Biomedical subjects

Shinzo Miyamoto

Publications and source records attributed to Shinzo Miyamoto.

At least 19 recordsLinked to original sources

PubMed2006

The relationship between endothelial function in the brachial artery and intima plus media thickening of the coronary arteries in patients with chest pain syndrome.

Endothelial dysfunction precedes the development of clinical atherosclerosis. A decrease in endothelium-derived nitric oxide activity shows impaired vasodilator function and causes arterial intimal hyperplasia or thickening. Others and we have reported the close relation of endothelial function in brachial artery and coronary artery. To compare the flow-mediated endothelium-dependent vasodilation (FMD) in brachial artery and the intima+media area in coronary artery, we measured brachial artery vasodilator response following transient occlusion with high resolution ultrasound transducer and intima+media area in coronary arteries with intravascular ultrasound in 25 patients with normal coronary angiograms (age 61.6+/-8.7 years old, men 14 and women 11). FMD was measured at least 7 days after the cessation of all vasodilators. The mean FMD of 25 patients was 3.83+/-2.38%, the mean intima+media area in coronary arteries of 25 patients was 39.9+/-15.5% of total vessel wall. FMD has a close negative relation with the largest percent intima+media area (r=-0.77, p<0.01). Especially, the patients whose FMD was less than 3.83% had larger percent intima+media area than those whose FMD was 3.83% or more (48.7+/-10.7% versus 30.3+/-14.2%, p<0.01). There is an intima+media thickening even in the patients who had normal coronary angiograms, and that the percent intima+media area correlated with FMD. The measurement of FMD is useful for screening the coronary artery intima+media thickening noninvasively. The pathogenesis of acute coronary syndrome has been reported to be the plaque rupture even in the patients with normal coronary angiograms. Thus, we must pay much attention in the patients with impaired FMD even in the normal coronary angiograms.

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PubMed2006

Prognostic value of flow-mediated dilation of the brachial artery in patients with cardiovascular disease.

OBJECTIVE: Endothelial dysfunction is thought to represent the initial stage in the development of atherosclerosis. Recently, noninvasive examination of endothelial function has become possible using flow-mediated endothelium-dependent dilation of the brachial artery (FMD) during reactive hyperemia. We examined whether FMD has prognostic value for the prediction of subsequent cardiovascular events. METHODS: Patients were followed prospectively every month until the occurrence of the cardiovascular events. PATIENTS: The study subjects comprised 221 consecutive patients (men 108, mean age 61.4+/-10.6, ischemic heart disease 152, cardiomyopathy 28, arrhythmia 12, valvular disease 5, congenital heart disease 3, and cardioneurosis 21). The mean FMD was 4.77+/-2.85% and this value was used to divide the patients into the 2 groups (Group 1: FMD > or =4.7%; Group 2: FMD <4.7%). RESULTS: There were 110 patients in Group 1 (men 36, mean age 60.5+/-10.9), and 111 patients in Group 2 (men 72, mean age 62.2+/-10.3). Patients were followed until the occurrence of at least 1 of the major clinical cardiovascular events. Seven cardiovascular events occurred in Group 1 (6.4%, 1.14 events per 100 patient-years), while 16 occurred in Group 2 (2.88 events per 100 patient-years). Kaplan-Meier analysis demonstrated a significantly higher probability of developing cardiovascular events in Group 2 than in Group 1. CONCLUSION: The present results demonstrated that the magnitude of FMD in the brachial artery was a good predictor of subsequent cardiovascular events.

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PubMed2006

Relation between platelet microaggregates and ankle brachial index in patients with peripheral arterial disease.

INTRODUCTION: Peripheral arterial disease is one of the systemic atherosclerotic diseases, and patients with the disorder are classified in the high risk group of coronary artery disease. A lower ankle brachial index is a frequent finding in peripheral arterial disease. While platelet microaggregates are a significant predictor of adverse clinical outcome in coronary artery disease, the significance of platelet aggregability in peripheral arterial disease has not been elucidated. MATERIALS AND METHODS: Small platelet aggregates measured using laser-light scattering and ankle brachial index were determined in 42 patients with both coronary artery disease and peripheral arterial disease (peripheral group), 56 patients with only coronary artery disease (coronary group) and 32 patients without both (control group). RESULTS: The level of small platelet aggregates was increased significantly in the peripheral group (4.3 x 10(4) [range 2.2 x 10(4) to 7.4 x 10(4)]) compared with both the coronary (1.1 x 10(4) [range 0.3 x 10(4) to 5.0 x 10(4)]) and control groups (0.5 x 10(4) [range 0.1 x 10(4) to 0.9 x 10(4)]). There was a significant inverse correlation between log small platelet aggregates and ankle brachial index (n=130, r=-0.422, p<0.001). Multivariate logistic regression analysis revealed that a lower ankle brachial index (<0.90) was an independent determinant of increased levels of small platelet aggregates. CONCLUSIONS: Platelet aggregability was increased in patients with peripheral arterial disease with the degree of platelet aggregation being closely associated with ankle brachial index. It is possible that this change in platelet activity may be one mechanism to explain why a lower ankle brachial index is a predictor of poor prognosis in patients with peripheral arterial disease.

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PubMed2005

Usefulness of preprocedural platelet aggregation to predict restenosis after percutaneous coronary intervention.

We investigated whether the assessment of small platelet aggregates before percutaneous coronary intervention (PCI) could predict restenosis after PCI. This was a prospective cohort study that enrolled 189 consecutive patients who had coronary artery disease. In multiple logistic regression analysis, higher levels of preprocedural small platelet aggregates were independently associated with restenosis after PCI. Measurement of small platelet aggregates may serve as a useful clinical variable for stratifying patients who present for PCI.

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PubMed2005

Plasma thioredoxin levels in patients with unstable angina.

Plasma levels of human thioredoxin are indicative of the responses against oxidative stress. We measured the plasma thioredoxin levels in patients with unstable angina in order to examine the relationships between subsequent clinical course and plasma thioredoxin levels before and after treatment for unstable angina. Blood was sampled both on admission and after treatment in 44 patients with unstable angina. In addition, blood samples were obtained from 41 patients with stable exertional angina and 41 patients with chest pain syndrome after admission. The plasma levels of thioredoxin were the highest in the unstable angina group among three groups (p<0.001). Treatment of unstable angina decreased the plasma thioredoxin levels (p<0.01). We divided the patients with unstable angina into two groups according to the plasma thioredoxin levels on admission and after treatment. There was a significant difference in Braunwald's classification between the high thioredoxin and the low thioredoxin group on admission, as analyzed by the chi2 test with Yates's correction (p<0.05). Moreover, there was a significant difference in incidence of recurrent anginal attacks at rest between the high thioredoxin and the low thioredoxin group after treatment, as analyzed by the chi2 test with Yates's correction (p<0.001). The present study demonstrated that plasma thioredoxin levels are significantly increased in patients with unstable angina compared to those with stable exertional angina and chest pain syndrome. Thioredoxin levels were associated with recurrent myocardial ischemia in patients with unstable angina.

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PubMed2005

Urinary 8-hydroxy-2'-deoxyguanosine levels increase after reperfusion in acute myocardial infarction and may predict subsequent cardiac events.

We assessed serial changes in oxidative stress in patients with acute myocardial infarction by measuring urinary 8-hydroxy-2'-deoxyguanosine excretion. The urinary 8-hydroxy-2'-deoxyguanosine creatinine levels peaked at 4 hours after reperfusion therapy and the levels were higher in the cardiac event group than in the noncardiac event group before and after reperfusion.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2005

Levels of the adipocyte-derived plasma protein, adiponectin, have a close relationship with atheroma.

INTRODUCTION: Inflammation is a key process in atherosclerotic formation. Structural changes in the carotid arterial wall including detection of focal plaques are measured as the intima-media thickness (IMT) providing an index of atheroma. Coronary arterial plaques may be considered as vascular structural changes. Distensibility of the arteries can be assessed by functional changes in pulse wave velocity (PWV) providing an index of sclerosis. Adiponectin has potential antiatherosclerotic properties. We hypothesized that adiponectin was associated with atherosclerotic vascular changes involved in inflammation. MATERIALS AND METHODS: We enrolled 142 patients with coronary artery disease (CAD) and 108 control patients, matched for age, sex, and body mass index (BMI) with CAD patients. We investigated the relationship between adiponectin, C-reactive protein (CRP), and atherosclerotic vascular changes. RESULTS: CRP (p=0.0009), high-density lipoprotein cholesterol (HDL-C; p=0.02), and IMTmax (p=0.02) were determinants of adiponectin independent of glucose intolerance (p=0.0001), BMI (p=0.002), and CAD (p=0.03), all of which have been significantly associated with adiponectin (r=0.38). Adiponectin was not correlated with PWV. CRP, glucose intolerance, and HDL-C that correlated with adiponectin were inversely correlated with IMTmax and CAD. CRP was negatively correlated with HDL-C (r=-0.24, p=0.0002) and positively correlated with glucose intolerance (r=0.15, p=0.01). CONCLUSIONS: Adiponectin has a close relationship with CRP, IMTmax, CAD, HDL-C, and other established risk factors. CRP, glucose intolerance, and HDL-C are common mediators between adiponectin and atheromatous vascular changes, which are contrary to each other. The exacerbation of atherogenesis may be involved in a decrease of adiponectin through abnormal glyco- and lipid-metabolism by promoting inflammation.

Adiponectin↗

PubMed2005

Increased plasma levels of thioredoxin in patients with glucose intolerance.

OBJECTIVE: The aim of the present study was to determine the effects of glucose intolerance on oxidative stress in patients with coronary artery disease (CAD). METHODS: The patients were divided into 3 groups, diabetes mellitus (DM), IGT or normal glucose tolerance (NGT) according to the criteria of the American Diabetes Association. PATIENTS: The present study consisted of 178 consecutive patients who underwent diagnostic coronary arteriography and a 75-g glucose tolerance test. RESULTS: The level of plasma thioredoxin, a marker of oxidative stress was measured in every patient during the fasting state. The levels of plasma thioredoxin were significantly higher in the DM and IGT groups than the NGT group. Furthermore, we found that there was a positive association between thioredoxin levels and glycosylated hemoglobin (sigma=0.225, p=0.018). In multivariate logistic regression analysis, glucose intolerance (DM or IGT) was only independently associated with the high levels of thioredoxin. The levels of plasma thioredoxin were significantly higher in the CAD group compared to the non-CAD group. In multivariate logistic regression analysis, high levels of thioredoxin, male, age and hypertension were independently associated with the presence of CAD. CONCLUSION: Glucose intolerance was associated with the high levels of thioredoxin. High levels of thioredoxin were related to the presence of CAD. The measurement of thioredoxin as the marker of oxidative stress may be useful for monitoring the development of the cardiovascular diseases.

Adult↗

PubMed2005

Sensorineural hearing loss combined with Takayasu's arteritis.

A 49-year-old woman complained of hearing loss and diminution of left radial arterial pulsation. She had been diagnosed with sudden deafness and treated with corticosteroids. Her audibility deteriorated again after the cessation of the therapy. Angiograms showed stenosis in the bilateral carotid arteries, the left vertebral artery, the left subclavian artery, and the pulmonary arteries. She was diagnosed with Takayasu's arteritis. After steroid therapy was restarted, there were improvements in her audibility, radial arterial pulsation, and levels of inflammatory markers (erythrocyte sedimentation rate, C-reactive protein, and gamma-globulin), fibrinogen, interleukin-6, and RANTES (regulated on activation, normal T cell expressed and secreted).

Administration, Oral↗

PubMed2005

Dynamic electrocardiographic changes due to cardiac compression by a giant hiatal hernia.

A 79-year-old woman was admitted due to chest pain with T wave inversion and anasarca. Echocardiography demonstrated a mass compressing the heart and computed tomography revealed a giant hiatal hernia within the intrathoracic stomach located just behind the heart. After drainage of the gastric contents, the T wave inversion disappeared, but subsequent ST elevation in leads V1-V6 was noted. After surgical correction of the hiatal hernia, the ST segment elevation returned to a nearly normal level. The changes in the compressed heart induced by hiatal hernia may cause pericarditis resulting in electrocardiographic changes.

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PubMed2005

Platypnea-orthodeoxia syndrome combined with multiple congenital heart anomalies.

A 71-year-old woman was admitted for paralysis on the left side of her body. She developed dyspnea and hypoxemia after admission. Although pulmonary embolism was suspected, hypoxemia and dyspnea occurred repeatedly in spite of anticoagulation therapy. Transesophageal echocardiography revealed a patent foramen ovale (PFO), an atrial septal aneurysm (ASA), and a right-to-left shunt that appeared in an upright position. She was diagnosed with platypnea-orthodeoxia syndrome. Moreover, cardiac catheterization showed congenital anomalies, such as unroofed coronary sinus, partial anomalous pulmonary venous return and persistent left superior vena cava. Simple surgical closure of the ASA and PFO improved all of her symptoms.

Abnormalities, Multiple↗

PubMed2005

Successful coronary stenting of the left anterior descending artery at the branching site of the targeted septal perforator immediately after percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy.

We report a case of simultaneous percutaneous treatment of hypertrophic obstructive cardiomyopathy (HOCM) and coronary artery disease. Cardiac catheterization revealed a left ventricular outflow tract pressure gradient (LVOTPG) of 130 mmHg and a significant left anterior descending artery (LAD) stenosis at the site of the 1st major septal branch. The LVOTPG was eliminated by injection of ethanol into the branch. Subsequently, a coronary stent was implanted in the LAD. A coil stent was selected due to possibility of repeat septal ablation in the future. Simultaneous treatment of HOCM and LAD stenosis is considered safe and effective using a coil stent.

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PubMed2004

Urinary biopyrrins levels are elevated in relation to severity of heart failure.

OBJECTIVES: We investigated the relationship between the urinary levels of biopyrrins and the severity of heart failure (HF). BACKGROUND: Oxidative stress is evident in heart disease and contributes to the development of ventricular dysfunction in patients with HF. Biopyrrins, oxidative metabolites of bilirubin, have been discovered as potential markers of oxidative stress. METHODS: We measured the levels of urinary biopyrrins and plasma B-type natriuretic peptide (BNP) in 94 patients with HF (59 men; mean age 65 years) and 47 control subjects (30 men; mean age 65 years). Urine and blood samples were taken after admission in all subjects. Further urine samples were obtained from 40 patients after treatment of HF. RESULTS: The urinary biopyrrins/creatinine levels (micromol/g creatinine) were the highest in patients in New York Heart Association (NYHA) class III/IV (n = 26; 17.05 [range 7.85 to 42.91]). The urinary biopyrrins/creatinine levels in patients in NYHA class I (n = 35; 3.46 [range 2.60 to 5.42]) or II (n = 33; 5.39 [range 3.37 to 9.36]) were significantly higher than those in controls (2.38 [range 1.57 to 3.15]). There were significant differences in urinary biopyrrins/creatinine levels among each group. The treatment of HF significantly decreased both urinary biopyrrins/creatinine levels (from 7.43 [range 3.84 to 17.05] to 3.07 [range 2.21 to 5.71]) and NYHA class (from 2.5 +/- 0.1 to 1.7 +/- 0.1). Log biopyrrins/creatinine levels were positively correlated with log BNP levels (r = 0.650, p < 0.001). CONCLUSIONS: These results indicate that urinary biopyrrins levels are increased in patients with HF and are elevated in proportion to its severity.

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PubMed2004

Vitamin E improves fibrinolytic activity in patients with coronary spastic angina.

INTRODUCTION: The fibrinolytic system has a major role as a defense mechanism against thrombus formation. Net fibrinolytic activity in plasma reflects the balance between tissue-type plasminogen activator and plasminogen activator inhibitor (PAI). PAI is the main factor determining overall fibrinolytic activity. MATERIALS AND METHODS: We examined the effects of oral administration of vitamin E, an antioxidant, on fibrinolytic activity and oxidative stress in patients with coronary spastic angina. Forty patients with coronary spastic angina were randomly assigned into two treatment groups, either vitamin E group (alpha-tocopherol acetate, 400 mg/day) or placebo group by means of computerized system. PAI activity and thioredoxin, a marker of oxidative stress, levels were measured before and at the end of 1 month treatment. RESULTS: Before treatment, the levels of PAI activity and thioredoxin were increased in patients with coronary spastic angina as compared with control subjects (n=17) (PAI activity levels: 13.6+/-1.4 vs. 7.6+/-2.2 IU/ml, p<0.05, thioredoxin levels: 22.8+/-1.7 vs. 16.0+/-1.4 ng/ml, p<0.05). In patients with coronary spastic angina, administration of vitamin E decreased both PAI activity and thioredoxin levels (PAI activity levels: 14.7+/-1.7 to 7.5+/-1.6 IU/ml, p<0.01, thioredoxin levels: 23.3+/-2.4 to 15.1+/-2.5 ng/ml, p<0.01), whereas placebo had no effect on these variables. CONCLUSIONS: Oral administration of vitamin E improved fibrinolytic activity and the improvement was associated with a decrease in oxidative stress. Administration of vitamin E is possible to be an effective adjunct therapy of coronary spasm in the absence of coronary atherosclerosis.

Administration, Oral↗

PubMed2004

Increased plasma levels of thioredoxin in patients with coronary spastic angina.

To determine whether plasma levels of thioredoxin are associated with coronary spasm, we measured the plasma levels of thioredoxin in 170 patients who had <25% organic stenosis in coronary arteriography. According to the results of cardiac catheterization, we divided the patients into two groups: a coronary spastic angina group (n=84) and a chest pain syndrome group (n=86). The plasma levels of thioredoxin were significantly higher in the coronary spastic angina group than in the chest pain syndrome group (40.7 +/- 4.1 versus 18.2 +/- 1.1 ng/ml, p<0.0001). Furthermore, the increased plasma levels of thioredoxin were associated with high disease activity indicated by the frequency of angina attacks (p=0.0004). In multiple logistic regression analysis, the higher levels of thioredoxin [relative risk 14.8, 95% confidence interval (5.13-42.9), p<0.0001] and current smoking [relative risk 3.39, 95% confidence interval (1.31-8.75), p=0.012] were significant and independent variables associated with coronary spasm. We demonstrated that the plasma levels of thioredoxin were increased in the coronary spastic angina group, and increased levels of thioredoxin were associated with high disease activity. The plasma levels of thioredoxin and current smoking were risk factors for coronary spastic angina, and they were independent from other traditional risk factors.

Adult↗

PubMed2004

Adiponectin is inversely related to plasminogen activator inhibitor type 1 in patients with stable exertional angina.

Adipose tissue is a secretory organ producing a variety of bioactive substances, such as adiponectin. Adiponectin has antiatherogenic properties while plasminogen activator inhibitor type 1 (PAI-1) is closely involved in the development of atherosclerosis. The relationship between adiponectin and PAI-1 in patients with coronary artery disease (CAD) has not been clarified. This study examined plasma levels of adiponectin and PAI-1 in 64 patients with stable exertional angina (SEA) and 65 patients with the chest pain syndrome (CPS). Plasma log-adiponectin levels were significantly lower in patients with SEA (0.62+/-0.08 micro g/dL) compared to those with CPS (0.86+/-0.05 micro g/dL) (p<0.0001). The plasma levels of log-PAI-1 were significantly higher in patients with SEA (1.23+/-0.18 ng/mL) compared to those with CPS (1.15+/-0.22 ng/mL) (p<0.05). Plasma log-adiponectin levels correlated negatively with diabetes mellitus (DM), body mass index (BMI), log-PAI-1 (r=-0.284, p<0.001), triglyceride (TG), and remnant-like particles cholesterol (RLP-C), and positively with high-density lipoprotein cholesterol (HDL-C) levels. Plasma levels of log-PAI-1 correlated positively with DM, BMI,TG and RLP-C levels, and negatively with HDL-C levels. Multiple logistic regression analysis identified sex, angina pectoris, and PAI-1 as independent determinants of hyperadiponectinemia (p<0.05). Adiponectin is inversely related to PAI-1. DM, BMI,TG, HDL-C, and RLP-C are common mediators between adiponectin and PAI-1, and treatment for common mediators may prevent the development of CAD by reducing PAI-1 and increasing adiponectin levels.

Adiponectin↗

PubMed2004

Effects of nicorandil on endogenous fibrinolytic capacity in patients with coronary artery disease.

BACKGROUND: Nicorandil is a hybrid-type anti-anginal drug that combines a K(ATP) channel opener and a nitric oxide donor. Recently the IONA study reported that nicorandil improves the prognosis of patients with stable angina pectoris. METHODS AND RESULTS: To examine the effects of nicorandil on endogenous fibrinolysis, plasma concentrations of tissue-type plasminogen activator (t-PA) antigen, type-1 plasminogen activator inhibitor (PAI-1) antigen and PAI activity were measured in consecutive 11 patients (7 men and 4 women, mean age 63 years, ranges 41-84 years) with coronary artery disease. Nicorandil (15 mg/day) was administered orally to each patient for 2 weeks. Venous blood samples were obtained from each patient before and after the administration of the drug in the early morning before eating. There were no significant changes in the plasma concentrations of t-PA (12.4+/-1.9 to 9.8+/-1.5) or PAI-1 (26.3+/-3.9 to 21.5+/-4.9) antigens (ng/ml, mean +/- SEM) before and after nicorandil administration. On the other hand, the plasma activity of PAI (IU/ml, mean +/- SEM) decreased significantly after the treatment (12.9+/-3.2 to 5.6+/-1.9, p=0.039). CONCLUSIONS: It is well known that PAI activity determines the whole fibrinolytic capacity and oral administration of nicorandil decreased PAI activity in patients with coronary artery disease. This finding suggests that nicorandil improves the fibrinolytic capacity and may reduce the risk of coronary thrombus formation in such patients.

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PubMed2004

Coronary spastic angina in patients with connective tissue disease.

BACKGROUND: Connective tissue disease, which is an inflammatory condition represented by C-reactive protein (CRP), is a risk factor for ischemic heart disease. The aim of the present study was to examine if there is a relationship between connective tissue disease and coronary spastic angina, and whether the inflammatory condition was associated with ischemic heart disease, even in patients with connective tissue disease. METHODS AND RESULTS: The study group comprised 73 consecutive patients with connective tissue disease who were admitted to the Department of Cardiovascular Medicine between April 2000 and March 2003. Of the 73 patients, 38 (19 men, 19 women) were diagnosed as having an ischemic heart disease (7 patients acute coronary syndrome, 19 patients coronary spastic angina, 12 patients stable exertional angina). In the present study, 19 (50.0%) of the 38 patients of ischemic heart disease were diagnosed as having coronary spastic angina. In the same study period, 151 (38.7%) of 390 patients with ischemic heart disease (without connective tissue disease) were diagnosed as having coronary spastic angina. The frequency of the patients with coronary spastic angina tended to be higher in patients with connective tissue disease than in patients without connective tissue disease. Among the study patients, serum CRP concentrations (mg/dl) were higher in patients with acute coronary syndrome (1.50 +/- 1.19, n=7) and those with coronary spastic angina (1.06 +/- 1.78, n=19) than in those with non-ischemia (0.35 +/- 0.40, n=35, p<0.05). CONCLUSIONS: Coronary spastic angina is a frequent complication in patients with connective tissue disease and the inflammatory condition is associated with coronary spastic angina and unstable angina in patients with connective tissue disease.

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