Koichi Toda

Osaka City University, Ōsaka, Ōsaka, Japan

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Publications (134)371.41 Total impact

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    ABSTRACT: It is well-documented that persistent myocardial hypertrophy in patients with aortic stenosis is related to suboptimal postoperative outcomes after aortic valve replacement. Although diabetes is known to potentially exacerbate myocardial hypertrophy, it has yet to be examined if it affects postoperative left ventricular mass regression (LVMR). A single-centre, retrospective analysis was performed on 183 consecutive patients who underwent either surgical or transcatheter aortic valve replacement between 2010 and May 2013. Patient demographics, postoperative outcomes and echocardiographic data were obtained preoperatively and a year after surgery. There were 42 diabetic and 141 non-diabetic patients. Preoperative characteristics of diabetic patients were statistically similar to those of non-diabetic patients, except for higher prevalence of hyperlipidaemia (p <0.001) and history of cerebrovascular disorder (p=0.046) in diabetic patients. Median value of postoperative LVMR of all patients was -36.5g/m(2), and was significantly greater in the non-diabetics compared to the diabetics (-39.1 vs. -22.2g/m(2), p=0.008). Univariate and multivariate analyses were performed on preoperative variables, and stepwise multiple regression analysis demonstrated that diabetes (standardised partial regression coefficient (SPRC)=-0.187, p=0.018), female gender (SPRC=0.245, p=0.026) and age (SPRC=0.203, p=0.018) were associated with poor postoperative LVMR. Patients with diabetes showed suboptimal postoperative LVMR, and the disease was a prognostic factor that was associated with poor LVMR. These findings suggest that diabetes may predispose the particular group of patients to worse postoperative outcomes. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.
    Heart, Lung and Circulation 07/2015; DOI:10.1016/j.hlc.2015.05.019 · 1.17 Impact Factor
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    ABSTRACT: The aim of this study was to compare the cases of minimally invasive mitral valve surgery (MICS-mitral) performed using right mini-thoracotomy (RT) with those performed using median sternotomy (MS). Between 2008 and 2012, 6137 patients underwent isolated mitral valve repair at 210 institutions and were registered in the Japan Adult Cardiovascular Surgery Database. We compared 756 who underwent MICS-mitral via RT to 5381 MS patients and performed a one-to-one matched analysis based on the estimated propensity score. The in-hospital mortality was similar between both groups (RT vs. MS: 0.5 vs. 1.1 %). Although the incidence of postoperative stroke, renal failure, and prolonged ventilation was similar, the number of patients with mediastinitis was greater in the MS group (RT vs. MS: 0 vs. 0.7 %, p < 0.01). Reexploration for bleeding was more frequent in the RT group (RT vs. MS: 2.9 vs. 1.4 %, p < 0.01). Mortality and morbidity occurred at a higher rate in low-volume institutions. The propensity analysis showed that the operation-related times were significantly longer in the RT group, while the length of hospital stay was shorter. In a propensity analysis of patients <60 years of age, there was no in-hospital mortality. MICS-mitral via RT was successful without compromising the clinical outcomes. Although the operation time and postoperative bleeding should be improved, an RT approach is safe in appropriately selected patients, especially those <60 years of age or treated in a high-volume center.
    Surgery Today 06/2015; DOI:10.1007/s00595-015-1210-7 · 1.21 Impact Factor
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    ABSTRACT: Introduction Bone marrow-derived autologous human mesenchymal stem cells (MSC) are one of the most promising cell sources for cell therapy to treat heart failure. The cell sheet technique has allowed transplantation of a large number of cells and enhanced the efficacy of cell therapy. We hypothesized that the transplantation of MSC sheets may be a feasible, safe, and effective treatment for ischemic cardiomyopathy (ICM). Methods and Results Human MSCs acquired from bone marrow were positive for CD73, CD90, and CD105, and negative for CD11b and CD45 by flow cytometry. Ten MSC sheets were created from a total cell number of 1 × 108 MSCs using temperature-responsive culture dishes. These were successfully transplanted over the infarct myocardium of porcine ICM models induced by placing an ameroid constrictor on LAD without any procedural-related complications (MSC group = 6: sheet transplantation; sham group = 6, oral intake of tacrolimus in both groups). Premature ventricular contractions were rarely detected by Holter ECG in the MSC group in the first week after transplantation. On echocardiography, the cardiac performance of the MSC group was significantly better than that of the sham group at 8 weeks after transplantation. On histological examination 8 weeks after transplantation, LV remodeling was significantly attenuated compared with the sham group (cardiomyocyte size and interstitial fibrosis were measured). Immunohistochemistry of the vWF showed that the vascular density in the infarct-border area was significantly greater in the MSC group than the sham group. Expression of angiogenesis-related factors in the infarct-border area of the MSC group was significantly greater than that of the sham group, as measured by real-time PCR. Conclusions Bone marrow derived MSC sheets improved cardiac function and attenuated LV remodeling in ischemic cardiomyopathy without major complications, indicating that this strategy would be applicable in clinical settings.
    Tissue Engineering Part A 06/2015; DOI:10.1089/ten.TEA.2014.0036 · 4.64 Impact Factor
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    ABSTRACT: Neovascularization is closely associated with plaque progression in non-heart transplantation subjects; on the other hand, cardiac allograft vasculopathy causes unfavourable outcomes. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) can provide microscopic assessment in vivo. The aim of this study was to investigate the impact of neovascularization on intimal proliferation. Both IVUS and OCT were attempted in 45 consecutive patients during annual catheterization after heart transplantation. There were 115 vessels [28 vessels were catheterized within 8 weeks of heart transplantation (baseline)]. IVUS analysis assessed vessel, luminal, and intimal (vessel-lumen) volume using Simpson's method. Qualitative parameters including microchannel were assessed by OCT. A microchannel was defined as a no-signal tubuloluminal structure with a sharply delineated border considered to represent neovascularization. Microchannel was observed more often in patient who had their heart transplant more than a year prior to the imaging, compared with shorter periods (39.1 vs. 10.7%, P = 0.023). All microchannels were seen in thickness >0.5 mm, and intimal volume index (mm(3)/mm) correlated with frequency of microchannel (r = 0.54, P = 0.04). The risks for microchannels were donor age [odds ratio (OR) 1.11; 95% confidence interval (CI) 1.03-1.22; P = 0.007], cytomegalovirus infection (OR 16.21; 95% CI 1.79-220.09; P = 0.012), diabetes (OR 9.5; 95% CI 1.21-116.10; P = 0.032), LDL-cholesterol (OR 1.07; 95% CI 1.01-1.13; P = 0.010), and intimal volume (OR 2.47; 95% CI 1.13-6.36; P = 0.023). OCT-identified microchannels increased sharply within the first year and were correlated with intimal volume and coronary risks. This suggests that neovascularization may play an important role in the progression of cardiac allograft vasculopathy. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.
    European Heart Journal Cardiovascular Imaging 05/2015; DOI:10.1093/ehjci/jev110 · 3.67 Impact Factor
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    ABSTRACT: Infective endocarditis is often associated with cerebral complications, the most serious of which is intraoperative hemorrhagic stroke owing to anticoagulation for cardiopulmonary bypass. However, its prevalence and risk factors are unknown. We evaluated the prevalence and risk factors of intraoperative hemorrhagic stroke in patients with infective endocarditis. In 246 patients who underwent valve surgery for active endocarditis between 2005 and 2012, 127 patients had both preoperative and postoperative intracranial neuroimaging. The prevalence and risk factors of intraoperative stroke were analyzed in those 127 patients. Valve surgery was performed in 127 patients 19.6 ± 27.1 days after infective endocarditis diagnosis. Fourteen experienced intraoperative hemorrhagic stroke, and 1 died. None of 29 patients with preoperative hemorrhagic stroke showed exacerbation of hemorrhagic lesions, whereas 1 of 57 patients with preoperative cerebral infarction showed hemorrhagic transformation of infarct lesions. Thirteen of 14 hemorrhagic complications were new ectopic intracranial hemorrhage. Multivariate analysis showed not preoperative cerebral lesions but preoperative low hemoglobin level as the only risk factor for intraoperative hemorrhagic stroke (odds ratio, 0.51; 95% confidence interval, 0.26 to 0.87; p = 0.03). A preoperative hemoglobin cutoff value of 9.2 g/dL was determined by receiver operating curve analysis. Of 41 patients with preoperative hemoglobin level less than 9.2 g/dL, 9 (22%) had intraoperative new hemorrhage, whereas 4 (5%) of 86 patients with hemoglobin level of at least 9.2 g/dL had ectopic new hemorrhage. Intraoperative hemorrhagic stroke was not rare, and ectopic hemorrhagic stroke, associated with preoperative anemia, was more prevalent than hemorrhagic transformation of existing cerebral lesions. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
    The Annals of thoracic surgery 05/2015; DOI:10.1016/j.athoracsur.2015.02.056 · 3.65 Impact Factor
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    ABSTRACT: Heart failure mainly caused by ischemic or dilated cardiomyopathy is a life-threatening disorder worldwide. The previous work in cardiac surgery has led to many excellent surgical techniques for treating cardiac diseases, and these procedures are now able to prolong the human lifespan. However, surgical treatment for end-stage heart failure has been under-explored, although left ventricular assist device (LVAD) implantation and heart transplantation are options to treat the condition. LVAD can provide powerful circulatory support for end-stage heart failure patients and improve the survival and quality of life after implantation compared with the existing medical counterparts. Moreover, LVADs play a crucial role in the "bridge to transplantation", "bridge to recovery" and recently have served as "destination therapy". The structural and molecular changes that improve the cardiac function after LVAD implantation are called "reverse remodeling", which means that patients who have received a LVAD can be weaned from the LVAD with restoration of their cardiac function. This strategy is a desirable alternative to heart transplantation in terms of both the patient quality of life and due to the organ shortage. The mechanism of this bridge to recovery is interesting, and is different from other treatments for heart failure. Bridge to recovery therapy is one of the options in regenerative therapy which only a surgeon can provide. In this review, we pathophysiologically analyze the reverse remodeling phenomenon induced by LVAD and comment about the clinical evidence with regard to its impact on the bridge to recovery.
    Surgery Today 04/2015; DOI:10.1007/s00595-015-1149-8 · 1.21 Impact Factor
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    ABSTRACT: Restrictive mitral annuloplasty (RMA) can reverse left ventricular (LV) remodeling and reduce plasma B-type natriuretic peptide (BNP), a surrogate biomarker of heart failure. However, the relationship between reverse LV remodeling and plasma BNP changes after RMA is poorly defined. We explored the main hemodynamic factors contributing to change in plasma BNP after RMA in patients with functional mitral regurgitation (MR). Twenty-four patients with moderate to severe functional MR secondary to LV systolic dysfunction [ejection fraction (EF) <40%] underwent 64-row multidetector computed tomography (MDCT) before and 1.4 months after RMA. LV end-diastolic volume index (EDVI), end-systolic volume index (ESVI), LVEF, and regional and global end-systolic wall stress (ESS) were calculated from 3-dimensional MDCT images, with blood samples for plasma BNP measurement collected the same day. After RMA, LV volumes and global ESS were decreased, while LVEF improved (all p<0.01). There were significant correlations between changes in LVEDVI and LVESVI (r=0.90, p<0.0001), LVESVI and global ESS (r=0.54, p=0.006), and global ESS and LVEF (r=-0.60, p=0.002). The median value for the plasma BNP also decreased from 597pg/ml [interquartile range (IQR), 360-934pg/ml] to 207pg/ml (IQR, 124-271pg/ml), in association with changes in LVEDVI (r=0.47, p=0.019), LVESVI (r=0.56, p=0.004), LVEF (r=-0.60, p=0.002), and global ESS (r=0.74, p<0.0001). Multivariate regression analysis showed that global ESS change was the strongest contributor to change in natural-log-transformed plasma BNP (standardized partial regression coefficient=0.59, p=0.004), indicating a strong association between decrease in LV afterload and reduction in plasma BNP level after RMA. There may be a significant association between LV reverse remodeling and plasma BNP change after RMA. Furthermore, LV end-systolic myocardial stress may be the key mechanical stimulus influencing plasma BNP after surgical correction for functional MR. Whether these favorable BNP responses and reverse remodeling can predict improved survival requires further study. Copyright © 2015 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.
    Journal of Cardiology 04/2015; DOI:10.1016/j.jjcc.2015.02.015 · 2.57 Impact Factor
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    ABSTRACT: We conducted in vivo examinations of a newly designed stentless mitral valve (SMV), formed by suturing 2 leaflets with the "legs" serving as chorda tendinea, made from bovine pericardium, to a flexible ring.Methods and Results:Seven pigs underwent implantation of the SMV constructed with a 23-mm (n=5) or 25-mm (n=2) Duran ring. Baseline echocardiography examinations were used to evaluate the annular anteroposterior diameter, and distance between the mitral annulus (MA) and papillary muscles (PMs) to determine SMV-leg length. After removing the native valve, the SMV-legs were fixed to the anterior and posterior PMs, followed by fixation of the ring to the native MA. Immediately after surgery, all animals presented none or trivial mitral regurgitation, with mean and peak trans-SMV pressure gradient values of 1.9±0.8 and 6.0±3.1 mmHg, respectively. The mean length of the SMV-leg was 19.4±3.9 mm, which correlated with the distance between anterior and posterior MA-PM (r=0.96 and 0.94, respectively, P<0.01 for both). The discrepancy between the anteroposterior diameter of the ring (outside diameter) and that of the native valve was 1.0±2.9 mm, which correlated with the trans-SMV pressure gradient (r=0.81, P=0.025). In our preliminary study, the SMV demonstrated excellent diastolic inflow dynamics and closing function in vivo. Preoperative precise assessment of MV configuration may serve as a basis for selection of appropriate ring size and SMV-leg length. (Circ J 2015; 79: 553-559).
    Circulation Journal 02/2015; 79(3). DOI:10.1253/circj.CJ-14-1113 · 3.69 Impact Factor
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    ABSTRACT: Background:Feasibility and early results of transfemoral aortic valve implantation using the ACURATE neo/TF(TM)self-expanding stent are reported.Methods and Results:The study group of 15 patients (mean age 83.3±6.0) was enrolled with a mean EuroSCORE and STS score of 21.9±11.6% and 7.5±3.1%, respectively. Clinical and echocardiographic evaluations were performed at baseline, discharge, 30 days and 6 months. The primary endpoint was all-cause mortality at 30 days. Transcatheter aortic valve implantation (TAVI) using the ACURATE neo/TF device was successful in 14 patients; 1 patient underwent valve-in-valve implantation because the prosthetic valve embolized during withdrawal of the delivery system. Conversion to surgery, coronary obstruction, peri-operative stroke, and pacemaker implantation did not occur at 30 days. Mean transvalvular gradients at discharge significantly decreased from 44.2±10.5 mmHg (preprocedural) to 7.7±3.1 mmHg (P<0.0001) and effective orifice area significantly increased from 0.77±0.12 to 1.69±0.25 cm(2)(P<0.0001). None or trace paravalvular leak was revealed in 50.0%, and no patient exhibited moderate or higher paravalvular leak. The overall mortality at 30 days and 6 months was 0% and 6.7%, respectively.Conclusions:A new self-expanding TF TAVI device, ACURATE neo/TF, is safe and effective in the treatment of severe aortic stenosis in elderly patients at high risk for surgery.
    Circulation Journal 02/2015; DOI:10.1253/circj.CJ-14-1110 · 3.69 Impact Factor
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    ABSTRACT: Background:Little is known about the impact of tricuspid annuloplasty (TAP) on annular dynamics. We assessed tricuspid annular dynamics using 3-D transesophageal echocardiography (3D-TEE) before and after TAP with different types of prosthetic ring.Methods and Results:3D-TEE of the tricuspid valve was acquired in 30 patients (TAP with rigid ring [RR], n=8; TAP with flexible ring [FR], n=10; control, n=12). Tricuspid annular dimensions (circumference, area, annular height, anteroposterior [AP], septolateral [SL] diameter) were measured throughout the cardiac cycle. All postoperative tricuspid annular dimension parameters were significantly reduced by TAP, while the AP/SL ratio was significantly increased (before, 0.96±0.16; after, 1.03±0.06; P<0.05). The difference in annular area between diastole and systole was significantly smaller in the TAP groups (11.6%) than in the control (27.9%, P<0.05). Annular height in the FR patients was significantly lower than in the RR group, while the postoperative AP/SL ratio was lower in the RR than the FR and control groups. Change in annular area was not seen in RR patients, while it was seen in the FR and control groups.Conclusions:Annulus motion and shape differ according to the type of prosthetic ring used, although tricuspid regurgitation was well controlled by all types of ring utilized. The present results provide important information for selection of an appropriate prosthetic ring for TAP.
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    ABSTRACT: Left atrial (LA) dimension can predict atrial fibrillation (AF) recurrence after catheter-based or surgical ablation. Pulmonary vein isolation (PVI) may be a surgical option during aortic valve replacement (AVR) and/or coronary artery bypass grafting (CABG), though consensus regarding patient selection and late outcome is lacking. We studied 160 patients (mean age 70 ± 9 years) with paroxysmal AF who underwent radiofrequency-based PVI during AVR and/or CABG, and were followed up postoperatively for at least 6 months. Mean preoperative LA dimension was 44 ± 7 mm. Serial echocardiography was performed to evaluate left ventricular (LV) and LA dimensions, E/e', estimated systolic pulmonary artery (PA) pressure and degree of valvular regurgitation. Follow-up was completed with a mean duration of 47 ± 25 months. At the latest follow-up, 133 patients (83%) remained in sinus rhythm. Preoperative LA dimension was independently associated with increased risk of AF recurrence at 6 months after surgery [adjusted odds ratio 1.3 per 1-mm increase in LA dimension, 95% confidence interval (CI) 1.1-1.6, P < 0.001]. Receiver-operating characteristic curve analysis demonstrated an optimal cut-off value for preoperative LA dimension of 45 mm to predict sinus rhythm restoration (98% for <45 mm vs 55% for ≥45 mm, P < 0.001). Patients with LA dimension ≥45 mm had a significantly lower 5-year survival rate (62 ± 7 vs 82 ± 7%, P = 0.025) and freedom from adverse events defined as cerebral infarction/haemorrhage, admission for heart failure, catheter ablation and permanent pacemaker implantation (58 ± 7 vs 91 ± 4%, P < 0.001). Multivariate analysis showed that preoperative LA dimension ≥45 mm was independently associated with adverse events (adjusted hazards ratio 2.4, 95% CI 1.2-5.1, P = 0.019). Serial echocardiography demonstrated improvement in LV systolic function irrespective of LA dimension, whereas patients with LA dimension ≥45 mm showed less improvement in LA dimension and systolic PA pressure (interaction effect P < 0.001) and persistent higher E/e' (group effect P < 0.001), along with aggravated tricuspid regurgitation. In patients with paroxysmal AF related to aortic valve disease and/or coronary artery disease, a dilated left atrium (≥45 mm) was associated with inferior AF- and event-free survival after PVI, accompanied by persistent abnormalities in cardiac and haemodynamic function. These findings may assist patient selection for PVI during AVR and/or CABG. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 01/2015; DOI:10.1093/ejcts/ezu532 · 2.81 Impact Factor
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    ABSTRACT: Poor survival outcomes for patients with severe heart failure (HF) and the donor shortage for heart transplantation warrant the development of myocardial regenerative therapy. We performed a multicenter, phase II study to evaluate the safety and efficacy of autologous skeletal myoblast sheets (TCD-51073).Methods and Results:In 3 study sites, we enrolled 7 patients with severe chronic HF due to ischemic heart disease despite maximal therapy, all of whom underwent transplantation of TCD-51073. No serious arrhythmia was reported, and no changes were noted in the frequency of ventricular extrasystole frequency. The primary efficacy endpoint of the change in left ventricular ejection fraction (LVEF) on gated blood-pool scintigraphy at 26 weeks after transplantation showed that 5 subjects were responders (classified as "improved" or "unchanged"). In addition, LVEF on echocardiography improved over time, with a change in LVEF of 7.1±2.8% at 26 weeks posttransplantation. Among the 7 subjects, 6 showed improvement in New York Heart Association functional class by at least 1 class. The 6-min walk distance was 410.1±136.1 m before transplantation and 455.4±103.7 m at 26 weeks after transplantation. This study demonstrated the feasibility and safety of the transplantation of TCD-51073 in the patients with severe chronic HF due to ischemic heart disease, suggesting that TCD-51073 might maintain or improve cardiac function, symptoms, and physical function. (Circ J 2015; 79: 991-999).
    Circulation Journal 01/2015; 79(5):991-9. DOI:10.1253/circj.CJ-15-0243 · 3.69 Impact Factor
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    ABSTRACT: Severe donor shortage in Japan makes the waiting period for heart transplantation extremely long and the left ventricular assist devices (LVADs) are often used for bridge-to-transplant. We present three cases of infected and exposed DuraHeart(®) LVAD system treated with free flaps. Four free flaps (two latissimus flaps and two anterolateral thigh flaps) were transferred using the right internal thoracic vessels or left deep inferior epigastric vessels as recipients. The potential significance of the continuous low pressure blood flow generated by the LVAD system on microvascular patency has not been previously reported. All flaps survived and worked efficiently to control the infection and cover the devices. Heart transplantation was conducted in the two of three patients. Free flap transfer is an efficient treatment for the patients with infected and exposed implantable LVAD.
    Journal of Artificial Organs 12/2014; 18(2). DOI:10.1007/s10047-014-0812-y · 1.39 Impact Factor
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    ABSTRACT: Background:The aim of the present study was to assess the efficacy of a non-invasive method, transient elastography (FibroScan), in measuring liver stiffness (LS), and whether LS can be used as a marker of cardiac - and hence perioperative - status.Methods and Results:Perioperative LS was prospectively measured using a FibroScan in 30 patients (21 male; 42.2±13.3 years old) who underwent left ventricular assist device (LVAD) implantation. LS was checked pre- and postoperatively, then analyzed in regard to perioperative status. Preoperative LS was 13.3±13.0 kPa (normal, <5.5 kPa), and was abnormal in 77% of patients. Four required bilateral VAD. LS in patients with bilateral VAD tended to be higher than in LVAD patients (25.1±22.7 vs. 11.5±10.5 kPa, P=0.051). No patient with LS ≤7.0 kPa required a right VAD. The incidence of major adverse events was lower in patients with LS ≤12.5 kPa (25% vs. 80%, P<0.05). There were also no mortalities among patients with LS ≤12.5 kPa.Conclusions:LS was correlated with preoperative severity in patients with severe heart failure and reflected liver congestion, and may be useful to predict the requirement of right VAD, as well as postoperative complications in patients with LVAD implantation. This novel modality may be a useful non-invasive assessment method for management of severe heart failure.
    Circulation Journal 12/2014; 79(2). DOI:10.1253/circj.CJ-14-0929 · 3.69 Impact Factor
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    ABSTRACT: Cell-sheet transplantation induces angiogenesis for chronic myocardial infarction (MI), though insuf?cient capillary maturation and paucity of arteriogenesis may limit its therapeutic effects. Omentum has been used clinically to promote revascularization and healing of ischemic tissues. We hypothesized that cell-sheet transplantation covered with an omentum-flap would effectively establish mature blood vessels and improve coronary microcirculation physiology, enhancing the therapeutic effects of cell-sheet therapy. Rats were divided into 4 groups after coronary ligation; skeletal myoblast cell-sheet plus omentum-flap (combined), cell-sheet only, omentum-flap only, and sham operation. At 4 weeks after the treatment, the combined group showed attenuated cardiac hypertrophy and fibrosis, and a greater amount of functionally (CD31(+)/lectin(+)) and structurally (CD31(+)/α-SMA(+)) mature blood vessels, along with myocardial upregulation of relevant genes. Synchrotron-based microangiography revealed that the combined procedure increased vascularization in resistance arterial vessels with better dilatory responses to endothelium-dependent agents. Serial (13)N-ammonia PET showed better global coronary flow reserve in the combined group, mainly attributed by improvement in the basal left ventricle. Consequently, the combined group had sustained improvements in cardiac function parameters and better functional capacity. Cell-sheet transplantation with an omentum-flap better promoted arteriogenesis and improved coronary microcirculation physiology in ischemic myocardium, leading to potent functional recovery in failing heart.Molecular Therapy (2014); doi:10.1038/mt.2014.225.
    Molecular Therapy 11/2014; 23(2). DOI:10.1038/mt.2014.225 · 6.43 Impact Factor
  • Koichi Toda · Yoshiki Sawa
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    ABSTRACT: More than 250 continuous flow LVADs have been implanted in Japan during the last 3 years, with 1-year survival rates of 90 %. These excellent results cannot be achieved without VAD teams who know the detail of surgical techniques and perioperative management. Preoperative optimization of RV function is essential and intraoperative managements are focused on adequate balance between right and left ventricle to prevent right ventricular (RV) failure. For postoperative RV failure early institution of temporary RV mechanical support improves outcomes. Immediate CT scanning is crucial if LVAD patients complain of new neurological symptoms. When CT reveals cerebral hemorrhage, INR should be reduced as soon as possible. The driveline (DL) exit site remains a significant source of LVAD-related infections, and orientation and immobilization of the DL is important. Although vacuum assisted closure is useful to facilitate drainage and healing in pump pocket as well as DL infections, urgent heart transplantation, bridging to recovery, or pump exchange may become the only options to eradicate LVAD-related infections. Patients with continuous flow LVAD are more prone to developing de novo aortic insufficiency. Although majority of them can be managed medically, some require surgical intervention. The cause of pump thrombosis is multifactorial, including lowered INR and pump speed, and implantation techniques. It is important to exchange pumps in a timely manner either through a median sternotomy or subcostal incision in highly suspected patients indicated by elevated LDH and left-sided heart failure.
    General Thoracic and Cardiovascular Surgery 11/2014; 63(1). DOI:10.1007/s11748-014-0480-0
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    ABSTRACT: Myocardial recovery occurs in a small cohort of patients receiving left ventricular assist device (LVAD) support, but identification of candidates for device removal remains challenging. We hypothesized that hemodynamic evaluation using echocardiography and right heart catheter during temporary suspension of LVAD support (LVAD-off test) can assess cardiac recovery to predict successful device removal. To prove this hypothesis, we reviewed 44 patients who underwent LVAD-off test from January 2000 to March 2011 at Osaka University Hospital. Twenty-two of them underwent LVAD explant, 9 showed sustaining recovery (successful explant, SE-group); whereas 13 had a recurrent heart failure (failed explant, FE-group). The other 22 patients remained LVAD dependent (nonrecovery, NR-group). Echocardiography showed significant lower ejection fraction (LVEF) in NR-group than in SE- and FE-group after termination of LVAD support, but there was no difference between SE- and FE-group. On the other hand, elevation in pulmonary capillary wedge pressure (ΔPCWP) was significantly smaller in SE-group than in FE- and NR-groups. The degree of cardiac fibrosis significantly increased in FE- and NR-group during the LVAD support, while it did not increase in SE-group. The degree of cardiac fibrosis at the time of LVAD explantation correlated significantly with PCWP at LVAD halt and ΔPCWP, and it had significant impact on the outcome after LVAD weaning. In conclusion, the data obtained during LVAD-off test using echocardiography and right heart catheter significantly correlated with the degree of cardiac fibrosis at the time of LVAD explantation. LVAD-off test is a useful method to predict the successful LVAD explantation.
    Journal of Artificial Organs 11/2014; 18(1). DOI:10.1007/s10047-014-0802-0 · 1.39 Impact Factor
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    ABSTRACT: Recent evidence suggests that transcatheter aortic valve replacement (TAVR) is feasible for treating severe aortic valve stenosis (AS) in patients who are considered high risk for elective surgery. However, it is still unclear whether TAVR is a better option than surgical aortic valve replacement for severe AS with acute decompensated heart failure. We report a case of severe AS with acute heart failure, which was treated successfully by urgent TAVR, with cardiopulmonary support.
    Surgery Today 10/2014; 45(7). DOI:10.1007/s00595-014-1059-1 · 1.21 Impact Factor
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    ABSTRACT: Cell surface glycans vary widely, depending on cell properties. We hypothesized that glycan expression on induced pluripotent stem cells (iPSCs) might change during cardiomyogenic differentiation toward the myocardial phenotype. N-glycans were isolated from iPSCs, iPSC-derived cardiomyocytes (iPSC-CM), and original C57BL/6 mouse myocardium (Heart). Their structures were analyzed by a mapping technique based on HPLC elution times and MALDI-TOF/MS spectra. Sixty-eight different N-glycans were isolated; the structures of 60 of these N-glycans were identified. The quantity of high-mannose type (immature) N-glycans on the iPSCs decreased with cardiomyogenic differentiation, but did not reach the low levels observed in the heart. We observed a similar reduction in neutral N-glycans and an increase in fucosylated or sialyl N-glycans. Some structural differences were detected between iPSC-CM and Heart. No N-glycolyl neuraminic acid (NeuGc) structures were detected in iPSC-CM, whereas the heart contained numerous NeuGc structures, corresponding to the expression of cytidine monophosphate-N-acetylneuraminic acid hydroxylase. Furthermore, several glycans containing Galα1-6 Gal, rarely identified in the other cells, were detected in the iPSC-CM. The expression of N-glycan on murine iPSCs changed toward the myocardial phenotype during cardiomyogenic differentiation, leaving the structural differences of NeuGc content or Galα1-6 Gal structures. Further studies will be warranted to reveal the meaning of the difference of N-glycans between the iPSC-CM and the myocardium.
    PLoS ONE 10/2014; 9(10):e111064. DOI:10.1371/journal.pone.0111064 · 3.23 Impact Factor

Publication Stats

527 Citations
371.41 Total Impact Points

Institutions

  • 2006–2015
    • Osaka City University
      • Department of Cardiovascular Surgery
      Ōsaka, Ōsaka, Japan
  • 2012–2014
    • Osaka University
      • Division of Cardiovascular Surgery
      Suika, Ōsaka, Japan
  • 2009–2013
    • National Cardiovascular Center
      • Department of Cardiovascular Medicine
      Ōsaka, Ōsaka, Japan
  • 2007–2012
    • Osaka Rosai Hospital
      Ōsaka, Ōsaka, Japan
  • 2005–2007
    • Kure Medical Centre
      • Department of Cardiovascular Surgery
      Hirosima, Hiroshima, Japan
  • 2003
    • Sakurabashi Watanabe Hospital
      Ōsaka, Ōsaka, Japan
  • 1995
    • Texas Heart Institute
      Houston, Texas, United States