Non-missense variants of KCNH2 show better outcomes in type 2 long QT syndrome.

AIMS: More than one-third of type 2 long QT syndrome (LQT2) patients carry KCNH2 non-missense variants that can result in haploinsufficiency (HI), leading to mechanistic loss-of-function. However, their clinical phenotypes have not been fully investigated. The remaining two-thirds of patients harbour missense variants, and past studies uncovered that most of these variants cause trafficking deficiency, resulting in different functional changes: either HI or dominant-negative (DN) effects. In this study, we examined the impact of altered molecular mechanisms on clinical outcomes in LQT2 patients. METHODS AND RESULTS: We included 429 LQT2 patients (234 probands) carrying a rare KCNH2 variant from our patient cohort undergoing genetic testing. Non-missense variants showed shorter corrected QT (QTc) and less arrhythmic events (AEs) than missense variants. We found that 40% of missense variants in this study were previously reported as HI or DN. Non-missense and HI-groups had similar phenotypes, while both exhibited shorter QTc and less AEs than the DN-group. Based on previous work, we predicted the functional change of the unreported variants-whether they cause HI or DN via altered functional domains-and stratified them as predicted HI (pHI)- or pDN-group. The pHI-group including non-missense variants exhibited milder phenotypes compared to the pDN-group. Multivariable Cox model showed that the functional change was an independent risk of AEs (P = 0.005). CONCLUSION: Stratification based on molecular biological studies enables us to better predict clinical outcomes in the patients with LQT2.

Calmodulinopathy in Japanese Children　- Their Cardiac Phenotypes Are Severe and Show Early Onset in Fetal Life and Infancy.

BACKGROUND: Cardiac calmodulinopathy, characterized by a life-threatening arrhythmia and sudden death in the young, is extremely rare and caused by genes encoding calmodulin, namely calmodulin 1 (CALM1), CALM2, and CALM3.Methods and Results: We screened 195 symptomatic children (age 0-12 years) who were suspected of inherited arrhythmias for 48 candidate genes, using a next-generation sequencer. Ten probands were identified as carrying variants in any of CALM1-3 (5%; median age 5 years), who were initially diagnosed with long QT syndrome (LQTS; n=5), catecholaminergic polymorphic ventricular tachycardia (CPVT; n=3), and overlap syndrome (n=2). Two probands harbored a CALM1 variant and 8 probands harbored 6 CALM2 variants. There were 4 clinical phenotypes: (1) documented lethal arrhythmic events (LAEs): 4 carriers of N98S in CALM1 or CALM2; (2) suspected LAEs: CALM2 p.D96G and D132G carriers experienced syncope and transient cardiopulmonary arrest under emotional stimulation; (3) critical cardiac complication: CALM2 p.D96V and p.E141K carriers showed severe cardiac dysfunction with QTc prolongation; and (4) neurological and developmental disorders: 2 carriers of CALM2 p.E46K showed cardiac phenotypes of CPVT. Beta-blocker therapy was effective in all cases except cardiac dysfunction, especially in combination with flecainide (CPVT-like phenotype) and mexiletine (LQTS-like). CONCLUSIONS: Calmodulinopathy patients presented severe cardiac features, and their onset of LAEs was earlier in life, requiring diagnosis and treatment at the earliest age possible.

School-based routine screenings of electrocardiograms for the diagnosis of long QT syndrome.

AIMS: School-based routine screenings of electrocardiograms (ECGs) have been performed upon admission to primary school (PS), junior high school (JHS), and high school (HS) in Japan. Though ECGs with prolonged QT intervals are occasionally found, the role of regular ECG screening tests in identifying long QT syndrome (LQTS) remains to be determined. We investigated the usefulness of the ECG screenings by comparing the results of genetic tests between students who showed QT-prolongation in the screenings and patients with LQTS. METHODS AND RESULTS: We genetically screened 341 students (106 PS, 173 JHS, and 62 HS). Of these, 230 subjects showed QT-prolongation during regular screenings (S-S group), and the other 111 patients were clinically consulted with suspected LQTS by paediatricians (C-C group). Genotype-phenotype relationships were compared between the two groups. The positive rates in the genetic tests were comparable among the two groups; however, symptomatic subjects were significantly fewer in the S-S group than the C-C group (3% vs. 70%). Compared to the genotype-negative subjects, the positive subjects showed significantly longer QTc (P < 0.0001) and more frequently presented LQTS risk scores with ≥3.5 points (P < 0.0001). Lethal arrhythmic events (LAE) occurred only in the C-C group; 18 subjects experienced LAE and 83% of them were found to carry variant(s) in the LQTS-related genes. CONCLUSION: The school-based ECG screenings are effective in identifying young patients with LQTS who require genetic analysis. If individuals are screened at a younger age, we can identify patients at risk earlier and provide preventative treatments.

Loss-of-function mutations in cardiac ryanodine receptor channel cause various types of arrhythmias including long QT syndrome.

AIMS: Gain-of-function mutations in RYR2, encoding the cardiac ryanodine receptor channel (RyR2), cause catecholaminergic polymorphic ventricular tachycardia (CPVT). Whereas, genotype-phenotype correlations of loss-of-function mutations remains unknown, due to a small number of analysed mutations. In this study, we aimed to investigate their genotype-phenotype correlations in patients with loss-of-function RYR2 mutations. METHODS AND RESULTS: We performed targeted gene sequencing for 710 probands younger than 16-year-old with inherited primary arrhythmia syndromes (IPAS). RYR2 mutations were identified in 63 probands, and 3 probands displayed clinical features different from CPVT. A proband with p.E4146D developed ventricular fibrillation (VF) and QT prolongation whereas that with p.S4168P showed QT prolongation and bradycardia. Another proband with p.S4938F showed short-coupled variant of torsade de pointes (scTdP). To evaluate the functional alterations in these three mutant RyR2s and p.K4594Q previously reported in a long QT syndrome (LQTS), we measured Ca2+ signals in HEK293 cells and HL-1 cardiomyocytes as well as Ca2+-dependent [3H]ryanodine binding. All mutant RyR2s demonstrated a reduced Ca2+ release, an increased endoplasmic reticulum Ca2+, and a reduced [3H]ryanodine binding, indicating loss-of-functions. In HL-1 cells, the exogenous expression of S4168P and K4594Q reduced amplitude of Ca2+ transients without inducing Ca2+ waves, whereas that of E4146D and S4938F evoked frequent localized Ca2+ waves. CONCLUSION: Loss-of-function RYR2 mutations may be implicated in various types of arrhythmias including LQTS, VF, and scTdP, depending on alteration of the channel activity. Search of RYR2 mutations in IPAS patients clinically different from CPVT will be a useful strategy to effectively discover loss-of-function RYR2 mutations.

Oral Adrenergic Agents Produced Ventricular Fibrillation and QT Prolongation in an Elderly Patient Carrying an RYR2 Variant.

Mutant cardiac ryanodine receptor channels (RyR2) are "leaky," and spontaneous Ca2+ release through these channels causes delayed afterdepolarizations that can deteriorate into ventricular fibrillation. Some patients carrying RYR2 mutations in type 1 catecholaminergic polymorphic ventricular tachycardia exhibit QT prolongation and are initially diagnosed with long QT syndrome. However, none have been reported to cause drug-induced ventricular fibrillation in patients with RYR2 variants. We describe the first case of an elderly woman with drug-induced QT prolongation and ventricular fibrillation who carried a novel RYR2 variant but no other mutations related to long QT syndrome. Oral adrenergic agents might induce QT prolongation and subsequent ventricular fibrillation in patients carrying an RYR2 variant. Screening for RYR2 could be valuable in patients with suspected drug-induced long QT syndrome.

Enhancing rare variant interpretation in inherited arrhythmias through quantitative analysis of consortium disease cohorts and population controls.

PURPOSE: Stringent variant interpretation guidelines can lead to high rates of variants of uncertain significance (VUS) for genetically heterogeneous disease like long QT syndrome (LQTS) and Brugada syndrome (BrS). Quantitative and disease-specific customization of American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines can address this false negative rate. METHODS: We compared rare variant frequencies from 1847 LQTS (KCNQ1/KCNH2/SCN5A) and 3335 BrS (SCN5A) cases from the International LQTS/BrS Genetics Consortia to population-specific gnomAD data and developed disease-specific criteria for ACMG/AMP evidence classes-rarity (PM2/BS1 rules) and case enrichment of individual (PS4) and domain-specific (PM1) variants. RESULTS: Rare SCN5A variant prevalence differed between European (20.8%) and Japanese (8.9%) BrS patients (p = 5.7 × 10-18) and diagnosis with spontaneous (28.7%) versus induced (15.8%) Brugada type 1 electrocardiogram (ECG) (p = 1.3 × 10-13). Ion channel transmembrane regions and specific N-terminus (KCNH2) and C-terminus (KCNQ1/KCNH2) domains were characterized by high enrichment of case variants and >95% probability of pathogenicity. Applying the customized rules, 17.4% of European BrS and 74.8% of European LQTS cases had (likely) pathogenic variants, compared with estimated diagnostic yields (case excess over gnomAD) of 19.2%/82.1%, reducing VUS prevalence to close to background rare variant frequency. CONCLUSION: Large case-control data sets enable quantitative implementation of ACMG/AMP guidelines and increased sensitivity for inherited arrhythmia genetic testing.

Overview of the 84th Annual Scientific Meeting of the Japanese Circulation Society　- Change Practice!

Due to the COVID-19 pandemic, the 84thAnnual Meeting of the Japanese Circulation Society (JCS) was held in a web-based format for the first time in its history as "The Week for JCS 2020" from Monday, July 27 to Sunday, August 2, 2020. All sessions, including general abstracts, were streamed live or on-demand. The main theme of the meeting was "Change Practice!" and the aim was to organize the latest findings in the field of cardiovascular medicine and discuss how to change practice. The total number of registered attendees was over 16,800, far exceeding our expectations, and many of the sessions were viewed by far more people than at conventional face-to-face scientific meetings. At this conference, the power of online information dissemination was fully demonstrated, and the evolution of online academic meetings will be a direction that cannot be reversed in the future. The meeting was completed with great success, and we express our heartfelt gratitude to all affiliates for their enormous amount of work, cooperation, and support.

Clinical characteristics and outcomes of patients with venous thromboembolism according to diagnosis on weekends versus on weekdays.

There are uncertainties on the influence of the days of diagnosis in a week (weekends versus weekdays) on clinical outcomes in patients with acute venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis (DVT). The COMMAND VTE registry is a multicenter cohort study enrolling 3027 consecutive patients with acute symptomatic VTE. The current study population consisted of 337 patients diagnosed on weekends and 2690 patients diagnosed on weekdays. We compared the clinical characteristics, management strategies and 30-day outcomes between the 2 groups. The patients diagnosed on weekends more often presented with PE (72% vs. 55%, P < 0.001), and with more severe hemodynamic condition for PE patients. The patients diagnosed on weekends more often received initial parenteral anticoagulation therapy and thrombolysis than those diagnosed on weekdays. The cumulative 30-day incidence of all-cause death was not significantly different between the two groups among PE patients (diagnosis on weekends: 6.2% vs. diagnosis on weekdays: 6.5%, P = 0.87), as well as among DVT patients (0.0% vs. 1.5%, P = 0.24). The most frequent cause of deaths was fatal PE in both groups among PE patients. The risks for recurrent VTE and major bleeding at 30-day were not significantly different between the 2 groups among PE patients, nor among DVT only patients. In conclusion, the VTE patients diagnosed on weekends presented more often with PE, and with more severe condition for PE patients. Nevertheless, the risk for 30-day mortality was not significantly different between patients diagnosed on weekends and on weekdays.

Mutant KCNJ3 and KCNJ5 Potassium Channels as Novel Molecular Targets in Bradyarrhythmias and Atrial Fibrillation.

BACKGROUND: Bradyarrhythmia is a common clinical manifestation. Although the majority of cases are acquired, genetic analysis of families with bradyarrhythmia has identified a growing number of causative gene mutations. Because the only ultimate treatment for symptomatic bradyarrhythmia has been invasive surgical implantation of a pacemaker, the discovery of novel therapeutic molecular targets is necessary to improve prognosis and quality of life. METHODS: We investigated a family containing 7 individuals with autosomal dominant bradyarrhythmias of sinus node dysfunction, atrial fibrillation with slow ventricular response, and atrioventricular block. To identify the causative mutation, we conducted the family-based whole exome sequencing and genome-wide linkage analysis. We characterized the mutation-related mechanisms based on the pathophysiology in vitro. After generating a transgenic animal model to confirm the human phenotypes of bradyarrhythmia, we also evaluated the efficacy of a newly identified molecular-targeted compound to upregulate heart rate in bradyarrhythmias by using the animal model. RESULTS: We identified one heterozygous mutation, KCNJ3 c.247A>C, p.N83H, as a novel cause of hereditary bradyarrhythmias in this family. KCNJ3 encodes the inwardly rectifying potassium channel Kir3.1, which combines with Kir3.4 (encoded by KCNJ5) to form the acetylcholine-activated potassium channel ( IKACh channel) with specific expression in the atrium. An additional study using a genome cohort of 2185 patients with sporadic atrial fibrillation revealed another 5 rare mutations in KCNJ3 and KCNJ5, suggesting the relevance of both genes to these arrhythmias. Cellular electrophysiological studies revealed that the KCNJ3 p.N83H mutation caused a gain of IKACh channel function by increasing the basal current, even in the absence of m2 muscarinic receptor stimulation. We generated transgenic zebrafish expressing mutant human KCNJ3 in the atrium specifically. It is interesting to note that the selective IKACh channel blocker NIP-151 repressed the increased current and improved bradyarrhythmia phenotypes in the mutant zebrafish. CONCLUSIONS: The IKACh channel is associated with the pathophysiology of bradyarrhythmia and atrial fibrillation, and the mutant IKACh channel ( KCNJ3 p.N83H) can be effectively inhibited by NIP-151, a selective IKACh channel blocker. Thus, the IKACh channel might be considered to be a suitable pharmacological target for patients who have bradyarrhythmia with a gain-of-function mutation in the IKACh channel.

An NGS-based genotyping in LQTS; minor genes are no longer minor.

Mutations in KCNQ1, KCNH2, and SCN5A are the major cause of long QT syndrome (LQTS). More than 90% of the genotyped patients have been reported to carry mutations in any of these three genes. Thanks to increasing popularity of next generation sequencer (NGS), novel CACNA1C mutations have been identified among LQTS patients without extra-cardiac phenotypes. We aimed to clarify the frequency of genotypes in LQTS patients in the era of NGS. The study comprised 160 congenital LQTS patients (71 males) registered from November 2015 to September 2018. Inclusion criteria was QTc > 460 ms and Schwartz score ≥ 3. We performed genetic analysis using target gene method by NGS and confirmed the mutations by Sanger method. The median age for genetic screening was 13 (0-68) years. Sixteen patients suffered cardiac arrest, 47 syncope, and 97 were asymptomatic. We identified genetic mutations in 111 (69.4%) patients including 6 CACNA1C (5.4% of the genotyped patients) with 4 asymptomatic patients. Five (3.1%) patients carried double mutations; three out of them with RYR2 and KCNQ1 or KCNH2. In conclusion, CACNA1C screening would be recommended even if the patient is asymptomatic to elucidate the genetic background of the LQTS patients.

High Prevalence of Late-Appearing T-Wave in Patients With Long QT Syndrome Type 8.

BACKGROUND: Long QT syndrome type 8 (LQT8) is a rare genotype of long QT syndrome. Late-appearing T-waves (LaT) are often documented in patients with LQT8, as in long QT syndrome type 3 (LQT3); however, the frequency of LaT and its relevance to the clinical severity of LQT8 remains unclear. This study investigated T-wave morphology (TWM) in LQT3 and LQT8 patients and compared the phenotypes of different TWMs.Methods and Results:TWMs were classified into 3 types: early onset T-waves (EoT), LaT, and bifid T-waves (biT). Electrocardiogram (ECG) measurements, symptoms, and topology were compared among TWM types. The study cohort comprised 25 patients with LQT8 (14 mutations) and 25 patients with LQT3 (14 mutations). LaT was detected in 17 (68%) and 13 (52%) LQT8 and LQT3 patients, respectively. There were no significant differences in ECG measurements or the severity of symptoms between patients with LaT and those with other TWMs in either the LQT8 or LQT3 group. However, only patients with LaT experienced cardiopulmonary arrest. Compared with the LQT3 group, in the LQT8 group there was a tendency for mutations in patients with LaT to be located in domain-linking regions. CONCLUSIONS: In this study, two-thirds of patients with LQT8 exhibited LaT on ECG, and nearly one-third of those experienced cardiopulmonary arrest. Further investigations are warranted to differentiate between LQT3 and LQT8 in patients exhibiting LaT to optimize therapy.

Risk Factors for Major Bleeding During Anticoagulation Therapy in Cancer-Associated Venous Thromboembolism　- From the COMMAND VTE Registry.

BACKGROUND: Patients with cancer-associated venous thromboembolism (VTE) are at high risk for recurrent VTE and are recommended to receive prolonged anticoagulation therapy if they are at a low risk for bleeding. However, there are no established risk factors for bleeding during anticoagulation therapy.Methods and Results:The COMMAND VTE Registry is a multicenter retrospective registry enrolling 3,027 consecutive patients with acute symptomatic VTE among 29 Japanese centers. The present study population consisted of 592 cancer-associated VTE patients with anticoagulation therapy. We constructed a multivariable Cox proportional hazard model to estimate the hazard ratio (HR) and 95% confidence interval (CI) of the potential risk factors for major bleeding. During a median follow-up period of 199 days, major bleeding occurred in 72 patients. The cumulative incidence of major bleeding was 5.8% at 3 months, 13.8% at 1 year, 17.5% at 2 years, and 28.1% at 5 years. The most frequent major bleeding site was gastrointestinal tract (47%). Terminal cancer (adjusted HR, 4.17; 95% CI, 2.22-7.85, P<0.001), chronic kidney disease (adjusted HR, 1.89; 95% CI 1.06-3.37, P=0.031), and gastrointestinal cancer (adjusted HR, 1.78; 95% CI, 1.04-3.04, P=0.037) were independently associated with an increased risk of major bleeding. CONCLUSIONS: Major bleeding events were common during anticoagulation therapy in real-world cancer-associated VTE patients. Terminal cancer, chronic kidney disease, and gastrointestinal cancer were the independent risk factors for major bleeding.

SCN5A mutation identified in a patient with short-coupled variant of torsades de pointes.

BACKGROUND: Short-coupled variant of torsades de pointes (scTdP) is a disease characterized by TdP without QT prolongation, which is initiated by extremely short-coupled ventricular extra-systoles. Its genetic background remains rarely unveiled. OBJECTIVE: We aimed to identify genetic variations in patients with scTdP and to analyze the functional change of the mutant Na+ channel identified in a scTdP patient. METHODS AND RESULTS: We performed genetic analysis for inherited arrhythmia-related 45 genes using next-generation sequencer (MiSeq, Illumina) among seven consecutive scTdP patients. We identified an SCN5A mutation R800H in a 38-year-old male who suffered ventricular fibrillation during dinner and was resuscitated. Two months later, he lost his consciousness at work. His Holter electrocardiogram showed scTdP. He had no family history of sudden cardiac death or heart disease. Functional analysis of the SCN5A-R800H channels showed a significantly shortened recovery time from inactivation. Peak sodium current densities in SCN5A-R800H were larger than those in wild type but the difference was not statistically significant. CONCLUSIONS: We identified an SCN5A mutation in a scTdP patient and confirmed that the mutant channel caused the shortness of recovery time from inactivation. SCN5A might be a candidate gene for scTdP.

Telethonin variants found in Brugada syndrome, J-wave pattern ECG, and ARVC reduce peak Nav 1.5 currents in HEK-293 cells.

BACKGROUND: Telethonin (TCAP) is a Z-disk protein that maintains cytoskeletal integrity and various signaling pathways in cardiomyocytes. TCAP is shown to modulate α-subunit of the human cardiac sodium channel (hNav 1.5) by direct interactions. Several TCAP variants are found in cardiomyopathies. We sought to investigate whether TCAP variants are associated with arrhythmia syndromes. METHODS: Mutational analyses for TCAP were performed in 303 Japanese patients with Brugada syndrome, arrhythmogenic right ventricular cardiomyopathy, and J-wave pattern ECG. Using patch-clamp techniques, electrophysiological characteristics of hNav 1.5 were studied in HEK-293 cells stably expressing hNav 1.5 and transiently transfected with wild-type (WT) or variant TCAP. RESULTS: We identified two TCAP variants, c.145G>A:p.E49K and c.458G>A:p.R153H, in four individuals. p.E49K was found in two patients with ARVC or BrS. p.R153H was found in two patients with BrS or J-wave pattern ECG. No patient had variant hNav 1.5. Patch-clamp experiments demonstrated that peak sodium currents were significantly reduced in cells expressing p.R153H and p.E49K compared with WT-TCAP (66%, p.R153H; 72%, p.E49K). Voltage dependency of peak IV curve was rightward-shifted by 5 mV in cells expressing p.E49K compared with WT-TCAP. Voltage dependency of activation was not leftward-shifted by p.R153H, while voltage dependency of steady-state inactivation was leftward-shifted by p.E49K. CONCLUSIONS: We found two TCAP variants in the patients with BrS, J-wave pattern ECG, and ARVC that can cause loss-of-function of the hNav 1.5 in heterologous expression systems. Our observation suggests that these variants might impair INa and be associated with the patients' electrophysiological phenotypes. Further studies linking our experimental data to clinical phenotypes are warranted.

D-dimer levels at diagnosis and long-term clinical outcomes in venous thromboembolism: from the COMMAND VTE Registry.

The relationship between D-dimer level at diagnosis and long-term clinical outcomes has not been fully evaluated in venous thromboembolism (VTE). The COMMAND VTE Registry is a multicenter registry enrolling consecutive acute symptomatic VTE patients in Japan. Patients with available D-dimer levels at diagnosis (N = 2852) were divided into 4 groups according to the D-dimer levels; Quartile 1 (0.0-4.9 µg/mL): N = 682, Quartile 2 (5.0-9.9 µg/mL) N = 694, Quartile 3 (10.0-19.9 µg/mL) N = 710, and Quartile 4 (≥ 20.0 µg/mL): N = 766. The cumulative incidence of all-cause death was higher in Quartile 4 throughout the entire follow-up period (19.9%, 24.9%, 28.8%, and 41.5% at 5-year, P < 0.0001), as well as both within and beyond 30-day. After adjustment, the excess risk of Quartile 4 relative to Quartile 1 for all-cause death remained significant (HR 1.60, 95% CI 1.29-2.03). Similarly, the excess risk of Quartile 4 relative to Quartile 1 for recurrent VTE was significant (HR 1.57, 95% CI 1.02-2.41), which was more prominent in the cancer subgroup. The dominant causes of death in Quartile 4 were pulmonary embolism within 30-day, and cancer beyond 30-day. In conclusions, in VTE patients, elevated D-dimer levels at diagnosis were associated with the increased risk for both short-term and long-term mortality. The higher mortality risk of patients with highest D-dimer levels was driven by the higher risk for fatal PE within 30-day, and by the higher risk for cancer death beyond 30-day. Elevated D-dimer levels were also associated with the increased risk for long-term recurrent VTE, which was more prominent in patients with active cancer.

Allele-specific ablation rescues electrophysiological abnormalities in a human iPS cell model of long-QT syndrome with a CALM2 mutation.

Calmodulin is a ubiquitous Ca2+ sensor molecule encoded by three distinct calmodulin genes, CALM1-3. Recently, mutations in CALM1-3 have been reported to be associated with severe early-onset long-QT syndrome (LQTS). However, the underlying mechanism through which heterozygous calmodulin mutations lead to severe LQTS remains unknown, particularly in human cardiomyocytes. We aimed to establish an LQTS disease model associated with a CALM2 mutation (LQT15) using human induced pluripotent stem cells (hiPSCs) and to assess mutant allele-specific ablation by genome editing for the treatment of LQT15. We generated LQT15-hiPSCs from a 12-year-old boy with LQTS carrying a CALM2-N98S mutation and differentiated these hiPSCs into cardiomyocytes (LQT15-hiPSC-CMs). Action potentials (APs) and L-type Ca2+ channel (LTCC) currents in hiPSC-CMs were analyzed by the patch-clamp technique and compared with those of healthy controls. Furthermore, we performed mutant allele-specific knockout using a CRISPR-Cas9 system and analyzed electrophysiological properties. Electrophysiological analyses revealed that LQT15-hiPSC-CMs exhibited significantly lower beating rates, prolonged AP durations, and impaired inactivation of LTCC currents compared with control cells, consistent with clinical phenotypes. Notably, ablation of the mutant allele rescued the electrophysiological abnormalities of LQT15-hiPSC-CMs, indicating that the mutant allele caused dominant-negative suppression of LTCC inactivation, resulting in prolonged AP duration. We successfully recapitulated the disease phenotypes of LQT15 and revealed that inactivation of LTCC currents was impaired in CALM2-N98S hiPSC model. Additionally, allele-specific ablation using the latest genome-editing technology provided important insights into a promising therapeutic approach for inherited cardiac diseases.

Clinical Characteristics and Outcomes of Venous Thromboembolisms According to an Out-of-Hospital vs. In-Hospital Onset　- From the COMMAND VTE Registry.

BACKGROUND: Differences in the clinical characteristics and outcomes of venous thromboembolisms (VTEs) based on different clinical situations surrounding the onset might be important for directing appropriate treatment strategies, but have not yet been appropriately evaluated. Methods and Results: The COMMAND VTE Registry is a multicenter registry enrolling 3,027 consecutive patients with acute symptomatic VTEs in Japan between January 2010 and August 2014. We divided the study population into 3 groups: Out-of-hospital onset (n=2,308), In-hospital onset with recent surgery (n=310), and In-hospital onset without recent surgery (n=374). Active cancer was most prevalent in the In-hospital onset without recent surgery group, and least in the Out-of-hospital onset group (Out-of-hospital onset group: 20%, In-hospital onset with recent surgery group: 26%, and In-hospital onset without recent surgery group: 38%, P<0.001). The cumulative 5-year incidence of recurrent VTEs did not significantly differ across the 3 groups (11.4%, 5.8%, and 8.7%, respectively; P=0.11). The cumulative 5-year incidences of major bleeding and all-cause death were highest in the In-hospital onset without recent surgery group (11.1%, 8.5%, and 23.3%, P<0.001; 26.8%, 24.9%, and 48.4%, P<0.001, respectively). CONCLUSIONS: In the real-world VTE registry, the clinical characteristics and long-term outcomes substantially differed according to the clinical situation of VTE onset, suggesting the need for different treatment strategies for VTEs in different clinical settings.

Sex Differences in Clinical Characteristics and Outcomes of Patients With Venous Thromboembolism　- From the COMMAND VTE Registry.

BACKGROUND: It remains controversial whether sex category is a risk for recurrent venous thromboembolism (VTE) and major bleeding among VTE patients.Methods and Results:The COMMAND VTE Registry is a multicenter registry enrolling 3,027 consecutive acute symptomatic VTE patients from 29 centers in Japan between January 2010 and August 2014. We compared the clinical characteristics and outcomes of men and women. Men accounted for 1,169 (39%) and women 1,858 (61%). Compared with women, men were younger (64.9±14.7 vs. 68.6±15.6 years old, P<0.001), more often had prior VTE (7.2% vs. 5.1%, P=0.02), and less often had transient risk factors for VTE (30% vs. 40%, P<0.001). The proportions of active cancer and pulmonary embolism were comparable between men and women (24% vs. 22%, P=0.26; 56% vs. 57%, P=0.48, respectively). The cumulative 3-year incidences of recurrent VTE, major bleeding, and all-cause death were not significantly different between men and women (7.0% vs. 8.6%, P=0.47; 10.6% vs. 9.2%, P=0.25; 25.2% vs. 23.4%, P=0.35, respectively). The adjusted risks of men relative to women for recurrent VTE and for major bleeding remained insignificant (HR 0.83, 95% CI 0.63-1.09, P=0.17; HR 1.15, 95% CI 0.90-1.47, P=0.25, respectively). CONCLUSIONS: In real-world VTE patients, the clinical characteristics differed between men and women, but there was not a large sex-related difference in the risks for recurrent VTE or major bleeding.

Cancer-Associated Venous Thromboembolism in the Real World　- From the COMMAND VTE Registry.

BACKGROUND: There is a paucity of data on the management and prognosis of cancer-associated venous thromboembolism (VTE), leading to uncertainty about optimal management strategies.Methods and Results:The COMMAND VTE Registry is a multicenter registry enrolling 3,027 consecutive acute symptomatic VTE patients in Japan between 2010 and 2014. We divided the entire cohort into 3 groups: active cancer (n=695, 23%), history of cancer (n=243, 8%), and no history of cancer (n=2089, 69%). The rate of anticoagulation discontinuation was higher in patients with active cancer (43.5%, 27.0%, and 27.0%, respectively, at 1 year, P<0.001). The cumulative 5-year incidences of recurrent VTE, major bleeding, and all-cause death were higher in patients with active cancer (recurrent VTE: 17.7%, 10.2%, and 8.6%, P<0.001; major bleeding: 26.6%, 8.8%, and 9.3%, P<0.001; all-cause death: 73.1%, 28.6%, 14.6%, P<0.001). Among the 4 groups classified according to active cancer status, the cumulative 1-year incidence of recurrent VTE was higher in the metastasis group (terminal stage group: 6.4%, metastasis group: 22.1%, under chemotherapy group: 10.8%, and other group: 5.8%, P<0.001). CONCLUSIONS: In a current real-world VTE registry, patients with active cancer had higher risk for VTE recurrence, bleeding, and death, with variations according to cancer status, than patients without active cancer. Anticoagulation therapy was frequently discontinued prematurely in patients with active cancer in discordance with current guideline recommendations.

Thrombolysis with tissue plasminogen activator in patients with acute pulmonary embolisms in the real world: from the COMMAND VTE registry.

There is still uncertainty about the optimal usage of thrombolysis for acute pulmonary embolisms (PEs), leading to a widely varying usage in the real world. The COMMAND VTE Registry is a multicenter retrospective registry enrolling consecutive patients with acute symptomatic venous thromboembolisms (VTEs) in Japan. The present study population consisted of 1549 patients with PEs treated with tissue plasminogen activator (t-PA) thrombolysis (N = 180, 12%) or without thrombolysis (N = 1369). Thrombolysis with t-PA was implemented in 33% of patients with severe PEs, and 9.2% of patients with mild PEs with a wide variation across the participating centers. Patients with t-PA thrombolysis were younger, and less frequently had active cancer, history of major bleeding, and anemia. At 30 days, t-PA thrombolysis as compared to no thrombolysis was associated with similar mortality rates (5.0% vs. 6.9%, P = 0.33), but a lower adjusted mortality risk (OR 0.41; 95% CI 0.18-0.90, P = 0.03), while it was associated with a trend for higher rates of major bleeding (5.6% vs. 2.9%, P = 0.06) and a significantly higher adjusted risk for major bleeding (OR 2.39; 95% CI 1.06-5.36, P = 0.03). In patients with severe PEs, the mortality rates at 30 days were significantly lower in the t-PA thrombolysis group than no thrombolysis group (15% vs. 37%, P = 0.006). In the present real-world VTE registry in Japan, t-PA thrombolysis was not infrequently implemented, not only in patients with severe PEs, but also in patients with mild PEs. A substantial mortality risk reduction might be suggested with t-PA thrombolysis in patients with severe PEs.