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Dive into the research topics where Naoya Asakawa is active.

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Featured researches published by Naoya Asakawa.


International Heart Journal | 2015

Adaptive Servo-Ventilation Has More Favorable Acute Effects on Hemodynamics Than Continuous Positive Airway Pressure in Patients With Heart Failure

Naoya Asakawa; Mamoru Sakakibara; Keiji Noguchi; Kiwamu Kamiya; Shiro Yamada; Takashi Yoshitani; Kota Ono; Koji Oba; Hiroyuki Tsutsui

Adaptive servo-ventilation (ASV) has been attracting attention as a novel respiratory support therapy for heart failure (HF). However, the acute hemodynamic effects have not been compared between ASV and continuous positive airway pressure (CPAP) in HF patients.We studied 12 consecutive patients with stable chronic HF. Hemodynamic measurement was performed by right heart catheterization before and after CPAP 5 cmH2O, CPAP 10 cmH2O, and ASV for 15 minutes each.Heart rate, blood pressure, pulmonary capillary wedge pressure (PCWP), and stroke volume index (SVI) were not changed by any intervention. Right atrial pressure significantly increased after CPAP 10 cmH2O (3.6 ± 3.3 to 6.7 ± 1.6 mmHg, P = 0.005) and ASV (4.1 ± 2.6 to 6.8 ± 1.5 mmHg, P = 0.026). Cardiac index was significantly decreased by CPAP 10 cmH2O (2.3 ± 0.4 to 1.9 ± 0.3 L/minute/m(2), P = 0.048), but was not changed by ASV (2.3 ± 0.4 to 2.0 ± 0.3 L/ minute/m(2), P = 0.299). There was a significant positive correlation between baseline PCWP and % of baseline SVI by CPAP 10 cmH2O (r = 0.705, P < 0.001) and ASV (r = 0.750, P < 0.001). ASV and CPAP 10 cmH2O had significantly greater slopes of this correlation than CPAP 5 cmH2O, suggesting that patients with higher PCWP had a greater increase in SVI by ASV and CPAP 10 cmH2O. The relationship between baseline PCWP and % of baseline SVI by ASV was shifted upwards compared to CPAP 10 cmH2O. Furthermore, based on the results of a questionnaire, patients accepted CPAP 5 cmH2O and ASV more favorably compared to CPAP 10 cmH2O.ASV had more beneficial effects on acute hemodynamics and acceptance than CPAP in HF patients.


Circulation | 2016

Value of Virtual Touch Quantification Elastography for Assessing Liver Congestion in Patients With Heart Failure

Takashi Yoshitani; Naoya Asakawa; Mamoru Sakakibara; Keiji Noguchi; Yusuke Tokuda; Kiwamu Kamiya; Hiroyuki Iwano; Satoshi Yamada; Yusuke Kudou; Mutsumi Nishida; Chikara Shimizu; Toraji Amano; Hiroyuki Tsutsui

BACKGROUND Heart failure (HF) causes organ congestion, which is thought to increase organ stiffness. The virtual touch quantification (VTQ) method can be used to assess liver stiffness in patients with chronic liver diseases. This study aimed to measure liver and kidney stiffness using VTQ and to determine its value for assessing organ congestion in patients with HF. METHODSANDRESULTS This study included 10 normal subjects and 38 HF patients (age 52.3±16.7 years, left ventricular ejection fraction 27.0±9.4%, plasma B-type natriuretic peptide [BNP] 1,297.3±1,155.1 pg/ml). We investigated the relationships between clinical characteristics and hemodynamics and liver and kidney stiffness, and assessed the effects of medical treatment on these measurements. Liver stiffness was significantly higher in HF patients (1.17±0.13 m/s vs. 2.03±0.91 m/s, P=0.004) compared with normal subjects, but kidney stiffness was similar in both groups. Central venous pressure (CVP) (P=0.021) and BNP (P=0.025) were independent predictive factors for increased liver stiffness in HF patients. Liver stiffness decreased significantly from 2.37±1.09 to 1.27±0.33 m/s (P<0.001) after treatment. Changes in liver stiffness in HF patients significantly correlated with changes in CVP (R=0.636, P=0.014) and cardiac index (R=-0.557, P=0.039) according to univariate analysis, and with changes in CVP in multivariate analysis. CONCLUSIONS Liver stiffness measured by noninvasive VTQ methods can be used to assess liver congestion and therapeutic effects in patients with HF. (Circ J 2016; 80: 1187-1195).


PLOS ONE | 2017

Immunohistochemical identification of Propionibacterium acnes in granuloma and inflammatory cells of myocardial tissues obtained from cardiac sarcoidosis patients

Naoya Asakawa; Keisuke Uchida; Mamoru Sakakibara; Kazunori Omote; Keiji Noguchi; Yusuke Tokuda; Kiwamu Kamiya; Kanako C. Hatanaka; Yoshihiro Matsuno; Shiro Yamada; Kyoko Asakawa; Yuichiro Fukasawa; Toshiyuki Nagai; Toshihisa Anzai; Yoshihiko Ikeda; Hatsue Ishibashi-Ueda; Masanori Hirota; Makoto Orii; Takashi Akasaka; Kenta Uto; Yasushige Shingu; Yoshiro Matsui; Shin ichiro Morimoto; Hiroyuki Tsutsui; Yoshinobu Eishi

Background Although rare, cardiac sarcoidosis (CS) is potentially fatal. Early diagnosis and intervention are essential, but histopathologic diagnosis is limited. We aimed to detect Propionibacterium acnes, a commonly implicated etiologic agent of sarcoidosis, in myocardial tissues obtained from CS patients. Methods and results We examined formalin-fixed paraffin-embedded myocardial tissues obtained by surgery or autopsy and endomyocardial biopsy from patients with CS (n = 26; CS-group), myocarditis (n = 15; M-group), or other cardiomyopathies (n = 39; CM-group) using immunohistochemistry (IHC) with a P. acnes-specific monoclonal antibody. We found granulomas in 16 (62%) CS-group samples. Massive (≥14 inflammatory cells) and minimal (<14 inflammatory cells) inflammatory foci, respectively, were detected in 16 (62%) and 11 (42%) of the CS-group samples, 10 (67%) and 10 (67%) of the M-group samples, and 1 (3%) and 18 (46%) of the CM-group samples. P. acnes-positive reactivity in granulomas, massive inflammatory foci, and minimal inflammatory foci were detected in 10 (63%), 10 (63%), and 8 (73%) of the CS-group samples, respectively, and in none of the M-group and CM-group samples. Conclusions Frequent identification of P. acnes in sarcoid granulomas of originally aseptic myocardial tissues suggests that this indigenous bacterium causes granuloma in many CS patients. IHC detection of P. acnes in massive or minimal inflammatory foci of myocardial biopsy samples without granulomas may be useful for differentiating sarcoidosis from myocarditis or other cardiomyopathies.


Journal of the American Heart Association | 2016

Myocardial immunocompetent cells and macrophage phenotypes as histopathological surrogates for diagnosis of cardiac sarcoidosis in Japanese

Yasuyuki Honda; Toshiyuki Nagai; Yoshihiko Ikeda; Mamoru Sakakibara; Naoya Asakawa; Nobutaka Nagano; Michikazu Nakai; Kunihiro Nishimura; Yasuo Sugano; Keiko Ohta-Ogo; Yasuhide Asaumi; Takeshi Aiba; Hideaki Kanzaki; Kengo Kusano; Teruo Noguchi; Satoshi Yasuda; Hiroyuki Tsutsui; Hatsue Ishibashi-Ueda; Toshihisa Anzai

Background The histological diagnosis of cardiac sarcoidosis (CS) is based on the presence of myocardial granulomas; however, the sensitivity of endomyocardial biopsy is relatively low. We investigated whether immunocompetent cells including dendritic cells (DC) and macrophages in nongranuloma sections of endomyocardial biopsy samples could be histopathological surrogates for CS diagnosis. Methods and Results The numbers of DC and macrophages were investigated in 95 consecutive CS patients and 50 patients with nonischemic cardiomyopathy as controls. All patients underwent endomyocardial biopsy, and immunohistochemical staining was performed on all samples. We examined these immunocompetent cells in nongranuloma sections in CS patients diagnosed by the presence of myocardial granulomas (n=26) and in CS patients without myocardial granulomas diagnosed by the Japanese Ministry of Health Welfare 2007 criteria (n=65) or the Heart Rhythm Society 2014 criteria (n=26). In CS patients with and without myocardial granulomas, CD209+ DC and CD68+ macrophages were more frequently observed (P<0.01) and CD163+M2 macrophages were less frequently observed (P<0.01) in nongranuloma sections compared to controls. Furthermore, the combination of decreased CD163+M2/CD68+ macrophage ratio and increased number of CD209+ DC in nongranuloma sections of CS patients demonstrated high specificity (100%, 95% CI 92.7–100) for CS diagnosis with each diagnostic criteria and the presence of myocardial granulomas. Conclusions Increased number of DC and decreased M2 among all macrophages in nongranuloma sections of myocardium showed high specificity for CS diagnosis, suggesting DC and macrophage phenotypes as histopathological surrogates for the diagnosis of CS.


European Journal of Echocardiography | 2018

Novel echocardiographic method to assess left ventricular chamber stiffness and elevated end-diastolic pressure based on time–velocity integral measurements of pulmonary venous and transmitral flows

Kazunori Okada; Sanae Kaga; Rika Abiko; Michito Murayama; Takuma Hioka; Masahiro Nakabachi; Shinobu Yokoyama; Hisao Nishino; Ayako Ichikawa; Ayumu Abe; Mutsumi Nishida; Naoya Asakawa; Shingo Tsujinaga; Taichi Hayashi; Hiroyuki Iwano; Satoshi Yamada; Nobuo Masauzi; Taisei Mikami

Aims The detection of increased left ventricular (LV) chamber stiffness may play an important role in assessing cardiac patients with potential but not overt heart failure. A non-invasive method to estimate it is not established. We investigated whether the echocardiographic backward/forward flow volume ratio from the left atrium (LA) during atrial contraction reflects the LV chamber stiffness. Methods and results We studied 62 patients who underwent cardiac catheterization and measured their left ventricular end-diastolic pressure (LVEDP) and pressure increase during atrial contraction (ΔPa) from the LV pressure waveform. Using the echocardiographic biplane method of disks, we measured the LV volume change during atrial contraction indexed to the body surface area (ΔVa), and ΔPa/ΔVa was calculated as a standard for the LV operating chamber stiffness. Using pulsed Doppler echocardiography, we measured the time-velocity integral (TVI) of the backward pulmonary venous (PV) flow during atrial contraction (IPVA) and the ratio of IPVA to the PV flow TVI throughout a cardiac cycle (FPVA). We also measured the TVI of the atrial systolic forward transmitral flow (IA) and the ratio of the IA to the transmitral TVI during a cardiac cycle (FA) and calculated IPVA/IA and FPVA/FA. IPVA/IA and FPVA/FA were well correlated with ΔPa/ΔVa (r = 0.79 and r = 0.81) and LVEDP (r = 0.73 and r = 0.77). The areas under the ROC curve to discriminate LVEDP >18 mmHg were 0.90 for IPVA/IA and 0.93 for FPVA/FA. Conclusion The FPVA/FA, the backward/forward flow volume ratio from the LA during atrial contraction, is useful for non-invasive assessments of LV chamber stiffness and elevated LVEDP.


Cardiovascular Research | 2018

Effects of coronary revascularization on global coronary flow reserve in stable coronary artery disease

Tadao Aikawa; Masanao Naya; Masahiko Obara; Osamu Manabe; Keiichi Magota; Kazuhiro Koyanagawa; Naoya Asakawa; Yoichi M. Ito; Tohru Shiga; Chietsugu Katoh; Toshihisa Anzai; Hiroyuki Tsutsui; Venkatesh L. Murthy; Nagara Tamaki

Abstract Aims Coronary flow reserve (CFR) is an integrated measure of the entire coronary vasculature, and is a powerful prognostic marker in coronary artery disease (CAD). The extent to which coronary revascularization can improve CFR is unclear. This study aimed to evaluate the impact of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) on CFR in patients with stable CAD. Methods and results In a prospective, multicentre observational study, CFR was measured by 15O-water positron emission tomography as the ratio of stress to rest myocardial blood flow at baseline and 6 months after optimal medical therapy (OMT) alone, PCI, or CABG. Changes in the SYNTAX and Leaman scores were angiographically evaluated as indicators of completeness of revascularization. Follow-up was completed by 75 (25 OMT alone, 28 PCI, and 22 CABG) out of 82 patients. The median SYNTAX and Leaman scores, and baseline CFR were 14.5 [interquartile range (IQR): 8–24.5], 5.5 (IQR: 2.5–12.5), and 1.94 (IQR: 1.67–2.66), respectively. Baseline CFR was negatively correlated with the SYNTAX (ρ = −0.40, P < 0.001) and Leaman scores (ρ = −0.33, P = 0.004). Overall, only CABG was associated with a significant increase in CFR [1.67 (IQR: 1.14–1.96) vs. 1.98 (IQR: 1.60–2.39), P < 0.001]. Among patients with CFR <2.0 (n = 41), CFR significantly increased in the PCI [1.70 (IQR: 1.42–1.79) vs. 2.21 (IQR: 1.78–2.49), P = 0.002, P < 0.001 for interaction between time and CFR] and CABG groups [1.28 (IQR: 1.13–1.80) vs. 1.86 (IQR: 1.57–2.22), P < 0.001]. The reduction in SYNTAX or Leaman scores after PCI or CABG was independently associated with the percent increase in CFR after adjusting for baseline characteristics (P = 0.012 and P = 0.011, respectively). Conclusion Coronary revascularization ameliorated reduced CFR in patients with obstructive CAD. The degree of improvement in angiographic CAD burden by revascularization was correlated with magnitude of improvement in CFR.


CASE | 2018

Clinical Utility of Echocardiographic Hemodynamic Monitoring during Manual Compression of Arteriovenous Shunt in a Patient with High-Output Heart Failure

Hiroyuki Iwano; Shingo Tsujinaga; Daiki Iwami; Naoya Asakawa; Satoshi Yamada; Toshihisa Anzai

Graphical abstract


Circulation | 2016

Higher Hemoglobin A1c After Discharge Is an Independent Predictor of Adverse Outcomes in Patients With Acute Coronary Syndrome – Findings From the PACIFIC Registry –

Keiji Noguchi; Mamoru Sakakibara; Naoya Asakawa; Yusuke Tokuda; Kiwamu Kamiya; Takashi Yoshitani; Koji Oba; Katsumi Miyauchi; Yuji Nishizaki; Hisao Ogawa; Hiroyoshi Yokoi; Masayasu Matsumoto; Masafumi Kitakaze; Takeshi Kimura; Tetsuo Matsubara; Yuji Ikari; Kazuo Kimura; Hideki Origasa; Takaaki Isshiki; Yoshihiro Morino; Hiroyuki Daida; Hiroyuki Tsutsui

BACKGROUND Optimal medical therapy (OMT) and the management of coronary risk factors are necessary for secondary prevention of major adverse cardiac and cerebrovascular events (MACCE) in post-acute coronary syndrome (ACS) patients. However, the effect of post-discharge patient adherence has not been investigated in Japanese patients. METHODSANDRESULTS The Prevention of AtherothrombotiC Incidents Following Ischemic Coronary Attack (PACIFIC) registry was a multicenter, prospective observational study of 3,597 patients with ACS. Death or MACCE occurred in 229 patients between hospitalization and up to 1 year after discharge. Among 2,587 patients, the association between OMT adherence and risk factor control at 1 year and MACCE occurring between 1 and 2 years after discharge was assessed. OMT was defined as the use of antiplatelet agents, angiotensin-converting enzyme inhibitors, β-blockers, and statins. Risk factor targets were: low-density lipoprotein-cholesterol <100 mg/dl, HbA1c <7.0%, non-smoking status, blood pressure <130/80 mmHg, and 18.5≤body mass index≤24.9 kg/m(2). The incidence of MACCE was 1.8% and associated with female sex (P=0.020), age ≥75 years (P=0.004), HbA1c ≥7.0% (P=0.004), LV ejection fraction <35% (P<0.001), estimated glomerular filtration rate <60 ml/min (P=0.008), and history of cerebral infarction (P=0.003). In multivariate analysis, lower post-discharge HbA1c was strongly associated with a lower risk of MACCE after ACS (P=0.004). CONCLUSIONS Hyperglycemia after discharge is a crucial target for the prevention of MACCE in post-ACS patients. (Circ J 2016; 80: 1607-1614).


Circulation | 2013

Acute hemodynamic effects of adaptive servo-ventilation in patients with heart failure.

Shiro Yamada; Mamoru Sakakibara; Takashi Yokota; Kiwamu Kamiya; Naoya Asakawa; Hiroyuki Iwano; Satoshi Yamada; Koji Oba; Hiroyuki Tsutsui


Clinica Chimica Acta | 2014

Serum choline plasmalogens-those with oleic acid in sn-2-are biomarkers for coronary artery disease.

Megumi Nishimukai; Ryouta Maeba; Akiko Ikuta; Naoya Asakawa; Kiwamu Kamiya; Shiro Yamada; Takashi Yokota; Mamoru Sakakibara; Hiroyuki Tsutsui; Toshihiro Sakurai; Yuji Takahashi; Shu-Ping Hui; Tomoki Okazaki; Hiroshi Hara

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