Myocardial T-Lymphocytes as a Prognostic Risk-Stratifying Marker of Dilated Cardiomyopathy - Results of the Multicenter Registry to Investigate Inflammatory Cell Infiltration in Dilated Cardiomyopathy in Tissues of Endomyocardial Biopsy (INDICATE Study)

BACKGROUND

Dilated cardiomyopathy (DCM) associated with inflammation is diagnosed by endomyocardial biopsy; patients with this have a poorer prognosis than patients without inflammation. To date, standard diagnostic criteria have not been established.Methods and Results:This study analyzed clinical records and endomyocardial biopsy samples of 261 patients with DCM (201 males, median left ventricular ejection fraction; 28%) from 8 institutions in a multicenter retrospective study. Based on the European Society of Cardiology criteria and CD3 (T-lymphocytes) and CD68 (macrophages) immunohistochemistry, 48% of patients were categorized as having inflammatory DCM. For risk-stratification, we divided patients into 3 groups using Akaike Information Criterion/log-rank tests, which can determine multiple cut-off points: CD3⁺-Low, <13/mm²(n=178, 68%); CD3⁺-Moderate, 13-24/mm²(n=58, 22%); and CD3⁺-High, ≥24/mm²(n=25, 10%). The survival curves for cardiac death or left ventricular assist device implantation differed significantly among the 3 groups (10-year survival rates: CD3⁺-Low: 83.4%; CD3⁺-Moderate: 68.4%; CD3⁺-High: 21.1%; Log-rank P<0.001). Multivariate Cox analysis revealed CD3⁺count as a potent independent predictive factor for survival (fully adjusted hazard ratio: CD3⁺-High: 5.70,P<0.001; CD3⁺-Moderate: 2.64, P<0.01). CD3⁺-High was also associated with poor left ventricular functional and morphological recovery at short-term follow up.

CONCLUSIONS

Myocardial CD3⁺T-lymphocyte infiltration has a significant prognostic impact in DCM and a 3-tiered risk-stratification model could be helpful to refine patient categorization.

Case Report: Acute Eosinophilic Myocarditis With a Low-Flow Heart Failure With Preserved Ejection Fraction Phenotype

Eosinophilic myocarditis is a rare subtype of myocarditis characterized by myocardial eosinophilic infiltration, and it is potentially fatal if left untreated. Although endomyocardial biopsy (EMB) is a cornerstone for the histological diagnosis of acute eosinophilic myocarditis (AEM), as it is an invasive procedure and has a low diagnostic accuracy, the diagnosis of AEM with hemodynamic instability remains challenging. We describe a case of AEM presenting as low-flow heart failure with preserved ejection fraction (HFpEF), with rapid progression to cardiogenic shock. The constellation of peripheral eosinophilia, increased left ventricular wall thickness, and HFpEF raised the suspicion of AEM. Contrast-enhanced computed tomography (CT) scan revealed heterogeneous hypoenhancement localized in the basal-to-mid septal and mid anterolateral walls of the left ventricle, strongly suggestive of acute inflammation. Based upon these findings, we performed CT-guided EMB, which lead to a definitive diagnosis. Subsequent high-dose corticosteroids allowed a rapid and dramatic recovery and normalization of cardiac structure and function. This case highlights the clinical importance of assessing AEM as a rare cause of HFpEF and the usefulness of CT-guided EMB in patients with hemodynamic instability.

A New Mouse Model of Chronic Myocarditis Induced by Recombinant Bacille Calmette-Guèrin Expressing a T-Cell Epitope of Cardiac Myosin Heavy Chain-α

Dilated cardiomyopathy (DCM) is a potentially lethal disorder characterized by progressive impairment of cardiac function. Chronic myocarditis has long been hypothesized to be one of the causes of DCM. However, owing to the lack of suitable animal models of chronic myocarditis, its pathophysiology remains unclear. Here, we report a novel mouse model of chronic myocarditis induced by recombinant bacille Calmette-Guérin (rBCG) expressing a CD4+ T-cell epitope of cardiac myosin heavy chain-α (rBCG-MyHCα). Mice immunized with rBCG-MyHCα developed chronic myocarditis, and echocardiography revealed dilation and impaired contraction of ventricles, similar to those observed in human DCM. In the heart, CD62L-CD4+ T cells were increased and produced significant amounts of IFN-γ and IL-17 in response to cardiac myosin. Adoptive transfer of CD62L-CD4+ T cells induced myocarditis in the recipient mice, which indicated that CD62L-CD4+ T cells were the effector cells in this model. rBCG-MyHCα-infected dendritic cells produced proinflammatory cytokines and induced MyHCα-specific T-cell proliferation and Th1 and Th17 polarization. This novel chronic myocarditis mouse model may allow the identification of the central pathophysiological and immunological processes involved in the progression to DCM.

Myocardial Native T1 Predicts Load-Independent Left Ventricular Chamber Stiffness In Patients With HFpEF

OBJECTIVES

This study sought to evaluate the potential of cardiac magnetic resonance T₁ mapping to detect load-independent left ventricular (LV) chamber stiffness by histological confirmation.

BACKGROUND

Accurate noninvasive diagnosis of LV diastolic dysfunction in heart failure with preserved ejection fraction (HFpEF) remains challenging.

METHODS

Nineteen HFpEF patients (14 female, 65 ± 16 years of age) without primary cardiomyopathy were prospectively enrolled. Cine, late gadolinium enhancement cardiac magnetic resonance, and triple-slice T₁ mapping using a modified Look-Locker inversion recovery sequence were performed at 3-T. Extracellular volume (ECV) was quantified from pre- and post-contrast T₁ values of the blood and myocardium with hematocrit correction. LV stiffness constant (beta) was assessed by calculating the slope of the end-diastolic pressure-volume relationship curve during vena cava occlusion. Biopsy samples were used for quantification of collagen volume fraction (CVF) and myocardial cell size.

RESULTS

Six patients showed focal scar on late gadolinium enhancement. There was no significant difference in histological CVF between patients with and without focal myocardial scarring (p = 0.2). Septal ECV rather than native T₁ was a better surrogate marker for detecting histological CVF (r = 0.54; p = 0.02, and r = 0.44; p = 0.06, respectively). Global native T₁ and ECV, but not native T₁ and ECV in the septal myocardium, correlated well with the beta of passive LV stiffness, and had similar ability for predicting LV stiffness to histological CVF (r = 0.54, 0.50, 0.53, all p < 0.05, respectively). When the beta ≥0.054 was considered as moderately increased LV stiffness, global native T₁ ≥1,362 ms provided 88% sensitivity and 64% specificity with the C-statistic of 0.81 (95% confidence interval: 0.56 to 0.95).

CONCLUSIONS

Myocardial native T₁ provides comparable ability in predicting LV stiffness to ECV and histological CVF and may be useful for monitoring patients with HFpEF who have renal dysfunction, allergy to gadolinium, or wheezing that can simulate asthma. Our feasibility study shows the potential of native T₁ to allow for insight of heterogeneous pathophysiology and better risk stratification of HFpEF.

Performance of 99mTc-aprotinin scintigraphy for diagnosing light chain (AL) cardiac amyloidosis confirmed by endomyocardial biopsy

BACKGROUND

Light chain (AL) cardiac amyloidosis is associated with a poor prognosis. Diagnosing at an early stage is critical for treatment and the management of cardiac complication.

PURPOSE

We aimed to evaluate the diagnostic performance of 99mTc-aprotinin images in patients with AL cardiac amyloidosis.

METHODS AND RESULTS

99mTc-aprotinin scintigraphy and endomyocardial biopsy were performed in 10 patients with suspected amyloidosis. Endomyocardial biopsy showed amyloid deposits in 5 of 10 patients. 99mTc-aprotinin (planer image) was positive in 4 of 5 patients who had amyloid deposits in endomyocardial biopsy. On the other hand, all 5 patients without amyloid deposits were negative in planer image. 99mTc-aprotinin (SPECT/CT image) was positive in all 5 patients who had amyloid deposits.

CONCLUSIONS

99mTc-aprotinin scintigraphy is valuable for the non-invasive diagnosis of AL cardiac amyloidosis.

Correction to: Performance of 99mTc-aprotinin scintigraphy for diagnosing light chain (AL) cardiac amyloidosis confirmed by endomyocardial biopsy

This prospective study was conducted according to the principles outlined within the Declaration of Helsinki, and approved by the Ethics Review Board of National Center for Global Health and Medicine (NCGM-G-00839-01, NCGM-G-00839-02).

Tenascin-C accelerates adverse ventricular remodelling after myocardial infarction by modulating macrophage polarization

AIMS

Tenascin-C (TN-C) is an extracellular matrix protein undetected in the normal adult heart, but expressed in several heart diseases associated with inflammation. We previously reported that serum TN-C levels of myocardial infarction (MI) patients were elevated during the acute stage, and that patients with high peak TN-C levels were at high risk of left ventricular (LV) remodelling and poor outcome, suggesting that TN-C could play a significant role in the progression of ventricular remodelling. However, the detailed molecular mechanisms associated with this process remain unknown. We aimed to elucidate the role and underlying mechanisms associated with TN-C in adverse remodelling after MI.

METHODS AND RESULTS

MI was induced by permanent ligation of the coronary artery of TN-C knockout (TN-C-KO) and wild type (WT) mice. In WT mice, TN-C was expressed at the borders between intact and necrotic areas, with a peak at 3 days post-MI and observed in the immediate vicinity of infiltrating macrophages. TN-C-KO mice were protected from ventricular adverse remodelling as evidenced by a higher LV ejection fraction as compared with WT mice (19.0 ± 6.3% vs. 10.6 ± 4.4%; P < 0.001) at 3 months post-MI. During the acute phase, flow-cytometric analyses showed a decrease in F4/80+CD206lowCD45+ M1 macrophages and an increase in F4/80+CD206highCD45+ M2 macrophages in the TN-C-KO heart. To clarify the role of TN-C on macrophage polarization, we examined the direct effect of TN-C on bone marrow-derived macrophages in culture, observing that TN-C promoted macrophage shifting into an M1 phenotype via Toll-like receptor 4 (TLR4). Under M2-skewing conditions, TN-C suppressed the expression of interferon regulatory factor 4, a key transcription factor that controls M2-macrophage polarization, via TLR4, thereby inhibiting M2 polarization.

CONCLUSION

These results suggested that TN-C accelerates LV remodelling after MI, at least in part, by modulating M1/M2-macrophage polarization.

Postconditioning Accelerates Myocardial Inflammatory Resolution Demonstrated by 14C-Methionine Imaging and Attenuates Ventricular Remodeling After Ischemia and Reperfusion

BACKGROUND

Methionine uptake after myocardial infarction has been proven to reflect myocardial inflammation. The effect of postconditioning on the post-infarction inflammatory process, however, remains to be elucidated.Methods and Results:In control (n=22) and postconditioning rats (n=23), the left coronary artery was occluded for 30 min, followed by reperfusion for 1, 3, 7, and 14 days. Postconditioning was performed immediately following the reperfusion. ¹⁴C-methinine (0.74 MBq) and ²⁰¹Tl (14.8 MBq) were injected 20 and 10 min prior to sacrifice, respectively. One minute before sacrifice, 150-180 MBq of ^{99 m}Tc-MIBI was injected immediately following the re-occlusion of the left coronary artery to verify the area at risk, and left ventricular triple-tracer autoradiography was performed. To examine the ventricular remodeling, echocardiography was performed 2 months after reperfusion in both groups (n=6 each). In the control rats, the methionine uptake ratios on days 1, 3, 7, and 14 were 0.74±0.12, 1.85±0.16, 1.48±0.10, 1.25±0.04, respectively. With postconditioning, methionine uptake was similar on day 3 (1.90±0.21), but was lower on day 7 (1.23±0.22, P<0.05) and day 14 (1.08±0.09, P<0.005). Echocardiography revealed that postconditioning reduced the ventricular end-diastolic (0.97±0.16 to 0.78±0.12 cm, P<0.05) and systolic (0.85±0.21 to 0.55±0.23 cm, P<0.05) dimensions and improved ventricular percentage fractional shortening (12±6.2 to 29±12 %, P=0.01).

CONCLUSIONS

¹⁴C-methinine imaging revealed that postconditioning accelerated resolution of inflammation and attenuated ventricular remodeling.

Hereditary cardiac amyloidosis associated with Pro24Ser transthyretin mutation: a case report

Background

Transthyretin amyloidosis is a systemic disorder caused by extracellular deposition of insoluble amyloid fibrils in peripheral and autonomic nerves, heart, kidney, gastrointestinal tract, and other organs. Hereditary transthyretin amyloidosis is an autosomal dominant disease. More than 120 mutations have been reported in the transthyretin gene with considerable phenotypic heterogeneity and geographic diversity. Among them, a sporadic case of hereditary transthyretin amyloidosis with cardiac-predominant phenotype is very rare, progressive, and potentially fatal if left undiagnosed. However, a clinical diagnosis of cardiac amyloidosis still remains challenging due to non-specific symptoms, and less sensitivity and specificity of medical examinations.

Case presentation

A 60-year-old Japanese man with a history of embolic stroke and hypertrophic cardiomyopathy visited our department for heart failure. The present case exhibited only cardiomyopathy without any clinical signs of systemic amyloidosis manifested as carpal tunnel syndrome, polyneuropathy, or autonomic dysfunction. An echocardiogram revealed severe asymmetric left ventricular hypertrophy, biatrial dilatation, pericardial effusion, and preserved left ventricular ejection fraction of 50% with severe diastolic dysfunction. Technetium pyrophosphate scintigraphy indicated marked diffuse myocardial uptake of technetium pyrophosphate, strongly suggesting transthyretin cardiac amyloidosis, which was firmly confirmed by a left ventricular endomyocardial biopsy. Genetic analysis demonstrated a transthyretin C70T (Pro24Ser) heterozygous mutation. Tafamidis, a transthyretin stabilizer, was started. His cardiac symptoms remained unchanged for 12 months.

Conclusions

Here we report the case of a patient with hereditary cardiac amyloidosis associated with a Pro24Ser mutation in transthyretin, which is the first case reported in Japan. Technetium pyrophosphate scintigraphy was extremely useful for definitive diagnosis. Thus, we propose that the nuclear imaging technique should be taken into account even for an exploratory diagnosis of transthyretin cardiac amyloidosis.

Successful Inflammation Imaging of Non-Human Primate Hearts Using an Antibody Specific for Tenascin-C

Inflammation after myocardial infarction (MI) may be a major factor influencing ventricular remodeling, leading to congestive heart failure and arrhythmia. Therefore, inflammation in the heart needs to be monitored. Tenascin-C (TNC) is an extracellular matrix molecule not normally expressed, but it is strongly upregulated when associated with active inflammation. Based on this characteristic, we successfully imaged in vivo inflammatory lesions in rat models using ¹¹¹Indium (¹¹¹In)-labeled anti-TNC antibodies. The aim of the present study was to further assess the applicability of this molecular imaging probe to detect inflammatory activity in primate hearts.We generated an MI model of cynomolgus monkeys (Macaca fascicularis) by coronary artery ligation and performed dual-isotope single-photon emission computed tomography (SPECT) imaging with an ¹¹¹In-labeled anti-TNC antibody Fab' fragment (¹¹¹In-TNC Fab') and ^99mtechnetium methoxy-isobutyl isonitrile (^99mTc-MIBI). Dual autoradiography was used to compare the uptake of ¹¹¹In-TNC Fab' with histology and immunostaining for TNC. Dual-isotope SPECT showed the regional myocardial uptake of ¹¹¹In-TNC Fab' complementary to a defect in the perfusion image by ^99mTc-MIBI. The high radioactivity of ¹¹¹In-TNC Fab' by autoradiography corresponded to immunostaining for TNC, which was observed in inflammatory lesions at the border zone between the infarcted and non-infarcted areas of the left ventricle and at the epi/pericarditis lesions of the right ventricle. These results demonstrate the potential of ¹¹¹In-TNC-Fab' imaging to monitor myocardial injury and inflammation and suggest the feasibility of the non-invasive detection of cardiac inflammation following acute MI in a preclinical stage before testing in humans.

A multicenter trial of extracorporeal cardiac shock wave therapy for refractory angina pectoris: report of the highly advanced medical treatment in Japan

We have previously demonstrated that cardiac shock wave therapy (CSWT) effectively improves myocardial ischemia through coronary neovascularization both in a porcine model of chronic myocardial ischemia and in patients with refractory angina pectoris (AP). In this study, we further addressed the efficacy and safety of CSWT in a single-arm multicenter study approved as a highly advanced medical treatment by the Japanese Ministry of Health, Labour and Welfare. Fifty patients with refractory AP [mean age 70.9 ± 12.6 (SD) years, M/F 38/12] without the indications of percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) were enrolled in 4 institutes in Japan. Ischemic myocardial regions in the left ventricle (LV) were identified by drug-induced stress myocardial perfusion imaging (MPI). Shock waves (200 shots/spot at 0.09 mJ/mm²) were applied to 40-60 spots in the ischemic myocardium 3 times in the first week. The patients were followed up for 3 months thereafter. Forty-one patients underwent CSWT and completed the follow-up at 3 months. CSWT markedly improved weekly nitroglycerin use [from 3.5 (IQR 2 to 6) to 0 (IQR 0 to 1)] and the symptoms [Canadian Cardiovascular Society functional class score, from 2 (IQR 2 to 3) to 1 (IQR 1 to 2)] (both P < 0.001). CSWT also significantly improved 6-min walking distance (from 384 ± 91 to 435 ± 122 m, P < 0.05). There were no significant changes in LV ejection fraction evaluated by echocardiography and LV stroke volume evaluated by cardiac magnetic resonance imaging (from 56.3 ± 14.7 to 58.8 ± 12.8%, P = 0.10, and from 52.3 ± 17.4 to 55.6 ± 15.7 mL, P = 0.15, respectively). Percent myocardium ischemia assessed by drug-induced stress MPI tended to be improved only in the treated segments (from 16.0 ± 11.1 to 12.1 ± 16.2%, P = 0.06), although no change was noted in the whole LV. No procedural complications or adverse effects related to the CSWT were noted. These results of the multicenter trial further indicate that CSWT is a useful and safe non-invasive strategy for patients with refractory AP with no options of PCI or CABG.

A case of cardiac sarcoidosis mimicking cardiac amyloidosis on cardiovascular magnetic resonance

A 52‐year‐old male visited our hospital with abnormal electrocardiogram and exertional fatigue. The electrocardiogram showed first‐degree atrioventricular block, complete right bundle branch block, and inverted T waves in Leads II, III, aVF, V3, and V4. Echocardiography showed biventricular wall thickening involving granular sparkling of the interventricular septum. Late gadolinium enhancement on cardiovascular magnetic resonance (CMR) was found at the circumferential right ventricular wall and patchy regions of the left ventricle. Although these findings strongly suggested cardiac amyloidosis, he was finally diagnosed with systemic sarcoidosis due to the following. First, endomyocardial biopsy revealed non‐caseating epithelioid granuloma with giant cells. Second, ¹⁸F‐fluorodeoxyglucose positron emission tomography showed uptake in bilateral hilar lymph nodes, para‐aortic lymph nodes, and the biventricular wall of the heart. Although echocardiography and CMR are very useful tools for diagnosis of cardiomyopathies, their specificity and accuracy need to be considered.

Serum Tenascin-C as a Novel Predictor for Risk of Coronary Artery Lesion and Resistance to Intravenous Immunoglobulin in Kawasaki Disease - A Multicenter Retrospective Study

BACKGROUND

Tenascin-C (TN-C) is an extracellular matrix glycoprotein that is heavily upregulated at sites of inflammation. We conducted a retrospective study to assess the utility of TN-C as a novel biomarker to predict the risk of developing coronary artery lesions (CAL) and resistance to intravenous immunoglobulin (IVIG) in patients with Kawasaki disease (KD).Methods and Results:We collected blood samples of 111 KD patients (IVIG-responder: 89, IVIG-resistant: 22; CAL: 8) and 23 healthy controls, and measured the serum levels of TN-C. TN-C levels on admission were significantly higher in patients than in healthy controls and in patients during convalescence after IVIG administration (69.6 vs. 20.4 vs. 39.7 ng/ml, respectively; P<0.001), and correlated positively with C-reactive protein (P<0.001), neutrophil (percentage; P=0.005), and ALT (P<0.001), and negatively with platelet count (P=0.023) and sodium level (P=0.025). On admission, TN-C levels in patients who later developed CAL were significantly higher than in those without CAL (P=0.010), and significantly higher in IVIG-resistant subjects than in IVIG-responders (P=0.003). The accuracy of TN-C testing for the prediction of IVIG resistance was comparable to that of the Kobayashi score.

CONCLUSIONS

Serum TN-C could be a biomarker for predicting the risk of developing CAL and IVIG resistance during the acute phase of KD. (Circ J 2016; 80: 2376-2381).

Steroid pulse therapy was effective for cardiac sarcoidosis with ventricular tachycardia and systolic dysfunction

A 32‐year‐old man presented with palpitation. He was diagnosed with pulmonary sarcoidosis by lung biopsy. The electrocardiogram showed first‐degree atrioventricular block and complete right bundle branch block (CRBBB). We planned to examine laboratory data, echocardiography, Holter monitoring, and gallium‐67 scintigraphy. Before he went through all these exams, he developed ventricular tachycardia. After defibrillation was performed, his electrocardiogram revealed complete atrioventricular block. We observed elevation of serum angiotensin‐converting enzyme levels. In addition, both of gallium‐67 scintigraphy and ¹⁸F‐fluorodeoxyglucose positron emission tomography showed abnormal uptake in the ventricular septum. We diagnosed the patient with cardiac sarcoidosis associated with these arrhythmias. We started treatment with methylprednisolone pulse therapy (1 g daily). After 3 days of steroid pulse therapy, we administered prednisolone 30 mg daily. On day 15, electrocardiogram changed from complete atrioventricular block to first‐degree atrioventricular block and CRBBB. He was discharged with no progression with cardiac sarcoidosis for 2 years.

Cardiac sarcoidosis, the complete atrioventricular block of which was completely recovered by intravenous steroid pulse therapy

Atrioventricular block (AVB) in individuals with cardiac sarcoidosis (CS) is one of the major complications caused by inflammation of the conducting system of the heart, as a sign of worse prognosis. We report the case of a 53-year-old Japanese woman whose electrocardiogram showed complete AVB by the clinical diagnosis of CS. We administered intravenous methylpredonisolone (1 g/day) for 3 days. On the second day of steroid pulse therapy, the complete AVB improved to sinus rhythm of 1st degree AVB and complete right bundle branch block. Normal sinus rhythm was then observed after oral steroid therapy. These results suggest that in cases of complete AVB, steroid pulse therapy with a strong anti-inflammatory effect may be recommended first. <Learning objective: This case illustrates a typical case of CS with complete AVB, but the cardiac contraction was normal. In this setting, steroid pulse therapy may be effective when (1) the active inflammation of the conduction system can be suppressed by steroid pulse therapy; (2) the time to start steroid therapy is short enough to recover.>.

Tenascin-C may accelerate cardiac fibrosis by activating macrophages via the integrin αVβ3/nuclear factor-κB/interleukin-6 axis

Tenascin-C (TN-C) is an extracellular matrix protein not detected in normal adult heart, but expressed in several heart diseases closely associated with inflammation. Accumulating data suggest that TN-C may play a significant role in progression of ventricular remodeling. In this study, we aimed to elucidate the role of TN-C in hypertensive cardiac fibrosis and underlying molecular mechanisms. Angiotensin II was administered to wild-type and TN-C knockout mice for 4 weeks. In wild-type mice, the treatment induced increase of collagen fibers and accumulation of macrophages in perivascular areas associated with deposition of TN-C and upregulated the expression levels of interleukin-6 and monocyte chemoattractant protein-1 as compared with wild-type/control mice. These changes were significantly reduced in TN-C knockout/angiotensin II mice. In vitro, TN-C accelerated macrophage migration and induced accumulation of integrin αVβ3 in focal adhesions, with phosphorylation of focal adhesion kinase (FAK) and Src. TN-C treatment also induced nuclear translocation of phospho-NF-κB and upregulated interleukin-6 expression of macrophages in an NF-κB-dependent manner; this being suppressed by inhibitors for integrin αVβ3 and Src. Furthermore, interleukin-6 upregulated expression of collagen I by cardiac fibroblasts. TN-C may enhance inflammatory responses by accelerating macrophage migration and synthesis of proinflammatory/profibrotic cytokines via integrin αVβ3/FAK-Src/NF-κB, resulting in increased fibrosis.

Effect of postconditioning on dynamic expression of tenascin-C and left ventricular remodeling after myocardial ischemia and reperfusion

Background

Tenascin-C (TNC), an extracellular matrix glycoprotein, is expressed transiently in distinct areas in association with active tissue remodeling. This study aimed to explore how ischemic postconditioning (PC) affects myocardial expression of TNC and ventricular remodeling using ¹²⁵I-labeled anti-TNC antibody (¹²⁵I-TNC-Ab) in a rat model of ischemia and reperfusion.

Methods

In control rats (n = 27), the left coronary artery (LCA) was occluded for 30 min followed by reperfusion for 1, 3, 7, and 14 days. PC (n = 27) was performed just after the reperfusion. At the time of the study, ¹²⁵I-TNC-Ab (1.0 to 2.5 MBq) was injected. Six to 9 h later, to verify the area at risk, ^99mTc-MIBI (100 to 200 MBq) was injected intravenously just after the LCA reocclusion, with the rats sacrificed 1 min later. Dual tracer autoradiography was performed to assess ¹²⁵I-TNC-Ab uptake and area at risk. To examine the ventricular remodeling, echocardiography was performed 2 M after reperfusion in both groups.

Results

In control rats, ¹²⁵I-TNC-Ab uptake ratio at 1 day after reperfusion was 3.73 ± 0.71 and increased at 3 days (4.65 ± 0.87), followed by a significant reduction at 7 days (2.91 ± 0.55, P < 0.005 vs 3 days) and14 days (2.01 ± 0.17, P < 0.005 vs 1 and 3 days). PC attenuated the ¹²⁵I-TNC-Ab uptake throughout the reperfusion time from 1 to 14 days; 2.59 ± 0.59 at 1 day, P < 0.05: 3.10 ± 0.42 at 3 days, P < 0.005: 1.93 ± 0.37 at 7 days, P < 0.05: 1.40 ± 0.07 at 14 days, P < 0.001. In echocardiography, PC reduced the ventricular end-diastolic and systolic dimensions (1.00 ± 0.06 cm to 0.83 ± 0.14 cm (P < 0.05) and 0.90 ± 0.15 cm to 0.62 ± 0.19 cm (P < 0.05), respectively) and prevented a decline of ventricular percentage fractional shortening (10.5 ± 3.7 to 28.2 ± 10.7, P < 0.005).

Conclusions

These data indicate that ¹²⁵I-TNC-Ab imaging may be a way to monitor myocardial injury, the subsequent repair process, and its response to novel therapeutic interventions like PC by visualizing TNC expression.

Tenascin-C aggravates autoimmune myocarditis via dendritic cell activation and Th17 cell differentiation

Background

Tenascin‐C (TN‐C), an extracellular matrix glycoprotein, appears at several important steps of cardiac development in the embryo, but is sparse in the normal adult heart. TN‐C re‐expresses under pathological conditions including myocarditis, and is closely associated with tissue injury and inflammation in both experimental and clinical settings. However, the pathophysiological role of TN‐C in the development of myocarditis is not clear. We examined how TN‐C affects the initiation of experimental autoimmune myocarditis, immunologically.

Methods and Results

A model of experimental autoimmune myocarditis was established in BALB/c mice by immunization with murine α‐myosin heavy chains. We found that TN‐C knockout mice were protected from severe myocarditis compared to wild‐type mice. TN‐C induced synthesis of proinflammatory cytokines, including interleukin (IL)‐6, in dendritic cells via activation of a Toll‐like receptor 4, which led to T‐helper (Th)17 cell differentiation and exacerbated the myocardial inflammation. In the transfer experiment, dendritic cells loaded with cardiac myosin peptide acquired the functional capacity to induce myocarditis when stimulated with TN‐C; however, TN‐C‐stimulated dendritic cells generated from Toll‐like receptor 4 knockout mice did not induce myocarditis in recipients.

Conclusions

Our results demonstrated that TN‐C aggravates autoimmune myocarditis by driving the dendritic cell activation and Th17 differentiation via Toll‐like receptor 4. The blockade of Toll‐like receptor 4‐mediated signaling to inhibit the proinflammatory effects of TN‐C could be a promising therapeutic strategy against autoimmune myocarditis.

Long fasting is effective in inhibiting physiological myocardial 18F-FDG uptake and for evaluating active lesions of cardiac sarcoidosis

BACKGROUND

F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is a promising modality for detecting active lesions of cardiac sarcoidosis (CS). However, determining whether 18F-FDG uptake in the myocardium is physiological is challenging due to metabolic shift in myocardial cells. Although methods for inhibiting physiological myocardial 18F-FDG uptake have been proposed, no standard methods exist. This study therefore aimed to compare the effect of an 18-h fast (long fasting (LF)) with heparin loading plus a 12-h fast (HEP) before 18F-FDG PET scan.

METHODS

We analyzed the effects of LF and HEP on the inhibition of physiological myocardial 18F-FDG uptake in healthy subjects (18 in HEP and 19 in LF) and in patients with known or suspected CS (96 in HEP and 69 in LF). In CS, the lower uptake of 18F-FDG in the myocardium was evaluated. A visual four-point scale was used to assess myocardial 18F-FDG uptake in comparison with hepatic uptake (1 lower, 2 similar, 3 somewhat higher, 4 noticeably higher).

RESULTS

Myocardial 18F-FDG uptake was 1.68 ± 1.06 in LF and 3.17 ± 1.16 in HEP in healthy subjects (p < 0.0001), whereas it was 1.48 ± 0.99 in LF and 2.48 ± 1.33 in HEP in CS patients (p < 0.0001). Logistic regression and regression trees revealed the LF was the most effective in inhibiting myocardial 18F-FDG uptake. In addition, serum free fatty acid levels on intravenous 18F-FDG injection were a possible biomarker.

CONCLUSIONS

LF is effective in inhibiting myocardial 18F-FDG uptake, and consequently, it could be useful for evaluating active lesions of CS in 18F-FDG PET images.

Visual findings of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with cardiac sarcoidosis

OBJECTIVE

The purpose of this study was to evaluate the cardiac sarcoidosis (CS) activity according to the classified visual uptake pattern using (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) and assess the uptake pattern based on the free fatty acid (FFA) levels.

METHODS

Nineteen CS subjects who underwent (18)F-FDG PET/CT examinations with heparin loading (HL) were recruited to evaluate their CS activity. The (18)F-FDG uptake in the heart was classified into five categories ("none," "diffuse" and "diffuse at base," regarded as stable CS, and "focal" and "focal on diffuse," regarded as de novo or worsening CS). The subject data were compared with the (18)F-FDG PET/CT findings in 13 healthy volunteers. The FFA serum levels were assessed in 10 patients with CS and all volunteers.

RESULTS

The sensitivity and specificity of (18)F-FDG PET/CT with HL were 75% (6/8) and 73% (8/11), respectively. The major pattern of cardiac (18)F-FDG uptake was "diffuse at base." Ten of the 32 subjects, including the control group, exhibited this pattern. The FFA serum levels before heparin administration were statistically significantly different between the patients with the "none" pattern and those with the "diffuse" and "diffuse at base" patterns. There were no significant correlations between the FFA serum levels after heparin administration and the (18)F-FDG uptake patterns.

CONCLUSION

"Diffuse at base" is the major (18)F-FDG uptake pattern associated with inadequate physiologic (18)F-FDG suppression. This pattern should be carefully interpreted when examining the (18)F-FDG PET/CT images of CS patients. Additionally, increased FFAs levels associated with HL may not completely suppress the physiologic myocardial FDG uptake.

Metabolic syndrome among pre- and post-menopausal rural women in Bangladesh: result from a population-based study

BACKGROUND

Prevalence of non-communicable diseases are a challenging problems among menopausal women specially in a least developed country like Bangladesh, where majority of women suffering from at least one chronic diseases after menopausal age. So, the main objective of this study was to determine the prevalence of metabolic syndrome and related risk factors in Bangladeshi pre- and post-menopausal women living in the rural setting.

METHODS

This study is based on a community based cross-sectional survey among 1802 rural women aged ≥15 years. Metabolic syndrome was defined according to the criteria of NCEP-ATP III. Logistic regression was used to estimate the association between menopausal status and metabolic syndrome and its components.

RESULTS

Metabolic syndrome was presented in 25.6% respondents and it was more prevalent among post-menopausal (39.3%) as compared to pre-menopausal (16.8%) women. Logistic regression analysis reveals that prevalence of metabolic syndrome was 1.78 times higher in post-menopausal women than pre-menopausal women (P = 0.001). Prevalence of high blood pressure, elevated fasting blood glucose, and high triglyceride were significantly higher in post-menopausal women than pre-menopausal women (P < 0.05). However, prevalence of low high-density lipoprotein cholesterol was significantly lower in post-menopausal women than pre-menopausal women (P < 0.001).

CONCLUSIONS

Metabolic syndrome seems to be a major health problem among post-menopausal women in many developing countries like Bangladesh and proper policy emphasis should be given on its prevention and control.

Disruption of components of vascular endothelial growth factor angiogenic signalling system in metabolic syndrome. Findings from a study conducted in rural Bangladeshi women

Metabolic syndrome (MetS) is associated with impaired angiogenesis, a process that is chiefly regulated by vascular endothelial growth factor (VEGF) upon binding to its specific receptors, VEGF-R1 and VEGF-R2. The purpose of the present study was to assess trends or patterns in plasma levels of VEGF and its soluble receptors in subjects with (MetS) or without (non-MetS) MetS; and further examine their association with clinical or metabolic parameters using a subpopulation of South Asian country. A total of 1,802 rural Bangladeshi women aged ≥15 years were studied using a population-based cross-sectional survey. Plasma levels of VEGF were found to be significantly increased (MetS vs. non-MetS: 483.9 vs. 386.9, p<0.001), whereas, the soluble forms of VEGF receptors, sVEGF-R1 and sVEGF-R2, were significantly decreased in subjects with Mets (sVEGF-R1, MetS vs. non-MetS: 512.5 vs. 631.3, p<0.001; sVEGF-R2, MetS vs. non-MetS: 9,302.8 vs. 9,787.4, p=0.004). After adjustment for age and all potential variables, multiple regression analysis revealed that plasma levels of VEGF had significant positive association with blood glucose (p = 0.019) and body mass index (p = 0.007). We also found that mean plasma levels of VEGF increased in direct proportion to levels of MetS components. The present study is the first ever to demonstrate a positive association between trends in levels of plasma VEGF and MetS using a large sample size from South Asia. The association between plasma VEGF and MetS needs further investigations in order to clearly decipher the clinical predictive value and accuracy of plasma VEGF in MetS.

14C-Methionine uptake as a potential marker of inflammatory processes after myocardial ischemia and reperfusion

A relationship between l-[methyl-(11)C]methionine ((11)C-methionine) uptake and angiogenesis has been suggested in gliomas. However, methionine uptake in myocardial ischemia and reperfusion has received little attention. We investigated the serial changes and mechanisms of (14)C-methionine uptake in a rat model of myocardial ischemia and reperfusion.

METHODS

The left coronary artery was occluded for 30 min, followed by reperfusion for 1-28 d. At the time of the study, (14)C-methionine (0.74 MBq) and (201)Tl (14.8 MBq) were injected intravenously at 20 and 10 min before sacrifice, respectively. One minute before sacrifice, the left coronary artery was reoccluded, and (99m)Tc-hexakis-2-methoxyisobutylisonitrile (150-180 MBq) was injected to verify the area at risk. Histologic sections of the heart were immunohistochemically analyzed using anti-CD68, anti-smooth-muscle α-actin (SMA), and antitroponin I and compared with the autoradiography findings.

RESULTS

Both (14)C-methionine (uptake ratio, 0.71 ± 0.13) and (201)Tl uptake were reduced in the area at risk at 1 d after reperfusion. However, 3 d after reperfusion, an increased (14)C-methionine uptake (1.79 ± 0.23) was observed corresponding to the area of still-reduced (201)Tl uptake, and the (14)C-methionine uptake gradually declined until 28 d. The increased (14)C-methionine uptake area at 3 and 7 d corresponded well to the macrophage infiltrations demonstrated by positive CD68 staining. Anti-SMA staining appeared at 7 d, after which CD68 staining was gradually replaced by the SMA staining, suggesting that methionine uptake in the early phase after ischemia and reperfusion might reflect inflammatory activity.

CONCLUSION

(14)C-methionine accumulated in the infarcted area, and its uptake corresponded closely to macrophage infiltration at 3-7 d after reperfusion. Methionine imaging may be useful for inflammatory imaging early after myocardial infarction.

Atrial natriuretic peptide exerts protective action against angiotensin II-induced cardiac remodeling by attenuating inflammation via endothelin-1/endothelin receptor A cascade

We aimed to investigate whether atrial natriuretic peptide (ANP) attenuates angiotensin II (Ang II)-induced myocardial remodeling and to clarify the possible molecular mechanisms involved. Thirty-five 8-week-old male Wistar-Kyoto rats were divided into control, Ang II, Ang II + ANP, and ANP groups. The Ang II and Ang II + ANP rats received 1 μg/kg/min Ang II for 14 days. The Ang II + ANP and ANP rats also received 0.1 μg/kg/min ANP intravenously. The Ang II and Ang II + ANP rats showed comparable blood pressure. Left ventricular fractional shortening and ejection fraction were lower in the Ang II rats than in controls; these indices were higher (P < 0.001) in the Ang II + ANP rats than in the Ang II rats. In the Ang II rats, the peak velocity of mitral early inflow and its ratio to atrial contraction-related peak flow velocity were lower, and the deceleration time of mitral early inflow was significantly prolonged; these changes were decreased by ANP. Percent fibrosis was higher (P < 0.001) and average myocyte diameters greater (P < 0.01) in the Ang II rats than in controls. ANP decreased both myocardial fibrosis (P < 0.01) and myocyte hypertrophy (P < 0.01). Macrophage infiltration, expression of mRNA levels of collagen types I and III, monocyte chemotactic protein-1, and a profibrotic/proinflammatory molecule, tenascin-C (TN-C) were increased in the Ang II rats; ANP significantly decreased these changes. In vitro, Ang II increased expression of TN-C and endothelin-1 (ET-1) in cardiac fibroblasts, which were reduced by ANP. ET-1 upregulated TN-C expression via endothelin type A receptor. These results suggest that ANP may protect the heart from Ang II-induced remodeling by attenuating inflammation, at least partly through endothelin 1/endothelin receptor A cascade.

Effects of anemia correction by erythropoiesis-stimulating agents on cardiovascular function in non-dialysis patients with chronic kidney disease

Anemia is a significant risk factor for patients with chronic kidney disease (CKD). Here, we investigated the effects of anemia correction on cardiac functions in CKD patients. Pre-dialysis CKD patients (n = 171) without known risk factors for cardiovascular disease (CVD) other than CKD with hemoglobin (Hb) concentrations < 10.0 g/dL were enrolled for evaluation of cardiac functions and biomarkers before and after the 16-week treatment of erythropoiesis-stimulating agents. The treatment significantly increased Hb concentrations in all patients who completed the study (n = 143, 8.91 ± 0.87 versus 11.27 ± 1.31 g/dL; n < 0.001) and among patients whose echocardiograms were available for evaluation (n = 77, 8.92 ± 0.94 versus 11.24 ± 1.13 g/dL; P < 0.001). The left ventricular mass index (LVMI) was decreased (121.3 ± 25.8 versus 114.7 ± 25.1 g/m(2), n = 77, P = 0.012) and significant correlation between the change in the LVMI and Hb concentration was noted (P = 0.011). The levels of B-type natriuretic peptide and human atrial natriuretic peptide, and the cardio-thoracic ratio were significantly increased among subjects with Hb concentrations < 11.0 g/dL at completion of the study. The changes in these parameters were significantly correlated with the Hb concentrations (P = 0.033, P = 0.011, and P < 0.001, respectively). No significant differences were observed in the electrocardiographic parameters. Correcting Hb levels higher than those conventionally recommended reduced left ventricular hypertrophy and myocardial stress, lowering risks for CVD in pre-dialysis CKD patients.

Time-dependent alterations of VEGF and its signaling molecules in acute lung injury in a rat model of sepsis

Molecular mechanisms of sepsis-associated acute lung injury (ALI) are poorly defined. Since vascular endothelial growth factor (VEGF) is a potent vascular permeability and mitogenic factor, it might contribute to the development of ALI in sepsis. Thus, using lipopolysaccharide (LPS)-induced (15 mg/kg, intraperitoneal) endotoxemic rat model, we studied the timeline (1, 3, 6, and 10 h) of pulmonary VEGF expression and its signaling machinery. Levels of pulmonary VEGF and its angiogenic-mediating receptor, Flk-1, were downregulated by LPS in a time-dependent manner; levels of plasma VEGF and its permeability-mediating receptor, Flt-1, in contrast, was upregulated with time. In addition, blockade of Flt-1 could improve the downregulated pulmonary VEGF level and attenuate the elevated plasma and pulmonary levels of TNF-α, followed by improvement of arterial oxygenation and wet-to-dry weight ratio of the lung. Expression of signaling, pro- and or apoptotic factors after LPS administration were as follows: phosphorylated Akt, a downstream molecule was downregulated time dependently; endothelial nitric oxide synthase levels were significantly reduced; pro-apoptotic markers caspase 3 and Bax were upregulated whereas levels of Bcl-2 were downregulated. The present findings show that VEGF may play a role through the expression of Flt-1 in LPS-induced ALI. Moreover, downregulation of VEGF signaling cascade may account for LPS-induced apoptosis and impaired physiological angiogenesis in lung tissues, which in turn may contribute to the development of ALI induced by LPS.

Abstract 170: Inflammation Imaging in the Primate Heart Using 111 In-Labeled Anti-Tenascin-C Antibody

Myocardial inflammation after myocardial infarction and myocarditis may cause cardiac remodeling, leading to congestive heart failure and arrhythmias. Tenascin-C (TNC), an extracellular matrix glycoprotein, is not normally expressed but specifically expressed associated with active inflammation. The aim of this study was to explore the myocardial expression of TNC after myocardial infarction in Macaca fascicularis (crab-eating monkey) using 111 In-labeled anti-TNC antibody ( 111 In-TNC-Fab’). The left coronary artery was permanently ligated in two monkies and 4 days later, we performed dual-isotope single-photon emission computed tomography imaging (SPECT) of 111 In-TNC-Fab’ and 99m Tc methoxy- isobutyl isonitrile (MIBI), and compared with those of an age-matched control. Then, dual autoradiography was compared with histology and immunostaining for TNC of the heart. Dual-isotope SPECT demonstrated the regional myocardial uptake of 111 In-TNC-Fab’ in the areas of decreased uptake of MIBI. On autoradiography, the radioactivities were observed in the border zone between the infarcted and the noninfarcted area of MI hearts. The hot spots corresponded with the positively immunostained areas. In contrast, no radioactivites of 111 In-TNC-Fab’ were detected in the control. These data clearly indicated that, using 111 In-TNC-Fab’, we can visualize the inflammatory lesions followed by myocardial infarction of the primate.

Abstract 129: Suppressor of Cytokine Signaling 1 in Dendritic Cells Inhibits Myocardial Inflammation in Experimental Autoimmune Myocarditis

Introduction: Autoimmunity is considered to play an important role in the development of myocarditis and dilated cardiomyopathy. Recent reports have indicated that a subgroup of myocarditis patients may benefit from immune-targeted therapies. Suppressor of cytokine signaling1 (SOCS1) is an intracellular, cytokine-inducible protein that regulates the responses of immune cells to cytokines. We therefore hypothesized that overexpression of SOCS1 may inhibit the inflammation of myocarditis and cardiomyopathy.

Methods and Results: Myocarditis was induced by subcutaneous immunization with cardiac specific peptides derived from α-myosin heavy chain in BALB/c mice on days 0 and 7. Plasmid DNA encoding SOCS1 (pSOCS1) was injected intraperitoneally into mice on days 0, 5 and 10. pSOCS1 treatment significantly decreased heart-to-body weight ratios and the number of infiltrating cells in the heart. Echocardiography showed preserved contractile function in pSOCS1-treated mice. Although autoimmune myocarditis is a CD4+ T cell-mediated disease, pSOCS1 treatment does not have a direct suppressive effect on autoreactive T-cell activation. The introduced pSOCS1 suppressed proinflammatory cytokine production and STAT1 phosphorylation in dendritic cells (DCs). In addition, the proliferative responses of autoreactive CD4+ T cells co-cultured with DCs from pSOCS1-treated mice were much weaker than those of cells cultured with DCs from control plasmid-injected mice. These results suggested that the inoculated pSOCS1 may have been transfected into DCs and impaired DC function in vivo.

Conclusion: The administration of pSOCS1 protected mice from the development of experimental autoimmune myocarditis, which was mediated by the inhibition of DC function that in turn reduced the activation of autoreactive CD4+ T cells.

Suppressor of cytokine signaling 1 DNA administration inhibits inflammatory and pathogenic responses in autoimmune myocarditis

Myocarditis and subsequent dilated cardiomyopathy are major causes of heart failure in young adults. Myocarditis in humans is highly heterogeneous in etiology. Recent studies have indicated that a subgroup of myocarditis patients may benefit from immune-targeted therapies, because autoimmunity plays an important role in myocarditis as well as contributing to the progression to cardiomyopathy and heart failure. Suppressor of cytokine signaling (SOCS) 1 plays a key role in the negative regulation of both TLR- and cytokine receptor-mediated signaling, which is involved in innate immunity and subsequent adaptive immunity. In this study, we investigated the therapeutic effect of SOCS1 DNA administration on experimental autoimmune myocarditis (EAM) in mice. EAM was induced by s.c. immunization with cardiac-specific peptides derived from α myosin H chain in BALB/c mice. In contrast to control myocarditis mice, SOCS1 DNA-injected mice were protected from development of EAM and heart failure. SOCS1 DNA administration was effective for reducing the activation of autoreactive CD4(+) T cells by inhibition of the function of Ag-presenting dendritic cells. Our findings suggest that SOCS1 DNA administration has considerable therapeutic potential in individuals with autoimmune myocarditis and dilated cardiomyopathy.

Role of coronary CT angiography in asymptomatic patients with type 2 diabetes mellitus

Diabetic patients with coronary artery disease are often asymptomatic, making appropriate care of such patients difficult. The purpose of this study was to investigate the prevalence of coronary lesions in asymptomatic diabetic patients. Coronary computed tomography (CT) angiography was performed in 120 consecutive diabetic patients (90 of whom were men, mean age 65, mean HbA1c 7.2%). Images from patients whose coronary artery calcium scores (CAC scores) were less than 400 were subjected to stenosis and plaque analysis. Significant stenosis was defined as coronary artery stenosis > 70%. High-risk plaque was defined as plaque having both a CT density < 30 Hounsfield Units (HU) and showing positive remodeling. Significant stenoses were identified in 30.5% of the patients. High-risk plaques were identified in 17.1% of the patients. Less than half of the high-risk plaques were obstructive plaques. There was a statistically significant association between significant stenosis and high-risk plaque by chi-square test (P = 0.022). We found significant stenosis even in patients whose CAC score = 0 at a rate of 5.0%. Using univariate logistic-regression analysis, we found that coronary risk factors associated with significant stenosis and high-risk plaque were dyslipidemia (P = 0.033) and current smoking (P = 0.030), respectively. We report for the first time, the prevalence of high-risk plaques in the arteries of patients with asymptomatic diabetes, as assessed by coronary CT angiography.

Prognostic value of myocardial contrast delayed enhancement with 64-slice multidetector computed tomography after acute myocardial infarction

OBJECTIVES

This study evaluated the clinical value of myocardial contrast delayed enhancement (DE) with multidetector computed tomography (MDCT) for predicting clinical outcome after acute myocardial infarction (AMI).

BACKGROUND

Although some studies have described the use of MDCT for assessment of myocardial viability after AMI, clinical experience remains limited.

METHODS

In 102 patients with first AMI, 64-slice MDCT without iodine reinjection was performed immediately following successful percutaneous coronary intervention (PCI). We measured the size of myocardial contrast DE on MDCT and compared it with clinical outcome. Primary composite cardiac events were cardiac death or hospitalization for worsening heart failure.

RESULTS

Among the 102 patients (24 ± 10 months follow-up), 19 patients experienced primary composite cardiac events (cardiac death, n = 7; heart failure, n = 12). Kaplan-Meier analysis showed higher risk of cardiac events for patients in the third tertile of myocardial contrast DE size (≥ 36 g) than for those in the other 2 tertiles (p < 0.0001). Multivariable Cox proportional hazards regression analysis indicated that myocardial contrast DE size (adjusted hazard ratio [HR] for tertile 3 vs. 1: 16.1, 95% confidence interval [CI]: 1.45 to 72.4, p = 0.022; HR for tertile 3 vs. 2: 5.06, 95% CI: 1.25 to 22.7, p = 0.039) was a significant independent predictor for cardiac events after adjustment for Thrombolysis In Myocardial Infarction risk score, left ventricular ejection fraction, total defect score on single-photon emission CT with technetium tetrofosmin, and transmural extent of myocardial contrast DE on MDCT.

CONCLUSIONS

Myocardial contrast DE size on MDCT immediately after primary PCI may provide promising information for predicting clinical outcome in patients with AMI.

Prognostic value of serum tenascin-C levels on long-term outcome after acute myocardial infarction

BACKGROUND

Tenascin-C (TN-C), an extracellular matrix glycoprotein, is not normally expressed in the adult heart but transiently reappears under various pathologic conditions to play important roles in tissue remodeling. It is unclear whether serum TN-C levels add prognostic information independent from traditional prognostic markers.

METHODS AND RESULTS

We assessed 239 patients with first ST-segment elevation myocardial infarction who underwent successful percutaneous coronary intervention. We measured serum TN-C and plasma B-type natriuretic peptide (BNP) levels on day 5 after admission and compared long-term clinical outcome. During the follow-up period (24.3 ± 13 months), 54 patients experienced primary composite cardiac events (cardiac death or hospitalization for worsening heart failure). Multivariable Cox proportional hazards analysis indicated that serum TN-C (hazard ratio 2.92, 95% confidence interval [CI] 1.55-5.67; P < .001) and plasma BNP levels (hazard ratio 1.84, 95% CI 1.17-2.97; P = .008) were significant independent predictors for cardiac events after adjustment for multiple confounders. The combination of TN-C and BNP resulted in an increase of the c-statistic from 0.821 to 0.877 (P < .001) and an integrated discrimination improvement gain of 14.0% (P < .001).

CONCLUSIONS

Serum TN-C level on day 5 after admission is potentially useful for early risk stratification after AMI beyond established prognostic markers.

Comprehensive assessment of metabolic syndrome among rural Bangladeshi women

BACKGROUND

Metabolic syndrome (MS), defined as a constellation of cardiovascular disease (CVD) risk factors, is one of the fastest growing public health burdens in the Asia-Pacific region. This trend is despite the fact that people in this region are no more overweight than Europeans and Americans. Unfortunately, in South Asia, MS screening has only been performed in a few countries other than Bangladesh. Therefore the present study is designed to conduct a comprehensive screening of MS in Bangladeshi rural women, which includes estimation of prevalence and assessment of risk factor.

METHODS

A total of 1535 rural Bangladesh women aged ≥ 15 years were studied using a population based cross-sectional survey. The prevalence of MS was estimated using NCEP ATP III, modified NCEP ATP III and IDF criteria.

RESULTS

The prevalence rates of MS were 25.60% (NCEP ATP III), 36.68% (modified NCEP ATP III), and 19.80% (IDF), as revealed by the present study. Furthermore, based on the NCEP ATP III criteria, 11.60% of the subjects were found to have excess waist circumference; 29.12% had elevated blood pressure, 30.42% had elevated fasting plasma glucose level, 85.47% had low HDL values and 26.91% had increased triglyceride values. Low plasma HDL level was found to be the most common abnormality in the target population and elevated waist circumference was the least frequent component.

CONCLUSIONS

The present study reveals a high prevalence of MS and its associated risk factors in rural Bangladeshi women. These findings are important in that they provide insights that will be helpful in formulating effective public health policy, notably the development of future health prevention strategies in Bangladesh.

Prevalence of metabolic syndrome among rural Bangladeshi women

We assessed prevalence of metabolic syndrome (MS) in rural women of Bangladesh using 1485 women aged ≥15 years. The prevalence rate of MS was 31.25% (NCEP ATP III modified). And 85.05% population had low HDL values. These findings are important in the development of future health prevention strategies in Bangladesh.

Toward in vivo imaging of heart disease using a radiolabeled single-chain Fv fragment targeting tenascin-C

Antibodies specific to a particular target molecule can be used as analytical reagents, not only for in vitro immunoassays but also for noninvasive in vivo imaging, e.g., immunoscintigraphies. In the latter case, it is important to reduce the size of antibody molecules in order to achieve suitable in vivo "diagnostic kinetics" and generate higher-resolution images. For these purposes, single-chain Fv fragments (scFvs; M(r) < 30 kDa) have greater potential than intact immunoglobulins (~150 kDa) or Fab (or Fab') fragments (~50 kDa). Our recent observation of enhanced tenascin-C (Tnc) expression at sites of cardiac repair after myocardial infarction prompted us to develop a radiolabeled scFv against Tnc for in vivo imaging of heart disease. We cloned the genes encoding the heavy and light chain variable domains of the mouse anti-Tnc monoclonal antibody 4F10, and combined them to create a single gene. The resulting scFv-4F10 gene was expressed in E. coli cells to produce soluble scFv proteins. scFv-4F10 has an affinity for Tnc (K(a) = 3.5 × 10(7) M(-1)), similar to the Fab fragment of antibody 4F10 (K(a) = 1.3 × 10(7) M(-1)) and high enough to be of practical use. A cysteine residue was then added to the C-terminus to achieve site-specific (111)In labeling via a chelating group. The resulting (111)In-labeled scFv was administered to a rat model of acute myocardial infarction. Biodistribution and quantitative autoradiographic studies indicated higher uptake of the radioactivity at the infarcted myocardium than the noninfarcted one. Single photon emission computed tomography (SPECT) provided in vivo cardiac images that coincided with the ex vivo observations. Our results will promote advances in diagnostic strategies for heart disease.

Tenascin-C is expressed in abdominal aortic aneurysm tissue with an active degradation process

Abdominal aortic aneurysm (AAA) is a common disease caused by segmental weakening of the aortic walls and progressive aortic dilation leading to the eventual rupture of the aorta. Currently no biomarkers have been established to indicate the disease status of AAA. Tenascin-C (TN-C) is a matricellular protein that is synthesized under pathological conditions. In the current study, we related TN-C expression to the clinical course and the histopathology of AAA to investigate whether the pattern of TN-C expression could indicate the status of AAA. We found that TN-C and matrix metalloproteinase (MMP)-9 were highly expressed in human AAA. In individual human AAA TN-C deposition associated with the tissue destruction, overlapped mainly with the smooth muscle actin-positive cells, and showed a pattern distinct from macrophages and MMP-9. In the mouse model of AAA high TN-C expression was associated with rapid expansion of the AAA diameter. Histological analysis revealed that TN-C was produced mainly by vascular smooth muscle cells and was deposited in the medial layer of the aorta during tissue inflammation and excessive destructive activities. Our findings suggest that TN-C may be a useful biomarker for indicating the pathological status of smooth muscle cells and interstitial cells in AAA.

Positive outcomes of high hemoglobin target in patients with chronic kidney disease not on dialysis: a randomized controlled study

Correcting anemia in patients with chronic kidney disease (CKD) to higher hemoglobin (Hb) levels may be associated with increased risk. No optimal target for Hb has been established. This controlled study examined 321 patients with CKD who were not on dialysis, had a Hb level of <10g/dL, and a serum creatinine of 2.0 to 6.0mg/dL. They were randomized into two target Hb groups: 161 to high Hb (11.0-13.0g/dL) to receive darbepoetin alfa and low Hb to 160 (9.0-11.0g/dL) to receive recombinant erythropoietin. The study lasted 48weeks. Of 154 and 153 patients with adverse events, cardiovascular adverse events developed in 42 and 51 patients in the high and low Hb groups, respectively, with no significant difference in the incidence. All quality of life scores improved in the high Hb group and vitality improved significantly more with high Hb (P=0.025). The left ventricular mass index (LVMI) remained stable in the low Hb group, but there was a significant decrease in LVMI in the high group (P<0.001). There were no safety concerns with targeting a higher Hb level during the 48weeks of this study. Patients with a higher Hb target had comparatively better outcomes with respect to quality of life and LVMI.