Holter monitoring for the screening of cardiac disease in diabetes mellitus: The non-invasive Holter monitoring observation of new cardiac events in diabetics study.

We investigated the usefulness of Holter monitoring to detect cardiac disease and predict future cardiovascular risk in asymptomatic diabetic patients. This is a multi-centre, prospective study in 406 asymptomatic diabetic patients. They were categorized into three groups based on findings of Holter monitoring. A total of 377 met inclusion criteria and were classified as low (n = 172), moderate (n = 136) and high risk (n = 69). In total, 86 in moderate and 53 in high risk receive further evaluation. In total, 29 in moderate and 25 in high risk were diagnosed as cardiac disease and 12 required additional treatment, including coronary intervention. Over 1.8 years of mean follow-up, 11 (16.5 per 1000 person-years) experienced cardiovascular events. The cumulative incidence in moderate and high risk was higher than that in low risk (p = 0.029 and p = 0.014, respectively). Our study suggests that Holter monitoring may be a useful screening tool to detect cardiac disease and predict future cardiovascular risk in asymptomatic diabetic patients.

Decrease in mortality rate of chronic obstructive pulmonary disease (COPD) with statin use: a population-based analysis in Japan.

It has been well established that statins, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, reduce mortality from cardiovascular diseases. Statins, a class of cholesterol-lowering drug, may also affect mortality from various diseases by their pleiotropic effects of anti-inflammatory and anti-oxidative activities. However, there are only few reports concerning the effects of statins on diseases other than cardiovascular diseases. We therefore designed a population-based analysis, using the data from marketing surveys on statin sales and government reports on mortalities. We compared the statin use as expressed by statin sales per capita in the aged (> or = 65-year-old) population with mortality from major causes of death among 47 prefectures in Japan. As expected, there were significant negative correlations between statin sales per capita and mortality from cardiovascular diseases (p < 0.05). In addition, we found that there was a correlation between statin sales and the decrease in mortality from chronic obstructive pulmonary disease (COPD) (p < 0.0001), senility (p < 0.01), pneumonia (p < 0.05), accidents (p < 0.05), or all death causes (p < 0.05). However, statin sales were not associated with mortalities from renal failure, liver diseases, suicide, and malignant diseases. These results suggest a broad spectrum of beneficial effects of statins, including reduction of mortality rate of COPD as well as cardiovascular diseases. It will be worthy to confirm the protective effect of statins on COPD by prospective randomized clinical trials.

A novel N14Y mutation in Connexin26 in keratitis-ichthyosis-deafness syndrome: analyses of altered gap junctional communication and molecular structure of N terminus of mutated Connexin26.

Connexins (Cxs) are transmembranous proteins that connect adjacent cells via channels known as gap junctions. The N-terminal 21 amino acids of Cx26 are located at the cytoplasmic side of the channel pore and are thought to be essential for the regulation of channel selectivity. We have found a novel mutation, N14Y, in the N-terminal domain of Cx26 in a case of keratitis-ichthyosis-deafness syndrome. Reduced gap junctional intercellular communication was observed in the patient's keratinocytes by the dye transfer assay using scrape-loading methods. The effect of this mutation on molecular structure was investigated using synthetic N-terminal peptides from both wild-type and mutated Cx26. Two-dimensional (1)H nuclear magnetic resonance and circular dichroism measurements demonstrated that the secondary structures of these two model peptides are similar to each other. However, several novel nuclear Overhauser effect signals appeared in the N14Y mutant, and the secondary structure of the mutant peptide was more susceptible to induction of 2,2,2-trifluoroethanol than wild type. Thus, it is likely that the N14Y mutation induces a change in local structural flexibility of the N-terminal domain, which is important for exerting the activity of the channel function, resulting in impaired gap junctional intercellular communication.

C-reactive protein co-expresses with tumor necrosis factor-alpha in the myocardium in human dilated cardiomyopathy.

BACKGROUND: C-reactive protein (CRP) has recently been reported to be present in cardiac tissue and to stimulate the production of proinflammatory cytokines. Cardiac expression of tumor necrosis factor-alpha (TNF-alpha) plays an important role in the pathogenesis of dilated cardiomyopathy (DCM). AIMS: To determine whether CRP co-expresses with TNF-alpha in the myocardium and to examine its association with clinical features in patients with DCM. METHODS AND RESULTS: Endomyocardial biopsy tissues were obtained from 41 DCM patients and 16 controls by right ventricular endomyocardial biopsy. Levels of CRP and TNF-alpha mRNA were measured by real-time RT-PCR. Immunohistochemistry and in situ hybridization were performed to identify the cellular sources of CRP and TNF-alpha. Both CRP and TNF-alpha mRNA were expressed in myocardium obtained from DCM patients, but not in controls. A positive correlation was found between CRP and TNF-alpha levels. CRP/TNF-alpha double staining was found to be colocalized in the cardiomyocytes of DCM patients. Both forms of mRNA were also expressed in cardiomyocytes. Both CRP and TNF-alpha mRNA levels were negatively correlated with systolic function and positively correlated with left ventricular volume in DCM patients. These mRNA levels were lower in DCM patients treated with a combination of spironolactone and either angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II type 1 receptor blockers (ARBs) than in patients not treated with these drugs. CONCLUSION: Cardiac expression of CRP with TNF-alpha may function as a proinflammatory mediator in DCM and may be related to the clinical severity of DCM. Expression of both of these proteins was decreased in DCM patients receiving spironolactone and either ACEIs or ARBs.

Myocardial osteopontin expression is associated with collagen fibrillogenesis in human dilated cardiomyopathy.

BACKGROUND: Osteopontin (OPN), an extracellular matrix (ECM) protein, plays an important role in myocardial remodeling by promoting collagen synthesis and accumulation in experimental animal models. AIMS: We hypothesized that OPN could be expressed in myocardial tissues and contribute to collagen accumulation and myocardial dysfunction in human dilated cardiomyopathy (DCM). METHODS AND RESULTS: Endomyocardial biopsy tissues were obtained from 51 patients with DCM and 15 controls by right ventricular endomyocardial biopsy. OPN, collagen types I (Col I) and III (Col III) mRNA levels were measured by real-time reverse transcriptase polymerase chain reaction (RT-PCR). The cellular source of OPN was analyzed using immunohistochemistry and in situ hybridization. Myocardial collagen volume fraction (CVF) was determined by digital planimetry. OPN, Col I and Col III mRNA levels were higher in DCM patients than in controls (P<0.01). OPN mRNA levels were positively correlated with Col I levels and CVF in DCM patients (OPN vs. Col I: r=0.60, P<0.01; OPN vs. CVF: r=0.52, P<0.001). Immunostaining of OPN was present in cardiomyocytes from DCM patients. In situ hybridization identified cardiomyocytes as the major source of OPN mRNA transcription in DCM patients. OPN and Col I mRNA levels were highly expressed in the DCM subgroup with large left ventricular (LV) end-systolic diameter (LVESD > or = 54.5 mm) or low LV ejection fraction (LVEF < 29.5%). There was a weak positive correlation between OPN mRNA levels and LV end-systolic diameter (r=0.39, P<0.01). Levels of OPN mRNA were also negatively correlated with LV ejection fraction (r=-0.43, P<0.01). CONCLUSIONS: These results suggest that OPN may play a pivotal role in the development of Col-I-induced cardiac fibrosis and dysfunction in human DCM.

Toll-like receptor 4 is expressed with enteroviral replication in myocardium from patients with dilated cardiomyopathy.

Expressions of innate immune response proteins, most notably proinflammatory cytokines, against enteroviral (EV) infection have been documented in the heart of human dilated cardiomyopathy (DCM). Toll-like receptor 4 (TLR4) activates signaling pathways leading to the expression of proinflammatory cytokines implicated the etiology of DCM. We sought to determine whether EV replication activates TLR4-dependent immune response in myocardium obtained from patients with DCM. Endomyocardial biopsy tissues were obtained from 56 patients with DCM and 10 controls. Levels of plus- and minus-strand EV RNA and TLR4 mRNA were measured by real-time RT-PCR. Immunohistochemical analysis was performed to identify the cellular source of EV capsid protein VP1 and TLR4. Both plus- and minus-strand EV RNA were detected in 19 DCM patients (34%). Neither strand of EV RNA was detected in controls. TLR4 mRNA levels were higher in DCM patients than in controls (P<0.001). A positive correlation was found between TLR4 levels and each strand type of EV RNA in EV RNA-positive patients (plus-strand vs TLR4: r=0.69, P<0.001; minus-strand vs TLR4: r=0.65, P=0.002). VP1/TLR4 double staining showed extensive colocalization of VP1 and TLR4 proteins in cytoplasm of cardiac myocytes in myocardium obtained from DCM patients. EV RNA-positive patients showed lower systolic function and larger ventricular volume compared with EV RNA-negative patients left ventricular ejection fraction (LVEF): P=0.002; left ventricular end-systolic diameter (LVESD): P=0.004). The DCM subgroup with high TLR4 levels showed lower LVEF and larger LVESD than the subgroup with TLR4 levels (both P<0.001). This study suggests that myocardial expression of TLR4 associates with EV replication in human DCM. EV RNA and TLR4 mRNA levels may correlate with LV dysfunction in DCM. The expression of TLR4 against EV replication may be involved in the pathogenesis of DCM.

A new method using pulmonary gas-exchange kinetics to evaluate efficacy of beta-blocking agents in patients with dilated cardiomyopathy.

BACKGROUND AND OBJECTIVES: The effects of beta-blocking agents on exercise tolerance in cardiopulmonary exercise testing (CPX) have not been fully identified. Because the negative chronotropic effects of these agents produce a sluggish increase in heart rate (HR) during CPX, exercise capacity is actually underestimated by methods that depend on HR-related variables such as peak oxygen uptake (O(2)) and anaerobic threshold (AT). The aim of this study was to clarify the efficacy of beta-blocking agents by means of O(2) kinetics, a parameter independent of HR, in patients with dilated cardiomyopathy (DCM). DESIGN AND PATIENTS: The exercise capacity of 12 patients (9 men and 3 women; mean +/- SD age, 54 +/- 12 years; New York Heart Association class I [n = 1], NYHA class 2 [n = 4], and NYHA class III [n = 6]) with DCM, who were treated with beta-blocking agents, was evaluated by CPX. O(2) was calculated from respiratory gas analysis on a breath-by-breath basis. Nine patients were treated with metoprolol (30 mg or 60 mg), two with carteolol (10 mg or 20 mg), and one patient with atenolol (25 mg). RESULTS: All patients showed a significantly favorable results (ie, improvement in symptoms of congestive heart failure). Peak O(2) (20.4 +/- 5.1 to 18.8 +/- 5.8 mL/min/kg), AT (12.7 +/- 3.5 to 12.1 +/- 2.1 mL/min/kg), and exercise time (4.8 +/- 2.2 to 4.5 +/- 2.1 s) were unchanged. The time constant of O(2) kinetics (tau) on response to constant low-dose work loading (warm up) decreased significantly (64 +/- 30 to 44 +/- 24 s; p < 0.01) and ejection fraction increased (30 +/- 14 to 44 +/- 15%, p < 0.01) significantly following treatment with beta-blocking agents. In spite of excluding two NYHA I patients, these changes were also statistically correlated. CONCLUSION: In the low level of exercise, tau was prolonged in patients with DCM. Although indexes of total exercise time and AT were not useful markers for clinical improvement in cardiac performance as assessed by echocardiography, measuring can validly assess the beneficial effects in heart failure treated with beta-blocking agents.

Expression of Toll-like receptor 4 is associated with enteroviral replication in human myocarditis.

Previous studies have demonstrated that inflammatory cytokine expression associated with enteroviral (EV) infection may play an important role in human myocarditis. However, the mechanism of the host immune response against viral pathogens has not been fully understood. The aim of the present study was to determine whether Toll-like receptor 4 (TLR4) and EV RNA are present in human myocarditis. Endomyocardial biopsy samples were obtained from 44 patients with myocarditis and five controls. Levels of plus- and minus-strand EV RNAs and TLR4 mRNA were measured by real-time reverse transcriptase-PCR. Immunohistochemical analysis was performed to identify the cellular source of TLR4 and the EV capsid protein VP1. EV RNA was present in 21 patients with myocarditis and these patients were defined as having either active viral replication ( n =15) or latent viral persistence ( n =6). Neither strand of EV RNA was detected in controls. TLR4 mRNA expression levels were higher in myocarditis patients than in controls (TLR4/glyceraldehyde-3-phosphate dehydrogenase ratio 1.48+/-0.17 compared with 0.08+/-0.06, P <0.001). A positive correlation was found between EV RNA and TLR4 levels (plus-strand vs TLR4: r =0.66, P <0.001; minus-strand vs TLR4: r =0.48, P <0.001). TLR4 immunostaining was observed in infiltrating cells and myocytes in patients with myocarditis. The EV capsid protein VP1 was also found in myocytes. The myocarditis group with EV replication and high levels of TLR4 showed significantly lower systolic function. The present study has shown that increased expression of TLR4 is associated with EV replication and that these RNA levels are related to cardiac dysfunction in human myocarditis.