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Dive into the research topics where Akinori Sawamura is active.

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Featured researches published by Akinori Sawamura.


Journal of Atherosclerosis and Thrombosis | 2017

Impact of Renal Functional/Morphological Dynamics on the Calcification of Coronary and Abdominal Arteries in Patients with Chronic Kidney Disease

Takeo Ichii; Ryota Morimoto; Takahiro Okumura; Hideki Ishii; Yosuke Tatami; Dai Yamamoto; Soichiro Aoki; Hiroaki Hiraiwa; Kenji Furusawa; Toru Kondo; Naoki Watanabe; Naoaki Kano; Kenji Fukaya; Akinori Sawamura; Susumu Suzuki; Yoshinari Yasuda; Toyoaki Murohara

Aim: Fast-progressing vascular calcification (VC) is accompanied by renal atrophy and functional deterioration along with atherosclerosis in patients with chronic kidney disease (CKD). However, the relationship between VC progression and renal functional and/or morphological changes remains unclear. Methods: We included 70 asymptomatic patients with CKD without hemodialysis in our study. To identify temporal variations, the coronary artery calcification score (CACS), abdominal aortic calcification index (ACI), and renal parenchymal volume index (RPVI) were determined via spiral computed tomography scans taken during the study. We investigated significant factors related to annualized variations of CACS (ΔCACS/y) and ACI (ΔACI/y). Results: During the follow-up period (4.6 years), median values of CACS [in Agatston units (AU)] and ACI increased from 40.2 to 113.3 AU (p = 0.053) and from 13.2 to 21.7% (p = 0.036), respectively. Multivariate analysis revealed that CACS at baseline (p < 0.001) and diabetes mellitus (DM) status (p = 0.037) for ΔCACS/y and ACI at baseline (p = 0.017) and hypertension (HT) status (p = 0.046) for ΔACI/y were significant independent predictors. Furthermore, annualized RPVI variation was significantly related to both ΔCACS/y and ΔACI/y (R = −0.565, p < 0.001, and R = −0.289, p = 0.015, respectively). On the other hand, independent contributions of the estimated glomerular filtration rate (eGFR) and annualized eGFR variation to VC progression were not confirmed. Conclusion: The degree of VC at baseline, DM, HT, and changes in renal volume, but not eGFR, had a strong impact on VC progression in patients with CKD.


The Cardiology | 2017

Abnormal Circadian Blood Pressure Profile as a Prognostic Marker in Patients with Nonischemic Dilated Cardiomyopathy

Akinori Sawamura; Takahiro Okumura; Kyosuke Takeshita; Naoki Watanabe; Naoaki Kano; Hiroaki Mori; Kenji Fukaya; Ryota Morimoto; Akihiro Hirashiki; Yasuko Bando; Toyoaki Murohara

Objectives: An abnormal circadian blood pressure (BP) profile is considered a risk factor for cardiovascular disease. However, its significance in heart failure patients with nonischemic etiology is unknown. Herein, we investigated the prognostic value of a circadian BP profile in patients with nonischemic dilated cardiomyopathy (NIDCM). Methods: We enrolled 114 NIDCM patients (76 males, mean age 53.1 years). The percent nighttime BP fall (%NBPF) was defined using ambulatory BP monitoring as a percent decrease in mean systolic BP in nighttime from daytime. All patients were divided into three groups: dipper (%NBPF ≥10), non-dipper (0 ≤ %NBPF < 10), and riser (%NBPF <0). Results: Riser patients had the highest serum creatinine levels (dipper, 0.78 ± 0.20 mg/dl; non-dipper, 0.85 ± 0.21 mg/dl; riser, 0.99 ± 0.23 mg/dl; p = 0.006). In survival analysis, riser patients had the highest cumulative cardiac-related deaths (log-rank, p = 0.001), which was an independent predictor of cardiac-related deaths (hazard ratio, 12.6; 95% confidence interval, 1.76-253; p = 0.01). Multivariate analysis revealed that the norepinephrine level at 24-hour collected urine (24 h U-NE) and the serum creatinine level were independent determinants of %NBPF (adjusted R2 = 0.20; 24 h U-NE, p = 0.0001; serum creatinine, p = 0.04). Conclusions: The riser profile was associated with poor prognosis of NIDCM, which may reflect impaired sympathetic nervous system activity. Evaluating the circadian BP profile may be useful for risk stratification in NIDCM patients.


Cardiovascular Intervention and Therapeutics | 2012

Intravascular ultrasound-guided percutaneous coronary intervention for total occlusion of the proximal left anterior descending artery caused by spontaneous coronary dissection in a young woman

Naoaki Kano; Katsuhiro Kawaguchi; Junya Funabiki; Yoshihiro Kamimura; Akinori Sawamura; Kentaro Mukai; Hajime Imai; Yasuhiro Ogawa; Taizo Kondo

A 35-year-old woman was admitted to our hospital because of a sudden cardiac arrest caused by an acute anterior myocardial infarction. Emergency coronary angiography showed total occlusion of the proximal left anterior descending artery (LAD). We performed an intravascular ultrasound (IVUS) to detect the LAD orifice and successfully inserted the guidewire to the occluded LAD. An IVUS revealed coronary dissection and no atheromatous plaque from the orifice to the mid-portion of the LAD and the guidewire was in the true lumen. Two bare metal stents were implanted in the proximal and mid portion of the LAD. After stenting to the LAD, coronary dissection retrogradely extended to the left circumflex artery (LCx). Therefore, we performed additional stent implantation from the left main trunk (LMT) to the proximal LCx and the just proximal LAD. An IVUS guided percutaneous coronary intervention (PCI) enabled complete revascularization to spontaneous coronary artery dissection.


Circulation | 2018

Prognostic Value of Electrocardiography in Patients With Fulminant Myocarditis Supported by Percutaneous Venoarterial Extracorporeal Membrane Oxygenation ― Analysis From the CHANGE PUMP Study ―

Akinori Sawamura; Takahiro Okumura; Masaaki Ito; Yukio Ozaki; Nobuyuki Ohte; Tetsuya Amano; Toyoaki Murohara

BACKGROUND Fulminant myocarditis (FM) presents various abnormal findings on ECG, the prognostic impact of which has not been not fully elucidated. The aim of this study was therefore to clarify the prognostic value of ECG data in FM patients supported by venoarterial extracorporeal membrane oxygenation (VA-ECMO).Methods and Results:In this multicenter chart review, we investigated 99 patients with FM supported by VA-ECMO. The final cohort consisted of 87 patients (mean age, 52±16 years; female, 42%) after 12 patients who required conversion to other forms of mechanical circulatory support were excluded. The median LVEF was 14.5%. At the time of VA-ECMO initiation, 38 patients (44%) had arrhythmias including atrial fibrillation (6%), complete atrioventricular block (CAVB; 17%), and ventricular tachycardia or fibrillation (VT/VF; 15%). Of the 49 patients with sinus rhythm (SR), 26 had QRS duration ≥120 ms (wide QRS). On logistic regression analysis, wide QRS predicted in-hospital death in patients with SR (OR, 3.6; 95% CI: 1.07-13.61, P=0.04). Compared with SR with narrow QRS (QRS duration <120 ms), CAVB and VT/VF had a higher risk of in-hospital death (CAVB: OR, 7.20; 95% CI: 1.78-34.15, P=0.005; VT/VF: OR, 8.10; 95% CI: 1.86-42.31, P=0.005). CONCLUSIONS In patients with FM, CAVB and VT/VF carried a higher risk of in-hospital death. Wide QRS also predicted a higher risk of in-hospital death in patients with SR.


Journal of Cardiology | 2017

Cholesterol metabolism as a prognostic marker in patients with mildly symptomatic nonischemic dilated cardiomyopathy

Akinori Sawamura; Takahiro Okumura; Hiroaki Hiraiwa; Soichiro Aoki; Toru Kondo; Takeo Ichii; Kenji Furusawa; Naoki Watanabe; Naoaki Kano; Kenji Fukaya; Ryota Morimoto; Yasuko Bando; Toyoaki Murohara

BACKGROUND Little is known about whether the alteration of cholesterol metabolism reflects abdominal organ impairments due to heart failure. Therefore, we investigated the prognostic value of cholesterol metabolism by evaluating serum campesterol and lathosterol levels in patients with early-stage nonischemic dilated cardiomyopathy (NIDCM). METHODS We enrolled 64 patients with NIDCM (median age 57.5 years, 31% female) with New York Heart Association functional class I/II. Serum campesterol and lathosterol levels were measured in all patients. The patients were then divided into four subsets based on the median non-cholesterol sterol levels (campesterol 3.6μg/mL, lathosterol 1.4μg/mL): reference (R-subset), high-campesterol/high-lathosterol; absorption-reduced (A-subset), low-campesterol/high-lathosterol; synthesis-reduced (S-subset), high-campesterol/low-lathosterol; double-reduced (D-subset), low-campesterol/low-lathosterol. Endpoint was a composite of cardiac events, including cardiac-related death, hospitalization for worsening heart failure, and lethal arrhythmia. RESULTS Median brain natriuretic peptide (BNP) level was 114pg/mL. Mean left ventricular ejection fraction was 31.4%. D-subset had the lowest total cholesterol level and cardiac index and the highest BNP level and pulmonary capillary wedge pressure. D-subset also had the highest cardiac event rate during the mean 3.8 years of follow-up (log-rank p=0.001). Multivariate regression analysis showed that D-subset was an independent determinant of cardiac events. The receiver operating characteristic curve analysis revealed that total cholesterol <153mg/dL was a best cut-off value for discrimination of the D-subset. CONCLUSIONS The combined reduction of campesterol and lathosterol that indicated intestinal cholesterol absorption and liver synthesis predicts future cardiac events in patients with mildly symptomatic NIDCM.


Circulation-heart Failure | 2017

Long-Term Pathological Follow-Up of Myocardium in a Carrier of Duchenne Muscular Dystrophy With Dilated Cardiomyopathy

Toru Kondo; Takahiro Okumura; Mikito Takefuji; Hiroaki Hiraiwa; Yuki Sugiura; Naoki Watanabe; Soichiro Aoki; Takeo Ichii; Katsuhide Kitagawa; Naoaki Kano; Kenji Fukaya; Kenji Furusawa; Akinori Sawamura; Ryota Morimoto; Yasuko Bando; Genzou Takemura; Toyoaki Murohara

Duchenne muscular dystrophy (DMD) is a fatal X-linked disorder, with an incidence of ≈1 in 3600 to 6000 male births. DMD is caused by mutations in the dystrophin gene located at Xp21.2 and is clinically characterized by progressive muscle degeneration and dilated cardiomyopathy (DCM). Some female DMD carriers show a variety of clinical manifestations, ranging from creatine kinase elevation to severe muscle weakness. DCM has been reported in 8% to 18% of female DMD carriers and sometimes results in a lethal course. Here, we describe long-term follow-up observations of myocardial changes in a DMD carrier with DCM. A 29-year-old female presented with progressive shortness of breath, increasing ankle edema, and orthopnea after a full-term normal delivery. A chest X ray showed cardiomegaly and bilateral pleural effusions, and echocardiography showed a severely reduced left ventricular ejection fraction of 24%, with a markedly increased left ventricular end-diastolic diameter of 71 mm. She was admitted for heart failure, and her symptoms improved with furosemide and inotropes. There were no symptoms to suggest myopathy, and blood analysis revealed no elevation of creatine kinase (60 U/L). Her newborn boy showed extreme elevation of creatine kinase (105 868 U/L) and was diagnosed with DMD …


Circulation | 2017

Biphasic Force-Frequency Relation Predicts Primary Cardiac Events in Patients With Hypertrophic Cardiomyopathy

Ryota Morimoto; Takahiro Okumura; Yasuko Bando; Kenji Fukaya; Akinori Sawamura; Haruya Kawase; Shinya Shimizu; Shuzo Shimazu; Akihiro Hirashiki; Kyosuke Takeshita; Toyoaki Murohara

BACKGROUND The force-frequency relation (FFR) is a hemodynamic index of the chronotropic relationship between left ventricular (LV) systolic function (percent change in dP/dtmax) and elevation of heart rate. FFR is a marker of myocardial contractile reserve and follows an upward slope in healthy myocardium [monophasic FFR (MoF)], a pattern that becomes biphasic (BiF) under pathological conditions. However, it remains uncertain whether the FFR determines a patients prognosis. We investigated the promising role of the FFR as a predictor of cardiac events in the setting of hypertrophic cardiomyopathy (HCM).Methods and Results:A total of 113 consecutive patients with HCM (New York Heart Association (NYHA) class I-II) were retrospectively evaluated; 27 (23.9%) had a BiF pattern and they experienced a higher incidence of cardiac events compared with those showing an MoF pattern (median follow-up, 4.7 years; P<0.001). Furthermore, Cox proportional hazard regression analysis revealed that the LV end-diastolic volume index (hazard ratio: 1.051, P=0.014) and BiF pattern (hazard ratio: 15.260, P=0.001) were independent predictors of primary cardiac events. Interestingly, abnormal reductions in myocardial regulatory molecules related to contractility (SERCA2α) were observed exclusively in the patients exhibiting a BiF pattern. CONCLUSIONS The FFR reflects latent myocardial abnormalities and predicts cardiac events in the setting of HCM, even during the asymptomatic stages of the disease.


Circulation | 2017

Early Prediction Model for Successful Bridge to Recovery in Patients With Fulminant Myocarditis Supported With Percutaneous Venoarterial Extracorporeal Membrane Oxygenation ― Insights From the CHANGE PUMP Study ―

Akinori Sawamura; Takahiro Okumura; Akihiro Hirakawa; Masaaki Ito; Yukio Ozaki; Nobuyuki Ohte; Tetsuya Amano; Toyoaki Murohara

BACKGROUND Cardiac recovery and prevention of end-organ damage are the cornerstones of establishing successful bridge to recovery (BTR) in patients with fulminant myocarditis (FM) supported with percutaneous venoarterial extracorporeal membrane oxygenation (VA-ECMO). However, the timing and method of successful BTR prediction still remain unclear. We aimed to develop a prediction model for successful BTR in patients with FM supported with percutaneous VA-ECMO.Methods and Results:This was a retrospective multicenter chart review enrolling 99 patients (52±16 years; female, 42%) with FM treated with percutaneous VA-ECMO. The S-group comprised patients who experienced percutaneous VA-ECMO decannulation and subsequent discharge (n=46), and the F-group comprised patients who either died in hospital or required conversion to other forms of mechanical circulatory support (n=53). At VA-ECMO initiation (0-h), the S-group had significantly higher left ventricular ejection fraction (LVEF) and lower aspartate aminotransferase (AST) concentration than the F-group. At 48 h, the LVEF, increase in the LVEF, and reduction of AST from 0-h were identified as independent predictors in the S-group. Finally, we developed an S-group prediction model comprising these 3 variables (area under the curve, 0.844; 95% confidence interval, 0.745-0.944). CONCLUSIONS We developed a model for use 48 h after VA-ECMO initiation to predict successful BTR in patients with FM.


Annals of Noninvasive Electrocardiology | 2017

Sokolow-Lyon voltage is suitable for monitoring improvement in cardiac function and prognosis of patients with idiopathic dilated cardiomyopathy

Kenji Fukaya; Kyosuke Takeshita; Takahiro Okumura; Hiroaki Hiraiwa; Soichiro Aoki; Takeo Ichii; Yuki Sugiura; Katsuhide Kitagawa; Toru Kondo; Naoki Watanabe; Naoaki Kano; Kenji Furusawa; Akinori Sawamura; Ryota Morimoto; Yasuko Bando; Toyoaki Murohara

The clinical significance of electrocardiogram in the assessment of patients with idiopathic dilated cardiomyopathy (IDCM) is currently unknown. The aim of this study was to determine the feasibility of recording serial changes in Sokolow–Lyon voltage (∆%QRS‐voltage) in one year to estimate left ventricular reverse remodeling (LVRR) and predict a prognosis of IDCM patients under tailored medical therapy.


The Korean Journal of Internal Medicine | 2018

Palliative and end-of-life care for heart failure patients in an aging society

Takahiro Okumura; Akinori Sawamura; Toyoaki Murohara

The populations of Asian countries are expected to age rapidly in the near future, with a dramatic increase in the number of heart failure (HF) patients also anticipated. The need for palliative and end-of-life care for elderly patients with advanced HF is currently recognized in aging societies. However, palliative care and active treatment for HF are not mutually exclusive, and palliative care should be provided to reduce suffering occurring at any stage of symptomatic HF after the point of diagnosis. HF patients are at high risk of sudden cardiac death from the early stages of the disease onwards. The decision of whether to perform cardiopulmonary resuscitation in the event of an emergency is challenging, especially in elderly HF patients, because of the difficulty in accurately predicting the prognosis of the condition. Furthermore, advanced HF patients are often fitted with a device, and device deactivation at the end of life is a complicated process. Treatment strategies should thus be discussed by multi-disciplinary teams, including palliative experts, and should consider patient directives to address the problems discussed above. Open communication with the HF patient regarding the expected prognosis, course, and treatment options will serve to support the patient and aid in future planning.

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