High prevalence and distinctive clinical features of LMNA-associated atrioventricular block in young patients.

BACKGROUND AND AIMS: Atrioventricular block (AVB) is a degenerative disease and more commonly encountered in elderly patients, but unusual and often of unknown etiology in young patients. This study aimed to investigate the potential contributions of genetic variations to AVB of unknown reasons in young patients. METHODS: We enrolled 41 patients aged <55 years with high-degree AVB of unknown etiology whose clinical and genetic data were collected. RESULTS: Genetic variants were identified in 20 (20/41, 48.8%) patients, 11 (11/20, 55%) of whom had LMNA variants including 3 pathogenic (c.961C > T, c.936+1G > T and c.646C > T), 4 likely pathogenic (c.1489-1G > C, c.265C > A, c.1609-2A > G and c.1129C > T) and 3 of uncertain significance (c.1158-3C > G, c.776A > G and c.674G > T). Compared to those without LMNA variants, patients with LMNA variants demonstrated a later age at onset of AVB (41.45 ± 9.89 years vs 32.93 ± 12.07 years, P = .043), had more prevalent family history of cardiac events (81.8% vs 16.7%, P < .000), suffered more frequently atrial (81.8% vs 10.0%, P < .000) and ventricular (72.7% vs 10.0%, P < .000) arrhythmias, and were more significantly associated with enlargement of left atrium (39.91 ± 7.83 mm vs 34.30 ± 7.54 mm, P = .043) and left ventricle (53.27 ± 8.53 mm vs 47.77 ± 6.66 mm, P = .036). CONCLUSIONS: Our findings provide insights into the genetic etiology of AVB in young patients. LMNA variants are predominant in genotype positive patients and relevant to distinctive phenotypic properties.

Current Anticoagulation Statuses among Older Chinese People with Nonvalvular Atrial Fibrillation.

Background: The reported anticoagulation rate may be overestimated among Chinese patients with atrial fibrillation (AF). Therefore, we aimed to understand the current status and time trends of anticoagulation among older people in the Chinese community. Methods: Data were obtained from the physical examination program for the elderly (aged ≥ 65 years) in Guangzhou. During 2017-2020, a total of 31,829, 58,573, 55,483, and 54,845 older people underwent annual physical examinations, respectively, where their general information, AF-related medical history, and use of oral anticoagulants (OACs) were collected for analysis. Results: From 2017 to 2020, the estimated annual prevalence of older people with nonvalvular atrial fibrillation (NVAF) in Guangzhou was 0.99%, 0.92%, 1.05%, and 1.14%, respectively. In patients with high stroke risk (CHA2DS2-VASc score ≥ 2 for males or ≥ 3 for females), the annual anticoagulation rates were 2.83%, 2.05%, 5.29%, and 5.82%, respectively. The proportion of NVAF patients prescribed non-vitamin K antagonist oral anticoagulants (NOACs) increased gradually over the same period (p = 0.004). Males (odds ratios (OR), 1.797; 95% confidence interval (CI), 1.169-2.763; p = 0.008), ages over 75 (OR, 1.858; 95% CI, 1.212-2.849; p = 0.005), low education levels (OR, 1.737; 95% CI, 1.132-2.665; p = 0.011), and lacking the ability for self-care (OR, 4.432; 95% CI, 1.067-18.418; p = 0.041) were less likely to receive OAC therapy. Conclusions: The low anticoagulation rate of older people with NVAF in the Chinese community has not significantly improved in recent years, with only 5.82% of patients with high stroke risk being prescribed OACs. Therefore, it is necessary to establish an appropriate mode of anticoagulant management to improve the current situation.

Etiologies of atrioventricular block in young patients: A single-center study in China.

BACKGROUND: Atrioventricular block (AVB) is common in the elderly and therefore considered to be a degenerative disease of the cardiac conduction system. However, there exist other etiologies contributing to AVB in young patients. This study aimed to determine the etiologies in patients aged before 60 years receiving their first pacemaker implantation for AVB in China. METHODS AND RESULTS: Medical records and diagnostic tests of AVB patients were reviewed to identify the etiologies between 2010 and 2021 at Guangdong Provincial People's Hospital. Eight hundred and twenty-six patients (median age 47 years; 47.9% males) were included. The etiologies were identified in 336 (40.7%) cases, including complications to cardiac surgery (n = 190 [23.0%]), myocarditis (n = 57 [6.9%]), myocardial infarction (n = 25 [3.0%]), complications to catheter-based interventional procedures (n = 21 [2.5%]) and others (n = 43 [5.2%]). AVB caused by myocardial infarction was more common in men (5.8% vs. 0.5%, p < .001), while women received pacing treatment earlier (48 vs. 46 years, p = .019). Men were more likely to suffer from dilated cardiomyopathy (6.6% vs. 2.1%, p = .001) and atrial fibrillation/flutter (23.0% vs. 12.8%, p < .001). The number of first pacemaker implantation increased with age especially among patients with unclear etiologies. CONCLUSION: The etiology of AVB was only determined in approximately 40% of patients receiving their first pacemaker implantation aged before 60 years. The predominance of AVB with unknown etiology and potential gender differences warrants further studies.

Comparison of strategies for catheter ablation of left posterior fascicular ventricular tachycardia.

AIMS: Traditional ablation strategies including targeting the earliest Purkinje potential (PP) during left posterior fascicular (LPF) ventricular tachycardia (VT) or linear ablation at the middle segment of LPF during sinus rhythm are commonly used for the treatment of LPF-VT. Catheter ablation for LPF-VT targeting fragmented antegrade Purkinje (FAP) potential during sinus rhythm is a novel approach. We aimed to compare safety and efficacy of different ablation strategies (FAP ablation vs. traditional ablation) for the treatment of LPF-VT. METHODS AND RESULTS: Consecutive patients with electrocardiographically documented LPF-VT referred for catheter ablation received either FAP ablation approach or traditional ablation approach. Electrophysiological characteristics, procedural complications, and long-term clinical outcome were assessed. A total of 189 consecutive patients who underwent catheter ablation for LPF-VT were included. Fragmented antegrade Purkinje ablation was attempted in 95 patients, and traditional ablation was attempted in 94 patients. Acute ablation success with elimination of LPF-VT was achieved in all patients. Left posterior fascicular block occurred in 11 of 95 (11.6%) patients in the FAP group compared with 75 of 94 (79.8%) patients in the traditional group (P < 0.001). Fragmented antegrade Purkinje ablation was associated with significant shorter procedure time (94 ± 26 vs. 117 ± 23 min, P = 0.03) and fewer radiofrequency energy applications (4.1 ± 2.4 vs. 6.3 ± 3.5, P = 0.003) compared with the traditional group. One complete atrioventricular block and one left bundle branch block were seen in the traditional group. Over mean follow-up of 65 months, 89 (93.7%) patients in the FAP group and 81 (86.2%) patients in the traditional group remained free of recurrent VT off antiarrhythmic drugs (P = 0.157). CONCLUSION: Left posterior fascicular-ventricular tachycardia ablation utilizing FAP and traditional ablation approaches resulted in similar acute and long-term procedural outcomes. Serious His-Purkinje injury did occur infrequently during traditional ablation. The use of FAP ablation approach was associated with shorter procedure time and fewer radiofrequency energy applications, especially for non-inducible patients.

Electrophysiological characteristics and long-term outcome of substrate-based catheter ablation for left posterior fascicular ventricular tachycardia targeting fragmented antegrade Purkinje potentials during sinus rhythm.

AIMS: The aim of this study was to investigate the electrophysiological characteristics and long-term outcome of patients undergoing substrate-based ablation of left posterior fascicular ventricular tachycardia (LPF-VT) guided by targeting of fragmented antegrade Purkinje potentials (FAPs) during sinus rhythm. METHODS AND RESULTS: This study retrospectively analysed 50 consecutive patients referred for ablation. Substrate mapping during sinus rhythm was performed to identify the FAP that was targeted by ablation. FAPs were recorded in 48 of 50 (96%) patients during sinus rhythm. The distribution of FAPs was located at the proximal segment of posterior septal left ventricle (LV) in two (4.2%) patients, middle segment in 33 (68.8%) patients, and distal segment in 13 (27.1%) patients. In 32 of 48 (66.7%) patients, the FAP displayed a continuous multicomponent fragmented electrogram, while a fragmented, split, and uncoupled electrogram was recorded in 16 (33.3%) patients. Entrainment attempts at FAP region were performed successfully in seven patients, demonstrating concealed fusion and the critical isthmus of LPF-VT. Catheter ablation targeting at the FAPs successfully terminated the LPF-VT in all 48 patients in whom they were seen. Left posterior fascicular (LPF) block occurred in four (8%) patients after ablation. During a median follow-up period of 61.2 ± 16.8 months, 47 of 50 (94%) patients remained free from recurrent LPF-VT. CONCLUSION: Ablation of LPF-VT targeting FAP during sinus rhythm results in excellent long-term clinical outcome. FAPs were commonly located at the middle segment of posterior septal LV. Region with FAPs during sinus rhythm was predictive of critical site for re-entry.

Conduction system pacing following septal myectomy: Insights into site of conduction block.

INTRODUCTION: Septal myectomy for obstructive hypertrophic cardiomyopathy (HCM) is associated with conduction block; however, the electrophysiological characteristics of conduction block have not been well characterized. The aim of study was to assess the feasibility and safety of His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) in patients with septal myectomy-associated conduction block. METHODS AND RESULTS: Patients with HCM and indications for pacing or cardiac resynchronization therapy after septal myectomy were included. Electrophysiological mapping was performed to identify the site of block. The success rates and pacing characteristics of HBP and LBBAP were also recorded. The echocardiographic data and complications were documented and tracked during follow-up. Ten patients with atrioventricular block (AVB) or left bundle branch block (LBBB) post-myectomy were included in the study. The site of block was infranodal in the nine patients with AVB. HBP failed due to the lack of distal His bundle capture (N = 7) or LBBB correction (N = 3). LBBAP was successful in nine patients and failed in one. QRS duration narrowed from 163.3 ± 16.6 ms after surgery to 123.6 ± 15.8 ms during LBBAP (p < .001). The mean depth of the leads was 13.3 ± 4.0 mm (range from 10 to 20 mm). At a mean follow-up of 5.3 ± 3.9 months, pacing parameters and left ventricular ejection fraction remained stable. CONCLUSIONS: Electrophysiological mapping revealed that the site of block was infra-Hisian and not correctable with HBP in patients with HCM post-myectomy. LBBAP appears to be a more feasible physiological strategy for these patients.

Novel Strategy for Predicting Conduction Abnormalities During Transcatheter Closure of Perimembranous Ventricular Septal Defect in Adults.

BACKGROUND: In this study we evaluated the feasibility and efficacy of predicting conduction system abnormalities under 3-dimensional (3D) electroanatomic mapping guidance during transcatheter closure of perimembranous ventricular septal defects (pmVSDs) in adults.Methods and Results:The distribution of the His-Purkinje system (HPS) close to the margins of pmVSDs in the left ventricle was identified using 3D electroanatomic mapping and near-field HPS was further confirmed by different pacing protocols. Of the 20 patients in the study, 17 (85%) were successfully treated by transcatheter intervention. The minimum distance between the margins of the pmVSD and near-field HPS, as measured by 3D electroanatomic mapping, ranged from 1.3 to 3.9 mm (mean [± SD] 2.5±0.7 mm). Five patients with a minimum distance <2 mm had a higher risk (3/5; 60%) for adverse arrhythmic events, whereas patients with a distance >2 mm were at a much lower risk (1/15; 6.7%) of procedure-related conduction block (P=0.032). No other adverse events were recorded during the follow-up period (median 30 months). CONCLUSIONS: A minimum distance between the pmVSD and near-field HPS <2 mm was associated with a relatively high risk of closure-related conduction block. 3D electroanatomic mapping may be helpful in guiding decision making for transcatheter closure and reduce the incidence of adverse arrhythmic events.

Genetic Variants on SCN5A, KCNQ1, and KCNH2 in Patients with Ventricular Arrhythmias during Acute Myocardial Infarction in a Chinese Population.

OBJECTIVE: Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide. About half of sudden deaths from AMI are mainly because of malignant ventricular arrhythmias (VA) after AMI. The sodium channel gene SCN5A and potassium channel genes KCNQ1 and KCNH2 have been widely reported to be genetic risk factors for arrhythmia including Brugada syndrome and long QT syndrome (LQTS). A few studies reported the association of SCN5A variant with ventricular tachycardia (VT)/ventricular fibrillation (VF) complicating AMI. However, little is known about the role of KCNQ1 and KCNH2 in AMI with VA (AMI_VA). This study focuses on investigating the potential variants on SCN5A, KCNQ1, and KCNH2 contributing to AMI with VA in a Chinese population. MATERIALS AND METHODS: In total, 139 patients with AMI_VA, and 337 patients with AMI only, were included. Thirty exonic sites were selected to be screened. Sanger sequencing was used to detect variants. A subsequent association study was also performed between AMI_VA and AMI. RESULTS: Twelve variants [5 on KCNH2(NM_000238.3), 3 on KCNQ1(NM_000218.2), and 4 on SCN5A(NM_198056.2)] were identified in AMI_VA patients. Only 5 (KCNH2: c.2690A>C; KCNQ1: c.1927G>A, c.1343delC; SCN5A: c.1673A>G, c.3578G>A) of them are missense variants. Two (KCNQ1: c.1343delC and SCN5A: c.3578G>A) of the missense variants were predicted to be clinically pathogenic. All these variants were further genotyped in an AMI without VA group. The association study identified a statistically significant difference in genotype frequency of KCNH2: c.1539C>T and KCNH2: c.1467C>T between the AMI and AMI_VA groups. Moreover, 2 rare variants (KCNQ1: c.1944C>T and SCN5A: c.3621C>T) showed an elevated allelic frequency (more than 1.5-fold) in the AMI_VA group when compared to the AMI group. CONCLUSION: Twelve variants (predicting from benign/VUS to pathogenic) were identified on KCNH2, KCNQ1, and SCN5A in patients with AMI_VA. Genotype frequency comparison between AMI_VA and AMI identified 2 significant common variants on KCNH2. Meanwhile, the allelic frequency of 2 rare variants on KCNQ1 and SCN5A, respectively, were identified to be enriched in AMI_VA, although there was no statistical significance. The present study suggests that the ion-channel genes KCNH2, KCNQ1, and SCN5A may contribute to the pathogenesis of VA during AMI.

Novel role of the clustered miR-23b-3p and miR-27b-3p in enhanced expression of fibrosis-associated genes by targeting TGFBR3 in atrial fibroblasts.

Atrial fibrillation (AF) is the most common type of arrhythmia in cardiovascular diseases. Atrial fibrosis is an important pathophysiological contributor to AF. This study aimed to investigate the role of the clustered miR-23b-3p and miR-27b-3p in atrial fibrosis. Human atrial fibroblasts (HAFs) were isolated from atrial appendage tissue of patients with sinus rhythm. A cell model of atrial fibrosis was achieved in Ang-II-induced HAFs. Cell proliferation and migration were detected. We found that miR-23b-3p and miR-27b-3p were markedly increased in atrial appendage tissues of AF patients and in Ang-II-treated HAFs. Overexpression of miR-23b-3p and miR-27b-3p enhanced the expression of collagen, type I, alpha 1 (COL1A1), COL3A1 and ACTA2 in HAFs without significant effects on their proliferation and migration. Luciferase assay showed that miR-23b-3p and miR-27b-3p targeted two different sites in 3'-UTR of transforming growth factor (TGF)-ß1 receptor 3 (TGFBR3) respectively. Consistently, TGFBR3 siRNA could increase fibrosis-related genes expression, along with the Smad1 inactivation and Smad3 activation in HAFs. Additionally, overexpression of TGFBR3 could alleviate the increase of COL1A1, COL3A1 and ACTA2 in HAFs after transfection with miR-23b-3p and miR-27b-3p respectively. Moreover, Smad3 was activated in HAFs in response to Ang-II treatment and inactivation of Smad3 attenuated up-regulation of miR-23b-3p and miR-27b-3p in Ang-II-treated HAFs. Taken together, these results suggest that the clustered miR-23b-3p and miR-27b-3p consistently promote atrial fibrosis by targeting TGFBR3 to activate Smad3 signalling in HAFs, suggesting that miR-23b-3p and miR-27b-3p are potential therapeutic targets for atrial fibrosis.

Invasive therapies for patients with concomitant heart failure and atrial fibrillation.

Atrial fibrillation (AF) and heart failure (HF) are two clinical entities that can present either separately or concurrently. One entity can lead to the other and vice versa as AF can not only be the underlying etiology of HF but also exacerbate HF due to other cardiac diseases. Besides prevention of cerebral and systemic embolism and elimination of AF-related symptoms, restoration of sinus rhythm for AF patients helps to avoid or reduce HF, irrespective of their underlying heart disease. Successful rates of medical therapy for AF are low in persistent AF, and much lower in long-standing AF, while invasive procedures for AF yield promising results. In this review, the authors evaluate the value of invasive therapies for HF patients complicated with non-valvular AF. We examine this clinical problem by interpreting the relationships between these two entities: the mechanism of tachycardia-induced cardiomyopathy (TIC), past opinions about rhythm control and rate control of AF, discrimination of HF-related AF and AF-induced HF, how to identify the AF patients that could benefit from invasive therapies, and how to select invasive therapies for different AF patients and peri-operative treatments.

Association between elevated blood glucose level and non-valvular atrial fibrillation: a report from the Guangzhou heart study.

BACKGROUND: To estimate the prevalence of elevated blood glucose level (EBG, including type 2 diabetes mellitus and impaired fasting glucose), and its association with non-valvular atrial fibrillation (NVAF) in Guangzhou, China. METHODS: The population-based follow-up Guangzhou Heart Study collected baseline data from July 2015 to August 2017 among 12,013 permanent residents aged > 35 from 4 Guangzhou districts. Two streets (Dadong and Baiyun) in the Yuexiu District, and one street (Xiaoguwei) and two towns (Xinzao and Nancun) in the Panyu District were chosen as representative of urban and rural areas, respectively. Each participant completed a comprehensive questionnaire, and underwent physical examination, blood sample collection for laboratory testing, electrocardiography, and other evaluations. Multivariable logistic regression analyses were used to estimate the independent association between hyperglycemia and NVAF prevalence. RESULTS: The prevalence of EBG in overall study population was 29.9%. Compared with residents without EBG, the odds ratio (OR) for AF among residents with EBG was significantly higher (1.94, 95% confidence interval [CI]: 1.40-2.70, P <  0.001), even after multivariate adjustment for metabolic abnormalities (OR = 1.60, 95% CI: 1.14-2.25, P = 0.007), and driven by women (OR = 1.80, 95% CI: 1.12-2.91, P = 0.016). CONCLUSIONS: In Guangzhou, China, prevalence of EBG is high among residents aged > 35 years and associated with a multivariate adjusted increase in prevalence of NVAF overall and in women.

Mid-term outcomes of concomitant left atrial appendage closure and catheter ablation for non-valvular atrial fibrillation: a multicenter registry.

To investigate the safety and midterm outcome of concomitant left atrial appendage (LAA) closure and catheter ablation (CA) as a one-stage hybrid procedure for non-valvular atrial fibrillation (AF) in a multicenter registry. A total of 50 consecutive patients with symptomatic drug-resistant non-valvular AF with CHA2DS2-VASc score ≥ 2 and contraindications for antithrombotic therapy were included in the prospectively established LAA closure registry, and underwent concomitant LAA closure (48 for WATCHMAN and 2 for ACP) and CA procedure (40 for radiofrequency and 10 for cryoballoon CA). Two cardiac tamponades, one peripheral vascular complications and one mild air embolism were observed during perioperative period. After mean follow-up of 20.2 ± 11.5 months, 18 (36%) patients presented with atrial arrhythmia relapse and 45 (91.8%) patients presented with complete sealing; furthermore, there were two transient ischemic attacks and one ischemic stroke under an off-oral anticoagulant situation, respectively. Concomitant CA and LAA closure as a one-stage hybrid procedure might be feasible and potentially decrease costs in patients with symptomatic non-valvular AF with high stroke risk and contraindication to antithrombotic treatment, and as safe as LAA closure procedure only during the perioperative period. However, it was necessary to further validate the mid-term safety.

Characteristics, Mechanism and Long-Term Ablation Outcome of Atrial Tachycardias After Mitral Valvular Surgery and Concomitant Cox-MAZE IV Procedure.

The incidence of atrial tachycardia (AT) after rheumatic mitral valvular (RMV) surgery has been well described. However, there have been few reports on the characteristics, mechanism, and long-term ablation outcome of ATs after RMV surgery and concomitant Cox-MAZE IV procedure.The present study reviewed consecutive patients who underwent AT ablation between May 2008 and July 2013. All patients were refractory to antiarrhythmic drugs (AADs) and had a history of RMV surgery and Cox-MAZE IV procedure. A total of 34 patients underwent AT ablation after RMV surgery and concomitant Cox-MAZE IV procedure, and presented 57 mappable and 2 unmappable ATs. The 57 mappable ATs included 14 focal-ATs and 43 reentry-ATs. Ten of the 14 focal-like ATs were located at the pulmonary vein (PV) antrum and border of a box lesion. Of the 43 reentry-ATs, 16 were marco-reentrant around the mitral annulus (MA) and 16 around the tricuspid annulus. There were 41 atypical ATs (non-cavotricuspid isthmus related) including 16 ATs related to the box lesion and 21 ATs related to other Cox-MAZE IV lesions. The AT were successfully terminated in 33 (97.1%) patients. After mean follow-up of 46.9 ± 15.7 months, 25 (73.5%) patients maintained sinus rhythm without AADs after a single procedure and 28 (82.4%) patients after repeated procedures.The recurrent ATs after RMV surgery and concomitant Cox-MAZE IV were mainly reentry mechanism, and largely related to LA. An incomplete lesion or re-conductive gaps in a prior lesion might be the predominant mechanisms for these ATs. Catheter-based mapping and ablation of these ATs seems to be effective and safe during a long-term follow-up.

Association of Thromboembolic Risk Score with Left Atrial Thrombus and Spontaneous Echocardiographic Contrast in Non-Anticoagulated Nonvalvular Atrial Fibrillation Patients.

OBJECTIVES: The aim of the study was to examine the association of CHADS2/CHA2DS2-VASc scores with left atrial thrombus (LAT) and spontaneous echocardiographic contrast (SEC) in non-anticoagulated nonvalvular atrial fibrillation (NVAF) spontaneous patients, and to develop a new scoring system for LAT/SEC prediction. METHODS: Consecutive non-anticoagulated NVAF patients with or without LAT/SEC by transesophageal echocardiography were identified in the Guangdong General Hospital. RESULTS: Among 2,173 patients, the prevalence of LAT/SEC was 4.9%. Both predictive values of CHADS2 and CHA2DS2-VASc scores for the presence of LAT/SEC were low-to-moderate (receiver operating characteristic [ROC] = 0.591 and 0.608, respectively, p = 0.90). By multivariate analysis, non-paroxysmal AF, decreased left ventricular ejection fraction, and left atrial enlargement were positively associated with LAT/SEC, while CHADS2/CHA2DS2VASc scores were not. A new scoring system based on these 3 factors above significantly improved the discrimination for LAT/SEC (ROC = 0.792). CONCLUSIONS: CHADS2/CHA2DS2-VASc scores had limited value in predicting LAT/SEC; a new scoring system that combines AF type and echocardiographic parameters may better predict LAT/SEC as a surrogate for cardioembolic risk in NVAF patients.

Using the MB-LATER score for predicting arrhythmia outcome after catheter ablation for atrial fibrillation: The Guangzhou atrial fibrillation project.

INTRODUCTION: Several clinical scoring systems have been derived to predict the arrhythmia outcome of catheter ablation (CA) for atrial fibrillation (AF) but which is better is not clear. Simple clinical risk scores (that any clinician can use in the everyday clinic) can help assess the likelihood of recurrence of AF following CA and the simple MB-LATER score has recently been described. We compare the predictive ability of seven existing clinical scoring systems (HATCH, CHADS2 , CHA2 DS2 -VASc, BASE-AF2 , APPLE, CAAP-AF, and MB-LATER) in a Chinese cohort of AF patients undergoing CA. METHODS AND RESULTS: 1410 patients (mean age 57.2 ± 11.6 years; 68% male) with AF undergoing CA during 2011-2015 were enrolled in final analysis. Symptoms, 12 lead ECG and Holter ECGs were recorded before discharge, and at 1, 3, 6 months, and every 6 months thereafter to detect the arrhythmia relapse. During a mean 20.7 ± 8.8-month follow-up, recurrence occurred in 365 patients(25.9%). All tested scores were predictors of AF recurrence with areas under the curve (AUCs) of 0.58, 0.57, 0.57, 0.75, 0.74, 0.71, and 0.73 respectively (all P < 0.01). Compared to all other scores, the MB-LATER score showed improved reclassification (NRI range 30%-82.6%, P < 0.01) and discrimination indexes (IDI range 2.6%-18.6%, all P < 0.01) in predicting AF recurrence. CONCLUSION: Based on net reclassification and discrimination analysis, the MB-LATER score performed best for predicting AF recurrent postablation, in a large "all comers" Chinese cohort. This simple clinical risk score (that any clinician can use in the everyday clinic) can help assess the likelihood of recurrence of AF following catheter ablation.

Incidence and outcomes of cerebrovascular events complicating catheter ablation for atrial fibrillation.

AIMS: Cerebrovascular complications are relatively uncommon, but severe adverse events are associated with catheter ablation of atrial fibrillation (AF). This study aimed to investigate the incidence, risk factors, and hospital outcomes of cerebrovascular events complicating AF ablation. METHODS AND RESULTS: Cerebrovascular complications occurring during the procedure or hospitalization after AF ablation were assessed. Cerebrovascular events occurred in 9 of 1946 consecutive procedures (0.46%). Seven patients (0.36% per procedure) were diagnosed with ischaemic stroke and two patients (0.1% per procedure) with intracranial haemorrhage (ICH). Six events (6/9, 66.7%) occurred during the ablation and the remainders within 24 h after the ablation. Multivariable analysis revealed that previous ischaemic stroke [odds ratio (OR) 10.549; 95% confidence interval (CI) 2.551-43.625, P = 0.001] and mechanical valve replacement (OR 3.261; 95% CI 1.337-7.953, P = 0.009) were independent predictors. In a separate model, CHA2DS2-VASc score ≥3 (OR 7.992; 95% CI 2.046-31.215, P = 0.003) and mechanical valve replacement (OR 4.104; 95% CI 1.644-10.245, P = 0.002) were significantly associated with cerebrovascular complications. All patients survived to discharge except the two cases with ICH. CONCLUSION: Cerebrovascular complications related to catheter ablation of AF are relatively infrequent and typically occur early either during the procedure or within the first 24 h after AF ablation. Previous ischaemic stroke, mechanical valve replacement, and CHA2DS2-VASc score ≥3 are independent predictors of such complications. The majority of these events are ischaemic stroke with a benign clinical outcome, while ICH may correlate with poor prognosis.

Features of accessory pathways in adult Ebstein's anomaly.

AIMS: The aim of the study was to describe the complex electrophysiological features of accessory pathways (APs) in adult Ebstein's anomaly (EA). METHODS AND RESULTS: We performed a retrospective study of 17 consecutive adult EA cases with APs who underwent electrophysiological study and radiofrequency catheter ablation (RFCA) from November 2011 to May 2013. There were a total of 24 atrioventricular reentrant tachycardias (AVRTs) due to 23 APs, including 20 (87.0%) non-decremental conducting, 2 (8.7%) decremental conducting, and 1 (4.3%) nodofascicular bundle. Six (6/17 = 35.3%) patients had two APs while others had only one. Twenty-one APs (91.3%) in 15 patients were manifested and 2 APs (8.7%) in 2 patients were concealed. Six APs (26.1%) were broad, while 17 APs (73.9%) were narrow in width. Two patients suffered from duodromic tachycardias mediated by two APs. Accessory pathways were mainly located on the posterior, posteroseptal, and posterolateral tricuspid annulus (TA). Right ventriculography confirmed that all APs were located on the anatomic TA. All the patients remained free from tachycardias during 11.9 ± 6.8 months of follow-up after RFCA. For the 15 patients with manifest APs, 10 patients' electrocardiograms (ECGs) after RFCA demonstrated morphologies of right bundle branch block, while 5 patients' ECGs were normal. CONCLUSIONS: Accessory pathways in EA are predominantly right-sided, manifest and localize to the lower half of the anatomic TA. A number of APs in EA have broad widths. The incidence of multiple APs is high in these patients and RFCA is effective.

Combined approach improves the outcomes of catheter ablation of idiopathic ventricular arrhythmias originating from the vicinity of tricuspid annulus.

BACKGROUND: Ablation of idiopathic ventricular arrhythmias (VAs) originating from the vicinity of tricuspid annulus (TA) is often unsuccessful via inferior approach. We report the initial experience with catheter ablation of VAs arising from the vicinity of the TA via superior approach. METHODS: We retrospectively studied 36 patients with VAs arising from the vicinity of TA who underwent ablation via transfemoral vein approach first. If patients had a failed prior ablation or VAs recurred during follow-up, they were referred for repeat ablation via transsubclavian vein approach. RESULTS: Among 36 patients, 11 (30.6%) patients (five failed during the index procedure and six recurred during the follow-up) were assigned to perform repeat ablation via the transsubclavian vein approach. After the final procedure two patients recurred again, and success rate increased from 69.5% (25/36) to 94.4% (34/36). Amplitudes of the atrial electrograms of all successful ablation sites via the transsubclavian vein approach was <0.036 mV. CONCLUSIONS: The transsubclavian vein approach plus transfemoral vein approach improve the outcomes of catheter ablation of idiopathic VAs originating from the vicinity of TA. The transsubclavian vein approach is a feasible alternative for VAs, which has been refractory to ablation via the inferior approach.