Detection of Epicardial Connection Through Intercaval Bundle Involving Right Pulmonary Veins After Ipsilateral Circumferential Ablation by Intra-Atrial Activation Sequence Pacing From the Right Pulmonary Vein

BACKGROUND

An epicardial connection (EC) through the intercaval bundle (EC-ICB) between the right pulmonary vein (RPV) and right atrium (RA) is one of the reasons for the need for carina ablation for PV isolation and may reduce the acute and chronic success of PV isolation. We evaluated the intra-atrial activation sequence during RPV pacing after failure of ipsilateral RPV isolation and sought to identify specific conduction patterns in the presence of EC-ICB.

METHODS AND RESULTS

This study included 223 consecutive patients who underwent initial catheter ablation of atrial fibrillation. If the RPV was not isolated using circumferential ablation or reconnected during the waiting period, an exit map was created during mid-RPV carina pacing. If the earliest site on the exit map was the RA, the patient was classified into the EC-ICB group. The exit map, intra-atrial activation sequence, and RPV-high RA time were evaluated. First-pass isolation of the RPV was not achieved in 36 patients (16.1%), and 22 patients (9.9%) showed reconnection. Twelve and 28 patients were classified into the EC-ICB and non-EC-ICB groups, respectively, after excluding those with multiple ablation lesion sets or incomplete mapping. The intra-atrial activation sequence showed different patterns between the 2 groups. The RPV-high RA time was significantly shorter in the EC-ICB than in the non-EC-ICB group (69.2±15.2 versus 148.6±51.2 ms; P<0.001), and RPV-high RA time<89.0 ms was highly predictive of the existence of an EC-ICB (sensitivity, 91.7%; specificity, 89.3%).

CONCLUSIONS

An EC-ICB can be effectively detected by intra-atrial sequencing during RPV pacing, and an RPV-high RA time of <89.0 ms was highly predictive.

Preclose Versus Postclose Using Suture-Mediated Vascular Closure System for Catheter Ablation With Femoral Vein Access

BACKGROUND

Differences in the efficacy and safety between the preclose and postclose suture-mediated vascular closure systems for femoral vein access have not been adequately studied.

OBJECTIVES

This study aimed to evaluate the efficacy and safety of these 2 suturing techniques in femoral vein access.

METHODS

Patients subjected to elective catheter ablation via the femoral vein using a sheath of 8- to 13-F inner diameter (n = 282) were randomized to the preclose or postclose groups for the single-suture technique using ProGlide/ProStyle (Abbott Vascular). Duplex ultrasound was performed on days 1 and 90 after the procedure to evaluate vascular complications. The primary efficacy endpoint was rebleeding requiring recompression, and the primary safety endpoint was any major complication occurring within 90 days. The secondary efficacy endpoints included time to hemostasis and time to ambulation, and the secondary safety endpoint was any minor complication occurring within 90 days.

RESULTS

The preclose group demonstrated a significantly lower rebleeding rate (5 of 141 [3.5%] vs 15 of 141 [10.6%]; P = 0.03) and shorter time to hemostasis (254.0 ± 120.4 seconds vs 299.8 ± 208.2 seconds; P = 0.02) compared with the postclose group. Five patients in each group were lost to follow-up at 90 days. Incidence of major complications were similar in both groups (1 of 136 [0.7%]; P = 1.00), whereas minor complications were observed in 18 of 136 (13.2%) and 21 of 136 (15.4%) patients in the preclose and postclose groups, respectively, without a significant difference (P = 0.73).

CONCLUSIONS

In femoral vein access using the single-suture technique with ProGlide/ProStyle, the preclose technique presented a higher hemostasis rate than the postclose technique, without compromising safety.

Efficacy of High-Density Three-Dimensional Mapping for Verapamil-Sensitive Left Posterior Fascicular Ventricular Tachycardia in Pediatric Patients

In verapamil-sensitive left posterior fascicular ventricular tachycardia (LPF-VT), radiofrequency catheter ablation (RFA) is performed targeting mid-to-late diastolic potential (P1) and presystolic potential (P2) during tachycardia. This study included four patients who had undergone electrophysiological study (EPS) and pediatric patients with verapamil-sensitive LPF-VT who had undergone RFA using high-density three-dimensional (3D) mapping. The included patients were 11-14 years old. During EPS, right bundle branch block and superior configuration VT were induced in all patients. VT mapping was performed via the transseptal approach. P1 and P2 during VT were recorded in three of the four patients. All patients initially underwent RFA via the transseptal approach. In three patients, P1 during VT was targeted, and VT was terminated. The lesion size indices in which VT was terminated were 4.6, 4.6, and 4.7. For one patient whose P1 could not be recorded, linear ablation was performed perpendicularly in the area where P2 was recorded during VT. Among the three patients in whom VT was terminated, linear ablation was performed in two to eliminate the ventricular echo beats. In all patients, VT became uninducible in the acute phase and had not recurred 8-24 months after RFA. High-density 3D mapping with an HD Grid Mapping Catheter allows recording of P1 and P2 during VT and may improve the success rate of RFA in pediatric patients with verapamil-sensitive LPF-VT.

Prediction of atrioventricular conduction disturbance after ablation of persistent atrial fibrillation

The prevalence of atrioventricular conduction disturbance (AVCD) in patients with persistent atrial fibrillation (AF) has not yet been fully investigated. We sought to identify the predictors of AVCD in patients with AF by analyzing the relationship between pre-ablation heart rate during AF and the PR interval in sinus rhythm after ablation. We analyzed pre-ablation 24-h Holter electrocardiogram (ECG) and 12 lead ECG 12 months after ablation of 121 consecutive patients with persistent AF who underwent their first ablation procedure and maintained sinus rhythm at 12 months. AVCD was defined as a first-degree atrioventricular block (AVB), second-degree AVB, high-degree AVB, or third-degree AVB observed on ECG at 12 months after ablation. Seventeen out of 121 patients (14.0%) had AVCD at 12 months. In the group with AVCD, total heartbeat (THB) and maximum heart rate (Max HR) were significantly lower, and the prevalence of concomitant Cavo-tricuspid isthmus-dependent atrial flutter before ablation and the appearance of macro reentrant atrial tachycardia (AT) during the procedure were significantly higher than those in the group without AVCD. Multiple regression analysis revealed that maximum HR and macro reentrant AT were significant predictors of AVCD. Receiver operating characteristic curve analysis revealed that Max HR of <165.0 bpm predicts AVCD with a sensitivity of 76.47% and a specificity of 74.00%. In patients with persistent AF, low Max HR and the presence of macro reentrant AT during the ablation procedure were predictors of AVCD.

Utility of in vivo zebrafish cardiac assay to predict the functional impact of KCNQ1 variants

Background

Genetic testing for inherited arrhythmias and discriminating pathogenic from benign variants are integral for the gene-based medicine. However, the high throughput in vivo functional analysis for the rare variants of the KCNQ1 potassium channel is scarce.

Purpose

We tested the utility of the in vivo zebrafish cardiac assay for determining the pathogenicity of the KCNQ1 variants identified in patients with long QT syndrome (LQTS) and atrial fibrillation (AF).

Methods

We generated a knock-out zebrafish with CRISPR-mediated insertions or deletions of the KCNQ1 homolog in zebrafish (kcnq1+/+). To test the utility of the cardiac assay, we used five KCNQ1 variants identified in patients with LQTS or familial AF. Human wild-type or mutant KCNQ1 cRNA (Q1) was co-injected with human KCNE1 cRNA (E1) into the F3 generation embryos with homozygous deletions. We dissected the hearts from the thorax at 72 hour-post-fertilization and measured transmembrane potential in zebrafish heart using the disrupted patch technique. Action potential duration was calculated as the time interval between the peak maximum upstroke velocity and 90% of repolarization (APD90). We compared the APD90s with patients' clinical phenotype and IKs density measured by patch-clamp technique in heterologous system.

Results

The mean APD90 of embryos with kcnq1del/del was 279±48 ms, which was restored by injecting Q1 WT and E1 (159±29 ms) to that with kcnq1+/+ (167±28 ms). We tested if the mean APD90 of embryos with kcnq1del/del was restored (shortened) by injecting the KCNQ1 variants. First we tested the dominant negative variant p.S277L and the trafficking deficient variant p.T587M. Patients with these variants showed significant prolonged QT intervals, and patch clamp study showed both variants caused the non-functional channels. Zebrafish cardiac assay showed the mean APD90 of embryos with kcnq1del/del+ Q1 S277L+E1 or Q1 T587M+E1 was significantly longer than that with kcnq1del/del+Q1 WT+E1 (Table). Next we tested in-frame variant c.1472_1473 ins GGACCT, which was identified from a patient with AF and normal QT interval. Patch clamp study showed the current density of the mutant KCNQ1 channel with KCNE1 was comparable to that of wild-type KCNQ1 channel with KCNE1. Zebrafish assay showed the mean APD90 of embryos with kcnq1del/del shortened by injecting Q1 insACCTGG +E1 (Table). Finally we tested a missense variant p.R451Q, which was identified from a patient with LQTS. Patch clamp study showed the currents in the cells transfected with R451Q+KCNE1 were similar to those with WT+KCNE1. Zebrafish assay showed the mean APD90 of embryos with kcnq1del/del+Q1 R451Q+E1 was longer than that with kcnq1del/del+Q1 WT+E1 (Table).

Conclusions

Functional analysis of in vivo zebrafish cardiac assay might be useful for determining the pathogenicity of rare variants in patients with LQTS.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): The Grant-in-Aid for Scientific Research (C)

Successful revascularization with percutaneous coronary intervention using a combination of the subintimal transcatheter withdrawal technique and coronary artery fenestration for spontaneous coronary artery dissection

The combination of the STRAW technique and coronary artery fenestration using a cutting balloon could be effective in SCAD patients, especially with dissection to the distal end of the coronary artery.

Novel variant of the glycerol-3-phosphate dehydrogenase-1 Like (GPD1-L) gene in Japanese Brugada syndrome patients

Background

The incidence of Brugada syndrome (BrS) varies among racial groups. Several studies reported Glycerol-3-Phosphate Dehydrogenase 1-Like (GPD1-L) gene is associated with BrS. However, most of these studies were reported from Western countries, so the evidence about GPD1-L mutation is limited especially among Asian BrS patients. This study aimed to search for rare variants in GPD1-L among Japanese BrS patients and to investigate the pathogenicity.

Method

We performed whole-exome sequencing for patients with Brugada type 1 ECG pattern from Japanese multicenter BrS cohort consisting of SCN5A-negative BrS probands (n=288) and controls (n=372). We conducted patch-clamp study in human embryonic kidney (HEK) 293 cells cotransfected with the wild-type sodium channel (SCN5A) and wild-type or mutant GPD1-L expression plasmid.

Results

We identified a rare variant in GPD1-L, p.D262N (c.784g&gt;a) in 2 of 288 BrS probands, which was not identified in 372 controls. The minor allele frequency of the variant is 0.0014% in the Genome Aggregation Database. One proband was a 49-year-old man and the other was 34-year-old man who both developed a ventricular fibrillation. ECGs of both probands showed Brugada Type 1 pattern after administration of the pilsicainide. In functional study, coexpression of D262N GPD1-L with SCN5A in HEK293 cells significantly reduced inward sodium currents compared with wild-type GPD1-L. Additionally, inward sodium currents with D262N were similar to those with A280V GPD1-L, which was associated with BrS in previous reports (Figure). Also, several pathogenicity prediction programs, such as SIFT (score: 0.031) and PolyPhen2 (score: 0.937) predicted deleterious effects of GPD1-L D262N.

Conclusion

We identified a rare variant in GPD1-L at the rate of 0.7% in Japanese BrS patients without SCN5A mutations. GPD1-L, p.D262N reduces inward sodium currents and may be a novel susceptible variant for BrS in the Japanese population.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Current–voltage curve

Torsade de Pointes Due to QT Prolongation after Pulmonary Vein Isolation for Persistent Atrial Fibrillation

We herein report a 60-year-old woman with long-standing persistent atrial fibrillation (AF) who developed QT prolongation and torsade de pointes (TdP) after pulmonary vein isolation (PVI). When electrical cardioversion was performed three months before PVI, prominent QT prolongation was not observed. QT prolongation emerged after PVI and was sustained until AF recurrence on the third day after ablation, and TdP disappeared along with AF recurrence. PVI affects the ganglionated plexi around the atrium, leading to modification of the intrinsic cardiac autonomic system. This case indicates that PVI has the potential risk of inducing lethal ventricular arrhythmias due to QT prolongation.

Recurrence of atrial fibrillation after catheter ablation is associated with major adverse cardiac and cerebrovascular events: insights from AF frontier ablation registry

Background

Recent observational studies have suggested that catheter ablation for atrial fibrillation (AF) is significantly associated with reduced risk for stroke, cardiovascular events and all-cause death. However, little is known whether late recurrence of AF after catheter ablation is associated with worse clinical outcomes.

Purpose

We aimed to clarify whether late recurrence of AF after catheter ablation is associated with major adverse cardiac and cerebrovascular events (MACCE).

Methods

We retrospectively investigated 2,737 participants (74.4% men, mean age 63.4±10.3 years, 62.7% paroxysmal AF) who received first catheter ablation for AF and completed follow-up more than 3 months after the procedure from AF Frontier Ablation Registry, a multicenter cohort study in Japan. We evaluated an association between late recurrence of AF after catheter ablation and first MACCE in cox-regression hazard models adjusted for known risk factors. MACCE were defined as stroke/transient ischemic attack (TIA), cardiovascular events or all-cause death. Late recurrence was defined as AF relapse more than 3 months after the procedure.

Results

During a mean follow-up period of 25.2 months, 2,070 patients (75.6%) were free from AF after catheter ablation and 122 patients (4.5%) had MACCE (ischemic stroke 18 [14.8%], hemorrhagic stroke 16 [13.1%], TIA 7 [5.7%], hospitalization for heart failure 19 [15.6%], acute coronary syndrome 19 [15.6%], hospitalization for other cardiovascular events 24 [20%] and all-cause death 19 [15.6%]). The MACCE occurred significantly more frequently in the recurrence group than in non-recurrence group (7.5% vs. 3.5%; hazard ratio [HR] 1.85; 95% confidence interval [CI] 1.28–2.65; P=0.001) (Figure). Multivariate analysis revealed that baseline age (HR 1.05; 95% CI 1.03–1.08; P&lt;0.001), heart failure (HR 1.76; 95% CI 1.17–2.66; P=0.007), old myocardial infarction (HR 4.49; 95% CI 2.59–7.81; P&lt;0.001), non-ischemic cardiomyopathy (HR 2.56; 95% CI 1.47–4.46; P=0.001), left atrial diameter (HR 1.22 per 5-mm increase; 95% CI, 1.06–1.41; P=0.006) and recurrence of AF (HR 1.69; 95% CI 1.17–2.44; P=0.005) were independently associated with the incidence of MACCE after catheter ablation.

Conclusion

In the Japanese multicenter cohort of AF ablation, late recurrence of AF was independently associated with increased MACCE, suggesting the significance of sinus rhythm maintenance by catheter ablation.

Kaplan-Meier curves for MACCE

Funding Acknowledgement

Type of funding source: None

B-Type natriuretic peptide predicts major adverse cardiac and cerebrovascular events after catheter ablation of atrial fibrillation: insights from AF frontier ablation registry

Background

High plasma B-Type natriuretic peptide (BNP) level is associated with cardiac events or stroke in patients with atrial fibrillation (AF). However, it is still unknown whether BNP predicts worse clinical outcomes after catheter ablation ofAF.

Purpose

We aimed to see if plasma BNP level is associated with major adverse cardiac and cerebrovascular events (MACCE) after catheter ablation of AF.

Methods

We retrospectively analyzed 1,853 participants (73.1% men, mean age 63.3±10.3 years, 60.7% paroxysmal AF) who received first catheter ablation of AF with pre-ablation plasma BNP level measurement and completed follow-up more than 3 months after the procedure from AF Frontier Ablation Registry, a multicenter cohort study in Japan. We evaluated an association between plasma BNP level before catheter ablation and first MACCE in cox-regression hazard models adjusted for known risk factors. MACCE were defined as stroke/transient ischemic attack (TIA), cardiovascular events or all-cause death.

Results

The mean plasma BNP level was 120.2±3.7 pg/mL. During a mean follow-up period of 21.9 months, 57 patients (3.1%) suffered MACCE (ischemic stroke 8 [14.0%], hemorrhagic stroke 5 [8.8%], TIA 5 [8.8%], hospitalization for heart failure 11 [19.2%], acute coronary syndrome 9 [15.8%], hospitalization for other cardiovascular events 8 [14.0%] and all-cause death 11 [19.2%]). Plasma BNP level of patients with MACCE were significantly higher than those without MACCE (291.7±47.0 vs 114.7±3.42 pg/mL, P&lt;0.001). Multivariate analysis revealed that plasma BNP level (hazard ratio [HR] per 10 pg/mL increase 1.014; 95% confidence interval [CI] 1.005–1.023; P=0.001), baseline age (HR 1.052; 95% CI 1.022–1.084; P=0.001), heart failure (HR 2.698; 95% CI 1.512–4.815; P=0.001), old myocardial infarction (HR 3.593; 95% CI 1.675–7.708; P=0.001) and non-ischemic cardiomyopathy (HR 2.676; 95% CI 1.337 - 5.355; P=0.005) were independently associated with MACCE. At receiver-operating characteristic curve analysis, plasma BNP level before catheter ablation ≥162.7 pg/mL was the best threshold to predict MACCE (area under the curve: 0.71). Kaplan-Meier curve analysis (Figure) showed that the cumulative incidence of MACCE was significantly higher in patients with a BNP ≥162.7 pg/mL than in those with a BNP below 162.7 pg/mL (HR 4.85; 95% CI 2.86–8.21; P&lt;0.001).

Conclusions

Elevation of plasma BNP level was independently related to the increased risk of MACCE after catheter ablation ofAF.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Bristol-Meiers Squibb

Hokuriku-plus familial hypercholesterolaemia registry study: rationale and study design

INTRODUCTION

Familial hypercholesterolaemia (FH) is an autosomal-dominant inherited genetic disease. It carries an extremely high cardiovascular risk associated with significantly elevated low-density lipoprotein (LDL) cholesterol. The diagnostic rate of this disease in some European nations is quite high, due to the presence of multiple prospective registries. On the other hand, few data-and in particular multicentre data-exist regarding this issue among Japanese subjects. Therefore, this study intends to assemble a multicentre registry that aims to comprehensively assess cardiovascular risk among Japanese FH patients while taking into account their genetic backgrounds.

METHODS AND ANALYSIS

The Hokuriku-plus FH registry is a prospective, observational, multicentre cohort study, enrolling consecutive FH patients who fulfil the clinical criteria of FH in Japan from 37 participating hospitals mostly in Hokuriku region of Japan from April 2020 to March 2024. A total of 1000 patients will be enrolled into the study, and we plan to follow-up participants over 5 years. We will collect clinical parameters, including lipids, physical findings, genetic backgrounds and clinical events covering atherosclerotic and other important events, such as malignancies. The primary endpoint of this study is new atherosclerotic cardiovascular disease (ASCVD) events. The secondary endpoints are as follows: LDL cholesterol, secondary ASCVD events and the occurrence of other diseases including hypertension, diabetes and malignancies.

ETHICS AND DISSEMINATION

This study is being conducted in compliance with the Declaration of Helsinki, the Ethical Guidelines for Medical and Health Research Involving Human Subjects, and all other applicable laws and guidelines in Japan. This study protocol has been approved by the Institutional Review Board at Kanazawa University. We will disseminate the final results at international conferences and in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

UMIN000038210.

P2850Time to isolation guided hot balloon ablation for pulmonary vein isolation

Background

One disadvantage of hot balloon ablation (HBA) system is that real time monitoring of pulmonary vein (PV) potential is technically impossible. Therefore, the optimal radiofrequency-generated thermal energy application duration and application number are not completely established.

Purpose

The aim of this study is to evaluate the utility of 2Fr 4-electrode unidirectional catheter inserted into PV along with HB for real time monitoring of PV potential and investigate the time to isolation (TTI) guided optimal application strategy for HB based PV isolation in the acute phase.

Methods

We evaluated 23 consecutive patients who performed PV isolation using HBA system. Real time monitoring of PV potential was performed by 2Fr 4-electrode unidirectional catheter inserted into PV along with HB (Figure1A). After HBA applications, PV isolation was validated by high-resolution mapping with the 20-pole steerable mapping (PENTARAY) catheter as a standard. PV potentials during HBA application were categorized into five patterns. PV potentials disappeared during HBA applications and not emerged again (acute isolation), disappeared but verified by PENTARAY catheter (pseudo isolation), once disappeared but emerged again during the same application (acute reconnection), visible but not disappeared (ineffective application) and Invisible (Figure1B).

TTI, difference between TTI and time to reach target temperature (TTRT), balloon temperature at isolation and ablation time after isolation were examined for each applications.

Results

Out of 92 PVs, 69/92 (75.0%) PVs were isolated using HBA and 23/92 (25.0%) PVs required touch up ablation. In total, 120 applications were performed. Real time monitoring of the PV activity was obtained in 114 of 120 applications (95.0%). The distribution of PV potential patterns were 64/120 (53.3%), 2/120 (1.7%), 27/120 (22.5%), 23/120 (19.2%), for acute isolation, pseudo isolation, acute reconnection, ineffective application, respectively.

TTI and difference between TTI and TTRT were significantly shorter in the acute isolation group. Balloon temperature at isolation was significantly lower, TTRT and ablation time after isolation was significantly longer in the acute isolation group. Among them, TTI and difference between TTI and TTRT were highly predictive by receiver operation characteristics curve analysis. TTI <36.5s predicted successful application with sensitivity 83.9% and specificity 79.3%. Difference between TTI and TTRT <6.5s predicted with sensitivity 82.3% and specificity 89.7%.

Figure 1

Conclusions

In HBA system, real time monitoring of PV potentials can be obtained using 2Fr 4-electrode unidirectional catheter and accuracy to confirm an ostial PV isolation is relatively high.

TTI <36.5s and difference between TTI and TTRT <6.5s could be a suitable target for effective application.

P1580Left atrial volume index predicts improvement in renal function after catheter ablation of atrial fibrillation

Background

Atrial fibrillation (AF) increased the risk of development of kidney disease. The elimination of AF by catheter ablation is associated with improvement in renal function. However, the mechanism of cardio-renal interaction in AF has not been fully elucidated.

Purpose

We tested the hypothesis that left atrial volume index (LAVI), which is a marker of left atrial mechanical reserve, predicts improvement in renal function after restoring sinus rhythm with catheter ablation of AF.

Methods

We analyzed consecutive patients who underwent catheter ablation of AF from January 2012 to October 2018 and had completed follow-up more than 3 months after catheter ablation. Exclusion criteria were need for hemodialysis and acute hospitalization. Estimated glomerular filtration rate (eGFR) was assessed on admission and at the end of follow-up periods after catheter ablation and the difference was defined as ΔeGFR. Left atrial volume index was derived using the biplane area-length method.

Results

A total of 159 AF patients (paroxysmal 112 [70%], persistent 47 [30%]) were included in this study. The mean age was 65±11 years and 74% were male. During the mean follow-up period of 7.9±3.2 months, 105 patients (66%) were free from atrial tachyarrhythmias and 54 (34%) experienced the recurrence. Baseline eGFR and LAVI were not significantly different between the non-recurrence group and the recurrence group (71.0±17.4 and 75.1±22.8 mL/min/1.73m2; p=0.24, 35.7±12.5 and 37.9±15.0 ml/m2; p=0.34). ΔeGFR in the non-recurrence group was significantly greater compared with the recurrence group (+1.5±1.0 versus −4.3±1.4 mL/min/1.73m2; p=0.001). Baseline LAVI was negatively correlated with ΔeGFR in the non-recurrence group (r=−0.3; p=0.002; Figure), but not in the recurrence group (p=0.1). Multiple regression analysis in the non-recurrence group identified baseline LAVI (β=−0.35, p<0.001), baseline age (β=−0.31, p<0.001) and baseline eGFR (β=−0.59, p<0.001) as independent predictors for eGFR improvement after catheter ablation. In the patients with LAVI <34 ml/m2, age <70 years and eGFR <90 mL/min/1.73m2, the mean ΔeGFR was +6.3±1.9 mL/min/1.73m2.

Figure 1

Conclusions

LAVI, a marker of left atrial mechanical reserve, was an independent predictor of improvement in renal function after restoring sinus rhythm with catheter ablation of AF. This observation suggests that AF-related deterioration of renal function is due at least in part to impaired atrial mechanical function.

Coronary sinus catheter placement via left cubital vein for phrenic nerve stimulation during pulmonary vein isolation

Phrenic nerve (PN) stimulation is essential for the elimination of PN palsy during balloon-based pulmonary vein isolation (PVI). Although ultrasound-guided vascular access is safe, insertion of a PN stimulation catheter via central venous access carries a potential risk of the development of mechanical complications. We evaluated the safety of a left cubital vein approach for positioning a 20-electrode atrial cardioversion (BeeAT) catheter in the coronary sinus (CS), and the feasibility of right PN pacing from the superior vena cava (SVC) using proximal electrodes of the BeeAT catheter. In total, 106 consecutive patients who underwent balloon-based PVI with a left cubital vein approach for BeeAT catheter positioning were retrospectively assessed. The left cubital approach was successful in 105 patients (99.1%), and catheter insertion into the CS was possible for 104 patients (99.0%). Among these patients, constant right PN pacing from the SVC was obtained for 89 patients (89/104, 85.6%). In five patients, transient loss of right PN capture occurred during right pulmonary vein ablation. No persistent right PN palsy was observed. Small subcutaneous hemorrhage was observed in eight patients (7.5%). Neuropathy, pseudoaneurysm, arteriovenous fistula, and perforations associated with the left cubital approach were not detected. Body mass index was significantly higher in the right PN pacing failure group than in the right PN pacing success group (26.2 ± 3.2 vs. 23.8 ± 3.8; P = 0.025). CS catheter placement with a left cubital vein approach for right PN stimulation was found to be safe and feasible. Right PN pacing from the SVC using a BeeAT catheter was successfully achieved in the majority of the patients. This approach may prove to be preferable for non-obese patients.

Catecholaminergic polymorphic ventricular tachycardia managed as orthostatic dysregulation and epilepsy in 11- and 15-year-old sisters

BACKGROUND

In pediatric patients, syncope commonly occurs as vasovagal syncope, or in epilepsy or orthostatic dysregulation. Cardiogenic syncope is rare but it is lethal, and needs to be promptly diagnosed and treated.

METHODS AND RESULTS

We describe the cases of 11- and 15-year-old sisters with frequent syncope during exercise and emotional stress since the age of 10 and 12, respectively. There were no abnormalities on 12-lead electrocardiogram (ECG) at rest. They were first diagnosed with orthostatic dysregulation and epilepsy. Because of recurrent exercise-induced syncope, cardiac examinations were performed. On treadmill exercise stress test, bidirectional ventricular tachycardia was induced in the 11-year-old girl, which degenerated into ventricular fibrillation; frequent polymorphic premature ventricular contractions were induced in her elder sister. They were diagnosed with catecholaminergic polymorphic ventricular tachycardia (CPVT) and started on oral beta-blockers and exercise restriction.

CONCLUSIONS

It is important to suspect CPVT in pediatric exercise-induced syncope, and to recognize that CPVT does not show ECG abnormalities at rest.

Impact of left atrial size on isolation area in the acute phase of pulmonary vein isolation using 28 mm cryoballoon

BACKGROUND

The impact of left atrial (LA) size on isolation area (ISA) using a 28-mm second-generation cryoballoon (CB) in the acute phase after pulmonary vein isolation (PVI) and the differences of CB from contact force-guided radiofrequency (RF) ablation have not been fully investigated.

METHODS

We examined 85 consecutive patients (CB group, 35; RF group, 50) with drug-refractory paroxysmal atrial fibrillation who underwent their first PVI procedure at two institutions. We evaluated ISA after PVI using 3D-Merge computed tomography images (GE Healthcare, Little Chalfont, UK) and high-resolution electroanatomical mapping.

RESULTS

Total ISA was significantly smaller in the CB group (20.6 ± 6.0 cm² ) than in the RF group (29.0 ± 7.1 cm² ; P < 0.0001). In the CB group, ISA of the left pulmonary vein (LPV), right pulmonary vein (RPV), and total ISA were not correlated with the left atrial surface area (LASA). The ratios of ISA to LASA (%ISA) of LPV and total ISA negatively correlated with LASA in the CB group (LPV: r = -0.4001, P = 0.0173; total ISA: r = -0.4733, P = 0.0041). In contrast, in the RF group, ISA of LPV, RPV, and total ISA positively correlated with LASA; (LPV: r = 0.5155, P = 0.001; RPV: r = 0.6398, P < 0.0001; total ISA: r = 0.7299, P < 0.0001).

CONCLUSION

ISA created using CB was significantly smaller than that using RF and did not change regardless of LASA increment. Differences in ISA between the two groups became more prominent in the large atrium.

Ability of the prognostic model of J-ACCESS study to predict cardiac events in a clinical setting: The APPROACH study

BACKGROUND

In patients with coronary artery disease (CAD), one of the risk models available in Japan was a multivariate risk prediction model based on a Japanese multicenter database: the Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT (J-ACCESS). The aim of this study was to clinically validate the accuracy of this risk model.

METHODS

We evaluated the performance of the J-ACCESS model using data derived from the Assessment of the Predicted value of PROgnosis of cArdiaC events in Hokuriku (APPROACH) registry. Variables of age, summed stress score (SSS), left ventricular ejection fraction (LVEF), estimated glomerular filtration rate (eGFR), and diabetes mellitus were included. The major cardiac events were defined as cardiac death, non-fatal myocardial infarction, and heart failure that required hospitalization. The patients were followed up for three years to compare between predicted risk and actual events.

RESULTS

We evaluated 283 patients with suspected or confirmed CAD receiving myocardial perfusion imaging using ^99mTc-tetrofosmin between March 2009 and August 2011. Mean age was 68.9±10.1 years, mean eGFR 67.4±24.3mL/min/1.73m², mean SSS 5.2±7.2, and mean LVEF 65.4±14.0%. Fourteen (4.9%) patients experienced major cardiac events including cardiac death in 4 patients (1.4%), non-fatal myocardial infarction in 1 patient (0.3%), and severe heart failure in 9 patients (3.2%), respectively. While SSS≥8, LVEF<50%, eGFR<45mL/min/1.73m², and event risk≥10% were significant variables in survival analysis, multivariate proportional hazard analysis showed that only LVEF and eGFR were significant. The event rate estimated from the J-ACCESS model was comparable to the actual number of major cardiac events (9 and 6, respectively, p=0.58 by Chi-square test).

CONCLUSIONS

The predictive ability of the J-ACCESS risk model is clinically valid among patients with CAD and could be applicable in clinical practice.

Adaptive cardiac resynchronization therapy for dilated cardiomyopathy with functional mitral regurgitation

We report the case of a man in his 60s who had dilated cardiomyopathy with severe functional mitral regurgitation. Four years after a cardiac resynchronization therapy (CRT) device with an implantable cardioverter defibrillator was implanted, this device was replaced with an adaptive CRT device because of battery consumption. Seven months after replacement of this device, the left ventricular pacing to right ventricular activation and the atrioventricular delay from automatic adjustments contributed to less functional mitral regurgitation. The findings from our case suggest that optimal CRT, by measuring intracardiac conduction parameters, is effective for functional mitral regurgitation.

Overview of the 81st Annual Scientific Meeting of the Japanese Circulation Society - Cardiovascular Medicine for the Next Generation

The 81^stAnnual Scientific Meeting of the Japanese Circulation Society was held in Kanazawa, Japan, on March 17-19, 2017 under a miraculously clear sky. The frontlines of healthcare and medicine are dramatically changing. Thus, "Cardiovascular Medicine for Next Generation" was chosen as the main theme of this meeting. The program was constructed around major identified issues, including renewal of our understanding of basic cardiovascular medicine, translational research, and preventive molecular medicine, all of which are anticipated to transcend the medical field over the next generation. Despite the provincial location, 15,672 participants, including more than 400 from overseas countries, attended the 3-day meeting, and there were in-depth discussions in the various sessions. In particular, to our great pleasure, Her Imperial Highness Princess Takamado kindly attended the opening ceremony and extended congratulations to us. The meeting successfully completed and we sincerely appreciate the great cooperation and support from all affiliates.

Congenital left main coronary artery atresia presenting as syncope and generalized seizure during exercise in a 13-year-old boy

We report the case of a 13-year-old boy who, while running in a school gymnasium, experienced sudden syncope and seizure. CPR was started immediately, and an automated external defibrillator (AED) was attached, but shock was not induced. He was referred to our hospital for loss of consciousness and intermittent general tonic-clonic seizure. A 12-lead electrocardiogram showed normal sinus rhythm and no ST-T wave abnormalities. Echocardiography showed normal structural heart and normal cardiac function. On the second day of hospitalization, AED electrocardiogram showed complete atrioventricular (AV) block at syncope and seizure. After the patient recovered from this neurological state, we performed the treadmill exercise test, and it did not show ST-T wave abnormalities or AV block, and he did not complain of chest pain. Coronary angiography showed atresia of the left main trunk and the collateral vessel from the right coronary artery connected to the left coronary artery. He was diagnosed with congenital left main coronary artery atresia. We began administration of calcium antagonist and aspirin to prevent a coronary artery spasm and then performed a coronary artery bypass graft (CABG) to prevent sudden cardiac death. After CABG, he has had no syncope episodes at rest or during light exercise. <Learning objective: In pediatric patients, syncope during strenuous exercise should mandate exclusion of cardiac events, especially coronary artery anomalies. Coronary artery anomalies that could cause sudden cardiac death sometimes show no abnormalities at rest or even during exercise stress on 12-lead electrocardiogram. It is very important to suspect cardiogenic syncope during strenuous exercise.>.

Altered gene expression in T-cell receptor signalling in peripheral blood leucocytes in acute coronary syndrome predicts secondary coronary events

Objective

Comprehensive profiling of gene expression in peripheral blood leucocytes (PBLs) in patients with acute coronary syndrome (ACS) as a prognosticator is needed. We explored the specific profile of gene expression in PBLs in ACS for long-term risk stratification.

Methods

30 patients with ACS who underwent primary percutaneous coronary intervention (PCI) and 15 age-matched adults who participated in medical check-ups were enrolled from three centres. Peripheral blood samples were collected to extract RNA for microarray analyses.

Results

During the 5-year follow-up, 36% of this cohort developed the expected non-fatal coronary events (NFEs) of target lesion revascularisation (TLR) and PCI for a de novo lesion. Class comparison analysis (p<0.005) demonstrated that 83 genes among 7785 prefiltered genes (41 upregulated vs 42 downregulated genes) were extracted to classify the patients according to the occurrence of NFE. Pathway analysis based on gene ontology revealed that the NFEs were associated with altered gene expression regarding the T-cell receptor signalling pathway in ACS. Univariate t test showed that the expression level of death-associated protein kinase1 (DAPK1), known to regulate inflammation, was the most significantly negatively regulated gene in the event group (0.61-fold, p<0.0005). Kaplan-Meier curve analysis and multivariate analysis adjusted for baseline characteristics or clinical biomarkers demonstrated that lower DAPK1 expression in PBL emerged as an independent risk factor for the NFEs (HR: 8.73; CI 1.05 to 72.8, p=0.045).

Conclusions

Altered gene expression in T-cell receptor signalling in PBL in ACS could be a prognosticator for secondary coronary events.

Trial registration number

UMIN000001932; Results.

Catheter ablation for Wolff-Parkinson-White syndrome with coronary sinus diverticulum in a 15-year-old boy

The left posterior and posteroseptal accessory pathways often have an epicardial accessory and are associated with coronary vein anomalies, such as diverticulum, fusiform, or bulbous enlargement. We report the case of a 15-year-old boy who suffered from palpitation due to Wolff-Parkinson-White syndrome with coronary sinus diverticulum. An electrophysiology study revealed a left posterior accessory pathway and orthodromic atrioventricular reciprocating tachycardia. After the transseptal puncture, we performed mapping around the mitral annulus during sinus rhythm. We could not detect typical atrioventricular fusion accompanied with accessory pathway potential and failed to ablate around the mitral annulus. We revealed typical accessory pathway potential in a coronary vein and successfully ablated. After ablation, a right atrium angiography showed a successful ablation site was just at the neck of coronary sinus diverticulum. It is important for a successful and safe ablation to evaluate coronary vein anomalies in patients with left posterior and posteroseptal accessory pathways. <Learning objective: In pediatric patients, Wolff-Parkinson-White syndrome with the posteroseptal accessory pathway with coronary sinus diverticulum is rare. It is important to predict the left posterior and posteroseptal accessory pathways from the polarity of the delta wave; ablation for pediatric patients seems to be more effective and safe in confirming coronary sinus diverticulum by echocardiogram before electrophysiology study and performing coronary vein angiography before mapping of the accessory pathway.>.

CPEB1 mediates epithelial-to-mesenchyme transition and breast cancer metastasis

In mouse mammary epithelial cells, CPEB1 mediates the apical localization of ZO-1 mRNA, which encodes a critical tight junction component. In mice lacking CPEB1 and in cultured cells from which CPEB has been depleted, randomly distributed ZO-1 mRNA leads to the loss of cell polarity. We have investigated whether this diminution of polarity results in an epithelial-to-mesenchyme (EMT) transition and possible increased metastatic potential. Here, we show that CPEB1-depleted mammary epithelial cells alter their gene expression profile in a manner consistent with an EMT and also become motile, which are made particularly robust when cells are treated with TGF-β, an enhancer of EMT. CPEB1-depleted mammary cells become metastatic to the lung following injection into mouse fat pads while ectopically-expressed CPEB1 prevents metastasis. Surprisingly, CPEB1 depletion causes some EMT/metastasis-related mRNAs to have shorter poly(A) tails while other mRNAs to have longer poly(A) tails. Matrix metalloproteinase 9 (MMP9) mRNA, which encodes a metastasis-promoting factor, undergoes poly(A) lengthening and enhanced translation upon CPEB reduction. Moreover, in human breast cancer cells that become progressively more metastatic, CPEB1 is reduced while MMP9 becomes more abundant. These data suggest that at least in part, CPEB1 regulation of MMP9 mRNA expression mediates metastasis of breast cancer cells.

A case of delayed occlusive dissection of the right coronary artery during coronary intervention of the left anterior descending artery

Catheter-induced coronary artery dissection occurs rarely during selective coronary angiography but generally progresses to complete coronary occlusion. We present a case of delayed occlusive dissection of the right coronary artery during coronary intervention of the left anterior descending artery. Bailout stenting was employed to treat the giant hematoma quickly using a unique technique. The use of two guidewires created a high probability that the true lumen was selected, and aspiration of the hematoma with the microcatheter and indeflator effectively repaired a catheter-induced coronary artery dissection.