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Featured researches published by Takao Konishi.


Coronary Artery Disease | 2016

Relationship between left coronary artery bifurcation angle and restenosis after stenting of the proximal left anterior descending artery.

Takao Konishi; Tadashi Yamamoto; Naohiro Funayama; Hiroshi Nishihara; Daisuke Hotta

IntroductionRestenosis after a percutaneous coronary intervention for proximal left anterior descending (pLAD) coronary artery disease remains a clinical challenge. However, the relationship between the left main trunk (LMT)/LAD bifurcation angle and the pLAD artery restenosis is unclear. This study examined the relationship between the LMT–LAD bifurcation angle and restenosis after stent implantation for pLAD disease. MethodsWe analysed the data of 177 consecutive patients who underwent stent implantation for pLAD disease, followed by coronary angiography between December 2008 and September 2013. The LMT–LAD bifurcation angle was measured in the left or the right anterior oblique caudal (CAU) angiographic view. Results and discussionOut of 177 patients, 12 developed in-stent restenosis and 21 developed in-segment restenosis. The mean angle in patients with in-stent restenosis (52.2°±14.5°) in the left anterior oblique CAU view was significantly larger than that in patients without restenosis (32.0°±18.1°; P<0.001). The LMT–LAD angle in the right anterior oblique CAU view was significantly larger in patients with in-segment restenosis (27.3°±14.3°) than in patients without restenosis (17.5°±10.1°; P<0.001). Moreover, by multivariate analysis, the LMT–LAD angle was an independent predictor of in-stent and in-segment restenosis, after adjustment for significant confounders such as diabetes, hypertension, dyslipidaemia, final minimum lesion diameter and lesion length. ConclusionThis study suggests that a wide LMT–LAD angle is a predictor of restenosis after stent implantation for pLAD artery disease.


Circulation | 2018

Pathological Quantification of Carotid Artery Plaque Instability in Patients Undergoing Carotid Endarterectomy

Takao Konishi; Naohiro Funayama; Tadashi Yamamoto; Tohru Morita; Daisuke Hotta; Ryota Nomura; Yusuke Nakagaki; Takeo Murahashi; Kenji Kamiyama; Tetsuyuki Yoshimoto; Takeshi Aoki; Hiroshi Nishihara; Shinya Tanaka

BACKGROUND Unstable atherosclerotic carotid plaques cause cerebral thromboemboli and ischemic events. However, this instability has not been pathologically quantified, so we sought to quantify it in patients undergoing carotid endarterectomy (CEA).Methods and Results:Carotid plaques were collected during CEA from 67 symptomatic and 15 asymptomatic patients between May 2015 and August 2016. The specimens were stained with hematoxylin-eosin and elastica-Masson. Immunohistochemistry was performed using an endothelial-specific antibody to CD31, CD34 and PDGFRβ. The histopathological characteristics of the plaques were studied. By multiple-variable logistic regression analysis, plaque instability correlated with the presence of plaque rupture [odds ratio (OR), 9.75; P=0.013], minimum fibrous cap thickness (OR per 10 μm 0.70; P=0.025), presence of microcalcifications in the fibrous cap (OR 7.82; P=0.022) and intraplaque microvessels (OR 1.91; P=0.043). Receiver-operating characteristics analyses showed that these factors combined into a single score diagnosed symptomatic carotid plaques in patients with carotid artery stenosis with a high level of accuracy (area under the curve 0.92; 95% confidence interval 0.85-0.99 vs. asymptomatic). CONCLUSIONS This analysis of carotid plaque instability strongly suggested that the diagnostic scoring of carotid plaque instability improves the understanding and treatment of carotid artery disease in patients undergoing CEA.


Journal of Atherosclerosis and Thrombosis | 2017

Prognostic Value of Eosinophil to Leukocyte Ratio in Patients with ST-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Takao Konishi; Naohiro Funayama; Tadashi Yamamoto; Toru Morita; Daisuke Hotta; Hiroshi Nishihara; Shinya Tanaka

Aim: Leukocyte profile has been related to clinical outcome in patients with ST-segment elevation (STE) myocardial infarction (MI). However, whether eosinophil to leukocyte ratio (ELR) predicts clinical outcome in patients who have undergone primary percutaneous coronary intervention (PCI) remains unclear. Therefore, we examined the prognostic value of ELR in this patient population. Methods: We retrospectively analyzed the data of 331 consecutive patients who underwent primary PCI for STEMI between January 2009 and March 2015. All leukocyte types were counted and ELR was calculated for all patients 24 h after hospital admission. The primary study endpoint was major adverse cardiac events (MACEs) within up to one year of follow-up duration. Results: MACEs including cardiac deaths in 9.4% of the patients, MI in 1.5%, and target lesion or vessel revascularization in 10.3%, occurred within one year in 68 patients (20.5%). The mean ELR was significantly lower in patients with MACEs than in patients without MACEs (0.20 ± 0.51 vs. 0.49 ± 0.66, respectively; p < 0.001). An ELR < 0.1 at 24 h was identified as the best cut-off value for mortality prediction. Multivariate analysis identified that an ELR < 0.1 (odds ratio [OR] = 0.38; 95% confidence interval [CI] = 0.22–0.67; p < 0.001) and chronic kidney disease (OR = 2.38; CI = 1.33–4.24; p = 0.003) are independent predictors of MACEs. Conclusion: In primary PCI patients with STEMI, ELR at 24 h was an independent predictor of MACEs in addition to the usual coronary risk factors and commonly used biomarkers.


Cardiovascular Pharmacology: Open Access | 2015

Resolution of Left Ventricular Thrombus after Dabigatran Therapy in TwoPatients with Old Anteroseptal Myocardial Infarction

Tadashi Yamamoto; Takao Konishi; Naohiro Funayama; Beni Kikuchi; Daisuke Hotta; Katsumi Ohori

Dabigatran has been used recently as an alternative to warfarin therapy for the prevention of thromboembolism in patients with myocardial infarction or atrial fibrillation, but treatment of established intracardiac thrombus with dabigatran has seldom been reported. We report two patients with left ventricular (LV) thrombus who were successfully treated with dabigatran. The first patient was a 52-year-old man with no clear symptoms who was referred for investigation of abnormal electrocardiography findings, and the second patient was a 51-year-old man with recent onset of heart failure and a history of chest pain 1 month previously. Both patients were diagnosed with old anteroseptal myocardial infarction after echocardiography showed abnormal LV wall motion and LV thrombus. The thrombus was thought to be chronic in the first patient, and to have formed within the preceding month in the second patient. After treatment with dabigatran 220 mg/day and antiplatelet drugs, repeat echocardiography showed resolution of the thrombus after 6 weeks and 2 weeks, respectively. These cases illustrate that dabigatran 220 mg/ day may be useful for the treatment of established LV thrombus.


Circulation-cardiovascular Imaging | 2014

Successful diagnosis of an atypical prosthetic vascular graft infection without perivascular abscess: luminal vegetation as the hidden septic source.

Tomoo Nagai; Akira Hamabe; Junko Arakawa; Mikoto Yoshida; Takao Konishi; Takumi Toya; Norio Ishigami; Shuichi Katsushika; Hideki Hisadome; Yukishige Kyoto; Hitoshi Nakanowatari; Tadashi Ito; Atsuhiro Mitsumaru; Yoshiaki Tanaka; Hirotsugu Tabata

A 62-year-old woman with a vascular prosthesis for a common hepatic artery aneurysm (3 years ago) was hospitalized because of a 2-week history of lumbago and fever. Six months previously, she was hospitalized at another medical facility for 1 month because of a fever of unknown pathogenesis. Laboratory examination revealed moderate inflammation with an elevated C-reactive protein level of 6.5 mg/dL and a white blood cell count of 7070/mm3. Initial 8-row multi-detector computed tomography (CT) with contrast agent in the emergency department did not show any focus for the origin of the fever. She was referred to the orthopedic surgery department, and MRI of the pelvis revealed inflammation of the left sacroiliac joint (Figure 1). Her first 2 sets of blood cultures were positive for Streptococcus anginosus . Intravenous administration of ampicillin/cloxacillin sodium was started. She was then transferred to the cardiology department for the evaluation of septicemia, which could have been caused by infectious endocarditis. A transthoracic echocardiogram showed severe aortic regurgitation, which was not seen at the time of previous surgery for the vascular prosthesis (Figure 2A). However, a transesophageal echocardiogram only detected a small degenerative change in the right coronary cusp of the aortic valve, which could be healed …


BMC Cardiovascular Disorders | 2015

Infective endocarditis presenting initially with ileus complicated by dehiscence of annuloplasty ring

Takao Konishi; Hiroshi Nishihara; Tadashi Ito; Yoshiaki Tanaka

BackgroundInfective endocarditis (IE) on an annuloplasty ring dehiscence is uncommon after mitral valve repair.Case PresentationA 53-year-old man underwent mitral annuloplasty with a 24-mm ring for posterior mitral valve prolapse. He underwent repeat valve repair for recurrent mitral valve regurgitation 4 years later. He was re-hospitalised complaining of vomiting, nausea, general fatigue and left abdominal pain 2 months later, and presented with low-grade fever, leukocytosis and an elevated blood concentration of C-reactive protein. An abdominal computed tomography scan showed multiple embolisms in the liver, kidney and spleen. Transoesophageal echocardiography revealed mitral annuloplasty ring dehiscence and vegetations consistent with IE. The infected annuloplasty ring and vegetations were surgically excised. Blood cultures grew coagulasenegative staphylococcus aureus, consistent with the excised mitral valve histology. The postoperative course was uneventful, without recurrence of IE.ConclusionsEmbolic ileus as initial manifestation of IE is rare and might confuse the diagnosis and delay its management. Gastrointestinal signs and symptoms may be the initial manifestations of systemic embolization from infective endocarditis. Transoesophageal echocardiography effectively identified the presence of vegetations and mitral annuloplasty ring dehiscence.


European Journal of Echocardiography | 2014

Synchronicity of echocardiography and cardiac nuclear medicine in mid-ventricular ballooning syndrome: paired ‘ring signs’ on polar maps

Tomoo Nagai; Takao Konishi; Junko Arakawa; Hideki Hisadome; Hirotsugu Tabata

A 74-year-old woman was hospitalized for chest pain. A coronary angiogram showed no organic stenosis in the coronary arteries. However, a left ventriculogram showed akinesis in the middle portion of the left ventricle (Supplementary data online, Movie S1 ). A transthoracic echocardiography (TTE) was performed, and two-dimensional longitudinal strain images obtained on the apical four-chamber view, …


PLOS ONE | 2018

Relationship between left main and left anterior descending arteries bifurcation angle and coronary artery calcium score in chronic kidney disease : A 3-dimensional analysis of coronary computed tomography

Takao Konishi; Naohiro Funayama; Tadashi Yamamoto; Daisuke Hotta; Shinya Tanaka

Background A high coronary artery calcium score (CACS) predicts a poor prognosis in patients with coronary artery disease. We examined the relationship between the bifurcation angle and the CACS of the left main (LM) and left anterior descending (LAD) arteries in patients suffering from chronic kidney disease (CKD). Methods We analyzed the data of 121 patients who underwent coronary computed tomography between October 2014 and June 2015 and whose estimated glomerular filtration rate (eGFR) was <60 ml/min/1.73 m2. The LM-LAD bifurcation angle was measured by 3-dimensional coronary computed tomography. The CACS of the LM-LAD arteries was also calculated. We excluded stent recipients and patient who had undergone coronary artery bypass graft surgery. Results In the overall sample, the mean ± standard deviation (range) LM-LAD bifurcation angle was 35.9 ± 11.4° (6.8–79.4°) and mean CACS was 227 ± 351 (0 to 1,695). The mean LM-LAD arteries angle was 40.3° ± 10.0° in 39 patients whose CACS was ≥200, versus 33.8° ± 11.6° in 82 patients with CACS <200 (p = 0.003). A weak, but positive correlation (r = 0.269, p = 0.003) was observed between the LM-LAD arteries angle and CACS of the LM-LAD arteries. By multiple variable analysis, hemoglobin A1c, triglycerides, eGFR and the LM-LAD arteries angle were independent predictors of a high CACS of the LM-LAD arteries. Conclusion In patients with CKD, a wide LM-LAD arteries angle was associated with a high CACS of the LM-LAD arteries. The prognostic value of this observation warrants further evaluation.


Heart | 2018

Woman in her 50s with shortness of breath on exertion

Takao Konishi; Hironori Murakami; Shinya Tanaka

Clinical introduction A 59-year-old woman visited an outpatient cardiology clinic due to shortness of breath on exertion. Physical examination showed no significant abnormality of vital signs. A III/VI systolic murmur was heard on the fourth intercostal space at the right sternal border. The majority of laboratory tests were normal. Chest X-ray showed a curved vessel shadow (figure 1A). Initial transthoracic echocardiography showed abnormal blood flow into the inferior vena cava (IVC) in the subxiphoid long axis view (figure 1B) and mild right heart dilatation (online supplementary figure 1). Transoesophageal echocardiography showed severe tricuspid regurgitation (online supplementary figure 2). Figure 1 (A) Chest X-ray. (B) Colour Doppler image in the subxiphoid long axis view. 10.1136/heartjnl-2018-313655.supp1 Supplementary data 10.1136/heartjnl-2018-313655.supp2 Supplementary data Question What is the most likely underlying disease for the patient’s shortness of breath on exertion? Pulmonary arteriovenous fistula. Pulmonary arterial hypertension. Lung cancer. Partial anomalous pulmonary venous connection. Isolated tricuspid regurgitation.


Heartrhythm Case Reports | 2017

Acute right coronary artery occlusion after radiofrequency catheter ablation of cavotricuspid isthmus: Vascular response assessed by optical frequency domain imaging

Naohiro Funayama; Takao Konishi; Tadashi Yamamoto; Seiichiro Sakurai

Figure 1 Coronary angiography (A, B, C) and optical frequency domain imaging (D, E, F). A: Initial angiography. B: An immediate coronary angiography showed an occlusion (white arrow) of the posterolateral branch. C: Final angiography. D: Proximal site maintained a normal “three-layer” structure. E: Optical frequency domain imaging revealed thickening of the intima and thrombus at the target lesion. F: Distal site had fibrous and fibrocalcific plaques.

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Hirotsugu Tabata

National Defense Medical College

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Kenjiro Kikuchi

Asahikawa Medical College

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Tomoo Nagai

National Defense Medical College

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Akira Hamabe

National Defense Medical College

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Norio Ishigami

National Defense Medical College

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Shuichi Katsushika

National Defense Medical College

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