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Featured researches published by Yoichiro Otaki.


Journal of Cardiology | 2013

The prognostic importance of objective nutritional indexes in patients with chronic heart failure

Taro Narumi; Takanori Arimoto; Akira Funayama; Shinpei Kadowaki; Yoichiro Otaki; Satoshi Nishiyama; Hiroki Takahashi; Tetsuro Shishido; Takehiko Miyashita; Takuya Miyamoto; Tetsu Watanabe; Isao Kubota

BACKGROUND Although malnutrition indicates an unfavorable prognosis in some clinical settings, the association between nutritional indexes and outcomes for patients with chronic heart failure (CHF) is unclear. METHODS AND RESULTS All the previously established objective nutritional indexes were evaluated. The controlling nutritional status score (CONUT), prognostic nutritional index (PNI), and geriatric nutritional risk index (GNRI) were determined for 388 consecutive patients with CHF (mean age 69.6±12.3 years). The prevalence of malnutrition in this cohort was 60-69%. Patients were followed prospectively, with the endpoints being death due to a cardiovascular event or re-hospitalization. There were 130 events, including 33 deaths and 97 re-hospitalizations, during a mean follow-up period of 28.4 months. Patients experiencing cardiovascular events showed impaired nutritional status, higher CONUT scores, lower PNI scores, and lower GNRI scores, compared with those who did not experience cardiovascular events. CONUT score [hazard ratio 40.9, 95% confidence interval (CI) 10.8-154.8], PNI score (hazard ratio 6.4, 95% CI 5.4-25.1), and GNRI score (hazard ratio 11.6, 95% CI 3.7-10.0) were independently associated with cardiovascular events. Kaplan-Meier analysis showed that there was a significantly higher incidence of cardiovascular events in patients who were malnourished than in those who were not. CONCLUSION Malnutrition was common in patients with CHF. Evaluation of nutritional status may provide additional prognostic information in patients with CHF.


Cardiovascular Diabetology | 2014

Impact of serum omentin-1 levels on cardiac prognosis in patients with heart failure

Taro Narumi; Tetsu Watanabe; Shinpei Kadowaki; Daisuke Kinoshita; Miyuki Yokoyama; Yuki Honda; Yoichiro Otaki; Satoshi Nishiyama; Hiroki Takahashi; Takanori Arimoto; Tetsuro Shishido; Takuya Miyamoto; Isao Kubota

BackgroundVarious adipokines are reported to be associated with the development of heart failure (HF) through insulin resistance and chronic inflammation. Omentin-1 is a novel adipokine and is associated with incident coronary artery disease. However, it remains unclear whether serum omentin-1 levels are associated with cardiac prognosis in patients with HF.MethodsWe measured serum omentin-1 levels at admission in 136 consecutive patients with HF, and 20 control subjects without signs of significant heart disease. We prospectively followed patients with HF to endpoints of cardiac death or re-hospitalization for worsening HF.ResultsSerum omentin-1 levels were markedly lower in HF patients with cardiac events compared with to without. The patients who were in New York Heart Association (NYHA) functional class IV showed significantly lower serum omentin-1 levels compared to those in class II and III, whereas serum omentin-1 levels did not correlate with serum brain natriuretic peptide levels (r = 0.217, P = 0.011). We divided the HF patients into three groups based on the tertiles of serum omentin-1 level (low T1, middle T2, and high T3). Multivariate Cox hazard analysis showed that the lowest serum omentin-1 level (T1) was independently associated with cardiac events after adjustment for confounding factors (hazard ratio 5.78, 95% confidence interval 1.20-12.79). We divided the HF patients into two groups according to the median serum omentin-1 levels. Kaplan-Meier analysis revealed that the patients with low serum omentin-1 levels had a higher risk of cardiac events compared with those with high serum omentin-1 levels (log-rank test p < 0.001).ConclusionDecreased serum omentin-1 levels were associated with a poor cardiac outcome in patients with HF.


PLOS ONE | 2013

Long pentraxin PTX3 exacerbates pressure overload-induced left ventricular dysfunction.

Satoshi Suzuki; Tetsuro Shishido; Akira Funayama; Shunsuke Netsu; Mitsunori Ishino; Tatsuro Kitahara; Toshiki Sasaki; Shigehiko Katoh; Yoichiro Otaki; Tetsu Watanabe; Yoko Shibata; Alberto Mantovani; Yasuchika Takeishi; Isao Kubota

Background Left ventricular hypertrophy is enhanced by an inflammatory state and stimulation of various cytokines. Pentraxin 3 (PTX3) is rapidly produced in response to inflammatory signals, and high plasma PTX3 levels are seen in patients with heart failure. This study aimed to examine the influence of PTX3 on cardiac hypertrophy and left ventricular dysfunction with respect to pressure overload. Methods and Results PTX3 systemic knockout (PTX3-KO) mice, transgenic mice with cardiac-specific overexpression of PTX3 (PTX3-TG), and the respective wild-type (WT) littermate mice were subjected to transverse aortic constriction (TAC) or a sham operation. Cardiac PTX3 expression increased after TAC in WT mice. In vitro, hydrogen peroxide induced the expression of PTX3 in both cardiac myocytes and cardiac fibroblasts. Recombinant PTX3 phosphorylated extracellular signal–regulated kinase 1/2 (ERK1/2) in cardiac fibroblasts. Phosphorylation of cardiac ERK1/2 and nuclear factor kappa-B after TAC was attenuated in the PTX3-KO mice but was enhanced in the PTX3-TG mice compared with WT mice. Interleukin-6 and connective tissue growth factor production was lower in the PTX3-KO mice than in the WT mice, but this was augmented in the PTX3-TG mice than in the WT mice. Echocardiography revealed that adverse remodeling with left ventricular dysfunction, as well as with increased interstitial fibrosis, was enhanced in PTX3-TG mice, while these responses were suppressed in PTX3-KO mice. Conclusion The local inflammatory mediator PTX3 directly modulates the hypertrophic response and ventricular dysfunction following an increased afterload.


Journal of Molecular and Cellular Cardiology | 2015

High-mobility group box 1-mediated heat shock protein beta 1 expression attenuates mitochondrial dysfunction and apoptosis

Taro Narumi; Tetsuro Shishido; Yoichiro Otaki; Shinpei Kadowaki; Yuki Honda; Akira Funayama; Shintaro Honda; Hiromasa Hasegawa; Daisuke Kinoshita; Miyuki Yokoyama; Satoshi Nishiyama; Hiroki Takahashi; Takanori Arimoto; Takuya Miyamoto; Tetsu Watanabe; Atsushi Tanaka; Chang Hoon Woo; Jun Ichi Abe; Yasuchika Takeishi; Isao Kubota

AIMS Apoptosis of cardiomyocytes is thought to account for doxorubicin cardiotoxicity as it contributes to loss of myocardial tissue and contractile dysfunction. Given that high-mobility group box 1 (HMGB1) is a nuclear DNA-binding protein capable of inhibiting apoptosis, we aimed to clarify the role of HMGB1 in heat shock protein beta 1 (HSPB1) expression during doxorubicin-induced cardiomyopathy. METHODS AND RESULTS Mitochondrial damage, cardiomyocyte apoptosis, and cardiac dysfunction after doxorubicin administration were significantly attenuated in mice with cardiac-specific overexpression of HMGB1 (HMGB1-Tg) compared with wild type (WT) -mice. HSPB1 levels after doxorubicin administration were significantly higher in HMGB1-Tg mice than in WT mice. Transfection with HMGB1 increased the expression of HSPB1 at both the protein and mRNA levels, and HMGB1 inhibited mitochondrial dysfunction and apoptosis after exposure of cardiomyocytes to doxorubicin. HSPB1 silencing abrogated the inhibitory effect of HMGB1 on cardiomyocyte apoptosis. Doxorubicin increased the binding of HMGB1 to heat shock factor 2 and enhanced heat shock element promoter activity. Moreover, HMGB1 overexpression greatly enhanced heat shock element promoter activity. Silencing of heat shock factor 2 attenuated HMGB1-dependent HSPB1 expression and abrogated the ability of HMGB1 to suppress cleaved caspase-3 accumulation after doxorubicin stimulation. CONCLUSIONS We report the first in vivo and in vitro evidence that cardiac HMGB1 increases HSPB1 expression and attenuates cardiomyocyte apoptosis associated with doxorubicin-induced cardiomyopathy. Cardiac HMGB1 increases HSPB1 expression in cardiomyocytes in a heat shock factor 2-dependent manner.


PLOS ONE | 2014

Association of heart-type fatty acid-binding protein with cardiovascular risk factors and all-cause mortality in the general population: the Takahata study.

Yoichiro Otaki; Tetsu Watanabe; Hiroki Takahashi; Atushi Hirayama; Taro Narumi; Shinpei Kadowaki; Yuki Honda; Takanori Arimoto; Tetsuro Shishido; Takuya Miyamoto; Tsuneo Konta; Yoko Shibata; Akira Fukao; Makoto Daimon; Yoshiyuki Ueno; Takeo Kato; Takamasa Kayama; Isao Kubota

Background Despite many recent advances in medicine, preventing the development of cardiovascular diseases remains a challenge. Heart-type fatty acid-binding protein (H-FABP) is a marker of ongoing myocardial damage and has been reported to be a useful indicator for future cardiovascular events. However, it remains to be determined whether H-FABP can predict all-cause and cardiovascular deaths in the general population. Methods and Results This longitudinal cohort study included 3,503 subjects who participated in a community-based health checkup with a 7-year follow-up. Serum H-FABP was measured in registered subjects. The results demonstrated that higher H-FABP levels were associated with increasing numbers of cardiovascular risk factors, including hypertension, diabetes mellitus, obesity, and metabolic syndrome. There were 158 deaths during the follow-up period, including 50 cardiovascular deaths. Deceased subjects had higher H-FABP levels compared to surviving subjects. Multivariate Cox proportional hazard regression analysis revealed that H-FABP is an independent predictor of all-cause and cardiovascular deaths after adjustments for confounding factors. Subjects were divided into four quartiles according to H-FABP level, and Kaplan-Meier analysis demonstrated that the highest H-FABP quartile was associated with the greatest risks for all-cause and cardiovascular deaths. Net reclassification index and integrated discrimination index were significantly increased by addition of H-FABP to cardiovascular risk factors. Conclusions H-FABP level was increased in association with greater numbers of cardiovascular risk factors and was an independent risk factor for all-cause and cardiovascular deaths. H-FABP could be a useful indicator for the early identification of high-risk subjects in the general population.


Arteriosclerosis, Thrombosis, and Vascular Biology | 2014

A Novel Mouse Model of Aortic Valve Stenosis Induced by Direct Wire Injury

Shintaro Honda; Takuya Miyamoto; Tetsu Watanabe; Taro Narumi; Shinpei Kadowaki; Yuki Honda; Yoichiro Otaki; Hiromasa Hasegawa; Shunsuke Netsu; Akira Funayama; Mitsunori Ishino; Satoshi Nishiyama; Hiroki Takahashi; Takanori Arimoto; Tetsuro Shishido; Takehiko Miyashita; Isao Kubota

Objective—The response-to-tissue-injury theory is currently the favorite paradigm to investigate valve pathology. To the best of our knowledge, there are currently no in vivo valve injury models. There are few calcific aortic valve stenosis (AVS) models that develop hemodynamically significant stenosis. Here, we investigated the effect of direct mechanical injury on aortic valves in vivo and developed a novel mouse model of calcific AVS. Approach and Results—Aortic valve injury was created by inserting and moving a spring guidewire under echocardiographic guidance into the left ventricle of male C57/BL6 mice via right common carotid artery. Serial echocardiographic measurements revealed that aortic velocity was increased 1 week after injury and persistently increased until 16 weeks after injury. AVS mice showed a higher heart weight/body weight ratio and decreased left ventricular fractioning shortening 4 weeks after injury, compared with sham mice. We found remarkable proliferation of valve leaflets 4 weeks after injury. Proliferative valves showed increased production of reactive oxygen species and expression of inflammatory cytokines and osteochondrogenic factors. Alizarin red staining showed valvular calcification 12 weeks after injury. Conclusions—We report a novel calcific AVS model to support the response-to-tissue-injury theory. This model may be a valuable tool for analyzing the mechanism of AVS and assessing therapeutic options.


International Journal of Cardiology | 2017

Association of plasma xanthine oxidoreductase activity with severity and clinical outcome in patients with chronic heart failure

Yoichiro Otaki; Tetsu Watanabe; Daisuke Kinoshita; Miyuki Yokoyama; Tetsuya Takahashi; Taku Toshima; Takayuki Sugai; Takayo Murase; Takashi Nakamura; Satoshi Nishiyama; Hiroki Takahashi; Takanori Arimoto; Tetsuro Shishido; Takuya Miyamoto; Isao Kubota

BACKGROUND Oxidative stress due to purine degradation is associated with the development of chronic heart failure (CHF). Xanthine oxidoreductase (XOR) is a rate-limiting enzyme of purine degradation that plays a key role in uric acid (UA) production with a resultant increase in reactive oxygen species. However, the relationship between plasma XOR activity and CHF severity and clinical outcome remains unclear. METHODS AND RESULTS We measured XOR activity in 440 patients with CHF and 44 control subjects. Abnormally high and low XOR activities were identified based on the results for 95% of the control subjects (high and low XOR activities ≥120 and <33pmol/100μL/h, respectively). The prevalence rates of high and low XOR activities increased with advancing New York Heart Association functional class. There were 158 cardiac events during a median follow-up period of 1034days. Multivariate Cox proportional hazard regression analysis showed that both high and low XOR activities were significantly associated with cardiac events in patients with CHF after adjustment for confounding risk factors including serum UA and loop diuretic use. Kaplan-Meier analysis revealed that the cardiac event rate was significantly higher in patients with either high or low XOR activity. The net reclassification index was significantly improved by adding XOR activity to the basic risk factors. CONCLUSIONS We provide the first evidence of an association of plasma XOR activity with CHF severity and clinical outcome. Plasma XOR activity could be used to identify high-risk CHF patients and could be a therapeutic target for XOR inhibitors.


Journal of Atherosclerosis and Thrombosis | 2016

Impact of Serum Uric Acid Levels on Coronary Plaque Stability Evaluated Using Integrated Backscatter Intravascular Ultrasound in Patients with Coronary Artery Disease

Kaoru Ando; Hiroki Takahashi; Tetsu Watanabe; Hyuma Daidoji; Yoichiro Otaki; Satoshi Nishiyama; Takanori Arimoto; Tetsuro Shishido; Takehiko Miyashita; Takuya Miyamoto; Isao Kubota

AIM Because the prevalence of hyperuricemia is lower in females than in males, the association between hyperuricemia and cardiovascular disease has been frequently reported in females. Increased serum uric acid levels are associated with the presence of cardiovascular risk factors such as hypertension, renal dysfunction, insulin resistance, and metabolic syndrome. However, it is controversial whether hyperuricemia is an independent risk factor for coronary artery disease in both the genders. The purpose of this study was to investigate the relationship between serum uric acid levels and coronary plaque components assessed using integrated backscatter intravascular ultrasound (IB-IVUS) in males and females. METHODS In total, 385 patients (298 males and 87 females) who underwent percutaneous coronary intervention using IB-IVUS were divided into three groups in each gender according to their serum uric acid levels. We characterized tissue from coronary plaques in culprit lesions. RESULTS Serum uric acid levels significantly correlated with percent lipid volume (r=0.37) and inversely correlated with percent fibrous volume (r=-0.35). Multivariate analysis showed that the uric acid level was independently associated with lipid-rich plaques (odds ratio 2.43, 95%, confidence interval 1.75-3.47). The prevalence of lipid-rich plaques increased with increasing uric acid levels in both genders. CONCLUSION Increased serum uric acid levels were associated with larger lipid content plaques in both genders.


Circulation | 2015

Cystatin C-Based eGFR Is a Superior Prognostic Parameter to Creatinine-Based eGFR in Post-Endovascular Therapy Peripheral Artery Disease Patients

Yoichiro Otaki; Hiroki Takahashi; Tetsu Watanabe; Gensai Yamaura; Akira Funayama; Takanori Arimoto; Tetsuro Shishido; Takuya Miyamoto; Isao Kubota

BACKGROUND Kidney dysfunction is reportedly associated with adverse outcome in patients with peripheral artery disease (PAD). Estimated glomerular filtration rate (eGFR), a recently popularized index for assessing kidney function, is calculated using serum creatinine or cystatin C. Compared with creatinine-based eGFR (eGFRcr), cystatin C-based eGFR (eGFRcys) is less affected by age, gender, and muscle mass. We hypothesized that eGFRcys is a feasible prognostic biomarker despite muscle sarcopenia in patients with PAD. METHODSANDRESULTS We calculated both eGFRcr and eGFRcys according to the Kidney Disease: Improving Global Outcomes (KDIGO) guideline in 234 PAD patients who underwent endovascular therapy. Patients were prospectively followed during a median follow-up period of 964 days for the endpoint of major adverse cardiovascular and cerebrovascular events (MACCE). On multivariate Cox proportional hazard analysis eGFRcys, but not eGFRcr, was an independent predictor of MACCE. The C index was larger for eGFRcys than eGFRcr (0.69 vs. 0.57, P=0.0006). On Kaplan-Meier analysis the incidence of MACCE was increased with advancing chronic kidney disease stage based on eGFRcys, but not on eGFRcr, in patients with PAD. Net reclassification index was improved with the addition of eGFRcys to basic predictors. CONCLUSIONS Compared with eGFRcr, eGFRcys may be a more reliable biomarker for MACCE and patient risk stratification.


Heart and Vessels | 2013

Acidic urine is associated with poor prognosis in patients with chronic heart failure

Yoichiro Otaki; Tetsu Watanabe; Hiroki Takahashi; Hiromasa Hasegawa; Shintaro Honda; Akira Funayama; Shunsuke Netsu; Mitsunori Ishino; Takanori Arimoto; Tetsuro Shishido; Takehiko Miyashita; Takuya Miyamoto; Tsuneo Konta; Isao Kubota

Renal dysfunction is reported to be associated with poor outcomes in patients with chronic heart failure (CHF). A recent study showed that acidic urine is related to chronic kidney disease, which is a risk factor for the development of CHF. However, it remains to be determined whether acidic urine is associated with poor outcomes in patients with CHF. We measured urine pH using dipsticks in 537 patients with CHF. Acidic urine was defined as urine pH ≤5.5. Patients were prospectively followed during a median follow-up period of 556 days. There were 145 cardiac events. Prevalence of acidic urine was increased with advancing stage of chronic kidney disease. Patients with acidic urine had a more severe New York Heart Association functional class compared with those with normal urine. In the multivariate Cox proportional hazard analysis, acidic urine was independently associated with poor outcomes in patients with CHF after adjustment of confounding factors. A Kaplan–Meier analysis demonstrated that the rate of cardiac events was higher in patients with acidic urine than in those with normal urine. The presence of acidic urine can reliably identify patients at high risk of future cardiac events in patients with CHF.

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