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Dive into the research topics where Tomokazu Okimoto is active.

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Featured researches published by Tomokazu Okimoto.


Circulation | 2005

Pulse Wave Velocity Predicts Cardiovascular Mortality

Tomoki Shokawa; Michinori Imazu; Hideya Yamamoto; Mamoru Toyofuku; Naohito Tasaki; Tomokazu Okimoto; Kiminori Yamane; Nobuoki Kohno

Background Arterial stiffness measurements, generally from pulse wave velocity (PWV), are widely used with little knowledge of their relationship to long-term cardiovascular mortality in general populations. Methods and Results We studied a cohort of 492 Japanese-Americans living in Hawaii (mean age: 63.7 ±8.8 years) to assess the relationship between PWV and cardiovascular disease mortality and all-cause mortality. During the 10-year follow-up, 43 patients died (14 from cardiovascular events). The cohort was divided into 2 groups by the cut-off value of PWV (9.9 m/s) represented in the receiver operating characteristic curve. The risk ratio for PWV values >9.9 m/s to all-cause mortality was 1.28 [95% confidence interval (CI): 1.14-1.42], and adjusted for other risk factors this ratio was 1.42 (95% CI: 0.96-2.11). The corresponding risk ratios for cardiovascular mortality was 4.46 (95% CI: 1.61-12.32) and 4.24 (95% CI: 1.39-12.96), respectively. Conclusions The present study demonstrated that an increased PWV value is associated with future cardiovascular disease death in Japanese-Americans living in Hawaii. (Circ J 2005; 69: 259 - 264)


American Journal of Cardiology | 2001

Optimal time for predicting myocardial viability after successful primary angioplasty in acute myocardial infarction : A study using myocardial contrast echocardiography

Tadamichi Sakuma; Masaya Otsuka; Tomokazu Okimoto; Hitoshi Fujiwara; Kotaro Sumii; Michinori Imazu; Yasuhiko Hayashi

This study sought to elucidate serial changes in microvascular integrity during papaverine-induced hyperemia in the risk area for myocardial infarction. In addition, we attempted to determine the optimal time for predicting myocardial viability. Seventy-two patients who underwent serial myocardial contrast echocardiography (MCE) before and shortly after (day 1), 1 day (day 2), and 3 weeks (day 21) after recanalization were studied. In 18 of 72 patients, MCE was performed at baseline and during hyperemia using selective intracoronary infusion of papaverine. Both the peak grayscale ratio (PGSR) within the risk area, and the no- and low-reflow ratio (LR ratio) were analyzed in each stage. Left ventricular regional wall motion (RWM) was determined 6 months after recanalization. The correlation coefficient between PGSR with papaverine on day 1 and that on day 2 was 0.54 (p = 0.02); it was 0.50 (p = 0.04) between day 1 and day 21, and 0.82 (p = 0.001) between day 2 and day 21. On day 1, the correlation coefficient between the LR ratio with papaverine and RWM was 0.60 (p = 0.02), which changed to 0.72 (p = 0.003) on day 2 and 0.54 (p = 0.04) on day 21, respectively. The best time to predict viable myocardium was established on day 2 by receiver operating characteristics curves. ST-segment re-elevation, elapsed time from onset to recanalization, and antecedent angina pectoris were independent factors for PGSR on day 2 using stepwise and multiple linear regression analysis. This study suggests that the optimal time to estimate microvascular integrity for predicting myocardial viability might be 1 day after recanalization, which is neither shortly after recanalization nor during the convalescent stage.


Journal of Cardiology | 2015

Validation of lactate level as a predictor of early mortality in acute decompensated heart failure patients who entered intensive care unit

Tomoharu Kawase; Mamoru Toyofuku; Tasuku Higashihara; Yousaku Okubo; Lisa Takahashi; Yuzo Kagawa; Kenichi Yamane; Shinji Mito; Hiromichi Tamekiyo; Masaya Otsuka; Tomokazu Okimoto; Yuji Muraoka; Yoshiko Masaoka; Nobuo Shiode; Yasuhiko Hayashi

BACKGROUND The significance of routine measurement of lactate level is unclear in patients with critical acute decompensated heart failure (ADHF). METHODS AND RESULTS Consecutive 754 patients who were admitted to the intensive care unit (ICU) in our hospital from January 2007 to March 2012 and given a diagnosis of ADHF were eligible for retrospective entry into the registry. Lactate level was measured on admission from routine arterial blood sample and we investigated by comparing the lactate level and parameters of conventional in-hospital mortality predictors. Among the patients, 88 (12%) died during hospitalization. The lactate level had great power to predict in-hospital mortality, as suggested by the c-statistics of 0.71. The occurrence of in-hospital death was more pronounced in patients with high levels of lactate (>3.2mmol/l) and the tendency was observed in patients in both the acute coronary syndrome (ACS) group and non-ACS group. In multivariate analysis, elevated lactate levels remained an independent predictor of in-hospital death (odds ratio, 2.14; 95% confidence interval, 1.10-4.21; p=0.03). CONCLUSIONS Elevated levels of arterial lactate on admission were related to worse in-hospital mortality in patients with ADHF either with or without ACS, suggesting that the presence of high lactate in patients who enter the ICU with ADHF could help stratify the initial risk of early mortality.


International Journal of Cardiology | 2013

Comparison of heart-type fatty acid binding protein and sensitive troponin for the diagnosis of early acute myocardial infarction

Yuzo Kagawa; Mamoru Toyofuku; Yoshiko Masaoka; Yuji Muraoka; Tomokazu Okimoto; Masaya Otsuka; Hiromichi Tamekiyo; Shinji Mito; Tomoharu Kawase; Kenichi Yamane; Atsuhiro Senoo; Michitaka Amioka; Nobuo Shiode; Yasuhiko Hayashi

BACKGROUND The current development of serological biomarkers allows detection of smaller myocardial necrosis and early acute myocardial infarction (AMI). We evaluated the relevance of the heart-type fatty acid binding protein (H-FABP) assay, which has recently been approved in Japan, for early diagnosis of AMI as compared with the sensitive troponin assay. METHODS This is an observational study in a single center. From 2010 July to 2011 January, 114 patients who presented with symptoms suggestive of AMI were enrolled. RESULTS AMI was adjudicated in 45 patients (40%). The diagnostic accuracy of measurements obtained at presentation for AMI, as quantified by the area under the receiver-operating-characteristic curve (AUC), was significantly lower with H-FABP assay than the sensitive troponin assay [AUC for H-FABP, 0.59; 95% confidence interval (CI) 0.48-0.70; and for troponin I, 0.89; 95% CI, 0.83-0.94; P<.0001]. Among patients who presented within 2h after the onset of chest pain, the AUC for H-FABP was even low as compared with sensitive troponin (0.55; 0.39-0.72 vs. 0.89; 0.80-0.98, p<0.001). The clinical sensitivity for the diagnosis of AMI with the cutoff point of 99 th percentile was similar in both assays (81% and 81%, respectively), however, the specificity was extremely low in the H-FABP assay as compared with sensitive troponin assay (19% and 79%, respectively). CONCLUSION The measurement of H-FABP in 114 consecutive patients with chest pain suggestive of AMI showed no improvement of diagnosis for early AMI as compared with the current sensitive troponin assay because of its extremely low specificity.


International Journal of Cardiology | 2010

Exogenous adenosine triphosphate disodium administration during primary percutaneous coronary intervention reduces no-reflow and preserves left ventricular function in patients with acute anterior myocardial infarction: A study using myocardial contrast echocardiography

Tadamichi Sakuma; Chikaaki Motoda; Takehito Tokuyama; Toshiharu Shin’oka; Hiromichi Tamekiyo; Takenori Okada; Masaya Otsuka; Tomokazu Okimoto; Mamoru Toyofuku; Hidekazu Hirao; Yuji Muraoka; Hironori Ueda; Yoshiko Masaoka; Yasuhiko Hayashi

BACKGROUND It is unknown whether adenosine triphosphate disodium (ATP) administration during primary percutaneous coronary intervention (PCI) is useful in anterior acute myocardial infarction (AMI). METHODS The study was a prospective, non-randomized, open-label trial. Primary PCI was successfully performed in 204 consecutive patients with first anterior AMI. ATP at a mean dose of 117 microg/kg/min for 45 min on an average was infused intravenously during PCI in 100 patients (Group 1). In the other 104 patients, normal saline was administered (Group 2). ST-segment resolution (STR) was estimated 90 min after recanalization. The no-reflow ratio was measured 2 weeks later, using intravenous myocardial contrast echocardiography. Left ventricular ejection fraction (LVEF), LV regional wall motion (LVRWM), and LV end-diastolic volume index (LVEDVI) were measured 6 months later. RESULTS Baseline patient characteristics of the two groups were similar, including TIMI risk scores. Significant STR (> or =50% resolution compared to baseline) (66% versus 50%; Group 1 versus Group 2, p=0.02), no-reflow ratio (24% versus 34%, indicated by mean values, p=0.02), LVEF (61% versus 55%, p=0.0007), LVRWM (-1.56 versus -2.05, using the SD/chord, p=0.0001), and LVEDVI (60 ml/m(2) versus 71 ml/m(2), p=0.0007) were significantly better in Group 1, and the no-reflow ratio, LVEF, LVRWM and LVEDVI were significantly better in ATP-administered patients, regardless of antecedent angina or advanced age. ATP Administration was consistently identified as a significant determinant for STR, no-reflow ratio, LVEF, LVRWM, and LVEDVI. CONCLUSIONS Intravenous ATP administration during reperfusion is an independent determinant of STR and the no-reflow ratio, and LVEF, LVRWM, and LVEDVI at 6 months after primary PCI.


Eurointervention | 2011

Clinical usefulness of drug-eluting stents in the treatment of dialysis patients with coronary artery disease

Masaya Otsuka; Mamoru Toyofuku; Noriaki Watanabe; Chikaaki Motoda; Tomoharu Kawase; Ryo Takeda; Shinji Mito; Hiromichi Tamekiyo; Tomokazu Okimoto; Hidekazu Hirao; Yuji Muraoka; Hironori Ueda; Yoshiko Masaoka; Yasuhiko Hayashi

AIMS To investigate the clinical outcomes of paclitaxel-eluting stents (PES) and sirolimus-eluting stents (SES) in patients on dialysis. METHODS AND RESULTS Between May 2004 and December 2008, 95 patients on dialysis with 124 lesions were treated with PES alone, and were compared to 184 patients on dialysis with 244 lesions treated with SES alone, retrospectively. One-year major adverse cardiac event (MACE) including stent thrombosis, target lesion revascularisation (TLR), myocardial infarction (MI) and cardiac death were compared. Baseline characteristics were similar except for previous CABG (p = 0.02) and reference vessel diameter (p = 0.04). During hospitalisation, all cause death was more frequently observed in the PES group (p = 0.004). In-hospital MACE was not significantly different (p = 0.8). The incidence of 1-year MACE in the PES group was lower than that in the SES group (14.7%, 28.3%, p = 0.04), mainly due to the reduction of TLR (11.6%, 25.0%, p = 0.03). Rates of stent thrombosis (0%, 2.7%, p = 0.1), MI (1.1%, 3.8%, p = 0.2), and cardiac death (3.2%, 4.4%, p = 0.6) were not significantly different. CONCLUSIONS PES appears to be more efficient in reducing angiographic and clinical restenosis in dialysis patients compared with SES.


Cardiovascular Drugs and Therapy | 2001

Quinapril with High Affinity to Tissue Angiotensin-Converting Enzyme Reduces Restenosis after Percutaneous Transcatheter Coronary Intervention

Tomokazu Okimoto; Michinori Imazu; Yasuhiko Hayashi; Yukihiko Gomyo; Yoshitaka Sekiguchi; Kaoru Yanagihara; Yasuaki Shimohara; Kotaro Sumii; Hideya Yamamoto; Futoshi Tadehara; Mamoru Toyofuku; Nobuoki Kohno

Experimental studies have demonstrated that vascular injury resulted in an induction of vascular angiotensin-converting enzyme (ACE), and have suggested that inhibition of vascular ACE might be important in the prevention of restenosis. The present study aimed to determine the effect of quinapril, an ACE inhibitor with high affinity to tissue ACE, on restenosis following coronary intervention. The design of this study was a prospective, randomized, open, and non-placebo controlled trial. Patients with ischemic heart disease were enrolled after successful percutaneous transluminal coronary angioplasty or stent implantation at 7 participating institutions. Two hundred and fifty-three patients with 294 lesions were randomly assigned to the quinapril (10–20 mg per day) group or control group. Administration of quinapril was continued for 3–6 months of the follow-up. Quantitative coronary angiography was performed before and after angioplasty and at follow-up. Core laboratory measurements were performed independently and blinded. Follow-up angiography was performed in 108 patients with 124 lesions in the quinapril group and in 107 patients with 130 lesions in the control group. The baseline characteristics and findings of angioplasty showed no significant differences between the two groups. However, in the quinapril group, restenosis per patient and per lesion was significantly lower (34.3% vs. 47.7%, p < 0.05 and 30.6% vs. 43.8%, p < 0.05). Multivariable analysis revealed that administration of quinapril independently contributed to reducing the restenosis per patient and per lesion (odds ratio, 0.73; 95% confidence interval, 0.54–0.99 and odds ratio, 0.75; 95% confidence interval, 0.57–0.99). In conclusion, quinapril significantly reduces restenosis following coronary intervention.


Journal of Cardiology | 2009

Intravenous administration of adenosine triphosphate disodium during primary percutaneous coronary intervention attenuates the transient rapid improvement of myocardial wall motion, not myocardial stunning, shortly after recanalization in acute anterior myocardial infarction.

Takehito Tokuyama; Tadamichi Sakuma; Chikaaki Motoda; Tomoharu Kawase; Ryou Takeda; Shinji Mito; Hiromichi Tamekiyo; Masaya Otsuka; Tomokazu Okimoto; Mamoru Toyofuku; Hidekazu Hirao; Yuji Muraoka; Hironori Ueda; Yoshiko Masaoka; Yasuhiko Hayashi

BACKGROUND AND PURPOSE Administration of adenosine attenuates myocardial stunning after reperfusion in a canine experimental ischemic model. However, it is unknown whether administration of adenosine triphosphate disodium (ATP) during reperfusion can attenuate myocardial stunning after coronary recanalization in patients with acute myocardial infarction (MI). Therefore, we sought to elucidate the effects of ATP administration on serial changes of left ventricular systolic function before and after coronary recanalization. METHODS In 27 patients with first ST-elevation acute anterior MI, in whom primary percutaneous coronary intervention (PCI) was completed within 10 h after symptom onset, ATP at a mean rate of 103 microg/kg/min (n=16) or normal saline (n=11) was intravenously administered for 1 h during reperfusion. Left ventricular regional wall motion within the initially severely ischemic region was serially analyzed using the standard wall motion score index (WMSI) by transthoracic echocardiography. RESULTS Means of WMSIs were similar shortly before primary PCI in both groups (2.79 in ATP group and 2.69 in controls). They changed to 2.56 and 2.22 shortly after PCI, 2.49 and 2.39 on day 2, 2.34 and 2.30 on day 3, 2.19 and 2.25 on day 10, and 1.85 and 2.02, 6 months later, respectively. Transient improved regional wall motion within the initially severely ischemic region was observed shortly after PCI in controls (10.3% of observed segments); however, it was significantly suppressed in the ATP group (2.55%). The percent recovery of WMSI on day 10, which was defined as WMSI on day 10 normalized by improvement of WMSI for 6 months, was 63.8% in ATP group and 65.7% in controls, implying ATP administration could not reduce myocardial stunning by day 10 after primary PCI. CONCLUSIONS The high-dose administration of ATP during primary PCI prevented transient improved wall motion shortly after coronary recanalization rather than preventing left ventricular stunning. These results suggest that ATP can prevent reperfusion injury during primary PCI.


Annals of Human Genetics | 2007

Non‐SCN5A Related Brugada Syndromes: Verification of Normal Splicing and Trafficking of SCN5A Without Exonic Mutations

Yukiko Nakano; Satoshi Tashiro; Eiji Kinoshita; Emiko Kikuta; Sou Takenaka; Miwa Miyoshi; Hiroshi Ogi; Eiichiro Sakoda; Noboru Oda; Kazuyoshi Suenari; Yukiji Tonouchi; Tomokazu Okimoto; Yukoh Hirai; Fumiharu Miura; Kazuko Yamaoka; Tohru Koike; Kazuaki Chayama

Recently, it has been reported that under 20% of Brugada syndrome cases are linked to SCN5A mutations. The purpose of this study was to clarify whether abnormalities other than exonic mutations, such as splicing disorders, decreased mRNA expression levels, or membrane transport abnormalities of SCN5A, play a role in the pathogenesis of Brugada syndrome.


Cardiovascular Revascularization Medicine | 2015

Comparison of everolimus- and paclitaxel-eluting stents in dialysis patients ☆

Masaya Otsuka; Nobuo Shiode; Yoshiko Masaoka; Tomokazu Okimoto; Hiromichi Tamekiyo; Tomoharu Kawase; Kenichi Yamane; Yuzo Kagawa; Naoya Hironobe; Tasuku Higashihara; Yuto Fujii; Yasuhiko Hayashi

BACKGROUND We previously reported that the incidence of 1-year major adverse cardiac events (MACE) in patients treated with paclitaxel-eluting stents (PES) was lower than that in the sirolimus-eluting stents in dialysis patients. However, it remains unclear whether there are differences in clinical outcomes between everolimus-eluting stents (EES) and PES. METHODS Between February 2010 and September 2013, 102 maintenance dialysis patients with 135 lesions treated with EES were compared to 107 maintenance dialysis patients with 147 lesions treated with PES. One-year clinical outcomes were investigated. RESULTS Diabetes mellitus was present in 64.7% in the EES group and 71.0% in the PES group (p = 0.33). Heavy calcification was in 27.4% vs. 34.0% (p = 0.23). Rotational atherectomy was undergone in 11.1% vs. 23.1% (p < 0.01). Total stented length was not significantly different (23.5 ± 14.6 mm vs. 24.4 ± 13.2 mm, p = 0.60). One patient in the EES group was lost to follow up. At 12 months, MACE occurred in 13.2% in the EES group and 17.4% in the PES group (p = 0.25). Target lesion revascularization (TLR) was observed in 9.5% vs. 10.4% respectively (p = 0.77). Mortality was 11.8% vs. 13.1% (p = 0.35). Cardiac death was 5.0% vs. 7.7% (p = 0.09). Definite stent thrombosis was observed in 2.0% vs. 0% (p = 0.14). Subgroup analysis in patients with diabetes mellitus revealed no significant differences in MACE (12.7% vs. 14.9%, p = 0.36), TLR (8.3% vs. 7.4%, p = 0.42), mortality (13.7% vs. 13.2%, p = 0.28), and cardiac death (6.3% vs. 8.0%, p = 0.15) between the two groups. CONCLUSIONS One-year clinical outcomes following EES and PES implantations are similar in dialysis patients.

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