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Dive into the research topics where Hirokazu Mitsuoka is active.

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Featured researches published by Hirokazu Mitsuoka.


BMJ | 2012

Association of onset to balloon and door to balloon time with long term clinical outcome in patients with ST elevation acute myocardial infarction having primary percutaneous coronary intervention: observational study.

Hiroki Shiomi; Yoshihisa Nakagawa; Takeshi Morimoto; Yutaka Furukawa; Akira Nakano; Shinichi Shirai; Ryoji Taniguchi; Kyohei Yamaji; Kazuya Nagao; Tamaki Suyama; Hirokazu Mitsuoka; Makoto Araki; Hiroyuki Takashima; Tetsu Mizoguchi; Hiroshi Eisawa; Seigo Sugiyama; Takeshi Kimura

Objective To evaluate the relation of symptom onset to balloon time and door to balloon time with long term clinical outcome in patients with ST segment elevation myocardial infarction (STEMI) having primary percutaneous coronary intervention. Design Observation of large cohort of patients with acute myocardial infarction. Setting 26 tertiary hospitals in Japan. Participants 3391 patients with STEMI who had primary percutaneous coronary intervention within 24 hours of symptom onset. Main outcome measures Composite of death and congestive heart failure, compared by onset to balloon time and door to balloon time. Results Compared with an onset to balloon time greater than 3 hours, a time of less than 3 hours was associated with a lower incidence of a composite of death and congestive heart failure (13.5% (123/964) v 19.2% (429/2427), P<0.001; relative risk reduction 29.7%). After adjustment for confounders, a short onset to balloon time was independently associated with a lower risk of the composite endpoint (adjusted hazard ratio 0.70, 95% confidence interval 0.56 to 0.88; P=0.002). However, no significant difference was found in the incidence of a composite of death and congestive heart failure between the two groups of patients with short (≤90 minutes) and long (>90 minutes) door to balloon time (16.7% (270/1671) v 18.4% (282/1720), P=0.54; relative risk reduction 9.2%). After adjustment for confounders, no significant difference was seen in the risk of the composite endpoint between the two groups of patients with short and long door to balloon time (adjusted hazard ratio: 0.98, 0.78 to 1.24: P=0.87). A door to balloon time of less than 90 minutes was associated with a lower incidence of a composite of death and congestive heart failure in patients who presented within 2 hours of symptom onset (11.9% (74/883) v 18.1% (147/655), P=0.01; relative risk reduction 34.3%) but not in patients who presented later (19.7% (196/788) v 18.7% (135/1065), P=0.44; −5.3%). Short door to balloon time was independently associated with a lower risk of a composite of death and congestive heart failure in patients with early presentation (adjusted hazard ratio 0.58, 0.38 to 0.87; P=0.009) but not in patients with delayed presentation (1.57, 1.12 to 2.18; P=0.008). A significant interaction was seen between door to balloon time and time to presentation (interaction P=0.01). Conclusions Short onset to balloon time was associated with better 3 year clinical outcome in patients with STEMI having primary percutaneous coronary intervention, whereas the benefit of short door to balloon time was limited to patients who presented early. Efforts to minimise onset to balloon time, including reduction of patient related delay, should be recommended to improve clinical outcome in STEMI patients.


Journal of the American College of Cardiology | 2015

Initial Surgical Versus Conservative Strategies in Patients With Asymptomatic Severe Aortic Stenosis.

Tomohiko Taniguchi; Takeshi Morimoto; Hiroki Shiomi; Kenji Ando; Norio Kanamori; Koichiro Murata; Takeshi Kitai; Yuichi Kawase; Chisato Izumi; Makoto Miyake; Hirokazu Mitsuoka; Masashi Kato; Yutaka Hirano; Shintaro Matsuda; Kazuya Nagao; Tsukasa Inada; Tomoyuki Murakami; Yasuyo Takeuchi; Keiichiro Yamane; Mamoru Toyofuku; Mitsuru Ishii; Eri Minamino-Muta; Takao Kato; Moriaki Inoko; Tomoyuki Ikeda; Akihiro Komasa; Katsuhisa Ishii; Kozo Hotta; Nobuya Higashitani; Yoshihiro Kato

BACKGROUND Current guidelines generally recommend watchful waiting until symptoms emerge for aortic valve replacement (AVR) in asymptomatic patients with severe aortic stenosis (AS). OBJECTIVES The study sought to compare the long-term outcomes of initial AVR versus conservative strategies following the diagnosis of asymptomatic severe AS. METHODS We used data from a large multicenter registry enrolling 3,815 consecutive patients with severe AS (peak aortic jet velocity >4.0 m/s, or mean aortic pressure gradient >40 mm Hg, or aortic valve area <1.0 cm(2)) between January 2003 and December 2011. Among 1,808 asymptomatic patients, the initial AVR and conservative strategies were chosen in 291 patients, and 1,517 patients, respectively. Median follow-up was 1,361 days with 90% follow-up rate at 2 years. The propensity score-matched cohort of 582 patients (n = 291 in each group) was developed as the main analysis set for the current report. RESULTS Baseline characteristics of the propensity score-matched cohort were largely comparable, except for the slightly younger age and the greater AS severity in the initial AVR group. In the conservative group, AVR was performed in 41% of patients during follow-up. The cumulative 5-year incidences of all-cause death and heart failure hospitalization were significantly lower in the initial AVR group than in the conservative group (15.4% vs. 26.4%, p = 0.009; 3.8% vs. 19.9%, p < 0.001, respectively). CONCLUSIONS The long-term outcome of asymptomatic patients with severe AS was dismal when managed conservatively in this real-world analysis and might be substantially improved by an initial AVR strategy. (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis Registry; UMIN000012140).


Circulation | 2008

Long-Term Outcomes of Coronary-Artery Bypass Graft Surgery Versus Percutaneous Coronary Intervention for Multivessel Coronary Artery Disease in the Bare-Metal Stent Era

Takeshi Kimura; Takeshi Morimoto; Yutaka Furukawa; Yoshihisa Nakagawa; Satoshi Shizuta; Natsuhiko Ehara; Ryoji Taniguchi; Takahiro Doi; Kei Nishiyama; Neiko Ozasa; Naritatsu Saito; Kozo Hoshino; Hirokazu Mitsuoka; Mitsuru Abe; Masanao Toma; Toshihiro Tamura; Yoshisumi Haruna; Yukiko Imai; Satoshi Teramukai; Masanori Fukushima; Toru Kita

Background— Observational registries comparing coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention (PCI) have reported long-term survival results that are discordant with those of randomized trials. Methods and Results— We conducted a multicenter study in Japan enrolling consecutive patients undergoing first CABG or PCI between January 2000 and December 2002. Among 9877 patients enrolled, 5420 (PCI: 3712, CABG: 1708) had multivessel disease without left main involvement. Because age is an important determinant when choosing revascularization strategies, survival analysis was stratified by either age ≥75 or <75 years. Analyses were also performed in other relevant subgroups. Median follow-up interval was 1284 days with 95% follow-up rate at 2 years. At 3 years, unadjusted survival rates were 91.7% and 89.6% in the CABG and PCI groups, respectively (log rank P=0.26). After adjustment for baseline characteristics, survival outcome tended to be better after CABG (hazard ratio for death after PCI versus CABG [HR], 95% confidence interval [CI]: 1.23 [0.99-1.53], P=0.06). Adjusted survival outcomes also tended to be better for CABG among elderly patients (HR [95%CI]: 1.37 [0.98-1.92] P=0.07), but not among nonelderly patients (HR [95% CI]: 1.09 [0.82-1.46], P=0.55). Unadjusted and adjusted survival outcome for CABG and PCI were not significantly different in any subgroups when elderly patients were excluded from analysis. Conclusions— In the CREDO-Kyoto registry, survival outcomes among patients <75 years of age were similar after PCI and CABG, a result that is consistent with those of randomized trials.


Journal of Cardiology | 2011

Pentraxin 3 as a biomarker for acute coronary syndrome: comparison with biomarkers for cardiac damage.

Noriaki Kume; Hirokazu Mitsuoka; Kazutaka Hayashida; Masaru Tanaka

BACKGROUND Pentraxin 3 (PTX3) is increased in circulating blood during the acute stage of acute coronary syndrome (ACS). Therefore, we compared diagnostic values of PTX3 for ACS with those of biomarkers for myocardial damage, such as troponin T (TnT) and heart-type fatty acid binding protein (H-FABP). METHODS AND RESULTS Patients (n = 87) undergoing coronary angiography (CAG), consisting of 16 ACS and 71 non-ACS patients were enrolled. Non-ACS consists of 12 patients with normal CAG, 30 stable angina pectoris (SAP) patients controlled by medical treatment, and 29 SAP patients who required elective coronary revascularization (percutaneous coronary intervention or coronary artery bypass graft). Age, gender, or prevalence of diabetes, hypertension, or smoking was not significantly different between ACS and non-ACS groups. Serum total, high-density lipoprotein, or low-density lipoprotein cholesterol, or triglyceride levels were not significantly different between ACS and non-ACS. PTX3 levels were not significantly correlated with lipid profiles or different between those with and without conventional risk factors. Circulating PTX3, TnT, and H-FABP levels were significantly higher in ACS than non-ACS. In receiver-operating characteristic (ROC) curves, area under the curve (AUC) values for PTX3, TnT and H-FABP were 0.920, 0.674, and 0.690, respectively. ROC curves of PTX3 (AUC: 0.901), TnT (AUC: 0.731), and H-FABP (AUC: 0.633) for ST-elevation ACS were similar to those for whole ACS. In a TnT-negative subgroup, the AUC values of PTX3 and H-FABP for ACS were 0.981 and 0.489, respectively. CONCLUSIONS PTX3 is a sensitive and specific biomarker for the diagnosis of ACS, and shows additional diagnostic values when measured in combination with TnT.


Circulation-cardiovascular Interventions | 2012

Duration of Dual Antiplatelet Therapy and Long-Term Clinical Outcome After Coronary Drug-Eluting Stent Implantation Landmark Analyses From the CREDO-Kyoto PCI/CABG Registry Cohort-2

Tomohisa Tada; Masahiro Natsuaki; Takeshi Morimoto; Yutaka Furukawa; Yoshihisa Nakagawa; Robert A. Byrne; Adnan Kastrati; Kazushige Kadota; Masashi Iwabuchi; Satoshi Shizuta; Junichi Tazaki; Hiroki Shiomi; Mitsuru Abe; Natsuhiko Ehara; Tetsu Mizoguchi; Hirokazu Mitsuoka; Tsukasa Inada; Makoto Araki; Satoshi Kaburagi; Ryoji Taniguchi; Hiroshi Eizawa; Akira Nakano; Satoru Suwa; Akinori Takizawa; Ryuji Nohara; Hisayoshi Fujiwara; Kazuaki Mitsudo; Masakiyo Nobuyoshi; Toru Kita; Takeshi Kimura

Background— Optimal duration of dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation has not been yet fully elucidated. Methods and Results— We assessed the influence of prolonged thienopyridine therapy on clinical outcomes with landmark analysis at 4 and 13 months after DES implantation. Among 6802 patients with at least 1 DES implantation in the CREDO-Kyoto Registry Cohort-2, 6309 patients (on thienopyridine, 5438 patients; off thienopyridine, 871 patients) and 5901 patients (on thienopyridine, 4098 patients; off thienopyridine, 1803 patients) were eligible for the 4- and 13-month landmark analyses, respectively. The majority of patients had stable coronary artery disease (73%) and received sirolimus-eluting stents (93%), and approximately 90% of thienopyridine was ticlopidine. Patients taking thienopyridine had more complex comorbidities and more complex lesion and procedural characteristics as compared with patients not taking thienopyridine. After adjusting for confounders, thienopyridine use was not associated with decreased risk for death/myocardial infarction/stroke (hazard ratio [HR], 1.13; 95% confidence interval [CI], 0.89–1.43, P=0.32 in the 4-month landmark analysis; HR, 1.14; 95% CI, 0.90–1.45, P=0.29 in the 13-month landmark analysis, respectively), whereas the risk for GUSTO moderate/severe bleeding tended to be higher in patients taking thienopyridine (HR, 1.51; 95% CI, 1.00–2.23, P=0.049 in the 4-month landmark analysis; HR, 1.44; 95% CI, 0.99–2.09, P=0.057 in the 13-month landmark analysis, respectively). Conclusions— Prolonged thienopyridine therapy beyond 4 and 13 months appeared not to be associated with reduction in ischemic events but to be associated with a trend toward increased bleeding. Optimal duration of DAPT after DES implantation might be shorter than the currently recommended 1-year interval.


Obesity | 2008

Elevated Soluble Lectin-like Oxidized LDL Receptor-1 (sLOX-1) Levels in Obese Postmenopausal Women

Tina E. Brinkley; Noriaki Kume; Hirokazu Mitsuoka; Dana A. Phares; James M. Hagberg

We investigated the association between soluble lectin‐like oxidized low‐density lipoprotein receptor‐1 (sLOX‐1) levels and obesity in older women. Fifty‐one postmenopausal women (10 lean, 22 overweight, and 19 obese) were included in this small retrospective analysis. Plasma sLOX‐1 levels were measured using a chemiluminescent enzyme‐linked immunoassay. Plasma levels of sLOX‐1 were significantly higher in obese women (55.33 ± 4.49 pg/ml) compared to lean (30.91 ± 6.19 pg/ml, P = 0.002) and overweight women (38.31 ± 4.18 pg/ml, P = 0.017). Plasma sLOX‐1 levels were positively associated with body weight, BMI, total body fat, and trunk fat. The relationship between sLOX‐1 and BMI was attenuated after adjustment for age, hormone replacement therapy, and body fat. In conclusion, obese women have higher sLOX‐1 levels, which may reflect increased LOX‐1 expression in adipose tissue.


Journal of Cardiology | 2010

Soluble lectin-like oxidized LDL receptor-1 (sLOX-1) as a sensitive and specific biomarker for acute coronary syndrome—Comparison with other biomarkers

Noriaki Kume; Hirokazu Mitsuoka; Kazutaka Hayashida; Masaru Tanaka; Goro Kominami; Toru Kita

BACKGROUND Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) appears to be involved in atherosclerotic plaque vulnerability and rupture. Circulating soluble LOX-1 (sLOX-1) levels are dramatically elevated in patients with acute coronary syndrome (ACS), and its diagnostic sensitivity and specificity is superior to high-sensitivity C-reactive protein (hs-CRP). In this study, we have compared the diagnostic value of sLOX-1 for ACS with those of troponin T (TnT) and heart-type fatty acid binding protein (H-FABP). METHODS One hundred and seven patients who underwent coronary angiography (CAG), including 18 ACS and 89 non-ACS patients were enrolled. Peripheral blood samples were obtained during the emergent or elective CAG. The non-ACS group consisted of 30 patients with normal CAG, 30 stable angina pectoris patients controlled by medical treatment, and 29 patients with stable angina who required elective coronary revascularization (percutaneous coronary intervention or coronary artery bypass graft). RESULTS Age, gender, lipid profiles, or prevalence of diabetes, smoking, or hypertension were not significantly different between ACS and non-ACS. These factors did not significantly affect blood sLOX-1 levels. Circulating sLOX-1, TnT, and H-FABP levels were significantly higher in ACS than non-ACS. Area under the curve (AUC) values of the receiver-operating characteristic curves were 0.948, 0.704, and 0.691 for sLOX-1, TnT, and H-FABP, respectively. In a TnT-negative (<0.03 ng/mL) subgroup, the AUC values for sLOX-1 and H-FABP were 0.848 and 0.476, respectively. CONCLUSION Circulating sLOX-1 is a more sensitive and specific biomarker for ACS than TnT and H-FABP, and provides additional diagnostic values when measured in combination with TnT.


Arthritis & Rheumatism | 2012

Lectin‐like oxidized low‐density lipoprotein receptor 1 signal is a potent biomarker and therapeutic target for human rheumatoid arthritis

Masahiro Ishikawa; Hiromu Ito; M. Akiyoshi; Noriaki Kume; Hiroyuki Yoshitomi; Hirokazu Mitsuoka; Shimei Tanida; Koichi Murata; Hideyuki Shibuya; Takashi Kasahara; Akemi Kakino; Yoshiko Fujita; Tatsuya Sawamura; Tadashi Yasuda; Takashi Nakamura

OBJECTIVE To determine whether lectin-like oxidized low-density lipoprotein (ox-LDL) receptor 1 (LOX-1) and the soluble form of LOX-1 (sLOX-1) are novel target molecules for the diagnosis and treatment of rheumatoid arthritis (RA). METHODS Expression of ox-LDL and LOX-1 proteins in human RA synovium was evaluated by immunohistochemistry. Human RA fibroblast-like synoviocytes (FLS) were assessed for ox-LDL-induced expression of LOX-1 and ox-LDL-induced production of matrix metalloproteinase 1 (MMP-1) and MMP-3. Levels of sLOX-1 in the plasma and synovial fluid of patients with RA, compared with patients with osteoarthritis (OA), were determined by a specific chemiluminescence enzyme-linked immunoassay. In animal experiments, ox-LDL was injected into the knee joints of mice, with or without an anti-LOX-1 neutralizing antibody or sLOX-1, and the severity of arthritis was analyzed by histology and immunohistochemistry. RESULTS Oxidized LDL and LOX-1 proteins were detected in the RA synovial tissue. Levels of MMP-1 and MMP-3 were enhanced by stimulation of RA FLS with ox-LDL, and the production of both MMPs was inhibited by blockade of the ox-LDL-LOX-1 interaction with the anti-LOX-1 neutralizing antibody or sLOX-1. Levels of sLOX-1 in the plasma and synovial fluid of RA patients were significantly higher than those in OA patients and healthy controls and were positively correlated with inflammation markers and the extent of RA disease activity. In the knees of mice, blockade of the ox-LDL-LOX-1 interaction suppressed arthritic changes and reduced the expression of MMP-3 induced by ox-LDL. CONCLUSION These findings strongly indicate that sLOX-1 is a novel biomarker that may be useful for the diagnosis of RA and for the evaluation of disease activity in RA. Furthermore, the results suggest that LOX-1 may be a potent therapeutic target for RA.


Atherosclerosis | 2009

Interleukin 18 stimulates release of soluble lectin-like oxidized LDL receptor-1 (sLOX-1)

Hirokazu Mitsuoka; Noriaki Kume; Kazutaka Hayashida; Atsuko Inui-Hayashiada; Yo Aramaki; Masako Toyohara; Toshikazu Jinnai; Eiichiro Nishi; Toru Kita

Lectin-like oxidized LDL receptor-1 (LOX-1) appears to play crucial roles in atherosclerotic plaque rupture. We previously reported that circulating soluble LOX-1 (sLOX-1) levels are elevated in acute coronary syndrome (ACS) and that sLOX-1 can be a specific and sensitive biomarker for ACS. A proinflammatory cytokine interleukin 18 (IL-18) and its receptor are prominently expressed in atherosclerotic plaques. In addition, circulating IL-18 levels were reported to be high in ACS. In this study, we have examined if IL-18 can stimulate shedding of LOX-1 and subsequent release of sLOX-1. After transfection with LOX-1 cDNA, HEK-293T cells were incubated with or without IL-18. Cell-conditioned media and total cell lysates were subjected to immunoblot analyses with an anti-LOX-1 monoclonal antibody. In addition, ADAM10 cDNA, ADAM10 siRNA or control vector were also co-transfected into HEK-293T cells, and the cell-conditioned media and total cell lysates were subjected to LOX-1 immunoblotting after treatment with or without IL-18. The cell-conditioned medium/total cell lysate ratios in the amounts of LOX-1 or sLOX-1 were determined as sLOX-1 cleavage ratios. IL-18 (10-100ng/mL) stimulation increased the sLOX-1 cleavage by 3-4-fold in a concentration- and time-dependent manner. ADAM10 overexpression alone similarly enhanced the sLOX-1 cleavage. ADAM10 inhibition by ADAM10 siRNA transfection significantly suppressed IL-18-induced sLOX-1 cleavage. IL-18 similarly enhanced sLOX-1 cleavage in TNF-alpha-activated cultured endothelial cells, as well as LOX-1 transgenic mice in vivo. IL-18 appears one of the stimuli that enhance sLOX-1 release in ACS and ADAM10 may be involved in this process.


International Journal of Cardiology | 2009

Serum soluble lectin-like oxidized low-density lipoprotein receptor-1 correlates with oxidative stress markers in stable coronary artery disease.

Fumihiko Kamezaki; Kazuhito Yamashita; Hiromi Tasaki; Noriaki Kume; Hirokazu Mitsuoka; Toru Kita; Tetsuo Adachi; Yutaka Otsuji

BACKGROUND Although serum soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) is reported to be associated with acute coronary syndrome (ACS), its correlation with oxidative stress markers has not been elucidated. We therefore investigated the association of serum sLOX-1 with the severity of CAD, and serum biomarkers for oxidative stress and inflammation, as well as extracellular superoxide dismutase (EC-SOD), which is protective against oxidative stress in the vascular wall. METHODS AND RESULTS Ninety-four patients with stable CAD were enrolled in this study. Serum sLOX-1, serum high-sensitivity C-reactive protein (hs-CRP), urinary 8-isoprostane, plasma BNP and serum lipid levels were measured. We also measured EC-SOD at baseline and post-heparin injection. Heparin-released EC-SOD (DeltaEC-SOD) was calculated as the difference between these two values. No significant correlation was found between log (sLOX-1) and log (basal EC-SOD) (p=0.096), log (hs-CRP) (p=0.108), or log (BNP) (p=0.908) levels, log (sLOX-1) had a significant correlation with DeltaEC-SOD (r=-0.325, p=0.0014) levels and urinary 8-isoprostane levels (r=0.243, p=0.020). In the multivariable analysis, DeltaEC-SOD (p=0.0177) and 8-isoprostane (p=0.0318) were independent predictors for log (sLOX-1). CONCLUSION Serum sLOX-1 levels were positively correlated with urinary 8-isoprostane levels and inversely correlated with EC-SOD levels. These results thus suggest that increased serum sLOX-1 levels may reflect enhanced oxidative stress in vascular walls.

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