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Biomedical subjects

Akira Yamashina

Publications and source records attributed to Akira Yamashina.

At least 19 recordsLinked to original sources
PubMed2007

Normal limits of ejection fraction and volumes determined by gated SPECT in clinically normal patients without cardiac events: a study based on the J-ACCESS database.

PURPOSE: Quantitative gated single-photon emission computed tomography (SPECT) is known to have high accuracy and precision for measurement of the principal cardiac functional parameters. We hypothesised that normal values for EF and LV volumes may differ among nationalities, and that optimal threshold values specific to the study population are required. METHODS: Among 4,670 consecutively registered patients for a J-ACCESS (Japanese investigation regarding prognosis based on gated SPECT) study from 117 hospitals, a total of 268 (149 women, 119 men) were selected who had no baseline cardiac diseases and had experienced no cardiac events during the preceding 3-year period. A gated SPECT study was performed with 99mTc-tetrofosmin and analysed with Cedars Sinai Medical Center's quantitative gated SPECT (QGS) software. The results in respect of ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV) and stroke volume (SV), and EDV, ESV and SV normalised by body surface area (EDVI, ESVI and SVI), were calculated and summarised to obtain normal limits. RESULTS: EF for women and men was 74 +/- 9% and 63 +/- 7%, respectively (p < 0.0001). EDV, ESV and SV were significantly smaller in women than in men. Based on multiple regressions for linear models, the primary and secondary predictors of EF, EDVI, ESVI were gender and age. By stepwise multiple regression analysis, a statistically significant third predictor for EDV, ESV, SV and SVI was body weight. No colinearity was found between age and body weight. Important factors for the studied Japanese population included a high incidence of small hearts in women and the relatively advanced age of the population (the mean age +/-SD was 64.1 +/- 10.0 years for women and 60.9 +/- 11.7 years for men). CONCLUSION: EF and volumes determined by gated SPECT with QGS were significantly affected by gender and age, with body weight as a third predictor for volumes. Moreover, the normal limits were so specific for the population studied that standards appropriate for the study in question should be utilised.

Databases, Factual↗
PubMed2007

Arterial stiffness and progression to hypertension in Japanese male subjects with high normal blood pressure.

OBJECTIVES: This observational study was conducted to compare the significance of the relationship between arterial stiffness and progression to higher blood pressure categories among middle-aged Japanese men with high normal blood pressure (HNP), normal blood pressure (NRP) and optimal blood pressure (OPP). METHODS AND RESULTS: During the 3-year observational period, 100 subjects with HNP developed hypertension (n=475; 42 +/- 9 years), and 175 of those with normal NRP (n=581; 41 +/- 8 years) and 249 of those with OPP (n=702; 39 +/- 8 years) showed progression to higher blood pressure categories. A binary logistic regression analysis adjusted for known risk factors revealed that values of the brachial-ankle pulse wave velocity, a surrogate marker of arterial stiffness, in the highest quartile, as compared with those in the lowest quartile, obtained at the start of the study were significantly predictive of the progression to hypertension [adjusted odds ratio = 9.4 (95% confidence interval, 3.0-29.8), P < 0.01]. The predictive value of this parameter for progression to higher blood pressure categories in subjects with HNP was more significant than that in those with NRP or OPP. CONCLUSIONS: Increased arterial stiffness and elevated blood pressure may be mutually causally related, and it appears that the significance of this relationship may increase with increasing blood pressure, even in subjects without hypertension. Assessment of arterial stiffness may be more reliable for predicting the progression to hypertension in cases of HNP than in cases with NRP or OPP.

Adult↗
PubMed2006

The role of 123I-metaiodobenzylguanidine myocardial scintigraphy in the diagnosis of Lewy body disease in patients with dementia in a memory clinic.

Reduction in cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake is a characteristic feature of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), and is useful in distinguishing them from other neurodegenerative disorders. The aim of this study was to investigate the role of this method of scintigraphy in the differential diagnosis of dementia in our Memory Clinic. We performed MIBG scintigraphy in patients with dementia referred to the Memory Clinic and compared the heart-to-mediastinum (H/M) ratio of MIBG uptake. Thirty out of 32 patients with DLB and all 9 PD with dementia patients had reduced H/M ratios, whereas 37 out of 40 patients with Alzheimer's disease had normal H/M ratios. Most patients with vascular dementia, frontotemporal dementia, and other dementias had normal H/M ratios. The overall sensitivity to positively identify patients with Lewy body disease (including DLB and PD with dementia) was 95%, and the specificity to distinguish them from patients with other types of dementias was 87%. MIBG scintigraphy showed a high sensitivity for the detection of Lewy body disease, and also a high specificity for discrimination from other types of dementia. The scintigraphy may provide a valuable and adjunctive method in the diagnosis of Lewy body disease and a differential diagnostic tool for patients with dementias.

3-Iodobenzylguanidine↗
PubMed2006

Usefulness of late gadolinium enhancement combined with MRI and 67-Ga scintigraphy in the diagnosis of cardiac sarcoidosis and disease activity evaluation.

We report a case in which late gadolinium enhancement (LGE) and 67-Ga scintigraphy were useful for the diagnosis of cardiac sarcoidosis and for the evaluation of the disease activity. The patient was a 60-year-old woman who had been diagnosed as having eye sarcoidosis when she was 48. Two years previously her electrocardiogram had shown abnormalities but the coronary angiography had shown normal coronary arteries; however, an aneurysm was detected in the apical portion by left ventriculography. A II degree AV block was noted on the electrocardiogram and she was referred to us for further detailed evaluation. Since the biopsy findings of skin eruptions on both eyelids indicated an epithelial cell granuloma, she was diagnosed as having cutaneous sarcoidosis. On the 67-Ga scintigram, myocardial accumulation of gallium was recognized, and on cardiovascular magnetic resonance (CMR), LGE was recognized. She was diagnosed as cardiac sarcoidosis and steroid therapy started with 30 mg prednisolone. The myocardial accumulation of gallium on the 67-Ga scintigram disappeared after the 30th day of steroid therapy. On the other hand, no changes in LGE patterns were seen after steroid therapy. In this case, LGE was useful for the diagnosis of cardiac sarcoidosis, and 67-Ga scintigram was useful for the evaluation of the disease activity. This case shows that both imaging techniques are important for the diagnosis of cardiac sarcoidosis and evaluation of the disease.

Anti-Inflammatory Agents↗
PubMed2006

The role of intravenous coronary thrombolysis for patients with acute myocardial infarction in different treatment strategies.

OBJECTIVE: To examine acute-phase outcomes in acute myocardial infarction (AMI) according to different initial treatments. PATIENTS AND METHODS: This retrospective study involved 405 patients with AMI who had undergone coronary angiography during the acute phase. The patients were retrospectively examined by dividing into groups according to treatment received: intravenous coronary thrombolysis (IVCT) (n=83), intracoronary thrombolysis (ICT) (n=62), and percutaneous coronary intervention (PCI) (n=221). RESULTS: TIMI 3 flow at the initial angiography was higher in the IVCT group (P<0.05) at 32.5% in the IVCT group and 21.7% in the non-IVCT group. The time from onset to initiation of treatment was shorter in the IVCT group (P<0.001) at 227 min in the IVCT group, 337 min in the ICT group, and 479 min in the PCI group. The acute-phase mortality was lower in the IVCT group (P<0.05) at 2.4% in the IVCT group, 3.2% in the ICT group, and 11.8% in the PCI group. According to sub-analysis, the restenosis rate during the chronic phase after PCI did not differ with or without antecedent administration of a thrombolytic agent. CONCLUSION: IVCT as an initial treatment for AMI enabled the fastest reperfusion at TIMI > or = 2 flow, resulting in a good acute-phase outcome.

Aged↗
PubMed2006

Alpha B-crystallin mutation in dilated cardiomyopathy.

Mutations in genes for sarcomeric proteins such as titin/connectin are known to cause dilated cardiomyopathy (DCM). However, disease-causing mutations can be identified only in a small proportion of the patients even in the familial cases, suggesting that there remains yet unidentified disease-causing gene(s) for DCM. To explore the novel disease gene for DCM, we examined CRYAB encoding alphaB-crystallin for mutation in the patients with DCM, since alphaB-crystallin was recently reported to associate with the heart-specific N2B domain and adjacent I26/I27 domain of titin/connectin, and we previously reported a N2B mutation, Gln4053ter, in DCM. A missense mutation of CRYAB, Arg157His, was found in a familial DCM patient and the mutation affected the evolutionary conserved amino acid residue among alpha-crystallins. Functional analysis revealed that the mutation decreased the binding to titin/connectin heart-specific N2B domain without affecting distribution of the mutant crystallin protein in cardiomyocytes. In contrast, another CRYAB mutation, Arg120Gly, reported in desmin-related myopathy decreased the binding to both N2B and striated muscle-specific I26/27 domains and showed intracellular aggregates of the mutant protein. These observations suggest that the Arg157His mutation may be involved in the pathogenesis of DCM via impaired accommodation to the heart-specific N2B domain of titin/connectin and its disease-causing mechanism is different from the mutation found in desmin-related myopathy.

Aged↗
PubMed2006

Elevated serum levels of alanine aminotransferase and gamma glutamyltransferase are markers of inflammation and oxidative stress independent of the metabolic syndrome.

The present study attempted to establish whether elevated serum levels of alanine aminotransferase (ALT) and gamma glutamyltransferase (GGT) are independent (of each other) markers of systemic inflammation and oxidative stress as assessed by the plasma levels of C-reactive protein (CRP) and lipid peroxides (lipOX), regardless of the presence of underlying metabolic syndrome (as defined by the modified Adult Treatment Panel III (ATPIII) criteria). The plasma levels of CRP and lipOX were determined in 1483 middle-age Japanese men (42+/-9 years). A general linear model analysis indicated that elevated serum ALT and/or serum GGT (levels in the respective highest quartiles) were significantly related to the logarithms of the plasma levels of CRP (Beta=0.08 (0.05-0.11) and 0.08 (0.05-0.11), respectively) and the logarithm of the plasma levels of lipOX (Beta=0.03 (0.01-0.05) and 0.03 (0.01-0.05), respectively), regardless of the presence of underlying metabolic syndrome (MetS) (p<0.01). In addition, the presence of MetS and elevated serum levels of both of these liver enzymes additively increased the plasma levels of CRP and lipOX. Thus, it is proposed that elevated serum ALT and elevated serum GGT are independent markers of the activation of systemic inflammation and increased oxidative stress, independent of their relationship to MetS, and that the presence of MetS and elevations of both of these liver enzymes may additively worsen the atherogenic state.

Adult↗
PubMed2006

Surveillance study for creating the national clinical database related to ECG-gated myocardial perfusion SPECT of ischemic heart disease: J-ACCESS study design.

BACKGROUND: ECG-gated myocardial perfusion SPECT is widely applied to diagnose ischemic heart disease, and such findings are useful to predict patient prognosis. However, Japan does not have a database that correlates SPECT image findings with the prognosis of patients who have ischemic heart disease. METHODS: A large-scale clinical study involving 117 medical facilities throughout Japan was established to survey the clinical background and image findings of patients who have undergone ECG-gated stress perfusion SPECT. These patients were followed up for three years to investigate the occurrence of cardiac events. RESULTS: The 4,629 registered patients comprised 2,989 males (age 64.9 +/- 10.3 y, mean +/- SD) and 1,640 females (age 67.2 +/- 9.7 y). The most frequent complication was hypertension (54.5%), followed by hyperlipidemia (47.2%) and diabetes (29.4%). Percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) was conducted on 1,925 of the patients. SPECT examinations were ordered for further examination of chest pain (32.8%), periodic follow-up after coronary artery intervention (24.2%), screening for coronary artery disease (15.1%), follow-up of old myocardial infarction (14.9%), more detailed investigation of ECG or echocardiographic abnormalities (13.1%), etiological assessment of heart failure (1.6%), and further inspection for acute coronary syndrome (0.3%). The method of inducing stress was most often exercise loading at 68.8%, and infusion of either dipyridamole (14.6%) or adenosine triphosphate (ATP, 13.8%). The most frequently applied amount of 99mTc-tetrofosmin was an initial dose of 200 to 300 MBq combined with a second dose of 700 to 800 MBq (37.7%). The mean doses were 305 +/- 81 at the initial and 709 +/- 132 MBq at the second administration. A history of angina pectoris (41.2%) was the most frequent, followed by myocardial infarction (29.5%). CONCLUSIONS: During the two years of follow-up after registration, 46 of the 4,629 subjects have discontinued or dropped out, 134 have died, and 4,449 (97.8%) continue to undergo follow-up investigations. A complete report will be presented when the follow-up data for 3 years have been compiled and analyzed.

Databases, Factual↗
PubMed2006

B-type natriuretic peptide and arterial stiffness in healthy Japanese men.

BACKGROUND: Recent evidence suggests that even a slight increase in the plasma level of B-type natriuretic peptide (BNP) may be a marker of cardiovascular risk; however, the mechanisms underlying the association are currently unclear. Because increased arterial stiffness, as reflected by an increase of the pulse wave velocity (PWV) or pulse pressure (PP), may contribute to increasing plasma BNP levels, in the present study we investigated the relationships between the plasma BNP level and the PWV and PP, all of which are known markers of cardiovascular risk, in a healthy male Japanese cohort. METHODS: This was a cross-sectional study of 725 healthy Japanese men (age, 54 +/- 4 years). The PWV was assessed by the volume-rendering method. Plasma BNP levels were determined with a high-sensitivity noncompetitive immunoradiometric assay. RESULTS: A univariate linear regression analysis demonstrated that the plasma BNP level was significantly correlated with age (r = 0.20, P < .01), PWV (r = 0.12, P < .01), and PP (r = 0.17, P < .01). A stepwise multivariate linear regression analysis demonstrated that both the PWV and PP were significantly associated with the plasma BNP level, independent of age. CONCLUSION: In healthy Japanese men, stiffening of large arteries, as evidenced by an increase of the PWV or PP, may account at least in part for elevated plasma BNP levels, even within the so-called normal range.

Aged↗
PubMed2006

Menopause is an independent factor augmenting the age-related increase in arterial stiffness in the early postmenopausal phase.

The present study examined whether the menopause augments the age-related increase in brachial-ankle pulse-wave velocity (PWV). In total, 3149 women (ranging in age from 21 to 94 years) undergoing an annual health screening examination were enrolled in a cross-sectional study. Conventional atherosclerotic risk factors were examined, and the brachial-ankle PWV of each subject was determined. The relationship between age and the brachial-ankle PWV assumed the form of a quadratic curve, and the slope of the curve was relatively steeper after the menopause (brachial-ankle PWV = 0.17 x age2 - 0.58 x age + 812) than before (brachial-ankle PWV = 0.23 x age2 - 8.92 x age + 1058). A logistic regression analysis conducted for subjects between the ages of 45 and 56 years (mean age of menopause +/- 2 standard deviations) demonstrated that women who had experienced the menopause at least 6 years previously demonstrated a significant risk of belonging to the highest PWV tertile {adjusted odds ratio: 2.08 (95% confidential interval: 1.04-4.17)}, independent of age and other atherosclerotic risk factors (hypertension, hypercholesterolemia, diabetes mellitus, obesity, and smoking). Thus, this study suggested that the menopause augments the age-related increase in arterial stiffness during the early postmenopausal phase and that this augmentation is probably related, at least in part, to estrogen deficiency. The contribution of this menopause-related increase in arterial stiffness to the risk of cardiovascular disease in postmenopausal women should be further evaluated.

Adult↗
PubMed2006

Decrease of fractional flow reserve shortly after percutaneous coronary intervention.

BACKGROUND: The aim of the present study was to quantitatively assess the physiological acute recoil after percutaneous coronary intervention (PCI), and to determine the relation between it and target lesion revascularization (TLR) in the chronic phase. METHODS AND RESULTS: This study evaluated 76 patients who underwent elective PCI between May 1997 and December 2001: plain old balloon angioplasty (POBA) in 50 patients and bare metal stent implantation in 26 patients. Fractional flow reserve (FFR) was measured immediately (FFR0m) and 15 min (FFR15m) after the final dilation, and the difference (dif-FFR) was calculated. In POBA patients with TLR, FFR15m was significantly low (0.79+/-0.05 vs 0.87 +/-0.08, p<0.001) and dif-FFR was significantly high (0.06+/-0.04 vs -0.01+/-0.04, p<0.001) compared with the patients without TLR. The patients with a larger dif-FFR value (> or =0.05) had a higher rate of TLR (92%). Dif-FFR was the strongest independent predictor of TLR. CONCLUSIONS: The changes in FFR during the time course shortly after coronary intervention can be detected and a decrease in the first 15 min after PCI is associated with a higher rate of TLR.

Aged↗
PubMed2006

Diagnostic significance of positive I-123 BMIPP despite negative stress Tl-201 myocardial imaging in patients with suspected coronary artery disease.

BACKGROUND: There is frequently discordance in the interpretation of myocardial single-photon emission computed tomography images using both rest iodine-123 15-(p-iodophenyl)-3-(R,S) methylpentadecanoic acid (BMIPP) and stress thallium-201 ((201)Tl); that is, negative BMIPP vs positive (201)Tl studies. However, little attention has been paid to reverse discordance (ie, positive BMIPP despite negative stress (201)Tl). METHODS AND RESULTS: In the present study 105 consecutive patients with suspected coronary artery disease (CAD) who underwent both rest BMIPP and stress (201)Tl imaging were evaluated. No patient with previous myocardial infarction was included. Scintigraphic studies revealed that BMIPP was in concordance with (201)Tl in 71 patients: both were positive in 38 and negative in 33, whereas both were discordant in 20 and reverse discordant in 14. In patients with reverse discordance, the pattern of BMIPP abnormality was segmental in 8 and spotty in 6; the former was related to coronary territory. Based on the BMIPP findings and clinical symptoms, 7 patients with positive BMIPP despite negative (201)Tl underwent coronary angiography: 3-vessel CAD was found in 3 patients, 2-vessel CAD in 1, coronary spasm in 2, and insignificant lesions in 1. In the remaining 7 patients, no cardiac event was observed during 2-year follow-up. CONCLUSIONS: In patients showing positive BMIPP despite negative (201)Tl, a segmental BMIPP perfusion abnormality indicates a high likelihood for CAD, despite normal stress (201)Tl imaging. Thus, adding BMIPP to (201)Tl imaging may help to better identify patients with significant CAD, including multivessel disease.

Aged↗
PubMed2006

Concurrent presence of metabolic syndrome in obstructive sleep apnea syndrome exacerbates the cardiovascular risk: a sleep clinic cohort study.

This cross-sectional study was conducted to examine whether the obstructive sleep apnea syndrome (OSAS) is associated with elevation of the pulse wave velocity (PWV) and increase in the plasma levels of C-reactive protein (CRP), both of which are known markers of cardiovascular risk, and also to determine if the concurrent presence of the metabolic syndrome might exacerbate this elevation in the levels of these cardiovascular risk markers in subjects with OSAS. With these objectives, the PWV and serum CRP were measured in 184 subjects attending a sleep clinic. It was found that the PWV and CRP were higher in the subjects with OSAS (n=94) than in those without OSAS (n=90). Furthermore, among the subjects with OSAS, the PWV and CRP were higher in those with the concurrent presence of the metabolic syndrome (n= 41; PWV=1,562+/-19 cm/s; CRP=1.8+/-0.2 mg/l) than in those without metabolic syndrome (n=53; PWV=1,432+/-21 cm/s; CRP=1.2+/-0.1 mg/l) (p<0.05). A general linear model analysis demonstrated that OSAS and metabolic syndrome were independently associated with elevated PWV and increase of the plasma levels of CRP. OSAS appears to be associated with increased cardiovascular risk, as reflected by both elevated PWV and increase of the plasma CRP. The concurrent presence of metabolic syndrome may exacerbate this increase in cardiovascular risk in subjects with OSAS. Therefore, the concurrent presence of metabolic syndrome may constitute an additive cardiovascular risk factor in subjects with OSAS.

Adult↗
PubMed2005

Synergistic acceleration of arterial stiffening in the presence of raised blood pressure and raised plasma glucose.

Arterial stiffness is recognized as a marker of arterial damage and an indicator of cardiovascular risk. This observational study was conducted to examine the synergistic effect of raised blood pressure (RBP; > or =130/85 mm Hg) and raised plasma glucose (RPG; > or =110 mg/dL) even at levels below those conventionally used to define hypertension and diabetes on the rate of increase of the pulse wave velocity (PWV) over a 3-year period in 2080 Japanese men (age 42+/-9 years). First, the subjects were classified into 4 groups based on the presence at the first examination of RBP, RPG, both abnormalities, or neither abnormality. The estimated annual rate of increase of the PWV was higher in subjects with both the abnormalities than in those with either abnormality alone or neither of the 2 abnormalities. Second, the subjects were also classified based on the evolutional status of these abnormalities during the study period; persistence of both of the abnormalities synergistically accelerated the rate of increase of the PWV (68.3+/-7.1 cm/s per year), as compared with the persistence of either abnormality alone (persistence of RBP alone: 18.2+/-1.6 cm/s per year; persistence of RPG alone: 21.2+/-7.4 cm/s per year) or persistence of neither abnormality (11.1+/-0.8 cm/s per year; P<0.01). Thus, blood pressure and fasting plasma glucose levels even below those defining hypertension and diabetes may synergistically lead to progression of arteriosclerotic arterial damage. This synergistic progression may contribute to the additive increases in the risk of cardiovascular events, at least in part.

Adult↗
PubMed2005

Comparative value of brain perfusion SPECT and [(123)I]MIBG myocardial scintigraphy in distinguishing between dementia with Lewy bodies and Alzheimer's disease.

PURPOSE: Both decreased occipital perfusion on brain single-photon emission computed tomography (SPECT) and reduction in cardiac (123)I-metaiodobenzylguanidine (MIBG) uptake are characteristic features of dementia with Lewy bodies (DLB), and potentially support the clinical diagnosis of DLB. The aim of this study was to compare the diagnostic value of these two methods for differentiation of DLB from Alzheimer's disease (AD). METHODS: The study population comprised 19 patients with probable DLB and 39 patients with probable AD who underwent both SPECT with N-isopropyl-p-[(123)I]iodoamphetamine and MIBG myocardial scintigraphy. Objective and quantitative measurement of perfusion in the medial occipital lobe, including the cuneus and lingual gyrus, was performed by the use of three-dimensional stereotactic surface projections. RESULTS: Medial occipital perfusion was significantly decreased in the DLB group compared with the AD group. The mean heart/mediastinum ratios of MIBG uptake were significantly lower in the DLB group than in the AD group. Although SPECT failed to demonstrate significant hypoperfusion in the medial occipital lobe in five patients with DLB, marked reduction of MIBG uptake was found in all patients with DLB. Receiver operating characteristic analysis revealed that MIBG myocardial scintigraphy enabled more accurate discrimination between DLB and AD than was possible with perfusion SPECT. CONCLUSION: MIBG myocardial scintigraphy may improve the sensitivity in the detection of DLB. In particular, this method may provide a powerful differential diagnostic tool when it is difficult to distinguish cases of DLB from AD using brain perfusion SPECT.

3-Iodobenzylguanidine↗