Circulation Journal
Online ISSN : 1347-4820
Print ISSN : 1346-9843
ISSN-L : 1346-9843
Volume 85, Issue 8
Displaying 1-31 of 31 articles from this issue
Focus on issue: Arrhythmia / Electrophysiology
Reviews
  • Wen-Han Cheng, Yi-Hsin Chan, Jo-Nan Liao, Ling Kuo, Shih-Ann Chen, Tze ...
    Article type: REVIEW
    2021 Volume 85 Issue 8 Pages 1245-1253
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: June 05, 2021
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    Stroke prevention is the cornerstone of management of atrial fibrillation (AF), and non-vitamin K antagonist oral anticoagulants (NOACs) are commonly prescribed. Because routine monitoring of anticoagulant effects of NOACs is not necessary, appropriate dosing following the criteria of each NOACs defined in pivotal randomized trials is important. Real-world data demonstrate that underdosing NOACs is associated with a higher risk of ischemic stroke without a lower risk of major bleeding. Furthermore, renal function of AF patients should be assessed using the Cockcroft-Gault formula to prevent overestimation that could result in overdosing of NOACs. The assessment of bleeding risk is important, and the HAS-BLED score should be used to help identify patients at high risk of bleeding (HAS-BLED score ≥3). Moreover, the HAS-BLED score should be reassessed at periodic intervals to address potentially modifiable bleeding risk factors because bleeding risks of AF patients are not static. When managing NOAC-related bleeding episodes, the possibility of occult malignancies (e.g., grastrointestinal [GI] tract cancers for patients experiencing GI bleeding and bladder cancer for patients with hematuria) should be kept in mind. Addressing all of these issues is crucial to achieving better clinical outcomes for anticoagulated AF patients. More efforts are necessary to incorporate clear and easy-to-follow recommendations about optimal management of anticoagulation into the guidelines to improve AF patient care.

Original Articles
Atrial Fibrillation
  • Ken Okumura, Hirofumi Tomita, Michikazu Nakai, Eitaro Kodani, Masaharu ...
    Article type: ORIGINAL ARTICLE
    Subject area: Atrial Fibrillation
    2021 Volume 85 Issue 8 Pages 1254-1262
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: March 25, 2021
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    Supplementary material

    Background:Recently, identification of independent risk factors for ischemic stroke in Japanese non-valvular atrial fibrillation (NVAF) patients was made by analyzing the 5 major Japanese registries: J-RHYTHM Registry, Fushimi AF Registry, Shinken Database, Keio interhospital Cardiovascular Studies, and the Hokuriku-Plus AF Registry.

    Methods and Results:The predictive value of the risk scheme in Japanese NVAF patients was assessed. Of 16,918 patients, 12,289 NVAF patients were analyzed (mean follow up, 649±181 days). Hazard ratios (HRs) of each significant, independent risk factor were determined by using adjusted Cox-hazard proportional analysis. Scoring system for ischemic stroke was created by transforming HR logarithmically and was estimated by c-statistic. During the 21,820 person-years follow up, 241 ischemic stroke events occurred. Significant risk factors were: being elderly (aged 75–84 years [E], HR=1.74), extreme elderly (≥85 years [EE], HR=2.41), having hypertension (H, HR=1.60), previous stroke (S, HR=2.75), type of AF (persistent/permanent) (T, HR=1.59), and low body mass index <18.5 kg/m2(L, HR=1.55) after adjusting for oral anticoagulant treatment. The score was assigned as follows: 1 point to H, E, L, and T, and 2 points to EE and S (HELT-E2S2score). The C-statistic, using this score, was 0.681 (95% confidence interval [CI]=0.647–0.714), which was significantly higher than those using CHADS2(0.647; 95% CI=0.614–0.681, P=0.027 for comparison) and CHA2DS2-VASc scores (0.641; 95% CI=0.608–0.673, P=0.008).

    Conclusions:The HELT-E2S2score may be useful for identifying Japanese NVAF patients at risk of ischemic stroke.

  • Seiji Takatsuki
    Article type: EDITORIAL
    2021 Volume 85 Issue 8 Pages 1263-1264
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: May 26, 2021
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  • Kenichi Sasaki, Ikutaro Nakajima, Takumi Higuma, Marika Yamada, Akira ...
    Article type: ORIGINAL ARTICLE
    Subject area: Atrial Fibrillation
    2021 Volume 85 Issue 8 Pages 1265-1272
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: April 01, 2021
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    Background:The optimum cut-off value of premature atrial contraction (PAC) burden (CV-PACb) in 24-h Holter electrocardiography (24-h ECG) for predicting atrial fibrillation (AF) is debatable, with few validation data.

    Methods and Results:We retrospectively analyzed 61 patients already diagnosed with AF (AD-AF) and 147 patients never diagnosed with AF (ND-AF), aged ≥50 years, free of heart disease, and who had undergone 24-h ECG and transthoracic echocardiography (TTE). Receiver operating characteristic analysis demonstrated that 0.4% was the optimal CV-PACb differentiating AD-AF from ND-AF, with 69% sensitivity and 72% specificity (area under the curve [AUC] 0.72; 95% confidence interval [CI] 0.65–0.79); however, the left atrial volume index was not significant (AUC 0.60; 95% CI 0.51–0.68). To verify the CV-PACb, new propensity-matched cohorts (i.e., subjects with a PAC burden ≥0.4% and <0.4%; n=69 in each group) were compared based on new detection of AF at a median follow-up of 50 months (interquartile range 12–60 months) Multivariable Cox regression analysis revealed that among 24-h ECG and TTE findings, only PAC burden ≥0.4% was independently associated with incident AF (hazard ratio 5.28; 95% CI 1.28–26.11; P=0.023).

    Conclusions:A high PAC burden (≥0.4%) in 24-h ECG was a reliable indicator to identify undiagnosed AF, whereas TTE parameters did not show any predictive value.

  • Kazuhiro Satomi, Yoshinao Yazaki
    Article type: EDITORIAL
    2021 Volume 85 Issue 8 Pages 1273-1274
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: April 21, 2021
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  • Kengo Kusano, Nobuyoshi Sugishita, Masaharu Akao, Hikari Tsuji, Kunihi ...
    Article type: ORIGINAL ARTICLE
    Subject area: Atrial Fibrillation
    2021 Volume 85 Issue 8 Pages 1275-1282
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: April 02, 2021
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    Supplementary material

    Background:Direct oral anticoagulants have become a standard therapy for non-valvular atrial fibrillation (NVAF). However, little is known about their effectiveness/safety when prescribed by general practitioners to treat high-risk populations such as the elderly, those who are frail or have cognitive dysfunction.

    Methods and Results:In this multicenter, prospective study, a total of 5,717 NVAF patients (mean age 73.9 years) receiving rivaroxaban were registered by general practitioners, with a maximum 3-year follow up (mean 2.0±0.5 years). The primary endpoint was a composite of stroke and systemic embolism (SE). The annual incidence (per 100 person-years) of stroke/SE was 1.23% and for major bleeding, it was 0.63%. Multivariate analyses identified age ≥75 years (hazard ratio [HR]; 2.67, P<0.001) and history of ischemic stroke (HR; 1.89, P=0.005) as significant risk factors of stroke/SE, with history of major bleeding (HR; 14.9, P<0.001) and warfarin use (HR; 2.15, P=0.002) as risk factors for major bleeding events. Neither cognitive dysfunction, defined by the receipt of anti-dementia medications, nor frailty, evaluated by the classification of the Japanese Long-term Care Insurance system, correlated with stroke/SE or major bleeding events.

    Conclusions:The low incidence of adverse events, including stroke/SE and bleeding, in patients prescribed rivaroxaban by general practitioners supports its use as a safe and efficacious treatment in the standard clinical care of high-risk patient populations.

Catheter Ablation
  • Keita Mamiya, Yasuya Inden, Satoshi Yanagisawa, Aya Fujii, Toshiro Tom ...
    Article type: ORIGINAL ARTICLE
    Subject area: Catheter Ablation
    2021 Volume 85 Issue 8 Pages 1283-1293
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: March 09, 2021
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    Supplementary material

    Background:Catheter ablation (CA) is effective for recurrent episodes of ventricular fibrillation (VF) in Brugada syndrome (BrS). VF development in BrS is associated with several electrocardiogram (ECG) abnormalities. This study investigated changes in ECG parameters in high-risk BrS patients who underwent epicardial CA.

    Methods and Results:In all, 27 BrS patients were implanted with an implantable cardioverter-defibrillator (ICD). Patients were divided into 2 groups: (1) an ablation group (n=11) that underwent epicardial CA because of VF recurrence; and (2) a primary prevention (PP) group (n=16) with ICD implantation only. ECG parameters were evaluated before and 12 months after CA and compared with ECG parameters in the PP group. The T wave peak-to-end interval was significantly longer and the number of abnormal spikes in leads V1–V3 at the second, third, and fourth intercostal spaces was greater in the ablation than PP group. After ablation, ST levels and the sum of abnormal spikes in leads V1–V3 were significantly decreased. The mean (±SD) number of ICD shocks decreased markedly during a mean follow-up period of 42.0 months (from 3.8±3.7 to 0.2±0.4/year). Four patients had an ICD shock following the ablation procedure. Greater reductions in ST-segment elevation and abnormal spikes were observed in the group without than with VF recurrence.

    Conclusions:Improvements in surface ECG parameters appear to be associated with successful ablation in high-risk BrS patients.

  • Yuki Komatsu, Akihiko Nogami, Masaki Ieda
    Article type: EDITORIAL
    2021 Volume 85 Issue 8 Pages 1294-1295
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: April 29, 2021
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  • Roland Richard Tilz, Roza Meyer-Saraei, Charlotte Eitel, Thomas Fink, ...
    Article type: ORIGINAL ARTICLE
    Subject area: Catheter Ablation
    2021 Volume 85 Issue 8 Pages 1296-1304
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: April 13, 2021
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    Background:The arctic front cryoballoon (AF-CB) provides effective and durable pulmonary vein isolation (PVI) associated with encouraging clinical outcome. The POLARx cryoballoon incorporates unique features and design changes that may translate into improved efficacy, safety and further simplified balloon-based procedures. Efficacy and safety of the novel POLARx cryoballoon was compared to the fourth generation AF-CB (AF-CB4).

    Methods and Results:Twenty-five consecutive patients with paroxysmal or persistent atrial fibrillation were prospectively enrolled, underwent POLARx-based PVI (POLARx group) and were compared to 25 consecutive patients treated with the AF-CB4 (AF-CB4 group). All PVs were successfully isolated utilizing the POLARx and AF-CB4. A significant difference regarding the mean minimal cryoballoon temperatures reached using the AF-CB4 and POLARx (−50±6℃ vs. −57±7℃, P=0.004) was observed. Real-time PVI was visualized in 81% of POLARx patients and 42% of AF-CB4 patients (P<0.001). Utilizing the POLARx, a trend towards shorter median procedure time (POLARx: 45 [39, 53] min vs. AF-CB4: 55 [50, 60] min; P=0.062) was found. No differences were observed between AF-CB4 and POLARx concerning catheter maneuverability, catheter stability and periprocedural complications.

    Conclusions:The novel POLARx showed similar safety and efficacy compared to the AF-CB4. A higher rate of real-time PV recordings and significantly lower minimal balloon temperatures were observed using the POLARx.

  • Pil-Sung Yang, Jung-Hoon Sung, Daehoon Kim, Eunsun Jang, Hee Tae Yu, T ...
    Article type: ORIGINAL ARTICLE
    Subject area: Catheter Ablation
    2021 Volume 85 Issue 8 Pages 1305-1313
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: March 16, 2021
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    Supplementary material

    Background:It is unclear whether catheter ablation is beneficial for frail elderly patients with atrial fibrillation (AF). This study evaluated the effect of ablation on outcomes in frail elderly patients with AF.

    Methods and Results:From the Korean National Health Insurance Service database, 194,928 newly diagnosed AF patients were treated with ablation or medical therapy (rhythm or rate control) between 2005 and 2015. Among these patients, the study included 1,818 (ablation; n=119) frail and 1,907 (ablation; n=230) non-frail elderly (≥75 years) patients. Propensity score matching was used to correct for differences between groups. During 28 months (median) follow up, the risk of all-cause death, composite outcome (all-cause death, heart failure admission, stroke/systemic embolism, and sudden cardiac arrest), and each outcome did not change after ablation in frail elderly patients. However, in non-frail elderly patients, ablation was associated with a lower risk of all-cause death (3.5 and 6.2 per 100 person-years; hazard ratio [HR] 0.48; 95% confidence interval [CI] 0.30–0.79; P=0.004), and composite outcome (6.9 and 11.2 per 100 person-years; HR 0.54; 95% CI 0.38–0.75; P<0.001).

    Conclusions:Ablation may be associated with a lower risk of death and composite outcome in non-frail elderly, but the beneficial effect of ablation was not significant in frail elderly patients with AF. The effect of frailty on the outcome of ablation should be evaluated in further studies.

  • Yukihiko Yoshida, Teiichi Yamane, Shiro Nakahara, Atsushi Kobori, Hiro ...
    Article type: ORIGINAL ARTICLE
    Subject area: Catheter Ablation
    2021 Volume 85 Issue 8 Pages 1314-1320
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: April 21, 2021
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    Supplementary material

    Background:SATAKE HotBalloon®catheter (HBC) is a radiofrequency balloon catheter for the treatment of atrial fibrillation (AF), and was approved for use in Japan to treat drug-resistant paroxysmal AF in 2015. Post-marketing surveillance study was conducted by Toray Industries, Inc. to evaluate the efficacy and safety of HBC treatment in patients with paroxysmal AF in a real-world setting. This study is the first nation-wide survey of HBC treatment for paroxysmal AF in clinical practice in Japan.

    Methods and Results:This was a single-arm, multicenter observational study with an observation period of 48 weeks after ablation. Pulmonary vein isolation and AF non-recurrence rates were evaluated and adverse events (AEs) were observed at 46 sites in Japan. An AF event was defined as recurrence of AF or re-ablation from 12 to 48 weeks after ablation. The success rate of pulmonary vein isolation was 99.0% (486/491) for patients with AF. The cumulative AF non-recurrence rate was 94.1% at 24 weeks and 87.8% at 48 weeks. AEs were found to occur 21.5% (114/530), and ablation-related AEs were found to occur 2.6% (14/530) during the study period, with the most common being pericardial effusion (0.8%, 4/530).

    Conclusions:This study demonstrates the efficacy and safety of HBC ablation in Japanese patients with recurrent symptomatic paroxysmal AF refractory to antiarrhythmic therapy.

  • Naohiko Kawaguchi, Atsushi Suzuki, Michio Usui, Shunji Yoshikawa, Shin ...
    Article type: ORIGINAL ARTICLE
    Subject area: Catheter Ablation
    2021 Volume 85 Issue 8 Pages 1321-1328
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: April 13, 2021
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    Background:Sedation during pulmonary vein isolation (PVI) for atrial fibrillation often provokes a decline in left atrial (LA) pressure (LAP) under atmospheric pressure and increases the risk of systemic air embolisms. This study aimed to investigate the efficacy of adaptive servo-ventilation (ASV) on the LAP in sedated patients.

    Methods and Results:Fifty-one consecutive patients undergoing cryoballoon PVI were enrolled. All patients underwent sedation using propofol throughout the procedure. After the transseptal puncture and the insertion of a long sheath into the LA, the LAP was measured. Then, the ASV treatment was started, and the LAP was re-measured. The LAP before and after the ASV support was investigated. Before ASV, the LAP during the inspiratory phase was significantly smaller than that during the expiratory phase (4.9±5.4 mmHg vs. 14.0±5.2 mmHg, P<0.01). The lowest LAP was −2.2±5.1 mmHg and was under 0 mmHg in 37 (73%) patients. After the ASV, the LAP during the inspiratory phase significantly increased to 8.9±4.1 mmHg (P<0.01), and lowest LAP increased to 4.7±5.9 mmHg (P<0.01). The negative lowest LAP value became positive in 30/37 (81%) patients. There were no statistical differences regarding obstructive sleep apnea (OSA), obesity, gender, or other comorbidities between patients with and without a negative lowest LAP after ASV support.

    Conclusions:ASV is effective for increasing the LAP above 0 mmHg and might prevent air embolisms during PVI.

Devices
  • Hironori Ishiguchi, Akihiko Shimizu, Masahiro Ishikura, Masaaki Yoshid ...
    Article type: ORIGINAL ARTICLE
    Subject area: Devices
    2021 Volume 85 Issue 8 Pages 1329-1337
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: April 16, 2021
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    Supplementary material

    Background:An association between atrial high-rate episode (AHRE) and stroke has been reported, although data for the Asian population are limited. This study aimed to investigate the role of AHRE in ischemic and major bleeding events in patients who underwent a cardiac implantable electronic device (CIED) procedure.

    Methods and Results:This single-center historical cohort study included 710 patients (age: 78±11 years, 374 women) who underwent a CIED-related procedure between October 2009 and September 2019 at Shimane Prefectural Central Hospital (median follow-up period: 4.5 [2.5, 7] years, 3439 person-years). Based on the maximum AHRE burden, patients were divided into: (1) <6 min; (2) ≥6 min to 24-h; and (3) ≥24-h groups. The cumulative incidence of ischemic (ischemic stroke, systemic embolism, and transient ischemic attack) and major bleeding (≥3 Bleeding Academic Research Consortium bleeding criteria) events after the procedure were compared. Uni- and multivariate analyses were performed to identify factors associated with these events. The incidence of both events increased with the rising AHRE burden, being significantly higher in the ≥24-h group than in the <6 min group. Multivariate analysis found age ≥85 years to be the only independent factor associated with both events.

    Conclusions:Longer AHRE duration is associated with a high number of major bleeding and ischemic events. Monitoring these bleeding risks is mandatory when clinicians are considering anticoagulation therapy for such patients.

  • Hidehira Fukaya
    Article type: EDITORIAL
    2021 Volume 85 Issue 8 Pages 1338-1340
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: June 03, 2021
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  • Yasuhiro Matsuda, Masaharu Masuda, Mitsutoshi Asai, Osamu Iida, Shin O ...
    Article type: ORIGINAL ARTICLE
    Subject area: Devices
    2021 Volume 85 Issue 8 Pages 1341-1348
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: February 09, 2021
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    Background:Although patients with poor ability to perform activities of daily living, such as those with high Clinical Frailty Score (CFS), will often receive a cardiac implantable electric device (CIED), the indications for implantation in these patients have not been clearly defined. We investigated the association between CFS and prognosis in patients with a CIED.

    Methods and Results:We retrospectively enrolled 323 consecutive patients who underwent initial device implantation (age, 77 (70–83) years; male, 181 [56%] patients; high-voltage device, 49 [15%] patients), and the CFS was retrospectively estimated. Primary outcome was all-cause death, and the secondary outcome was hospitalization due to heart failure (HF). Median CFS was 4 (3–5) points. During 2 years’ follow-up, all-cause death occurred in 32 patients (10%). Freedom from all-cause death was significantly lower in patients with a high CFS than in those with a low score (1–2 points: 100%, 3–4 points: 92.9%, 5–9 points: 77.3%, P<0.01). After adjustment for age and sex, the CFS was an independent predictor of the primary outcome (hazard ratio [HR] 2.0, 95% confidence interval [CI] 1.6–2.5, P<0.01), and of the secondary outcome (HR 1.6 [95% CI 1.2–2.0], P<0.01).

    Conclusions:The CFS is an independent predictor of both death and hospitalization due to HF in patients with a CIED.

  • Daigo Yagishita, Morio Shoda, Satoshi Saito, Shohei Kataoka, Kyoichiro ...
    Article type: ORIGINAL ARTICLE
    Subject area: Devices
    2021 Volume 85 Issue 8 Pages 1349-1355
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: April 02, 2021
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    Background:The number of patients undergoing cardiac resynchronization therapy has increased. Consequently, there is increased frequency in the removal and reimplantation of coronary venous (CV) leads due to infection or malfunction.

    Methods and Results:A total of 345 consecutive patients referred for lead(s) extraction were reviewed. Of these, 34 patients who underwent a CV lead removal were investigated. The indications for CV leads removal were device-related infections in 29 patients and lead malfunctions in 5 patients. The average duration of the CV leads was 4.1±3.8 years. All CV leads were successfully removed without any major complications, except for 1 in-hospital death. Successful CV lead removal by simple traction (ST) was achieved in 21 patients (62%), whereas extraction tools were required in 13 patients (38%). Local infection and CV lead dwell time were significantly associated with successful ST (P=0.04 and P=0.014, respectively). CV lead re-implantation was successfully performed in 25 patients; however, a right-side approach was required in 92%, and occlusion/stenosis of the previous CV was observed in 80% of the patients.

    Conclusions:CV lead removal is relatively successful and safe. The presence of local infection and a shorter lead duration may enable successful ST of a CV lead. However, the re-implantation procedure should be well prepared for the complexity related to the right-side approach and occlusion/stenosis of the previous CV.

  • Mi Kyoung Song, Jae-Sun Uhm, Jae Suk Baek, Ja Kyoung Yoon, Jae Yoon Na ...
    Article type: ORIGINAL ARTICLE
    Subject area: Devices
    2021 Volume 85 Issue 8 Pages 1356-1364
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: May 12, 2021
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    Supplementary material

    Background:Implantable cardioverter-defibrillator (ICD) therapy is important for the prevention of sudden cardiac death, but data on clinical outcomes of ICD therapy in Asian pediatric patients are scarce. The aim of this Korean multicenter study was to evaluate the current state and elucidate the clinical outcomes of ICD therapy in children.

    Methods and Results:Data from 5 pediatric cardiology centers were retrospectively collected from 2007 to 2019. Altogether, 99 patients were enrolled (mean age 13.9±4.1 years). The most common underlying disease was a primary electrical disease (56%). An ICD was implanted for primary prevention in 19%. Appropriate shock occurred in 44% of patients at a median of 1.6 years after implantation. There was no significant difference in the appropriate shock rate between patients with primary and secondary prevention indications (32% vs. 48%, respectively). A total of 33 patients (33%) experienced inappropriate shock, which was associated with primary electrical disease and follow-up duration on multivariate analysis. 17% of patients had ICD-related complications.

    Conclusions:The utilization rate of ICD for primary prevention was still low in the pediatric population in Korea, but there was a substantial rate of appropriate shock in these patients. Efforts to increase ICD usage to save the lives of high-risk patients and reduce the incidence of inappropriate shock are required.

Population Science
  • Tomoko Yoshikawa, Jun Hata, Satoko Sakata, Takuya Nagata, Yoichiro Hir ...
    Article type: ORIGINAL ARTICLE
    Subject area: Population Science
    2021 Volume 85 Issue 8 Pages 1365-1372
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: February 18, 2021
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    Supplementary material

    Background:Atrial fibrillation (AF) is a common arrhythmia in the elderly, and causes complications such as cardioembolic stroke. Serum high-sensitivity C-reactive protein (hs-CRP), a marker of systemic inflammation, has been reported to be a risk factor for developing AF in Western countries. However, few community-based studies have examined this issue in general Asian populations.

    Methods and Results:A total of 2,510 community-dwelling Japanese participants aged ≥40 years without a history of AF were divided into 4 groups according to the sex-specific quartiles of serum hs-CRP concentrations (Q1, lowest and Q4, highest) and followed up for 24 years. The hazard ratios and their 95% confidence intervals for the development of AF were estimated using a Cox proportional hazards model. During the follow up, 234 subjects developed AF. The risk of AF increased significantly with elevating serum hs-CRP levels after adjustment for potential confounding factors (hazard ratio [95% confidence interval], Q1, 1.00 [reference]; Q2, 1.26 [0.83–1.92]; Q3, 1.77 [1.18–2.66]; and Q4, 1.89 [1.24–2.86]; P for trend <0.001).

    Conclusions:The study findings suggest that elevated serum hs-CRP levels are an independent risk factor for the development of AF in a general Japanese population.

  • Jun Hata, Takuya Nagata, Satoko Sakata, Emi Oishi, Yoshihiko Furuta, Y ...
    Article type: ORIGINAL ARTICLE
    Subject area: Population Science
    2021 Volume 85 Issue 8 Pages 1373-1382
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: February 23, 2021
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    Supplementary material

    Background:The risk prediction of incident atrial fibrillation (AF) is useful to prevent AF and its complications. The aim of this study is to develop a new risk prediction model for incident AF using the prospective longitudinal data from a general Japanese population.

    Methods and Results:A total of 2,442 community-dwelling AF-free residents aged ≥40 years were followed up from 1988 to 2012 (46,422 person-years). The development of AF was confirmed by a standard 12-lead electrocardiogram at repeated health examinations and by medical records at clinics or hospitals. The risk prediction model for incident AF was developed using a Cox proportional hazards model. During the follow up, 230 AF events were confirmed. Age, sex, systolic blood pressure, waist circumference, estimated glomerular filtration rate, abnormal cardiac murmur, high R-wave amplitude, and arrhythmia other than AF were selected for inclusion in the model. This model showed good discrimination (Harrell’s c statistics: 0.785) and calibration (Greenwood-Nam-D’Agostino test: P=0.87) for AF risk at 10 years.

    Conclusions:The new risk prediction model showed good performance on the individual risk assessment of the future onset of AF in a general Japanese population. As this model included commonly used clinical parameters, it may be useful for determining the requirements for the careful evaluation of AF, such as frequent electrocardiogram examinations in clinical settings, and subsequent reductions in the risk of AF-related complications.

    Editor's pick

    Circulation Journal Awards for the Year 2021
    Second Place in the Clinical Investigation Section

Basic Science
  • Tomomi Matsuura, Takeshi Soeki, Daiju Fukuda, Etsuko Uematsu, Takeshi ...
    Article type: ORIGINAL ARTICLE
    Subject area: Basic Science
    2021 Volume 85 Issue 8 Pages 1383-1391
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: March 20, 2021
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    Supplementary material

    Background:Activated factor X (FXa), which contributes to chronic inflammation via protease-activated receptor 2 (PAR2), might play an important role in atrial fibrillation (AF) arrhythmogenesis. This study aimed to assess whether PAR2 signaling contributes to AF arrhythmogenesis and whether rivaroxaban ameliorates atrial inflammation and prevents AF.

    Methods and Results:In Study 1, PAR2 deficient (PAR2−/−) and wild-type mice were infused with angiotensin II (Ang II) or a vehicle via an osmotic minipump for 2 weeks. In Study 2, spontaneously hypertensive rats (SHRs) were treated with rivaroxaban, warfarin, or vehicle for 2 weeks after 8 h of right atrial rapid pacing. The AF inducibility and atrial remodeling in both studies were examined. Ang II-treated PAR2−/− mice had a lower incidence of AF and less mRNA expression of collagen1 and collagen3 in the atrium compared to wild-type mice treated with Ang II. Rivaroxaban significantly reduced AF inducibility compared with warfarin or vehicle. In SHRs treated with a vehicle, rapid atrial pacing promoted gene expression of inflammatory and fibrosis-related biomarkers in the atrium. Rivaroxaban, but not warfarin, significantly reduced expression levels of these genes.

    Conclusions:The FXa–PAR2 signaling pathway might contribute to AF arrhythmogenesis associated with atrial inflammation. A direct FXa inhibitor, rivaroxaban, could prevent atrial inflammation and reduce AF inducibility, probably by inhibiting the pro-inflammatory activation.

    Editor's pick

    Circulation Journal Awards for the Year 2021
    Second Place in the Experimental Investigation Section

  • Koichi Kaikita, Kenichi Tsujita
    Article type: EDITORIAL
    2021 Volume 85 Issue 8 Pages 1392-1393
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: April 02, 2021
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  • Yasuharu Matsunaga-Lee, Yasuyuki Egami, Hitoshi Nakamura, Yutaka Matsu ...
    Article type: ORIGINAL ARTICLE
    Subject area: Basic Science
    2021 Volume 85 Issue 8 Pages 1394-1399
    Published: July 21, 2021
    Released on J-STAGE: July 21, 2021
    Advance online publication: May 08, 2021
    JOURNAL OPEN ACCESS FULL-TEXT HTML

    Background:It is unclear whether balloon size can influence lesion formation. The aim of this study was to evaluate the impact of balloon size on lesion formation during laser balloon procedures in an in vitro model.

    Methods and Results:Laser energy was applied to chicken muscle using a first generation laser balloon. Laser ablation was performed with 2 different balloon sizes (18 mm and 32 mm) using 2 different power settings (12 W/20 s and 8.5 W/20 s) on the chicken muscle. The lesion characteristics, including maximum lesion depth, maximum lesion diameter, surface diameter and depth at maximum diameter, were compared between the 18-mm and 32-mm balloon groups at 12 W/20 s and 8.5 W/20 s, respectively. We created 40 lesions using laser energy at 12 W/20 s and 80 lesions at 8.5 W/20 s. At both power settings, the maximum lesion depth and the depth at the maximum diameter were larger in the 18-mm than in the 32-mm balloon group. At both power settings, the maximum lesion diameter and the surface diameter were smaller in the 18-mm than in the 32-mm balloon group.

    Conclusions:The balloon size could affect the lesion formation during laser balloon ablation. The lesion with the larger balloon size was wider and shallower than the lesion with the smaller balloon size.

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