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.

Specific immunoadsorption therapy using a tryptophan column in patients with refractory heart failure due to dilated cardiomyopathy

BACKGROUND

Certain cardiac-specific autoantibodies found in patients with dilated cardiomyopathy (DCM) play a role in mediating myocardial damage and fatal ventricular arrhythmias resulting in sudden cardiac death. Immunoadsorption therapy (IA) is one of the therapeutic tools to remove such autoantibodies. Clinical studies from Germany have shown that nonspecific IA using columns loaded by sheep antihuman IgG or protein A improved hemodynamic data and affected favorably cardiac function and survival in patients with heart failure (HF) due to DCM. The goal of this study is to determine if IA therapy using the high-profile tryptophan column, which has high affinity for IgG3 subclass, affects favorably cardiac function in patients with severe HF who are refractory to conventional therapy.

METHODS AND RESULTS

IA therapy was conducted in 16 patients with DCM (age 53 ± 4, male 8, New York Heart Association functional class III/IV, mean ejection fraction 18 ± 2%). Study subjects had autoantibodies directed against either β1-adrenergic or M2-muscarinic receptors. Plasma brain natriuretic peptide levels were significantly decreased after IA (P = 0.016). Plasma inflammatory cytokines including interleukin-6 and tumor necrosis factor-α did not change after each session of IA. Six-minute walk distance was significantly increased after IA (P = 0.01). Left ventricular ejection fraction increased by 3% 3 months after IA (P = 0.039).

CONCLUSIONS

Our initial experience demonstrated safety and short-term efficacy of IA using a new IgG3-specific tryptophan column for patients with advanced HF due to DCM. Long-term follow-up is needed to confirm the effects on cardiac function and morbidity/mortality in such patients.

Phosphorus: an elemental catalyst for diamond synthesis and growth

As diamond-producing catalysts, 12 transition metals such as iron, cobalt, and nickel were first reported by General Electric researchers more than 30 years ago. Since then, no additional elemental catalyst has been reported. An investigation of the catalytic action of group V elements is of great interest from the viewpoint of producing an n-type semiconducting diamond crystal. In the present study, diamond was synthesized from graphite in the presence of elemental phosphorus at high pressure and temperature (7.7 gigapascals and 1800 degrees C). Furthermore, single-crystal diamond was grown on a diamond seed crystal.

Complete elimination of cardiodepressant IgG3 autoantibodies by immunoadsorption in patients with severe heart failure

BACKGROUND

Cardiodepressant IgG3 autoantibodies (CD-Abs) can be targeted by apheresis. Using blinded measurements of CD-Abs before and after immunoadsorption (IA), the cardiac function of patients who did or did not achieve complete CD-Abs elimination was compared.

METHODS AND RESULTS

Autoantibodies were completely removed from 18 patients with heart failure (New York Heart Association class 3 or 4, left ventricular ejection fraction (LVEF) <30%) using a selective IgG3 adsorption column. All patients had anti-beta1-adrenergic and/or M2-muscarinic autoantibodies before IA, and all LVEF were measured on radionuclide ventriculography. CD-Abs were measured before and after IA, and patient status was blinded until all measurements were collected. Treatment was defined as complete when CD-Abs status changed from positive to negative after IA. Other instances were defined as incomplete. Six-min walk test results and brain natriuretic peptide levels improved significantly after IA (P<0.01). The increase in LVEF 3 months after IA was significantly greater after complete treatment in comparison to the incomplete treatment group (19+/-8-29+/-9% vs 18+/-9-17+/-8%, P<0.01). Cardiac insufficiency events were also more frequent in the incomplete treatment group.

CONCLUSIONS

Complete elimination of CD-Abs with apheresis may be related to improved cardiac function in the treatment of heart failure.

A case of echocardiographic evaluation of ruptured pseudoaneurysm of the mitral-aortic intervalvular fibrosa by infective endocarditis

This report describes an unusual case of ruptured pseudoaneurysm (PSA) of mitral-aortic intervalvular fibrosa (MAIVF) caused by infective endocarditis. The PSA ruptured into the left sinus of Valsalva in addition to the left atrium, resulting in complicated shunting among the aorta, left ventricle and left atrium, leading to refractory heart failure. The transesophageal echocardiography provided the precise information concerning the anatomical detail of the PSA, which is crucial for the surgical repair. This is the first report describing a patient with PSA of MAIVF with two rupture sites.

A low-cost digital filing system for echocardiography data with MPEG4 compression and its application to remote diagnosis

The high cost of digital echocardiographs and the large size of data files hinder the adoption of remote diagnosis of digitized echocardiography data. We have developed a low-cost digital filing system for echocardiography data. In this system, data from a conventional analog echocardiograph are captured using a personal computer (PC) equipped with an analog-to-digital converter board. Motion picture data are promptly compressed using a moving pictures expert group (MPEG) 4 codec. The digitized data with preliminary reports obtained in a rural hospital are then sent to cardiologists at distant urban general hospitals via the internet. The cardiologists can evaluate the data using widely available movie-viewing software (Windows Media Player). The diagnostic accuracy of this double-check system was confirmed by comparison with ordinary super-VHS videotapes. We have demonstrated that digitization of echocardiography data from a conventional analog echocardiograph and MPEG 4 compression can be performed using an ordinary PC-based system, and that this system enables highly efficient digital storage and remote diagnosis at low cost.

Current characteristics of infective endocarditis in Japan: an analysis of 848 cases in 2000 and 2001

The Japanese Circulation Society appointed a committee to develop guidelines for the prevention, diagnosis and management of infective endocarditis in Japan. In making such guidelines, the committee required information on the current clinical characteristics of infective endocarditis and therefore performed a nationwide questionnaire survey of cases from 2000 and 2001. In total, data were received for 848 cases from 277 of the 817 hospitals surveyed. Mean age was 55+/-18 years and most patients were aged in their 50 s or 60 s; 53.9% of the patients had infective endocarditis of unknown origin (without any prior predisposing conditions or procedures) and the second most common etiology was post dental procedures. The most common microorganism was Gram-positive cocci (345 streptococci and 221 staphylococci) and methicillin resistant Staphylococcus aureus (MRSA) was found in 7.3%. Although more than 90% of cases with Streptococcus viridans were sensitive to penicillin G, 6.6% were resistant. All MRSAs were sensitive to vancomycin. The information obtained from the survey assisted in the making of the guidelines, which should become an indispensable tool for all clinicians.

Autoantibodies against M2-muscarinic acetylcholine receptors: new upstream targets in atrial fibrillation in patients with dilated cardiomyopathy

AIM

To characterise the clinical significance of M2-muscarinic acetylcholine receptor autoantibodies (M2-AAB) in patients with dilated cardiomyopathy (DCM).

METHODS AND RESULTS

Sera from 104 patients with DCM, age-matched with 104 patients with idiopathic atrial fibrillation (Af) and 104 healthy control subjects, were screened for M2-AAB by enzyme-linked immunosorbent assay (ELISA). IgG purified by Protein-A column was also used as a primary antibody in ELISA. In DCM, M2-AAB were detected in 40% of patients using whole sera and in 36% of patients using purified IgG. M2-AAB were also found in several patients with idiopathic Af (23%, 23%), and these frequencies were significantly higher than those in healthy subjects (8%, 8%). Af was more common in AAB-positive than in AAB-negative patients with DCM. Multivariable analysis confirmed that M2-AAB were independent predictors of the presence of Af in such patients. We determined electrophysiological changes by adding patient purified M2-AAB to chick embryos. Purified IgG from both Af and DCM patients exhibited negative chronotropic effects and induced supraventricular arrhythmias.

CONCLUSION

M2-AAB may play a role in mediating the development of Af in patients with DCM.

[Comparison of myocardial perfusion imaging by thallium-201 single-photon emission computed tomography with SUNY4001 (adenosine) and exercise--crossover clinical trial at multi-center]

We compared the ischemic diagnosis ability and adverse events of 201Tl myocardial perfusion imaging with SUNY4001 (adenosine) stress to that with exercise (ergometer) stress both on random crossover trial. Thirty one known or suspected chronic stable angina patients who are able to exercise and 10 healthy volunteers were enrolled for the trial. The early and delayed images were obtained by SPECT imaging. The concordance of diagnoses [ischemia vs. no ischemia] between the two types of stresses was 97.3% (36/37) [Kappa: 0.9068]. The sensitivity and specificity based on the exercise test were 100% (6/6) and 96.8% (30/31) respectively. The incidence of adverse events caused by SUNY4001 and the exercise were 44.7% (17/38) and 52.6% (20/38), respectively. Major adverse events caused by SUNY4001 were BP decrease, flushing and headache. And those by exercise were ST decrease, dyspnea and chest pain. None of the adverse events required the intervention or caused life-threatening complication in the trial. The trial showed that the ischemic diagnosis ability and safety of 201Tl scintigraphy with SUNY4001 stress are almost equal to those of the exercise stress that is considered as the standard stress method. We concluded that 201Tl imaging with SUNY4001 is safe and useful for detecting ischemic heart disease, especially for patients unable to exercise adequately.

[Autoantibodies: new upstream targets of paroxysmal atrial fibrillation in patients with congestive heart failure]

OBJECTIVES

The clinical implications of autoantibodies (Abs) were investigated as upstream indicators of paroxysmal atrial fibrillation in patients with congestive heart failure.

METHODS

Circulating Abs against myosin (M-Abs) detected by immunofluorescence, Abs against beta 1-adrenergic receptors (Beta 1-Abs) detected by enzyme-linked immunosorbent assay (ELISA), and Abs against NA-K-ATPase (NKA-Abs) detected by ELISA were screened in 95 congestive heart failure patients with < or = 45% left ventricular ejection fraction (coronary artery disease, n = 48; dilated cardiomyopathy, n = 47) and 48 age-matched control patients with hypertension. No patient received antiarrhythmic therapy. All patients were enrolled with angiotensin converting enzyme inhibitors in the chronic stable state. Relationship of the presence of paroxysmal atrial fibrillation to other clinical variables were assessed by 48-hour Holter monitoring.

RESULTS

No control patient had Abs. However, M-Abs, Beta 1-Abs, and NKA-Abs were detected in 22%, 26% and 16% of patients with congestive heart failure (coronary artery disease; 8%, 10%, and 4%, dilated cardiomyopathy; 36%, 43%, and 28%, respectively). Paroxysmal atrial fibrillation was more frequent in patients with dilated cardiomyopathy than in those with coronary artery disease (47% vs 15%, p < 0.01). Multivariate analysis suggested that NKA-Abs was an independent risk factor for the occurrence of paroxysmal atrial fibrillation (p < 0.01), although there were no differences in other clinical factors: age, sex, New York Heart Association functional class, concomitant medication, left ventricular ejection fraction, left atrial diameter, severity of mitral regurgitation, serum potassium, plasma norepinephrine, and atrial natriuretic peptide concentration.

CONCLUSIONS

Autoantibodies against sarcolemmal Na-K-ATPase were closely related to the occurrence of paroxysmal atrial fibrillation in patients with congestive heart failure, so an autoimmune process may be an upstream factor in atrial fibrillation.

[Autoantibodies against sarcolemmal Na-K-ATPase in patients with dilated cardiomyopathy: autoimmune basis for ventricular arrhythmias in patients with congestive heart failure]

BACKGROUND

Autoimmunity is one of the mechanisms of pathogenesis of idiopathic dilated cardiomyopathy (DCM) as well as virus infection and genetic predisposition. Autoantibodies against sarcolemmal Na-K-ATPase may be involved in the development of ventricular tachycardia and cardiac sudden death in patients with DCM.

METHODS AND RESULTS

By using enzyme-linked immunosorbent assay, autoantibodies were detected in 26% patients with DCM and in 2% age-matched control subjects. Na-K-ATPase activity in the presence of patient IgG was lower in patients with autoantibodies than without autoantibodies, but there was no difference in the control subjects. Western blots showed that autoantibodies recognized the alpha-subunit of Na-K-ATPase, and 3H-ouabain bindings in the presence of patient IgG showed that the dissociation constant was higher in patients with autoantibodies than without autoantibodies, although maximal binding sites were similar between the two groups. No difference existed between subjects with regard to age, sex, New York Heart Association functional class, cardiac function, or neurohormone levels, except for plasma norepinephrine which was higher in patients with autoantibodies than without autoantibodies, Ventricular arrhythmias were more common in patients with autoantibodies than without autoantibodies, and multiple logistic regression analysis demonstrated that the presence of autoantibodies, but not plasma norepinephrine, was an independent predictor for the occurrence of ventricular tachycardia. Cardiac sudden death was independently predicted by the presence of autoantibodies, as well as poor systolic function.

CONCLUSIONS

Patients with DCM express autoantibodies against sarcolemmal Na-K-ATPase, and these autoantibodies could be responsible for the electrical instability in some patients.

Characterization of anti-myocardial autoantibodies in Japanese patients with dilated cardiomyopathy

Few previous reports have comprehensively screened all the anti-myocardial autoantibodies (AMCA) in relation to other clinical profiles in patients with idiopathic dilated cardiomyopathy (IDC), so the present study used both immunohistochemistry (FITC) and immunoblotting (IB) for screening patients with IDC in order to characterize the clinical significance of AMCA. Sera were collected from 100 patients with IDC and age-matched 100 healthy control subjects (CTL). For FITC, an unfixed frozen section of human myocardium was used for the standard indirect immunofluorescence; for IB, total cardiac homogenates of the same myocardium were blotted to serum at 2 sets of dilution (1:200 and 1:10,000). The positive rates of AMCA detection for each method were as follows (IDC vs CTL); 39% vs 6% for FITC, 38% vs 4% for IB (1:200), and 10% vs 0% for IB (1:10,000). Fifty-nine patients with IDC and 8 CTL were positive for AMCA by either method, and 18 patients with IDC and 2 CTL were positive for AMCA by both methods. IB-positivity at 1:200 was an independent predictor by multiple logistic regression analysis of non-sustained ventricular tachycardias as well as left ventricular end-diastolic diameter and plasma norepinephrine concentration.

Age-adjusted heart rate variability as an index of the severity and prognosis of heart failure

The age-adjusted, heart rate variability (HRV) was evaluated as a parameter for the severity of heart failure and its prognosis. HRV was obtained by 24-h Holter monitoring in patients with left ventricular dysfunction (LVD). New York Heart Association (NYHA) functional classification, echocardiography, radioisotope ventriculography, and blood examination were performed, and compared between patients and normal subjects. The evaluation was repeated during the follow-up period. Finally, using the lower limit of HRV, patients were divided into either normal or abnormal group for each low-frequency power (LF) and high-frequency power (HF) (age-adjusted HRV). Other parameters of heart failure and prognosis were compared between these 2 groups. HRV tended to be lower in patients with LVD. HF decreased at the early stage of heart failure, but did not decrease progressively. LF decreased progressively. HRV change paralleled the change of NYHA. The abnormal HRV group showed a poor prognosis for cardiac death, but not for sudden cardiac death. In patients with LVD, HRV was decreased compared with the normal subjects. Change in HRV correlated with the change in NYHA classification. Age-adjusted HRV correlated with cardiac-death prognosis, but not for sudden cardiac death.

Neurohumoral activations in congestive heart failure: correlations with cardiac function, heart rate variability, and baroreceptor sensitivity

BACKGROUND

The clinical significance of the determination of heart rate variability and baroreceptor sensitivity relating to cardiac function and neurohumoral factors remains to be established.

METHODS AND RESULTS

We investigated the relation between conventional clinical variables and frequency domain analysis of heart rate variability and baroreceptor sensitivity in 146 patients with heart failure. Cardiac function including left ventricular ejection fraction, left ventricular dimensions, and left atrial size was different by the plasma atrial natriuretic peptide level but not by the norepinephrine level. The total power and low-frequency power were correlated with plasma norepinephrine, whereas baroreceptor sensitivity was correlated with plasma atrial natriuretic peptide. None of the frequency domain variables and baroreceptor sensitivity was correlated with cardiac function. There was a positive correlation between the low-frequency power and baroreceptor sensitivity.

CONCLUSIONS

Heart rate variability and baroreceptor sensitivity, which reflect autonomic regulation, may be an indicator independent from cardiac function in patients with heart failure.