Harutoshi Tamura

Yamagata University, Ямагата, Yamagata, Japan

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Publications (16)35.51 Total impact

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    ABSTRACT: Background:The difference between left atrial (LA) and systemic coagulation activity in paroxysmal atrial fibrillation (PAF) is unclear.Methods and Results:We enrolled 100 patients with PAF who underwent AF ablation. Warfarin was stopped 1 day before the procedure. LA volume index and LA emptying fraction were measured by 64-slice multidetector computed tomography. Immediately after transseptal puncture, blood samples were simultaneously collected from the LA and systemic circulation (SC). In addition, to evaluate the effect of warfarin on D-dimer levels we recruited an additional 27 PAF patients on continuous warfarin. Even in patients with low CHADS2scores (mean 0.59±0.68) and during sinus rhythm, the prevalence of positive LA-D-dimer (≥0.5 µg/ml) was greater than that of SC-D-dimer (23% vs. 10%, P<0.01). The LA-D-dimer-positive patients had a larger mean LA volume index and reduced LA emptying fraction than the LA-D-dimer-negative patients. Multiple logistic regression analysis revealed that LA volume index was independently correlated with positive LA-D-dimer (odds ratio 2.245, 95% confidence interval 1.194-4.626, P=0.0112). The prevalence of positive LA-D-dimer was significantly lower in patients taking continuous warfarin, than in those on discontinuous warfarin (3.7% vs. 23%, P=0.025).Conclusions:An enlarged LA volume index was associated with high LA coagulation status in patients with paroxysmal AF. Adequate warfarin control during AF catheter ablation may reduce the prevalence of positive LA-D-dimer.
    Circulation journal : official journal of the Japanese Circulation Society. 11/2014;
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    ABSTRACT: A 14-year-old patient was diagnosed with hypertrophic cardiomyopathy associated with Wolff-Parkinson-White syndrome. The two-dimensional speckle tracking strain method showed normal left ventricular local contraction, but the peak systolic longitudinal strain of the right ventricular (RV) anterior wall was earlier than that of the septal wall. As expected, the location of the accessory pathway was at the RV anterior wall. The patient's RV local contraction was normalized by successful radiofrequency application.
    Internal Medicine 01/2014; 53(14):1527-30. · 0.97 Impact Factor
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    ABSTRACT: Background : Left atrial appendage (LAA) dysfunction predisposes patients with atrial fibrillation (AF) to cardioembolic stroke. Two-dimensional (2D) speckle tracking was reported to be useful for evaluating left atrial (LA) regional function, as well as left ventricular function. However, it remains unclear whether 2D speckle tracking is useful for evaluating LAA dysfunction. Therefore, we investigated whether decreased LA strain may predict LAA dysfunction and thrombus formation in patients with acute ischemic stroke. Methods We performed transthoracic and transesophageal echocardiography in 120 patients (83 males, mean age 72 ± 11 years) within 7 days of onset of an acute ischemic stroke. Longitudinal LA strain was evaluated using 2D speckle tracking imaging at each LA segment, and peak systolic strain was calculated by averaging the results for each segment. Results Forty-eight patients had LAA dysfunction as defined by the presence of LAA thrombus and/or severe spontaneous echo contrast. LA peak systolic strain was significantly decreased in patients with LAA dysfunction compared to those without (32.3 ± 13.7% vs. 12.1 ± 7.2%, p < 0.0001). LA peak systolic strain was significantly correlated with LAA emptying flow velocity (r = 0.693, p < 0.0001). The optimum LA peak systolic strain cut off value for predicting LAA dysfunction was 19%. Multivariate logistic regression analysis showed that LA peak systolic strain was an independent predictor of LAA dysfunction (odds ratio 0.059, 95% confidence interval 0.018-0.146; p < 0.0001). Conclusion Decreased LA peak systolic strain was independently associated with LAA dysfunction in patients with acute ischemic stroke.
    BBA Clinical. 01/2014;
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    ABSTRACT: Background Thioredoxin-1 (Trx-1) is an abundant 12.5 kDa redox protein expressed in almost all eukaryotic cells that protect against the development of heart failure and kidney dysfunction. Plasma Trx-1 levels are considered as a reliable marker for oxidative stress. However, it remains to be determined whether plasma Trx-1 levels can predict cardiac prognosis in patients with chronic heart failure (CHF). Methods and results We measured plasma Trx-1 levels and urinary β2-microglobulin–creatinine ratio (UBCR), a marker for renal tubular damage, in 156 consecutive patients with CHF and 17 control subjects. The patients were prospectively followed for a median follow-up period of 627 days and 46 cardiac events were observed. The patients with cardiac events had significantly higher plasma Trx-1 levels and UBCR levels than the cardiac event-free patients. Multivariate Cox proportional hazard analysis revealed that an elevated Trx-1 level was independently associated with poor outcome in patients with CHF after adjustment for confounding factors (hazard ratio, 1.74; 95% confidence interval, 1.33–2.29; p < 0.0001). UBCR was increased with higher plasma Trx-1 levels. Kaplan–Meier analysis demonstrated that the highest Trx-1 tertile was associated with the highest risk of cardiac events. Conclusion Plasma Trx-1 level was associated with renal tubular damage and cardiac prognosis, suggesting that it could be a useful marker to identify patients at high risk for comorbid heart failure and renal tubular damage.
    Journal of Cardiology 01/2014; · 2.30 Impact Factor
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    ABSTRACT: Aims: Previous studies reported that integrated backscatter intravascular ultrasound (IB-IVUS) provides high diagnostic accuracy for tissue characterization of coronary plaques and that pregnancy-associated plasma protein A (PAPP-A) could be a marker of adverse cardiac outcome in patients with cardiovascular disease. We examined whether IB-IVUS and PAPP-A levels could predict the incidence of no-reflow during percutaneous coronary intervention (PCI). Methods and Results: 176 consecutive patients (138 men, mean age 68 ± 11 years) who underwent PCI with IB-IVUS were prospectively enrolled. Combined no-reflow, including transient filter no-reflow by using distal protection devices, was observed in 31 patients. The percentages of coronary lipid volume (%LV) analyzed by IB-IVUS and serum PAPP-A were significantly higher in patients with combined no-reflow than normal-reflow. To predict no-reflow, a receiver operating characteristic (ROC) analysis determined cut-off values of %LV as 62% and serum PAPP-A as 7.71 ng/mL. The multivariate logistic regression analysis showed that %LV (hazard ratio 4.5, 95% confidence interval 1.6 to 13.4, P < 0.01) and PAPP-A (hazard ratio 4.32, 95% confidence interval 1.5 to 12.7, P < 0.01) were independent predictors of combined no-reflow. Conclusions: %LV analyzed by IB-IVUS and serum PAPP-A levels were closely associated with the coronary no-reflow phenomenon. © 2013 Wiley Periodicals, Inc.
    Catheterization and Cardiovascular Interventions 11/2013; · 2.51 Impact Factor
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    ABSTRACT: Epicardial adipose tissue (EAT) surrounding the heart may contribute to the development of coronary artery disease (CAD) through its local secretion of adipocytokines. Although the quantity of EAT is associated with obesity and metabolic syndrome, the role of EAT in the development of CAD in non-obese patients remains to be determined. This study included 41 patients with CAD who underwent coronary artery bypass graft surgery and 28 patients without CAD who underwent other cardiac surgery. EAT volume was measured by 64-slice multi-detector computed tomography before the surgery. We obtained pericardial fluid and epicardial and subcutaneous adipose tissue samples at the surgery. We investigated the relationship between EAT volume and adiponectin levels in pericardial fluid and incident CAD in patients with and without obesity (body mass index>25kg/m(2)). There was no significant difference in EAT volume between obese patients with and without CAD (55.5±40.2mL vs. 40.1±19.7mL, p=0.323). However, EAT volume was significantly greater in non-obese patients with CAD compared to those without CAD (35.0±18.8mL vs. 15.7±11.0mL, p<0.001). Adiponectin concentrations in pericardial fluid were significantly lower in non-obese patients with CAD compared to those without CAD (2.7±2.0μg/mL vs. 4.3±3.7μg/mL, p=0.049), whereas the adiponectin levels were decreased in obese patients regardless of the presence of CAD. Non-obese patients with CAD had significantly larger size adipocytes in EAT but not subcutaneous adipose tissue compared to those without CAD. Multiple logistic regression analysis showed that increased EAT volume was independently associated with incident CAD in non-obese patients. Increased EAT may play a crucial role in development of CAD through impairment of adiponectin secretion in non-obese patients.
    Journal of Cardiology 11/2013; · 2.30 Impact Factor
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    ABSTRACT: The association between ongoing myocardial damage and outcomes in patients who have received an implantable cardioverter-defibrillator (ICD) is unclear. Consecutive patients with cardiomyopathy, who had received an ICD (n = 107, mean age 65 ± 11 years), were prospectively enrolled. Myocardial membrane injury (heart-type fatty acid binding protein [H-FABP] >4.3 ng/mL) and myofibrillar injury (troponin T >0.01 ng/mL) were defined using receiver operating characteristic curves. Patients were followed for a median of 33.6 months, to an end point of appropriate ICD shock or cardiac death. Myocardial membrane injury (45%) and myofibrillar injury (41%) were equally prevalent among patients with cardiomyopathy who had received ICDs. Appropriate ICD shocks or cardiac death occurred in 31% and 15% of patients, respectively. Multivariate Cox regression analysis showed that serum H-FABP levels >4.3 ng/mL, but not troponin T levels, were a significant independent prognostic factor for cardiac events (hazard ratio 5.502, 95% confidence interval 1.705-17.75, P = .004). Subgroup analysis revealed that measuring H-FABP levels was valuable for anticipating event-free survival among patients with ICDs who were receiving amiodarone. High H-FABP levels also predicted subsequent outcomes in patients who had received ICDs for primary or secondary prevention. Evaluating myocardial damage using H-FABP may be a promising tool for predicting outcomes in patients with cardiomyopathy who have received ICDs.
    Journal of cardiac failure 07/2012; 18(7):556-63. · 3.25 Impact Factor
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    ABSTRACT: It is well known that left atrial appendage (LAA) dysfunction plays an important role in the occurrence of cardioembolic stroke. The atrium is the main source of brain natriuretic peptide (BNP) in patients with atrial fibrillation (AF). We hypothesized that the plasma BNP level would be a sensitive predictor of LAA dysfunction in patients with acute ischemic stroke. Transesophageal echocardiography was performed and plasma BNP levels were measured in 223 patients (145 males, age 69 ± 14 years), within 7 days after the onset of acute ischemic stroke. None of the patients had a history of congestive heart failure. LAA thrombus was detected in 23 of 77 (30%) patients with AF. Plasma BNP levels were markedly higher in patients with cardioembolic stroke compared to those without (144 pg/ml vs. 35 pg/ml, p<0.05). Plasma BNP levels were significantly correlated with LAA emptying flow velocity regardless of sinus rhythm (R=-0.352) or AF (R=-0.436). Furthermore, among patients with cardioembolic stroke, plasma BNP levels were markedly higher in patients with cardiogenic stroke, as diagnosed by transesophageal echocardiography, than in those with cryptogenic stroke (193 pg/ml vs. 14 pg/ml, p<0.05). Multivariate logistic regression analysis showed that a BNP concentration >90 pg/ml was an independent predictor of cardiogenic stroke (odds ratio 41.39, 95% confidence interval 1.28-138; p=0.0358). Elevated plasma BNP concentrations may be a reliable surrogate marker for the prediction of LAA dysfunction and cardiogenic stroke in patients with acute ischemic stroke.
    Journal of Cardiology 04/2012; 60(2):126-32. · 2.30 Impact Factor
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    ABSTRACT: It is important to evaluate left atrial appendage (LAA) dysfunction for primary and secondary prevention of stroke in patients with atrial fibrillation (AF). LAA dysfunction can reportedly be evaluated by LAA wall velocity (LAWV) measured by transthoracic echocardiographic (TTE) imaging. The aim of this study was to examine whether TTE-LAWV can predict long-term cerebrovascular events in patients with ischemic stroke with AF. TTE imaging and transesophageal echocardiographic imaging were performed <7 days after onset in 179 consecutive patients with stroke with AF. TTE-LAWV was measured using Doppler tissue imaging at the LAA tip from the parasternal short-axis view on TTE imaging, as previously reported. All patients were followed up prospectively. Cerebrovascular events were defined as cerebrovascular death and/or recurrent ischemic stroke requiring hospitalization. There were 32 cerebrovascular events during a median follow-up period of 397 days. TTE-LAWV was significantly lower in patients with cerebrovascular events than in patients without (8.3 ± 2.8 vs 11.3 ± 4.0 cm/sec, P < .01). Cox multivariate hazard analysis showed that low TTE-LAWV (<8.7 cm/sec) was an independent predictor of cerebrovascular events (hazard ratio, 3.460; P < .05). Kaplan-Meier analysis showed that cerebrovascular event rates were significantly higher in patients with low TTE-LAWV (<8.7 cm/sec) compared with those with high TTE-LAWV (34% vs 7%, P < .01). Impaired LAA function was associated with long-term cerebrovascular events in patients with stroke with AF. TTE-LAWV may be a feasible parameter for risk stratification in patients with AF.
    Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 02/2012; 25(5):576-83. · 2.98 Impact Factor
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    ABSTRACT: Aorto-pulmonary fistula caused by ruptured aortic aneurysm is rare and sometimes difficult to diagnose, resulting in progression of heart failure. We report a case of acute heart failure due to abrupt rupture of aortic aneurysm into the pulmonary artery. Although it is difficult to make an early diagnosis of aorto-pulmonary shunt, multi-detector computed tomography (MDCT) clearly detected this extracardiac shunt. Emergent surgical repair of aorto-pulmonary fistula was successfully achieved. MDCT is a useful modality to make an accurate diagnosis of extracardiac shunt and to decide the operative procedure non-invasively.
    Journal of Cardiology Cases 10/2011; 4(2):e90–e92.
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    ABSTRACT: Left atrial volume index (LAVI) is known to reflect the duration and severity of increased left atrial pressure caused by left ventricular (LV) diastolic dysfunction. However, the prognostic value of LAVI in patients with heart failure (HF) has not been fully investigated. Transthoracic echocardiography was performed in 146 consecutive patients (78 men, 68 women; mean age 72 ± 12 y) who were hospitalized for HF. There were 45 cardiac events (32%) during a median follow-up period of 448 days. There were no significant differences in LV end-diastolic dimensions or ejection fraction between patients who did or did not have cardiac events. However, LAVI was markedly higher in patients with, than those without, cardiac events (56 ± 26 vs 44 ± 22 mL/m(2); P < .01). Kaplan-Meier analysis showed that there was a stepwise increase in risk of cardiac events with each increment of LAVI category, and LAVI >53.3 mL/m(2) correlated with the highest risk of cardiac events (log-rank test; P < .01). Multivariate Cox proportional hazard analysis showed that high LAVI was an independent predictor for cardiac events (hazard ratio 1.427; 95% confidence interval 1.024-1.934; P < .05). LAVI may be useful for stratification of risk in patients with HF.
    Journal of cardiac failure 03/2011; 17(3):210-6. · 3.25 Impact Factor
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    ABSTRACT: Atrial fibrillation is associated with ischemic stroke because of thrombi that form within the left atrial appendage (LAA). The aim of this study was to develop a new parameter for LAA function that is easily performed using transthoracic echocardiography (TTE). TTE and transesophageal echocardiography were performed in 106 patients with stroke. LAA wall motion velocity (TTE-LAWV) was measured using Doppler tissue imaging at the LAA tip. TTE-LAWV was significantly lower in patients with atrial fibrillation and LAA thrombus than in those with atrial fibrillation and no LAA thrombus and in sinus rhythm (7.5 +/- 1.9 vs 10.0 +/- 3.4 and 13.8 +/- 5.7 cm/s, respectively, P < .05). TTE-LAWV was significantly correlated with LAA emptying flow velocity (R = 0.462, P < .05). The multivariate logistic regression analysis showed that TTE-LAWV < 8.7 cm/s was an independent predictor of LAA thrombus formation (odds ratio, 9.473; 95% confidence interval, 1.172-76.55; P < .05). TTE-LAWV can noninvasively evaluate LAA dysfunction and assist in the detection of LAA thrombus.
    Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 03/2010; 23(5):545-552.e1. · 2.98 Impact Factor
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    ABSTRACT: A 78-year-old man who had been treated with maintenance hemodialysis for chronic renal failure was admitted with severe edema in left arm for 1 month. Venous angiography showed a severe stenosis in left innominate vein, then, he underwent percutaneous balloon angioplasty and venous stenting (Wall Stent RP). His arm edema soon improved after angioplasty, however, he complained of general fatigue and bradycardia 2 days after the venous angioplasty. Electrocardiogram showed complete atrioventricular block with 35 wide QRS complexes per minute. His echocardiogram showed a pipe-shaped structure with multiple slit and acoustic shadow in right ventricle. His radiographical right ventriculogram revealed the migrated venous stent from innominate vein to right ventricle. We tried to perform percutaneous transvenous stent extraction using Goose-Neck snare catheter, however, the wall stent stuck in the right external iliac vein, and contrast media leaked to the outside of the vascular wall. Therefore, we implanted this stent in the iliac vein with optimal-sized balloon inflation, and succeeded in stopping bleeding. Complete atrioventricular block was recovered to sinus rhythm with left bundle branch block just after the removal of the venous stent from right ventricle, and no cardiovascular events occurred after the treatment.
    Journal of Cardiology 07/2009; 53(3):453-7. · 2.30 Impact Factor
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    ABSTRACT: Aortic arch plaques are associated with increased risk of stroke recurrence. The atherosclerotic process also affects aortic stiffness. The purpose of the present study was to evaluate aortic arch stiffness by transesophageal echocardiography (TEE) and its effect on recurrence of stroke. TEE was performed in 201 patients with stroke and the aortic stiffness parameter beta was measured as an expression of the elasticity of the aortic arch wall. Patients were followed during a median follow-up period of 459 days with the endpoint as stroke recurrence. There were 21 cases of stroke recurrence (10%) during the follow-up period and the stiffness parameter beta was significantly higher in those cases (16.8+/-4.6 vs 12.5+/-3.3 [no recurrence], p<0.01). Cox multivariate hazard analysis revealed that stiffness parameter beta was the only independent predictor for stroke recurrence (hazard ratio 1.683, p<0.01). Kaplan-Meier survival analysis revealed that stiffness parameter beta effectively risk stratified patients for stoke recurrence. Furthermore, in 3 groups based on the value of beta, the 3rd tertile had the highest stroke recurrent risk (relative risk 5.473, p<0.01). The value of beta in the aortic arch, assessed by TEE, may be a sensitive indicator of stroke recurrence.
    Circulation Journal 08/2008; 72(8):1296-302. · 3.58 Impact Factor
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    ABSTRACT: The left atrial appendage (LAA) is 1 of the common thromboembolic sources in patients with atrial fibrillation (AF) with stroke. The aim of this study was to examine the usefulness of LAA opacification seen on contrast echocardiography for predicting stroke recurrence in patients with AF. In 192 patients with stroke with AF who underwent transesophageal echocardiography within 7 days after the onset, intracardiac intensity variation at the orifice of the LAA just after intravenous infusion of Levovist (1,500 mg) was measured. During a mean follow-up of 450 days, the association between LAA intensity variation and recurrence of cerebrovascular events was assessed. LAA intensity variation was markedly lower in 19 patients with stroke recurrence than 173 patients without stroke recurrence (8.1 +/- 4.7 vs 12.1 +/- 5.1 dB; p <0.001). LAA thrombus-negative patients with low LAA intensity variation (< or =9.2 dB; n = 45) had higher cerebrovascular recurrent event rates than those with high LAA intensity variation (>9.2 dB; n = 109; 20.0% vs 3.7%; p <0.001) and thrombus-positive patients (15.8%). Cox multivariate hazard analysis showed that of routine echocardiographic parameters, decreased LAA intensity variation was the only independent predictor of stroke recurrence (hazard ratio 5.244, p <0.01). In conclusion, LAA intensity variation on contrast transesophageal echocardiography is a new sensitive index for LAA flow stagnation and recurrent cerebrovascular events in patients with AF with stroke.
    The American Journal of Cardiology 06/2008; 101(11):1630-7. · 3.21 Impact Factor
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    ABSTRACT: Serum fibrin-monomer (FM) is a precursor of stable fibrin, and is a sensitive marker of a systemic hypercoagulable state. It has been reported that, in patients with acute ischemic stroke, higher levels of serum FM reflect intracardiac thrombus formation. Serum coagulation and fibrinolytic activity were measured in 113 patients with acute ischemic stroke within 7 (6+/-1) days after onset. The patients were followed for a mean of 354 (range 36-585) days. The primary endpoints were ischemic stroke recurrence with/without death. FM was markedly higher in the 19 cases with stroke recurrence (49.6+/-53.6 microg/ml) than in the 94 patients without stroke recurrence (14.6+/-30.5 microg/ml; p=0.008). The cerebrovascular event rates were markedly higher in the 12 cases with FM > or =16.5 microg/ml (37.5%) than in the 7 cases with FM <16.5 microg/ml (8.6%; p<0.001). Cox proportional hazards multivariate analysis showed that the FM level was an independent predictor of ischemic stroke recurrence with/without death (hazard ratio, 1.516 per + 1 standard deviation increase; 95% confidence interval, 1.042-2.180; p=0.036). Elevated serum FM levels in hospitalized ischemic stroke patients may be associated with a persistent systemic hypercoagulable state and high long-term rates of cerebrovascular events.
    Circulation Journal 10/2007; 71(10):1573-9. · 3.58 Impact Factor