by the central ethics committee or the local ethics committee of each participating hospital and has been registered at UMIN Clinical Trials Registry (UMIN000049948). The trial will assign 200 patients with paroxysmal AF undergoing PVI to POLARx™ and AFA-Pro in a 1:1 randomization. The primary endpoint is the one-shot acute success rate of the right inferior pulmonary vein. Second endpoints include freedom from documented atrial fibrillation, atrial flutter, or atrial tachycardia without antiarrhythmic drugs at 12 months after the procedure, freedom from re-do procedures, the incidence of procedure-related adverse events, freezing duration, and the biophysical parameters during applications for each PV, total procedure and fluoroscopy time, and PVI durability during re-do procedures. CONCLUSION: The CONTRAST-CRYO trial is a prospective, multicenter, randomized study designed to elucidate the difference in the efficacy, safety, and biophysical parameters between POLARx™ and AFA-Pro in paroxysmal AF patients undergoing PVI. The findings from this trial may provide a valuable indication for selecting the optimal cryoballoon system. CLINICAL TRIAL REGISTRATION:  UMIN000049948.

A randomized controlled trial of the size-adjustable cryoballoon vs conventional cryoballoon for paroxysmal atrial fibrillation: The CONTRAST-CRYO II trial rationale and design.

Background: Pulmonary vein isolation (PVI) with cryoballoon technology is a well-established therapy for treatment of atrial fibrillation (AF). Recently, a size-adjustable cryoballoon (POLARxTM FIT) that enables delivery in a standard 28-mm or an expanded 31-mm size was introduced. Objective: The purpose of this study was to perform a randomized clinical trial to evaluate the safety and efficacy of this novel cryoballoon compared to the conventional cryoballoon. Methods: The CONTRAST-CRYO II trial is a multicenter, prospective, open-label, randomized controlled trial in which 214 patients with paroxysmal AF will be randomized 1:1 to cryoballoon ablation with either a conventional cryoballoon (Arctic Front AdvanceTM Pro) or a size-adjustable cryoballoon (POLARx FIT). The study was approved by the Institutional Review Boards at all investigational sites and has been registered in the UMIN Clinical Trials Registry (UMIN000052500). Results: The primary endpoint of this study will be the incidence of phrenic nerve injury. Secondary endpoints include procedural success, chronic success through 12 months, procedure-related adverse events, biophysiological parameters during applications for each pulmonary vein (PV), total procedural and fluoroscopy times, level of PVI and isolation area, and probability of non-PV foci initiating AF. Conclusion: The CONTRAST-CRYO II trial is a multicenter, prospective, randomized controlled trial designed to assess the safety and efficacy of the POLARx FIT vs the Arctic Front Advance Pro. The findings from this trial will provide additional utility data on the efficacy of the size-adjustable cryoballoon for isolating PVs in patients with paroxysmal AF.

Risk stratification and prognosis prediction using cardiac biomarkers in COVID-19: a single-centre retrospective cohort study.

OBJECTIVE: There is a need for a robust tool to stratify the patient's risk with COVID-19. We assessed the prognostic values of cardiac biomarkers for COVID-19 patients. METHODS: This is a single-centre retrospective cohort study. Consecutive laboratory-confirmed COVID-19 patients admitted to the Kobe City Medical Center General Hospital from July 2020 to September 2021 were included. We obtained cardiac biomarker values from electronic health records and institutional blood banks. We stratified patients with cardiac biomarkers as high-sensitive troponin I (hsTnI), N-terminal pro-B-type natriuretic peptide (NT-proBNP), creatine kinase (CK) and CK myocardial band (CK-MB), using the clinically relevant thresholds. Prespecified primary outcome measure was all-cause death. RESULTS: A total of 917 patients were included. hsTnI, NT-proBNP, CK and CK-MB were associated with the significantly higher cumulative 30-day incidence of all-cause death (hsTnI: <5.0 ng/L group; 4.3%, 5.0 ng/L-99%ile upper reference limit (URL) group; 8.8% and ≥99% ile URL group; 25.2%, p<0.001. NT-proBNP: <125 pg/mL group; 5.3%, 125-900 pg/mL group; 10.5% and ≥900 pg/mL group; 31.9%, p<0.001. CK: