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Dive into the research topics where Hideya Yamamoto is active.

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Featured researches published by Hideya Yamamoto.


Atherosclerosis | 2015

The relationship between inflammation and neoangiogenesis of epicardial adipose tissue and coronary atherosclerosis based on computed tomography analysis

Toshiro Kitagawa; Hideya Yamamoto; Kazuhiro Sentani; Shinya Takahashi; Hiroshi Tsushima; Atsuhiro Senoo; Wataru Yasui; Taijiro Sueda; Yasuki Kihara

OBJECTIVEnPrevious studies indicate that epicardial adipose tissue (EAT) biologically contributes to the progression of coronary atherosclerosis. We evaluated the relationship between EAT pathology, represented by inflammation and neoangiogenesis, and coronary atherosclerosis on computed tomography (CT) images.nnnMETHODSnWe performed CT examination in 45 patients scheduled for cardiac surgery (coronary artery bypass graft [CABG], n = 21; non-CABG, n = 24) to assess visceral adipose tissue (VAT) area, EAT volume, coronary calcium score (CCS), and presence of non-calcified coronary plaque (NCP) on CT angiography. Each patient was assessed with the numbers of CD68(+) individual macrophages and CD31(+) neovessels in six random high-power fields (400×) of EAT samples subsequently obtained during cardiac surgery.nnnRESULTSnIn three groups based on CCS (mild, 0-100; moderate, 101-400; severe, >400), the moderate group had the most extensive macrophage infiltration (p = 0.0025) and neoangiogenesis (p = 0.0036) in EAT. The patients with NCP had more extensive macrophage infiltration (p = 0.010) and neoangiogenesis (p = 0.0043) in EAT than those without. On multivariate analysis adjusted for age, sex, CABG versus. non-CABG, VAT area, and EAT volume, moderate CCS and the presence of NCP showed significant correlations with increased macrophage infiltration (β = 0.65; p < 0.0001, and β = 0.49; p = 0.0089, respectively) and neoangiogenesis (β = 0.55; p = 0.0011, and β = 0.53; p = 0.012, respectively) in EAT.nnnCONCLUSIONnInflammation and neoangiogenesis in EAT independently correlate with moderate coronary calcification and presence of NCP, suggesting that these two factors may have a role in promoting coronary atherosclerosis.


Circulation | 2015

Association of Epicardial and Abdominal Visceral Adipose Tissue With Coronary Atherosclerosis in Patients With a Coronary Artery Calcium Score of Zero

Hiroshi Tsushima; Hideya Yamamoto; Toshiro Kitagawa; Yoji Urabe; Fuminari Tatsugami; Kazuo Awai; Yasuki Kihara

BACKGROUNDnWe sought to examine whether epicardial and abdominal visceral adipose tissue distribution is associated with coronary atherosclerosis in patients with a coronary artery calcium (CAC) score of zero, assessed by coronary computed tomography angiography (CCTA).nnnMETHODS AND RESULTSnWe studied 352 patients with suspected coronary artery disease (mean age 61±11 years, 57% male) with a CAC score of zero who had undergone CCTA. Non-calcified coronary plaques (NCPs) were detected in 102 patients (29%); those causing ≥50% stenosis were found in 15 patients (4%). Patients were divided into 4 groups on the basis of CT-based epicardial adipose tissue (EAT) volume and abdominal visceral adipose tissue (VAT) area using the sex-specific median value. Multivariate analysis showed that the adjusted odds ratios for the presence of NCPs in the high VAT area/low EAT volume group, and the high VAT area/high EAT volume group were 2.80 (95% confidence interval [95% CI]: 1.25-6.35, P=0.01) and 2.68 (95% CI: 1.36-5.45, P=0.004), respectively. Interestingly, the low VAT area/high EAT volume group showed an equivalent adjusted odds ratio of 3.02 (95% CI: 1.33-6.90, P=0.008).nnnCONCLUSIONSnEAT volume is eligible as a marker to be evaluated in addition to VAT area in patients with a CAC score of zero.


International Journal of Cardiovascular Imaging | 2015

Radiation dose reduction for coronary artery calcium scoring at 320-detector CT with adaptive iterative dose reduction 3D

Fuminari Tatsugami; Toru Higaki; Wataru Fukumoto; Yoko Kaichi; Chikako Fujioka; Masao Kiguchi; Hideya Yamamoto; Yasuki Kihara; Kazuo Awai

To assess the possibility of reducing the radiation dose for coronary artery calcium (CAC) scoring by using adaptive iterative dose reduction 3D (AIDR 3D) on a 320-detector CT scanner. Fifty-four patients underwent routine- and low-dose CT for CAC scoring. Low-dose CT was performed at one-third of the tube current used for routine-dose CT. Routine-dose CT was reconstructed with filtered back projection (FBP) and low-dose CT was reconstructed with AIDR 3D. We compared the calculated Agatston-, volume-, and mass scores of these images. The overall percentage difference in the Agatston-, volume-, and mass scores between routine- and low-dose CT studies was 15.9, 11.6, and 12.6xa0%, respectively. There were no significant differences in the routine- and low-dose CT studies irrespective of the scoring algorithms applied. The CAC measurements of both imaging modalities were highly correlated with respect to the Agatston- (rxa0=xa00.996), volume- (rxa0=xa00.996), and mass score (rxa0=xa00.997; pxa0<xa00.001, all); the Bland–Altman limits of agreement scores were −37.4 to 51.4, −31.2 to 36.4 and −30.3 to 40.9xa0%, respectively, suggesting that AIDR 3D was a good alternative for FBP. The mean effective radiation dose for routine- and low-dose CT was 2.2 and 0.7xa0mSv, respectively. The use of AIDR 3D made it possible to reduce the radiation dose by 67xa0% for CAC scoring without impairing the quantification of coronary calcification.


Journal of Atherosclerosis and Thrombosis | 2016

Identifying Small Coronary Calcification in Non-Contrast 0.5-mm Slice Reconstruction to Diagnose Coronary Artery Disease in Patients with a Conventional Zero Coronary Artery Calcium Score

Yoji Urabe; Hideya Yamamoto; Toshiro Kitagawa; Hiroto Utsunomiya; Hiroshi Tsushima; Fuminari Tatsugami; Kazuo Awai; Yasuki Kihara

Aims: In a new-generation computed tomography (CT) scanner, coronary artery calcium (CAC) scores were measured using 3.0-mm slice reconstruction images originally acquired with 0.5 mm thickness scans in a single beat. This study investigated the usefulness of thin-slice (0.5 mm) reconstruction for identifying small calcifications in coronary arteries and evaluated the association with coronary plaques and stenosis compared to conventional 3.0-mm reconstruction images. Methods: We evaluated 132 patients with zero CAC scores in conventional 3.0-mm Agatston method using a 320-slice CT. Then, 0.5-mm slice reconstruction was performed to identify small calcifications. The presence of stenosis and coronary plaques was assessed using coronary CT angiography. Results: In total, 22 small calcifications were identified in 18 patients. There were 28 (21%) patients with any (≥ 25%) stenosis (34 lesions). Forty-seven coronary plaques were found in 33 patients (25%), including 7 calcified plaques in 7 patients (5%), 34 noncalcified plaques in 27 patients (20%), and 6 partially calcified plaques in 5 patients (4%). Patients with small calcifications had a significantly higher prevalence of noncalcified or partially calcified plaques (83% vs 14%; p < 0.001) and obstructive stenosis (33% vs 5.2%; p < 0.001) compared to those without small calcifications. The addition of small calcifications to the coronary risk factors when diagnosing stenosis significantly improved the diagnostic value. Conclusion: Small calcifications detected by thin-slice 0.5-mm reconstruction are useful for distinguishing coronary atherosclerotic lesions in patients with zero CAC scores from conventional CT reconstruction.


Circulation | 2015

Risk Factors for Progression of Degenerative Aortic Valve Disease in the Japanese – The Japanese Aortic Stenosis Study (JASS) Prospective Analysis –

Kazuhiro Yamamoto; Hideya Yamamoto; Masaaki Takeuchi; Akira Kisanuki; Takashi Akasaka; Nobuyuki Ohte; Yutaka Hirano; Kiyoshi Yoshida; Satoshi Nakatani; Yasuharu Takeda; Takashi Sozu; Tohru Masuyama

BACKGROUNDnBecause of ethnic difference in the risk of degenerative aortic valve disease (DAVD), risk factors should be clarified in each race to establish prophylactic strategies for severe aortic valve stenosis (AS).nnnMETHODSANDRESULTSnThis study prospectively followed 359 Japanese subjects with DAVD and age ≥50 years for 3 years. As both patients with peak aortic transvalvular flow velocity ≥2 m/s and <2 m/s were enrolled, subgroup analysis was also conducted. Most patients were under treatment for their comorbidities. The use of warfarin, but none of the traditional risk factors for atherosclerosis, was related to greater reduction in aortic valve area indexed to body surface area (iAVA). In patients with peak aortic transvalvular flow velocity <2 m/s, the use of an angiotensin-receptor blocker (ARB) was associated with less decrease in iAVA. In patients with peak velocity ≥2 m/s, changes in iAVA were not related to any baseline characteristics, but peak velocity was less increased under treatment with an angiotensin-converting enzyme inhibitor (ACEI).nnnCONCLUSIONSnIn Japanese, the use of warfarin may exacerbate DAVD, and augmented management of atherosclerotic risk factors beyond the recommendations in the current guidelines is unlikely to exert additional benefit. The prescription of ARB for DAVD patients before the development of AS or ACEI after the development of AS may be useful.


Atherosclerosis | 2017

18F-sodium fluoride positron emission tomography for molecular imaging of coronary atherosclerosis based on computed tomography analysis

Toshiro Kitagawa; Hideya Yamamoto; Shinya Toshimitsu; Ko Sasaki; Atsuhiro Senoo; Yumiko Kubo; Fuminari Tatsugami; Kazuo Awai; Yutaka Hirokawa; Yasuki Kihara

BACKGROUND AND AIMSnWe aimed at evaluating the relation of 18F-sodium fluoride (18F-NaF) uptake on positron emission tomography (PET) to coronary atherosclerosis detected and assessed by computed tomography (CT).nnnMETHODSnThirty-two patients with one or more coronary atherosclerotic lesions detected on cardiac CT underwent 18F-NaF PET/CT. Each coronary atherosclerotic lesion was evaluated on CT angiography for plaque types (calcified plaque [CP], non-calcified plaque [NCP], partially calcified plaque [PCP]), and the presence of CT-based high-risk features (minimum CT density <30 Hounsfield units and vascular remodeling index >1.1). Focal 18F-NaF uptake of each lesion was quantified using maximum tissue-to-background ratio (TBRmax).nnnRESULTSnA total of 111 lesions were studied. In a patient-based analysis, logarithmically transformed coronary calcium score correlated positively with maximum TBRmax per patient, and 15 patients with myocardial infarction or unstable angina history showed a higher maximum TBRmax per patient than those without (1.36xa0±xa00.15 versus 1.15xa0±xa00.15, pxa0=xa00.0006). In a lesion-based analysis, PCP showed a higher TBRmax than CP and NCP (1.17xa0±xa00.19 versus 1.00xa0±xa00.24 and 0.92xa0±xa00.18, respectively, pxa0<xa00.0001), and the lesions with high-risk features had a higher TBRmax than those without (1.20xa0±xa00.21 versus 1.02xa0±xa00.20, pxa0=xa00.0011).nnnCONCLUSIONSnCoronary arterial 18F-NaF uptake is related to total plaque burden, coronary event history, and specific features of coronary atherosclerosis based on CT analysis. 18F-NaF PET/CT, in combination with cardiac CT, may provide a new molecular imaging approach to identify high-risk patients and coronary atherosclerotic lesions.


Internal Medicine | 2015

Association between the postprandial glucose Levels and arterial stiffness measured according to the cardio-ankle vascular index in non-diabetic subjects.

Atsuko Tsuboi; Chikako Ito; Rumi Fujikawa; Hideya Yamamoto; Yasuki Kihara

OBJECTIVEnAlthough a relationship between post-challenge hyperglycemia and arterial stiffness has been reported, the relationship between the postprandial glucose levels and cardio-ankle vascular index (CAVI) in non-diabetic subjects is not clear. This study thus evaluated the association between the postprandial glucose levels after a composite meal and the degree of arterial stiffness measured according to CAVI in non-diabetic subjects.nnnMETHODSnThe subjects included 1,291 individuals (655 men and 636 women; mean age, 48.6 years; range, 23-85 years) who underwent medical examinations, including blood tests and CAVI assessments, between October 2005 and April 2012. The 1-hour postprandial glucose levels were determined after a 600-kcal traditional Japanese meal.nnnRESULTSnThe CAVI values were significantly higher in the subjects with higher 1-hour postprandial glucose levels (≥140 mg/dL in men; ≥158 mg/dL in women). A simple regression analysis indicated that the CAVI values were significantly correlated with the 1-hour postprandial glucose levels in men (r=0.286, p<0.0001) and women (r=0.228, p<0.0001). After adjusting for age, BMI, systolic blood pressure, triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, 1-hour postprandial glucose, homeostatis model assessment of insulin resistance, estimated glemerular filtration rate, and high sensitive C-reactive protein, stepwise multiple regression analysis demonstrated that the 1-hour postprandial glucose level was an independent predictor associated with the CAVI in men (p=0.003) and older women 50 years of age or older (p=0.003).nnnCONCLUSIONnThis study demonstrated that the 1-hour postprandial glucose levels are associated with increased CAVI values in non-diabetic men and older women 50 years of age or older.


Hypertension Research | 2017

Second derivative of the finger photoplethysmogram and cardiovascular mortality in middle-aged and elderly Japanese women.

Noriko Inoue; Hideshi Kawakami; Hideya Yamamoto; Chikako Ito; Saeko Fujiwara; Hideo Sasaki; Yasuki Kihara

The second derivative of the digital photoplethysmogram (SDPTG) is an indicator of arterial stiffness. The ratio of the height of the d wave to the a wave of the SDPTG (d/a) is associated with functional peripheral vascular tension and represents aortic-blood pressure (BP) augmented by reflection waves from the periphery. This longitudinal study aimed to investigate the relationship between SDPTG and cardiovascular mortality in middle-aged and elderly Japanese women. From 1998 to 2008, we recruited 4373 women (50–79 years old at baseline) who underwent medical check-ups and SDPTG measurement. The SDPTG index (d/a) was calculated from the wave component height, and was divided into quartiles (Q) according to the d/a value. The median follow-up period was 9.0 years. The d/a value was negatively associated with age and BP, and positively associated with heart rate and body height. Using the Cox proportional hazards model, the hazard ratios for cardiovascular mortality for Q2, Q3 and Q4 were significantly higher than that of Q1. In multivariate analysis, the hazard ratio was 2.30 for Q3 (95% confidence interval (CI): 1.06–4.99, P<0.05) and 2.60 for Q4 (95% CI: 1.21–5.60, P<0.05), after adjustment for age, height, body mass index, BP levels, heart rate and other atherosclerosis-related factors. The hazard ratios of cardiovascular mortality for Q3 and Q4 were significantly higher compared with the reference (Q1). Thus, the SDPTG d/a is an independent predictor of cardiovascular mortality in middle-aged and elderly Japanese women.


Heart and Vessels | 2017

Clinical features and predictive value of serum inflammatory markers of perivascular involvement in immunoglobulin G4-related disease

Hideya Yamamoto; Eiji Sugiyama; Masahiro Serikawa; Fuminari Tatsugami; Michiya Yokozaki; Toshiro Kitagawa; Atsushi Senoo; Yumiko Nakamoto; Kazuo Awai; Kazuaki Chayama; Yasuki Kihara

Vascular and/or perivascular involvements of sclerotic inflammation (perivasculitis) are a complication of immunoglobulin G4-related disease (IgG4-RD). We sought to examine clinical manifestations of perivasculitis by computed tomography (CT) in patients with elevated serum IgG4 levels, and then to evaluate some potential predictors of perivasculitis in definite IgG4-RD patients. From a database of patients with serum IgG4 measurements, we selected 81 patients with elevated serum IgG4 levels (≥135xa0mg/dl). Perivasculitis was defined radiologically as thickened contrast-enhanced rind surrounding the aorta and its major artery on CT imaging. We found 15 patients with perivasculitis; 10 patients in the definite (nxa0=xa037), four in the possible (nxa0=xa018), and one in the excluded (nxa0=xa026) IgG4-RD groups. Clinical predictors of perivasculitis were investigated in 34 untreated patients with definite IgG4-RD. Patients with perivasculitis (nxa0=xa010) had significantly higher age at diagnosis (74.2xa0±xa08.8 vs 63.5xa0±xa09.9xa0years, Pxa0=xa00.006), higher levels of serum IgG4 (754 vs 292xa0mg/dl, Pxa0=xa00.007) and C-reactive protein (CRP, 0.52xa0mg/dl vs 0.10xa0mg/dl, Pxa0=xa00.001) than patients without perivasculitis (nxa0=xa024). The sensitivity and specificity of serum CRP ≥0.25xa0mg/dl for identifying perivasculitis in the definite IgG4-RD group were 100 and 71%, respectively (area under the receiver operating characteristic curve 0.863). Our results indicate that IgG4-related perivasculitis was associated with elevated levels of serum CRP and older age, and that CRP may be a useful marker for detecting perivascular involvement in IgG4-RD.


Data in Brief | 2015

Data set for volumetric and pathological findings of epicardial adipose tissue

Toshiro Kitagawa; Hideya Yamamoto; Kazuhiro Sentani; Shinya Takahashi; Hiroshi Tsushima; Atsuhiro Senoo; Wataru Yasui; Taijiro Sueda; Yasuki Kihara

This article contains the data regarding clinically-assessed visceral adipose tissue (VAT) area and epicardial adipose tissue (EAT) volume on computed tomography (CT) images and EAT pathology, represented by inflammation and neoangiogenesis, complementing the data reported by Kitagawa et al. [1]. In 45 patients scheduled for cardiac surgery, we studied CT images obtained prior to surgery and the numbers of CD68+ individual macrophages and CD31+ neovessels in EAT samples subsequently obtained during surgery. The data revealed a moderate correlation between VAT area and EAT volume, and a strong correlation between EAT macrophage infiltration and neoangiogenesis.

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