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Although genetic abnormalities play a pivotal role in the development of dilated cardiomyopathy (DCM), acquired infection and autoimmune abnormalities, or both, appear to be predominant underlying disorders. Of these, viral infection causes target organ damage via perforin produced by suppressor T cells. Thereafter, various antigens released from damaged myocytes are presented on the major histocompatibility complex II, which is expressed in antigen-presenting cells, resulting in activation of both cellular (Th1) and humoral (Th2) immunity. Various antimyocardial antibodies are detected in the serum of patients with DCM and recent findings suggest that at least some of them are directly related to the pathophysiology of DCM. An autoantibody targeting the β1-adrenergic receptor is related to the persistent myocardial damage resulting in DCM and provides the substrate for fatal ventricular arrhythmias. An antibody for the muscarinic M2 receptor is related to atrial fibrillation, an antibody targeting Na-K-ATPase is closely related to sudden cardiac death from fatal ventricular arrhythmias, and an autoantibody for troponin I increases the L-type calcium current and is related to myocardial damage. On the other hand, genetic factors are also involved in susceptibility to viral infection and aberrations of acquired immunity, including antigen presentation and autoantibody production. In conclusion, acquired factors are predominant causes of DCM, although the 2 predisposing factors are also linked to genetic abnormalities.

Drug-eluting stent (DES) underexpansion has been reported as an independent factor for restenosis and thrombosis; therefore, adequate plaque modification prior to DES implantation is the key of calcified lesion treatment. Consecutive patients with severely calcified lesions undergoing rotational atherectomy (RA) followed by balloon dilatation before DES implantation were analyzed. Patients were divided into two groups based on the balloon type before stent implantation: the cutting balloon (ROTACUT group) and the plain balloon (control group). Twenty-five patients with 26 calcified lesions were identified: 10 patients (10 lesions) were included in the ROTACUT group and 15 patients (16 lesions) in the control group. There were statistically no differences in the final burr size (1.65 ± 0.21 mm vs 1.67 ± 0.22 mm; P=.803), the maximum (max) balloon diameter before stent implantation (2.85 ± 0.34 mm vs 2.72 ± 0.42 mm; P=.411), the max final balloon diameter (3.30 ± 0.33 mm vs 3.28 ± 0.44 mm; P=.908), and the max final balloon inflation pressure (15.3 ± 3.0 atm vs 16.4 ± 5.5 atm; P=.501). Final minimum stent cross-sectional area (CSA) was significantly larger in the ROTACUT group compared to the control group (6.80 ± 1.27 mm 2 vs 5.38 ± 1.89 mm 2; P=.048). RA followed by cutting balloon plaque modification for DES implantation in severely calcified lesions appears to be more efficacious including significantly larger final stent CSA.

Yoshikawa T.,Sakakibara Heart Institute
International Journal of Cardiology | Year: 2015

Takotsubo cardiomyopathy, a new concept of cardiomyopathy, is characterized by transient cardiac dysfunction, commonly triggered by physical or emotional stress. Differential diagnosis is important, since takotsubo cardiomyopathy presents similar images to those shown in acute coronary syndrome, with ST-segment elevation, T-wave inversion, QT-prolongation, and others on electrocardiogram. Typically, apical involvement with hypercontraction of basal left ventricle (apical type) is predominant, but atypical types involving basal, mid-ventricular, and right ventricular myocardium are also described. In-hospital death occurs at similar level with patients with acute coronary syndrome, but it is significantly affected by underlying diseases. This disease presents diverse cardiac complications in acute phase, such as life-threatening ventricular arrhythmias, pump failure, cardiac rupture, and systemic embolism. The pathogenic mechanism of this disease is still unclear but sympathetic hyperactivity, as well as coronary vasospasm, microcirculatory disorder, and estrogen deficiency, have been considered as one of the most likely pathogenic mechanism. Long-term prognosis is also largely unknown. Issues such as establishment of acute phase treatment, prediction of cardiac complications, and prophylactic measures against recurrence need to be further explored. © 2015 Elsevier Ireland Ltd. All rights reserved.

Park I.-S.,Sakakibara Heart Institute
International Heart Journal | Year: 2015

This study retrospectively evaluated the effectiveness of pulmonary vasodilator therapy with bosentan (n = 14) and/ or sildenafil (n = 23) in 34 patients with a functionally single ventricle. Vasodilator therapy was initiated before the Fontan procedure in 18 patients and after the procedure in 16 patients. The reasons for vasodilator treatment included high pulmonary artery pressure or pulmonary vascular resistance (n = 8), high central venous pressure after the Fontan or bidirectional Glenn procedure (n = 7), and ventilatory impairment (n = 8). In the 11 patients who underwent right heart catheterization before and after the initiation of therapy, the mean pulmonary artery pressure decreased significantly from 19.5 ± 5.5 mmHg to 14.3 ± 3.0 mmHg (P = 0.023) and the transpulmonary pressure gradient decreased significantly from 10.9 ± 4.6 mmHg to 7.2 ± 3.3 mmHg (P = 0.046). Of the 18 patients who started vasodilator therapy before the Fontan procedure, 10 survived surgery, 4 are awaiting surgery, 3 had not been evaluated for the Fontan procedure at the end of the study period, and 1 died of heart failure after discontinuing bosentan therapy. There were no deaths among the patients who started therapy after the Fontan procedure. Two of the 14 patients receiving bosentan discontinued treatment because of adverse effects (hepatic dysfunction and increased serum brain natriuretic peptide level). Bosentan or sildenafil therapy is usually safe and may contribute to reducing pulmonary vascular resistance in patients with a functionally single ventricle before and after a Fontan type operation. © 2015, International Heart Journal Association. All rights reserved.

Fukui T.,Sakakibara Heart Institute | Uchimuro T.,Sakakibara Heart Institute | Takanashi S.,Sakakibara Heart Institute
European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery | Year: 2015

OBJECTIVES: We evaluated the usefulness of the combination of European System for Cardiac Operative Risk Evaluation score (EuroSCORE II) and SYNergy between percutaneous intervention with TAXus drug-eluting stents and cardiac surgery (SYNTAX) score in predicting risks associated with early and late outcomes after coronary artery bypass grafting (CABG).METHODS: Between January 2010 and April 2012, 412 patients underwent isolated CABG at our institution. EuroSCORE II and SYNTAX score were calculated retrospectively, and their ability to predict early and long-term outcomes was evaluated. Patients were divided into four groups according to median EuroSCORE II and SYNTAX score: Group 1, low EuroSCORE II, low SYNTAX (n=103); Group 2, low EuroSCORE II, high SYNTAX (n=103); Group 3, high EuroSCORE II, low SYNTAX (n=99); and Group 4, high EuroSCORE II, high SYNTAX (n=107).RESULTS: Operative death was not different among the groups; however, Group 4 had the highest major complication rate of the four groups (0 in Group 1, 2.9% in Group 2, 3.0% in Group 3 and 8.4% in Group 4; P=0.011). Multivariate analyses revealed that both high EuroSCORE II (odds ratio [OR]: 4.154; P=0.030) and high SYNTAX score (OR: 3.988; P=0.035) were independent predictors of postoperative major complications and that high EuroSCORE II was an independent predictor of late mortality (OR: 4.673; P=0.016) but high SYNTAX score was not (OR: 0.808; P=0.662). Actuarial survival rate at 3 years was the lowest in Group 4 (99.0±1.0% in Group 1, 97.7±1.6% in Group 2, 91.9±2.7% in Group 3 and 90.5±4.7% in Group 4; P=0.045).CONCLUSIONS: The combination of EuroSCORE II and SYNTAX score was useful in predicting early major complications after CABG. In the long term, EuroSCORE II continued to be associated with late mortality, but SYNTAX score did not. © The Author 2014. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Ando M.,Sakakibara Heart Institute | Takahashi Y.,Sakakibara Heart Institute
Annals of Thoracic Surgery | Year: 2011

Background: Presently, there are wide variations in cardiac anatomies requiring single ventricular palliation and these variations may have an impact on the incidence of atrioventricular valve regurgitation. Methods: In all, 363 patients underwent single ventricular palliation (1978 to 2008). Hearts were first classified into single right ventricle (156), single left ventricle (140), and two ventricles (63); and secondly into single mitral (90), single tricuspid (64), two separate valves (110), and common atrioventricular valves (95). Results: The incidence of atrioventricular valve regurgitation and the necessity of repair were the highest with common atrioventricular valves, followed by tricuspid and mitral valves (p < 0.0001). The success rate (postoperative regurgitation of mild or less) of repair was similar (p = 0.9800). Estimated survival for patients having moderate or greater atrioventricular valve regurgitation was similar to the rest of the patients (p = 0.8705). Patients were more likely to have progressive mitral regurgitation in the presence of both mitral and tricuspid valves, compared with single mitral valve (p = 0.0207). There were 2 patients who had severe mitral regurgitation; both had a nonsystemic left ventricle isolated from the circulation by malposition of the great arteries and restrictive/remote ventricular septal defect. In contrast, coexisting mitral valves reduced the incidence of potential tricuspid regurgitation (p = 0.0012). Conclusions: If performed properly, atrioventricular valve repair may neutralize the risk of regurgitation regardless of the valve morphology. The effort to incorporate the mitral valve into the systemic circulation may be important to reduce tricuspid regurgitation. The effort to decompress a nonsystemic left ventricle, if present, may be important to avoid unfavorable ventricular interactions on the mitral valve. © 2011 The Society of Thoracic Surgeons.

Tabata M.,Sakakibara Heart Institute | Fukui T.,Sakakibara Heart Institute | Takanashi S.,Sakakibara Heart Institute
Circulation Journal | Year: 2013

With the development of techniques and technologies in the past decade, minimally invasive valve surgery (MIVS) has become a well-established surgical option for heart valve disease. Unlike emerging transcatheter valves, MIVS still requires cardiopulmonary bypass and cardiotomy. The only difference between minimally invasive and conventional valve operations is whether a full sternotomy is avoided or not. The minimally invasive approach has been shown to have some beneficial effects such as reduced blood transfusion and faster postoperative recovery. However, these could be limited and outweighed by the potential adverse effects of small access. Careful selection of patient, approach and perfusion strategy based on thorough preoperative assessment and each surgical team experience is necessary to perform MIVS safely.

Fukui T.,Sakakibara Heart Institute | Takanashi S.,Sakakibara Heart Institute
Circulation Journal | Year: 2010

Background: The impact of gender on outcome after coronary artery bypass grafting (CABG) is controversial. The aim of this study was to compare the differences of clinical and angiographic outcomes between female and male patients after CABG. Methods and Results: The records of 954 patients who underwent isolated CABG between 2004 and 2009 were reviewed. There were 188 female and 766 male patients. Female patients were smaller (P<0.0001) and had a more unstable status (P=0.0024) preoperatively compared with the male patients. Left internal thoracic artery (ITA) use was identical in both genders. However, the right ITA (P=0.006) and radial artery (P<0.0001) use were less frequent in females compared with that in males. Consequently, the use of saphenous vein grafts (SVGs) was more frequent in females than in males (P<0.0001). Mortality was similar between the genders (1.0% vs 1.1%). Although the rate of major complications was not significantly different between the genders (12.2% vs 9.5%), the cerebrovascular event rate was higher in females compared with that in males (4.3% vs 1.6%; P= 0.0432). Patency rates of arterial grafts were not significantly different between the genders; however, those of SVGs were lower in females than those in males (88.6% vs 96.1%; P=0.0003). Conclusions: The clinical outcomes of females after CABG were comparable with those of males.

Ando M.,Sakakibara Heart Institute | Takahashi Y.,Sakakibara Heart Institute
Annals of Thoracic Surgery | Year: 2010

Background: An additional malformation of the atrioventricular valve is occasionally encountered in patients with complete atrioventricular septal defect, and this may compromise accurate correction. Methods: We reviewed 138 patients undergoing complete repair with two-patch technique between 1992 and 2008. The mean age was 7.1 ± 8.3 months, and the mean body weight was 5.1 ± 2.1 kg. Preceding pulmonary arterial banding was performed in 23 patients. Results: The operative record delineated additional malformations of the atrioventricular valve that posed difficulty in positioning the ventricular septal patch and in accurately approximating the cleft in 45 patients. Of them, four types (n = 40) were associated with increased incidence of postoperative left valvular problems (moderate or worse regurgitation or stenosis). These included abnormalities of the papillary muscles that accompanied hypoplastic mural leaflet or incomplete opening of one commissure in (n = 15; p = 0.0054), dense insertion of the chords of the superior leaflet that obscured the right side of the ventricle septal crest in (n = 13; p = 0.0004), double orifice valve (n = 7; p = 0.0225), and severe length disparities of the cleft that resulted from either disproportional size of superior against inferior leaflets or redundant chord supporting the left extremity of one of these leaflets (n = 5; p < 0.0001). Neither greater age at operation (more than 6 months) nor preceding pulmonary arterial band reduced the incidence of left valvular problems in the malformation group. Conclusions: An individualized technique is required to maintain coaptation of the atrioventricular valve, but in many cases, they are not completely correctable. Deferring complete repair by placing a pulmonary arterial band did not reduce left valvular problems. © 2010 The Society of Thoracic Surgeons.

Fukui T.,Sakakibara Heart Institute
General thoracic and cardiovascular surgery | Year: 2011

This study aimed to assess the clinical and angiographic outcomes after coronary artery bypass grafting (CABG) in elderly patients (≥75 years). We reviewed the records of 1021 patients who underwent CABG between September 2004 and December 2009. We divided these patients into two groups: ≥75 years (group E, n = 292) versus <75 years (group N, n = 729). We compared operative and postoperative variables and early and 1-year angiographic patency rates of grafts between the groups. The rates of female sex (P < 0.01), unstable angina (P = 0.04), and history of congestive heart failure (P < 0.01) were higher in group E than in group N. More patients in group N had diabetes (P = 0.03) and hyperlipidemia (P < 0.01) than those in group E. Operative mortality (1.0% in group E vs. 0.3% in group N; P = 0.14) and the rate of major complications were not significantly different between the groups. The mean number of anastomoses per patient was similar in the groups. The rate of left internal thoracic artery use was not significantly different between the groups, although the use of other arterial grafts was significantly higher in group N than in group E. There were no significant differences in the early (98.5% vs. 97.2%, P = 0.08) or 1-year (91.6% vs. 89.3%, P = 0.28) patency rates of all grafts in the groups. The clinical and angiographic outcomes after CABG in elderly patients were almost identical to those in nonelderly patients.

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