Publications by authors named "Ken-ichi Hirata"

Deep vein thrombosis (DVT) remains a significant health problem. Although animal models have provided significant insights into the DVT pathophysiology, time-course assessment in a same animal is technically limited. Recently, we reported a novel murine saphenous DVT model for in vivo visualization of spatiotemporal dynamics of inflammatory cells.

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Background & Aims: In older patients undergoing cardiac surgery, physical function is a critical determinant of postoperative outcomes. Beta-hydroxy-beta-methylbutyrate (HMB) supplementation has been shown to promote muscle protein anabolism and inhibit catabolism, thereby preventing muscle weakness. However, its efficacy in older patients undergoing cardiac surgery remains unknown.

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Background: Prognosis of chronic thromboembolic pulmonary hypertension (CTEPH) has improved after the availability of balloon pulmonary angioplasty (BPA) and approved drugs. However, the clinical effects of cancer, which is one of the associated medical conditions of CTEPH, remain unclear. We aimed to investigate prognosis in patients with CTEPH and comorbid cancer.

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Atrial fibrillation (AF) is strongly associated with strokes, heart failure, and increased mortality. This study aims to identify the monocyte-macrophage heterogeneity and interactions of these cells with non-immune cells, and to identify functional biomarkers in patients with AF. Therefore, we assess the single cell landscape of left atria (LA), using a combination of single cell and nucleus RNA-seq.

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  • Optical coherence tomography (OCT) is used to identify dangerous plaques in patients with acute coronary syndrome (ACS), but manual analysis has its limitations.
  • This study developed a deep-learning model using convolutional neural networks (CNN) and transformers to automatically predict the prognosis of ACS patients from OCT images after they underwent percutaneous coronary intervention (PCI).
  • The deep-learning model showed superior predictive performance for target vessel failure compared to traditional models, indicating that it can effectively analyze OCT images as well as or better than human observers.
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Unlabelled: Superoxide dismutase (SOD) catalyzes the highly reactive superoxide anion to form hydrogen peroxide, which facilitates cell proliferation and death. We investigated whether red cell SOD (R-SOD) activity is associated with an increased risk of cancer in a Japanese general population. We prospectively analyzed data from 1,921 participants (800 men and 1,121 women; age, 58.

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Background: A novel cardioprotective drug, vericiguat, reduces the risk of cardiovascular mortality for patients already on guideline-directed medical therapy. However, the effect of vericiguat on left ventricular (LV) reverse remodeling in patients with reduced LV ejection fraction (LVEF) with or without guideline-directed medical therapy, known as quadruple medical therapy, remains undetermined.

Methods And Results: This study comprised 73 heart failure (HF) patients with reduced LVEF (<45%) from 5 institutions in Japan.

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  • Stage B heart failure (HF) involves structural heart disease without symptoms, and identifying risk in these patients is complex but crucial for early intervention.
  • A study of 1,646 heart failure patients established a scoring system called BEEAF to categorize stage B HF patients into low, moderate, and high-risk groups based on specific health indicators.
  • The results indicated that higher risk levels predicted worse outcomes, with high-risk stage B patients faring similarly to those in stage C HF.
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Background: Proprotein convertase subtilisin/kexin type 9 inhibitors stabilize vulnerable plaque, reducing cardiovascular events. However, manual optical coherence tomography (OCT) analysis of drug efficacy is challenging because of signal attenuation within lipid plaques.

Methods And Results: Twenty-four patients with thin-cap fibroatheroma were prospectively enrolled and randomized to receive alirocumab (75 mg every 2 weeks) plus rosuvastatin (10 mg/day) or rosuvastatin (10 mg/day) alone.

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  • Hemothorax from right intercostal artery (ICA) injury behind the left atrium (LA) is a serious complication in pulmonary vein isolation procedures, and this study aimed to explore their anatomical relationship.
  • A total of 100 patients were examined through cardiac computed tomography, focusing on the distance between the LA and right ICAs, finding an average of 3.7 right ICAs with varying closeness, particularly shorter in patients with atrial fibrillation.
  • The study concludes that understanding the proximity of right ICAs to the LA is crucial, especially in individuals with enlarged LA or thinner chest cavities, as they are at higher risk for ICA injury during surgery.
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Aims: Several algorithms can differentiate inferior axis premature ventricular contractions (PVCs) originating from the right side and left side on 12-lead electrocardiograms (ECGs). However, it is unclear whether distinguishing the origin should rely solely on PVC or incorporate sinus rhythm (SR). We compared the dual-rhythm model (incorporating both SR and PVC) to the PVC model (using PVC alone) and quantified the contribution of each ECG lead in predicting the PVC origin for each cardiac rotation.

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The pathophysiology of variant transthyretin (TTR) amyloidosis (ATTRv) is associated with destabilizing mutations in the TTR tetramer. However, why TTR with a wild-type genetic sequence misfolds and aggregates in wild-type transthyretin amyloidosis (ATTRwt) is unknown. Here, we evaluate kinetic TTR stability with a newly developed ELISA system in combination with urea-induced protein denaturation.

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  • This study investigates the effectiveness of velocity ratio (VR) in diagnosing severe aortic stenosis (AS) in patients with paradoxical low-flow/low-gradient AS using cardiac CT.
  • Out of 58 patients studied, nearly half were classified with severe AS according to CT results, with a significant correlation found between VR scores (specifically VR < 0.25) and severe AS diagnosis.
  • The research suggests that using VR < 0.25 is a practical approach for identifying severe AS in these patients, with potentially significant implications for clinical practice.
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  • The study investigates how thermal atrial fibrillation (AF) ablation impacts the cardiac autonomic nervous system (CANS) by focusing on the effects during the ablation of the right superior pulmonary vein (RSPV) and its influence on the heart rate (HR) post-ablation.
  • Researchers evaluated 97 patients undergoing first-time thermal ablation, analyzing HR changes and anatomical factors through pre- and post-procedural electrocardiograms and cardiac CT measurements.
  • Results showed that 38.1% of patients experienced a significant HR increase after the procedure, with key predictors being the distance between the RSPV and superior vena cava (SVC) and the patient's age,
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Background: Combining morphological and physiological evaluations might improve the risk stratification of patients who undergo percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) culprit lesions.

Aims: We aimed to investigate the clinical utility of morphofunctional evaluation after PCI for identifying ACS patients with increased risk of subsequent clinical events.

Methods: We retrospectively studied 298 consecutive ACS patients who had undergone optical coherence tomography (OCT)-guided PCI.

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The 88Annual Scientific Meeting of the Japanese Circulation Society (JCS2024) was held from Friday, March 8to Sunday, March 10in Kobe, Japan. The main theme of this 3-day meeting was "The Future of Cardiology: Challenges in Overcoming Cardiovascular Disease". As COVID-19 has been finally conquered, with revision of its categorization under the Infectious Disease Control Law and relaxation of infection prevention measures, it was once again possible to have face-to-face presentations and lively discussion.

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There is no treatment for acute aortic dissection (AAD) targeting inflammatory cells. We aimed to identify the new therapeutic targets associated with inflammatory cells. We characterized the specific distribution of myeloid cells of both human type A AAD samples and a murine AAD model generated using angiotensin II (ANGII) and β-aminopropionitrile (BAPN) by single-cell RNA sequencing (scRNA-seq).

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  • Recent guidelines recommend against using PAH-targeted therapies in patients with pulmonary hypertension (PH) linked to respiratory diseases, highlighting the need for better assessment of treatment effectiveness.
  • The study analyzed 270 patients with precapillary PH, categorizing them into severe and mild cases to evaluate the impact of initial treatments on their prognosis.
  • Findings indicated that patients with severe PH and mild ventilatory impairment who received initial treatment showed a significantly better response and prognosis compared to those who did not, while such benefits were not seen in mild PH cases.
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Transthyretin amyloid cardiomyopathy (ATTR-CM) is characterized by the functional and structural effects of amyloid infiltration, predominantly within the ventricles, causing biventricular wall thickening. Amyloid infiltration can be observed in the left atrium in ATTR-CM patients, but the association of left atrial (LA) myocardial function with cardiovascular events and of changes in LA myocardial function with tafamidis administration have not yet been clarified. Our aim was, therefore, to use speckle-tracking strain for investigating LA myocardial function in patients with ATTR-CM treated with tafamidis.

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Left ventricular (LV) longitudinal myocardial function is associated with the outcomes of heart failure (HF) patients. HF with improved ejection fraction (EF), known as HFimpEF, which is defined as current LVEF >40% but any previously documented LVEF ≤40%, has favorable outcomes compared with HF with preserved EF (HFpEF). However, LV longitudinal myocardial function in patients with previously reduced LVEF (<50%) but improved LVEF to within the normal range (≥50%) (HFnorEF) and its association with cardiovascular events remain unclear.

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  • The study investigates the use of maximum phonation time (MPT) to predict postoperative complications like dysphagia and major cardiovascular events in older patients undergoing cardiac surgery.
  • It analyzed data from 442 patients, measuring MPT before surgery and assessing complications afterward, finding a correlation between abnormal MPT and higher rates of dysphagia and major adverse events.
  • Results suggest that incorporating MPT in preoperative evaluations could help identify high-risk patients, leading to better management and potentially improved outcomes while reducing healthcare costs.
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In Japan, cerebrovascular diseases and cardiovascular diseases (CVDs) are major causes of death and long-term care. Against this, the Cerebrovascular and Cardiovascular Disease Control Act was passed by a legislative body and promulgated in December 2018, and enacted on December 1, 2019. Based on the Japanese National Plan for Promotion of Measures Against Cerebrovascular and Cardiovascular Disease (Japanese National Plan), prefectural plans have been formulated and published from March 2021 to January 2023.

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Background: Although low high-density lipoprotein cholesterol (HDL-C) levels are a common metabolic abnormality associated with insulin resistance, their role in cardiovascular risk stratification remains controversial. Recently, we developed a simple, high-throughput, cell-free assay system to evaluate the "cholesterol uptake capacity (CUC)" as a novel concept for HDL functionality. In this study, we assessed the CUC in patients with hypertriglyceridemia and diabetes mellitus.

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Background: Acute coronary syndrome (ACS) involves plaque-related thrombosis, causing primary ischemic cardiomyopathy or lethal arrhythmia. We previously demonstrated a unique immune landscape of myeloid cells in the culprit plaques causing ACS by using single-cell RNA sequencing. Here, we aimed to characterize T cells in a single-cell level, assess clonal expansion of T cells, and find a therapeutic target to prevent ACS.

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