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.

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.

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.

Consecutive electrocardiographic changes during percutaneous coronary intervention for acute coronary syndrome with high-grade atrioventricular block: a case report.

BACKGROUND: Acute coronary syndrome (ACS) with high-grade atrioventricular block (HAVB) still has a poor mortality risk, even in the current percutaneous coronary intervention (PCI) era. However, early PCI for ACS with HAVB is associated with improved in-hospital survival and a 6-month survival similar to that of ACS without HAVB. CASE PRESENTATION: A 70-year-old man was admitted to our hospital for ACS with HAVB. ECG showed complete AV block, complete right bundle branch block (CRBBB), and left axis deviation. Cardiac enzymes were elevated. He underwent temporary pacemaker insertion and coronary angiography, which showed severe stenosis of the proximal right coronary artery (RCA), 99% stenosis of the distal RCA with Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow, and total occlusion of the proximal left anterior descending artery (LAD). We performed primary PCI in both the RCA and LAD, which resulted in TIMI grade 3 flow in both. After PCI, the HAVB recovered to normal sinus rhythm with CRBBB; a normal QRS interval returned within three days. The patient was discharged from the hospital without complications. CONCLUSION: In this case of ACS with HAVB, early intensive coronary artery reperfusion resulted in long-term patient survival. The blood supply to the AV node and bilateral bundle branches is complex. Multivessel ischemia may compromise both primary and collateral blood flows to the AV node and septum, resulting in severe conduction impairment. Clinicians performing PCI should be aware of this anatomy and physiology.

The potential hazard of drug-eluting stent-induced coronary vasospasm causing subacute stent thrombosis: a case report.

BACKGROUND: Drug-eluting stent (DES) -induced coronary vasospasm is a well known phenomenon after stent implantation; however, the extent of this risk is still unknown. We report a case in which DES-induced severe coronary vasospasm was clinically suspected as a cause of subacute stent thrombosis (ST). CASE PRESENTATION: A 67-year-old man came to our hospital due to chest pain with mild exercise. He was diagnosed with effort angina by coronary angiography and underwent DES implantation in the mid-left ascending artery (LAD) after the administration of dual anti-platelet therapy. The procedure was uneventful, but his symptoms changed from effort angina to rest angina after stenting. Five days after the procedure, subacute ST occurred, requiring aspiration thrombectomy and balloon angioplasty. Thereafter, he continued to report early morning chest discomfort. We performed a spasm provocation test to evaluate the coronary vasomotor response; it revealed severe stent-edge spasm in the left main trunk to the LAD, except for the stented lesion, and total occlusion of the left circumflex artery. CONCLUSIONS: To our knowledge, the present case is the first report describing in-stent thrombosis secondary to stent-edge spasm. This case describes the potential hazard of DES-induced coronary vasospasm. Although there are several overlapping risk factors for ST development, we consider that stent-edge spasm also plays an important role in ST development. Therefore, we should monitor new-onset rest angina after stent implantation and carefully assess DES-induced coronary vasospasm.

Acute myocardial infarction with "wrap around" right coronary artery mimicking Takotsubo cardiomyopathy: a case report.

BACKGROUND: Takotsubo cardiomyopathy (TC) is a cardiomyopathy that shows distinctive clinical conditions first described more than 20 years ago. Because clinical features of TC mimic those of anterior acute myocardial infarction (AMI), the differential diagnosis is important in selecting the appropriate treatment strategy in the acute phase. But it was difficult to differentiate those two diseases because the TC-like findings; such as the electrocardiogram (ECG) changes and left ventricular wall motion abnormality can occur in AMI especially with the anatomical variance of the coronary artery. CASE PRESENTATION: A 63-year-old man was admitted due to sudden onset of chest pain and was in a cardiogenic shock state. His ECG showed ST-segment elevation in precordial (V2-6) and inferior leads (II, III, and aVF) and ST-segment depression in lead aVR. Blood biochemistry showed that cardiac enzymes were not elevated. Ultrasonic cardiography showed that the left ventricular apical level was akinetic, papillary muscle level was severely hypokinetic, and basal level was hyperkinetic, mimicking TC. However, coronary angiogram showed total occlusion of his right coronary artery wrapping around the cardiac apex. Successful percutaneous coronary intervention reversed his critical status. CONCLUSION: To our knowledge, the present case is the first report described AMI with wrap-around RCA, mimicking TC. Although TC is increasingly recognized as a true but relatively infrequent clinical entity, it is still important to carefully rule out obstructive coronary artery disease.

Atrial Fibrillation Ablation Outcomes and Heart Failure (from the Kansai Plus Atrial Fibrillation Registry).

The impact of rhythm outcomes on heart failure (HF) hospitalizations remains unknown after radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF). We sought to elucidate whether AF recurrence was associated with HF hospitalizations after AF RFCA. We conducted a large-scale, prospective, multicenter, observational study (Kansai Plus Atrial Fibrillation Registry), enrolling 5,010 consecutive patients (age 64 ± 10 years, 27.3% female, and 35.7% nonparoxysmal AF) who underwent an initial AF RFCA at 26 centers. The median follow-up duration was 2.9 years. The cumulative 3-year incidence of HF hospitalizations after the initial RFCA was 1.84% (0.69%/year). Hospitalized patients with HF were older with a higher prevalence of nonparoxysmal AF, renal dysfunction, diabetes, and underlying heart disease pre-RFCA. HF hospitalizations occurred more often in patients with than without recurrences (3.27 vs 0.84%, log-rank p <0.0001). After adjusting for confounders using a Cox model, AF recurrence remained an independent predictor of HF hospitalizations (hazard ratio [HR] 2.84, 95% confidence interval [CI] 1.80 to 4.47, p <0.0001). AF recurrence was a distinct HF hospitalization risk in patients with a left ventricular ejection fraction ≥50% (HR 4.54, 95% CI 2.38 to 8.65, p <0.0001) but not <50% (HR 1.31, 95% CI 0.65 to 2.62, p = 0.45), with significant interactions. Furthermore, patients with AF recurrences within 1 year had a greater HF hospitalization risk after 1 year (1.61% vs 0.79%, log-rank p = 0.019). In conclusion, AF recurrence after RFCA was independently associated with HF hospitalizations.

The potential hazard of a non-slip element balloon causing distal longitudinal stent deformation: the first clinical experience and in vitro assessment.

BACKGROUND: A new complication, longitudinal stent deformation (LSD), is increasingly reported with recent intracoronary stent designs. There have been experiences of unusual cases of distal LSD caused by entrapment of a Lacrosse® non-slip element (NSE) balloon (Goodman Co., Ltd., Nagoya, Japan), which has three flexible nylon elements to prevent slippage. Accordingly, the aim of this study is to report the clinical experience of distal LSD caused by the NSE in the documented center and to investigate the incidence and mechanisms involved. METHODS: Coronary intervention cases were retrospectively reviewed using the NSE balloon in hospital between May 2014 and June 2017. In bench testing, distal LSD was reproduced in a silicon tube model to identify its mechanism. RESULTS: A total of 95 patients with 107 lesions underwent coronary interventions with NSE. Of these, 72 lesions (12 de-novo lesions and 60 in-stent restenosis) were treated using in-stent dilatation. Two distal LSD cases occurred, representing an incidence of 2.78% (2/72) among all procedures; 16.7% (2/12) of the de-novo lesions developed LSD. In vitro experimentation allowed indentification of the mechanisms involved and bailout strategies. CONCLUSIONS: This is the first study to evaluate NSE balloon catheter entrapment complicated by distal LSD in which reconstruction of the deformed stent and retrieval of the NSE could be achieved successfully. There is a potential hazard for distal LSD during post-dilatation using the NSE balloon due to its structural characteristics. Careful assessment is needed to prevent this complication.

The effectiveness of super-selective injection with anchor balloon technique for collateral channel assessment.

The careful assessment of collateral channels is important for a retrograde approach for a chronic total coronary occlusion (CTO). This case report describes a percutaneous coronary intervention for CTO of the distal right coronary artery with good collateral circulation. All visible collateral channels failed by the retrograde approach; however, the procedure was successful using the distal atrial circumflex (AC) channel. Although this distal channel was poorly visualized on standard coronary angiography, it was clearly contrasted retrogradely from the CTO exit using a super-selective injection through the proximal AC channel as the antegrade flow was obstructed by the anchor balloon. This case highlights a unique super-selective injection with anchor balloon technique for collateral channel assessment.

A type 2 ryanodine receptor variant associated with reduced Ca2+ release and short-coupled torsades de pointes ventricular arrhythmia.

BACKGROUND: Ventricular fibrillation may be caused by premature ventricular contractions (PVCs) whose coupling intervals are <300 ms, a characteristic of the short-coupled variant of torsades de pointes (scTdP). OBJECTIVE: The purpose of this study was to analyze the underlying cardiac ryanodine receptor (RyR2) variants in patients with scTdP. METHODS: Seven patients with scTdP (mean age 34 ± 12 years; 4 men and 3 women) were enrolled in this study. The RyR2 gene was screened by targeted gene sequencing methods; variant minor allele frequency was confirmed in 3 databases; and the pathogenicity was investigated in silico analysis using multiple tools. The activity of wild-type and mutant RyR2 channels was evaluated by monitoring Ca2+ signals of HEK293 cells with a [3H]ryanodine binding assay. RESULTS: The mean coupling interval of PVCs was 282 ± 13 ms. The 12-lead electrocardiogram had no specific findings except PVCs with an extremely short-coupling interval. Genetic analysis revealed 3 novel RyR2 variants and 1 polymorphism, all located in the cytoplasmic region. p.Ser4938Phe was not detected in 3 databases, and in silico analysis indicated its pathogenicity. In functional analysis, p.Ser4938Phe demonstrated loss of function and impaired RyR2 channel Ca2+ release, while 2 other variants, p.Val1024Ile and p.Ala2673Val, had mild gain-of-function effects but were similar to the polymorphism p.Asn1551Ser. CONCLUSION: We identified an RyR2 variant associated with reduced Ca2+ release and short-coupled torsades de pointes ventricular arrhythmia. The mechanisms of arrhythmogenesis remain unclear.

Clinical significance of induced left atrial macro-reentrant tachycardia after pulmonary vein isolation.

BACKGROUND: The clinical significance of induced left atrial macro-reentrant tachycardia (LA-AT) after encircling pulmonary vein isolation (EPVI) is unclear. Our objective was to determine whether induced LA-ATs are associated with the clinical recurrence of ATs. METHODS: We studied 185 consecutive patients with paroxysmal atrial fibrillation (PAF) who underwent their first EPVI with an 8-mm tip, nonirrigated catheter approach. AT was induced by atrial burst pacing after the completion of EPVI, and the atrial activation pattern was evaluated using EnSite NavX. Induced LA-ATs were ablated only in patients with clinical ATs of suspected LA origin. The factors associated with occurrence of AT after the procedure were examined. RESULTS: LA-ATs were induced in 38 patients and ablated in 5 patients. During a follow-up of 23 ± 7 months, the occurrence of AT did not differ between patients with nonablated LA-ATs (4/33, 12 %) and those without any inducible ATs (16/113, 14 %, p > 0.99). In multivariate analysis, the number of ablation points for completing EPVI was the only independent predictor of AT occurrence (odds ratio 1.07, p < 0.01). A repeat procedure was performed in 22 of 26 patients who developed AT. Nineteen patients became free from AT and AF after ablation of the conduction gaps (EPVI, n = 17; another line, n = 4), extra PV firing (n = 4), focal AT (n = 4), and induced LA-ATs (n = 3). CONCLUSIONS: In patients who had EPVI for PAF using an 8-mm tip, nonirrigated catheter, the occurrence of AT after EPVI was mainly due to conduction gaps in the ablation line or extra PV triggers. In patients with PAF, LA-ATs induced during the first procedure did not require ablation if they were not associated with clinical AT.

Verapamil-Sensitive Upper Septal Idiopathic Left Ventricular Tachycardia: Prevalence, Mechanism, and Electrophysiological Characteristics.

OBJECTIVES: This study sought to demonstrate the prevalence, mechanism, and electrocardiographic and electrophysiological characteristics of upper septal idiopathic left fascicular ventricular tachycardia (US-ILVT). BACKGROUND: ILVT is classified into left anterior and posterior types with no clear data about US-ILVT. METHODS: Among 193 ILVT patients, we identified 12 patients (6.2%; age 41 ± 22 years, 7 men) with US-ILVT. RESULTS: Of 12 patients with US-ILVT, 6 patients (50%) had previous history of radiofrequency catheter ablation for common ILVT. Sustained VT (cycle length: 349 ± 53 ms) was seen in all patients with a QRS interval slightly wider (104 ± 18 ms) than that during sinus rhythm (90 ± 19 ms). The VT exhibited an identical QRS configuration as sinus rhythm in 6 (50%) and incomplete right bundle branch block configuration in another 6. His-ventricular interval during VT was always shorter than that during sinus rhythm (27 ± 5 ms vs. 47 ± 10 ms). Purkinje potentials were activated in a reverse direction to that of common ILVT; namely, the diastolic potential (P1) was activated retrogradely but the pre-systolic potential (P2) was activated antegradely. At the left upper-middle ventricular septum, P1 potential was recorded during VT, preceding the QRS by 54 ± 20 ms. Radiofrequency catheter ablation at that site eliminated the VT with no recurrence during a 58 ± 35 months of follow-up. CONCLUSIONS: US-ILVT is an identifiable VT that shares common criteria with ILVT and has a narrow QRS interval. Some US-ILVT cases appeared after common ILVT ablation. It is a reverse type of common ILVT (orthodromic form) with baseline morphological abnormalities that might provide a potential substrate for such VT.

Histopathologic background for resistance to conventional catheter ablation of common atrial flutter.

Histopathologic examination of the cavotricuspid isthmus in which a large-tip catheter was necessary to achieve conduction block is presented. No thickened myocardium or prominent trabeculation was observed on the ablation line. A small cardiac vein extending through the isthmus across the ablation scar was detected. The remaining myocardial cells were distributed along the small cardiac vein. It is possible that the luminal blood flow of the small cardiac vein protects the surrounding atrial muscle from effective delivery of radiofrequency energy.