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Dive into the research topics where Kazuo Usuda is active.

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Featured researches published by Kazuo Usuda.


Acta Haematologica | 2000

Brain Natriuretic Peptide Is a Predictor of Anthracycline-Induced Cardiotoxicity

Hirokazu Okumura; Kazuyuki Iuchi; Takashi Yoshida; Shinobu Nakamura; Minoru Takeshima; Hideyuki Takamatsu; Atsuhisa Ikeno; Kazuo Usuda; Tadao Ishikawa; Shigeki Ohtake; Tamotsu Matsuda

Anthracyclines are effective antineoplastic drugs, but they frequently cause dose-related cardiotoxicity. The cardiotoxicity of conventional anthracycline therapy highlights a need to search for methods that are highly sensitive and capable of predicting cardiac dysfunction. We measured the plasma level of brain natriuretic peptide (BNP) to determine whether BNP might serve as a simple diagnostic indicator of anthracycline-induced cardiotoxicity in patients with acute leukemia treated with a daunorubicin (DNR)-containing regimen. Thirteen patients with acute leukemia were treated with a DNR-containing regimen. Cardiac functions were evaluated with radionuclide angiography before chemotherapies. The plasma levels of atrial natriuretic peptide (ANP) and BNP were measured at the time of radionuclide angiography. Three patients developed congestive heart failure after the completion of chemotherapy. Five patients were diagnosed as having subclinical heart failure after the completion of chemotherapy. The plasma levels of BNP in all the patients with clinical and subclinical heart failure increased above the normal limit (40 pg/ml) before the detection of clinical or subclinical heart failure by radionuclide angiography. On the other hand, BNP did not increase in the patients without heart failure given DNR, even at more than 700 mg/m2. The plasma level of ANP did not always increase in all the patients with clinical and subclinical heart failure. These preliminary results suggest that BNP may be useful as an early and sensitive indicator of anthracycline-induced cardiotoxicity.


Angiology | 1997

Primary Antiphospholipid Syndrome and Pulmonary Hypertension with Prolonged Survival A Case Report

Hideo Nagai; Keiichi Yasuma; Tatsuo Katsuki; Atsuhiro Shimakura; Kazuo Usuda; Yukio Nakamura; Shigeo Takata; Kenichi Kobayashi

The outcome of patients with pulmonary hypertension (PHT) and antiphospholipid syndrome (APS) is usually fatal. The authors report the rare case of a patient with primary APS and nonthrombotic PHT who has survived for twenty years after the onset of PHT. In this case, the patients PHT resembled the primary idiopathic variety with clear lung fields and normal perfusion on the lung scan, and the combination therapy with nitrate, digoxin, and diuretics had been performed. During her clinical course over twenty years, she had not experienced any critical pulmonary thrombosis that influenced the progression of nonthrombotic PHT or any other severe systemic involvement of APS.


Angiology | 1996

Compensatory Enlargement of Angiographically Normal Coronary Segments in Patients with Coronary Artery Disease In Vivo Documentation Using Intravascular Ultrasound

Yukio Nakamura; Hitoshi Takemori; Kouichi Shiraishi; Isao Inoki; Manabu Sakagami; Atsuhiro Shimakura; Kazuo Usuda; Kouji Kubota; Shigeo Takata; Kenichi Kobayashi

Intravascular ultrasound (IVUS) frequently reveals plaque formation at sites with a normal angiographic appearance. However, whether angiographically normal coronary arteries undergo adaptive expansion in vivo remains uncertain. The authors studied 12 patients (11 men, 1 woman; mean age fifty-three ± ten years [mean ± SD]) with focal coronary stenosis. Sixty IVUS images from angiographically normal coronary segments were analyzed (14 left main, 44 left anterior descending, and 2 left circumflex coronary arteries). The mean percent area stenosis was 36 ± 5% and the circular shape factor of the lumen cross section averaged 0.97 ± 0.02. Both total arterial area and internal elastic lamina area increased as the plaque area expanded (y = 2.13x + 8.07, r = 0.87, P = 0.0001; y = 2.06x + 4.57, r = 0.87, P = 0.0001, respectively), suggesting that for every 1 mm2 increase in plaque area, the total arterial area increased by approximately 2.13 mm2 and the internal elastic lamina area increased by approximately 2.06 mm2. The lumen area also increased as the plaque area expanded (y = 1.06x + 4.57, r = 0.68, P = 0.0001), suggesting that for every 1 mm2 increase in plaque area, the lumen area increased by approximately 1.06 mm2. The medial area did not correlate with the plaque area (r = 0.15, P = 0.26). Thus, compensatory enlargement precedes development of angiographically detectable coronary atherosclerosis. Furthermore, in early stages of atherosclerosis, arterial enlargement may overcompensate for plaque area. The reduction of the total medial mass does not appear to contribute to the mechanism of compen satory enlargement.


Journal of Cardiology | 2018

Ability of the prognostic model of J-ACCESS study to predict cardiac events in a clinical setting: The APPROACH study

Isao Aburadani; Kazuo Usuda; Hisashi Sumiya; Satoru Sakagami; Hiroaki Kiyokawa; Shinro Matsuo; Masayuki Takamura; Hisayoshi Murai; Shinichiro Takashima; Teppei Kitano; Koichi Okuda; Kenichi Nakajima

BACKGROUND In patients with coronary artery disease (CAD), one of the risk models available in Japan was a multivariate risk prediction model based on a Japanese multicenter database: the Japanese Assessment of Cardiac Events and Survival Study by Quantitative Gated SPECT (J-ACCESS). The aim of this study was to clinically validate the accuracy of this risk model. METHODS We evaluated the performance of the J-ACCESS model using data derived from the Assessment of the Predicted value of PROgnosis of cArdiaC events in Hokuriku (APPROACH) registry. Variables of age, summed stress score (SSS), left ventricular ejection fraction (LVEF), estimated glomerular filtration rate (eGFR), and diabetes mellitus were included. The major cardiac events were defined as cardiac death, non-fatal myocardial infarction, and heart failure that required hospitalization. The patients were followed up for three years to compare between predicted risk and actual events. RESULTS We evaluated 283 patients with suspected or confirmed CAD receiving myocardial perfusion imaging using 99mTc-tetrofosmin between March 2009 and August 2011. Mean age was 68.9±10.1 years, mean eGFR 67.4±24.3mL/min/1.73m2, mean SSS 5.2±7.2, and mean LVEF 65.4±14.0%. Fourteen (4.9%) patients experienced major cardiac events including cardiac death in 4 patients (1.4%), non-fatal myocardial infarction in 1 patient (0.3%), and severe heart failure in 9 patients (3.2%), respectively. While SSS≥8, LVEF<50%, eGFR<45mL/min/1.73m2, and event risk≥10% were significant variables in survival analysis, multivariate proportional hazard analysis showed that only LVEF and eGFR were significant. The event rate estimated from the J-ACCESS model was comparable to the actual number of major cardiac events (9 and 6, respectively, p=0.58 by Chi-square test). CONCLUSIONS The predictive ability of the J-ACCESS risk model is clinically valid among patients with CAD and could be applicable in clinical practice.


Cardiovascular Intervention and Therapeutics | 2015

A case of delayed occlusive dissection of the right coronary artery during coronary intervention of the left anterior descending artery.

Yoshiki Nagata; Michiro Maruyama; Isao Aburadani; Motoaki Hirazawa; Takuya Mayumi; Kazuo Usuda

Abstract Catheter-induced coronary artery dissection occurs rarely during selective coronary angiography but generally progresses to complete coronary occlusion. We present a case of delayed occlusive dissection of the right coronary artery during coronary intervention of the left anterior descending artery. Bailout stenting was employed to treat the giant hematoma quickly using a unique technique. The use of two guidewires created a high probability that the true lumen was selected, and aspiration of the hematoma with the microcatheter and indeflator effectively repaired a catheter-induced coronary artery dissection.


Heart and Vessels | 1998

A new method for right ventricular endomyocardial biopsy via femoral veins: a novel approach employing a right ventriculography catheter (Nishiya type)

Yasushi Nishiya; Mitsuo Fujimura; Masahiro Toshima; Hirohumi Noto; Kazuo Usuda; Kazuyuki Iuchi; Tadao Ishikawa

SummaryWe have devised a new method for right ventricular endomyocardial biopsy, in which the use of a right ventriculography catheter (Nishiya Type) allows us to ensure the introduction of a guiding sheath (Cordis, right-angled long sheath) to the apical portion of the right ventricle by way of the femoral vein. With this method, we have biopsied the endomyocardium in 52 patients during the last 4 years. In each case, it only took us several minutes to complete the biopsy procedure. Neither failed applications nor significant complications were seen. We believe that this technique provides a clinically beneficial means as it enables us to readily and safely achieve right ventricular endomyocardial biopsy.


Pacing and Clinical Electrophysiology | 2018

Impact of left atrial size on isolation area in the acute phase of pulmonary vein isolation using 28 mm cryoballoon

Akio Chikata; Takeshi Kato; Kazuo Usuda; Shuhei Fujita; Michiro Maruyama; Yoshiki Nagata; Satoru Sakagami; Naomi Kanamori; Takanori Yaegashi; Takahiro Saeki; Takashi Kusayama; Soichiro Usui; Hiroshi Furusho; Shuichi Kaneko; Masayuki Takamura

The impact of left atrial (LA) size on isolation area (ISA) using a 28‐mm second‐generation cryoballoon (CB) in the acute phase after pulmonary vein isolation (PVI) and the differences of CB from contact force‐guided radiofrequency (RF) ablation have not been fully investigated.


Journal of Cardiology Cases | 2017

Congenital left main coronary artery atresia presenting as syncope and generalized seizure during exercise in a 13-year-old boy

Shuhei Fujita; Akira Sato; Yoshiki Nagata; Kazuo Usuda; Akira Murata; Kiyoshi Hatasaki

We report the case of a 13-year-old boy who, while running in a school gymnasium, experienced sudden syncope and seizure. CPR was started immediately, and an automated external defibrillator (AED) was attached, but shock was not induced. He was referred to our hospital for loss of consciousness and intermittent general tonic-clonic seizure. A 12-lead electrocardiogram showed normal sinus rhythm and no ST-T wave abnormalities. Echocardiography showed normal structural heart and normal cardiac function. On the second day of hospitalization, AED electrocardiogram showed complete atrioventricular (AV) block at syncope and seizure. After the patient recovered from this neurological state, we performed the treadmill exercise test, and it did not show ST-T wave abnormalities or AV block, and he did not complain of chest pain. Coronary angiography showed atresia of the left main trunk and the collateral vessel from the right coronary artery connected to the left coronary artery. He was diagnosed with congenital left main coronary artery atresia. We began administration of calcium antagonist and aspirin to prevent a coronary artery spasm and then performed a coronary artery bypass graft (CABG) to prevent sudden cardiac death. After CABG, he has had no syncope episodes at rest or during light exercise. <Learning objective: In pediatric patients, syncope during strenuous exercise should mandate exclusion of cardiac events, especially coronary artery anomalies. Coronary artery anomalies that could cause sudden cardiac death sometimes show no abnormalities at rest or even during exercise stress on 12-lead electrocardiogram. It is very important to suspect cardiogenic syncope during strenuous exercise.>.


Journal of Arrhythmia | 2017

Adaptive cardiac resynchronization therapy for dilated cardiomyopathy with functional mitral regurgitation

Yoshiki Nagata; Yoichiro Nakagawa; Yusuke Takeda; Kenji Emoto; Masaki Kinoshita; Akio Chikata; Michiro Maruyama; Kazuo Usuda

We report the case of a man in his 60s who had dilated cardiomyopathy with severe functional mitral regurgitation. Four years after a cardiac resynchronization therapy (CRT) device with an implantable cardioverter defibrillator was implanted, this device was replaced with an adaptive CRT device because of battery consumption. Seven months after replacement of this device, the left ventricular pacing to right ventricular activation and the atrioventricular delay from automatic adjustments contributed to less functional mitral regurgitation. The findings from our case suggest that optimal CRT, by measuring intracardiac conduction parameters, is effective for functional mitral regurgitation.


Open Heart | 2016

Altered gene expression in T-cell receptor signalling in peripheral blood leucocytes in acute coronary syndrome predicts secondary coronary events

Shinichiro Takashima; Soichiro Usui; Keisuke Kurokawa; Teppei Kitano; Takeshi Kato; Hisayoshi Murai; Hiroshi Furusho; Hiroyuki Oda; Michiro Maruyama; Yoshiki Nagata; Kazuo Usuda; Koji Kubota; Yumie Takeshita; Yoshio Sakai; Masao Honda; Shuichi Kaneko; Masayuki Takamura

Objective Comprehensive profiling of gene expression in peripheral blood leucocytes (PBLs) in patients with acute coronary syndrome (ACS) as a prognosticator is needed. We explored the specific profile of gene expression in PBLs in ACS for long-term risk stratification. Methods 30 patients with ACS who underwent primary percutaneous coronary intervention (PCI) and 15 age-matched adults who participated in medical check-ups were enrolled from three centres. Peripheral blood samples were collected to extract RNA for microarray analyses. Results During the 5-year follow-up, 36% of this cohort developed the expected non-fatal coronary events (NFEs) of target lesion revascularisation (TLR) and PCI for a de novo lesion. Class comparison analysis (p<0.005) demonstrated that 83 genes among 7785 prefiltered genes (41 upregulated vs 42 downregulated genes) were extracted to classify the patients according to the occurrence of NFE. Pathway analysis based on gene ontology revealed that the NFEs were associated with altered gene expression regarding the T-cell receptor signalling pathway in ACS. Univariate t test showed that the expression level of death-associated protein kinase1 (DAPK1), known to regulate inflammation, was the most significantly negatively regulated gene in the event group (0.61-fold, p<0.0005). Kaplan-Meier curve analysis and multivariate analysis adjusted for baseline characteristics or clinical biomarkers demonstrated that lower DAPK1 expression in PBL emerged as an independent risk factor for the NFEs (HR: 8.73; CI 1.05 to 72.8, p=0.045). Conclusions Altered gene expression in T-cell receptor signalling in PBL in ACS could be a prognosticator for secondary coronary events. Trial registration number UMIN000001932; Results.

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