Kunihiko Koshiba

Elevated concentrations of pentraxin 3 are associated with coronary plaque vulnerability

BACKGROUND Inflammation is a critical contributing factor to the development and progression of atherosclerosis. Pentraxin 3 (PTX3) is produced abundantly in atherosclerotic lesions while C-reactive protein (CRP) is mainly produced in the liver. In this study, we investigated whether plasma levels of PTX3 might be a sensitive marker both for the severity of coronary artery disease and vulnerable plaques. Next, we determined whether assays for inflammatory molecules can be used to monitor the therapeutic effects of telmisartan on stabilization of vulnerable atherosclerotic plaques. METHODS AND RESULTS We measured PTX3 concentrations in the peripheral and coronary sinus plasma of 40 patients with angina pectoris (AP) and 20 control subjects. Next, in 28 patients with AP, we determined the correlation between levels of inflammatory molecules and the computed tomography (CT) density of plaques as a quantitative index of plaque vulnerability. There was no significant difference in peripheral plasma PTX3 concentrations between patients with AP and control subjects, while coronary sinus plasma PTX3 concentrations were significantly higher in AP patients than control subjects. The concentrations of PTX3 in coronary sinus and peripheral plasma correlated with Gensini scores as an index of severity of coronary atherosclerosis. Interestingly, there was a significantly negative correlation between plasma PTX3 concentrations and CT density (r=-0.67, p<0.01). On the other hand, CT density did not correlate with the peripheral plasma concentrations of monocyte chemoattractant protein-1 (MCP-1) or high-sensitivity CRP (hsCRP). Furthermore, telmisartan treatment for 6 months decreased plasma concentrations of PTX3 but not those of MCP-1 or hsCRP in 12 patients with essential hypertension. Multivariate regression analysis revealed that changes in PTX3 levels were independent of blood pressure changes. CONCLUSIONS PTX3 is likely more specific than hsCRP as an indicator of coronary plaque vulnerability that could lead to plaque rupture.

Clinical study with azelnidipine in patients with essential hypertension. Antiarteriosclerotic and cardiac hypertrophy-inhibitory effects and influence on autonomic nervous activity.

A dihydropyridine calcium (Ca) antagonist, azelnidipine (CAS 123524-52-7, Calblock), exhibits hypotensive effects for a prolonged duration, and has been reported to have a strong antiarteriosclerotic action due to its high affinity for vascular tissues and antioxidative action. It has also been reported that azelnidipine does not cause tachycardia associated with the baroreceptor reflex due to vasodilatation. In this study, the antiarteriosclerotic and cardiac hypertrophy-inhibitory effects, and the autonomic nervous activity in essential hypertension of azelnidipine were investigated. The study was performed using the following 2 protocols: 1) Pulse wave velocity (PWV), carotid arterial intima media thickness (IMT), echocardiography, high sensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), adiponectin, brain natriuretic peptide (BNP), and 8-isoprostane were measured after an initial treatment with azelnidipine. 2) The treatment was switched to azelnidipine in patients who had previously been under treatment with amlodipine for essential hypertension, and 123I-metaiodobenzylguanidine myocardial scintigraphy (123I-MIBG), measurements of plasma norepinephrine, atrial natriuretic peptide (ANP), and BNP, Holter electrocardiography, and heart rate variability analysis were performed. PWV, IMT, hs-CRP, IL-6, and TNF-alpha significantly decreased. The levels of 8-isoprostane, an antioxidative marker, were also significantly decreased, while adioponectin levels were significantly increased after the initial treatment with azelnidipine. After switching from amlodipine, azelnidipine exhibited a hypotensive effects comparable to amlodipine, and significantly decreased heart rate and the total number of extrasystoles. Noradrenaline levels and the LF/HF ratio were significantly decreased, and the washout rate was significantly reduced on 123I-MIBG myocardial scintigraphy. These findings suggest that azelnidipine inhibits the enhancement of sympathetic nervous activity and the progression of arteriosclerosis through its antioxidative effects.

A case of neurogenic myocardial stunning presenting transient left ventricular mid-portion ballooning simulating atypical takotsubo cardiomyopathy

A 57-year-old female patient, who was initially suspected to have subarachnoid hemorrhage, was admitted to our hospital. She experienced severe dyspnea and chest pain owing to pneumonia on the fourth admission day. Electrocardiography showed ST-segment elevation in leads V(2) through V(5), and echocardiography revealed hypokinetic left ventricular wall motion. No stenosis was found in the coronary arteries by urgent coronary angiography. However, left ventriculography revealed that the basal and apical areas were hyperkinetic and the mid portion was akinetic. After a month, left ventricular wall motion was improved and coronary artery spasm provocation tests were negative. Although the clinical course of this patient was similar to that of neurogenic myocardial stunning, the shape of her left ventricle was not typical.

Ghrelin protects the heart against ischemia-induced arrhythmias by preserving connexin-43 protein

Vagal nerve stimulation has been postulated to confer an antifibrillatory effect. We studied whether ghrelin administration would exert an antiarrhythmic effect via modulation of autonomic nerve activity in rats after acute myocardial ischemia (MI). Male Sprague-Dawley rats were exposed to 30 min of ischemia following ligation of the left coronary artery. Animals were then randomized to receive either ghrelin (n = 26) or saline (n = 26) during the period of coronary ligation. Power spectral analysis of heart-rate variability revealed that the administration of ghrelin increased the high-frequency (HF) power and decreased the low-frequency (LF)/HF ratio. Ventricular tachyarrhythmias were less frequent in rats after MI who received ghrelin in comparison with rats that received saline. Immunoblotting and immunohistochemistry revealed that rats given saline alone during MI exhibited a marked reduction in phosphorylated connexin-43 within the left ventricle, whereas those that received ghrelin displayed only minor reductions in comparison with sham-operated rats. These effects of ghrelin were diminished by the coadministration of atropine or the blockade of vagal afferents. These data demonstrate that the beneficial effect of ghrelin might be mediated by modulation of cardiac autonomic nerve activity.

Renoprotective and antioxidant effects of cilnidipine in hypertensive patients

Cilnidipine, an L/N-type calcium channel blocker (CCB), has been reported to have more beneficial effects on proteinuria progression in hypertensive patients than amlodipine, an L-type CCB. The N-type calcium channel blockade that inhibits renal sympathetic nerve activity might reduce glomerular hypertension by facilitating vasodilation of the efferent arterioles. However, the precise mechanism of the renoprotective effect of cilnidipine remains unknown. Because cilnidipine exerted significantly higher antioxidant activity than amlodipine in cultured human mesangial cells, we hypothesized that cilnidipine might exert a renoprotective effect by suppressing oxidative stress. A total of 35 hypertensive patients receiving a renin–angiotensin system inhibitor were randomly assigned to a cilnidipine (n=18; 10 mg per day cilnidipine titrated to 20 mg per day) or amlodipine (n=17; 5 mg per day amlodipine titrated to 10 mg per day) group; the target blood pressure (BP) was set at 130/85 mmHg. After 6 months of treatment, systolic and diastolic BPs were significantly reduced in both of the groups, without any significant difference between the groups. The urinary albumin, 8-hydroxy-2′-deoxyguanosine (OHdG) and liver-type fatty-acid-binding protein (L-FABP) to creatinine ratios significantly decreased in the cilnidipine group (P<0.05) compared with those in the amlodipine group. The reductions in urinary albumin, 8-OHdG and L-FABP were not correlated with the change in systolic BP. In conclusion, cilnidipine, but not amlodipine, ameliorated urinary albumin excretion and decreased urinary 8-OHdG and L-FABP in the hypertensive patients. Cilnidipine probably exerts a greater renoprotective effect through its antioxidative properties.

Effect of ghrelin on autonomic activity in healthy volunteers.

Ghrelin is a novel growth hormone (GH)-releasing peptide originally isolated from the stomach. Recently, we have shown that ghrelin suppresses cardiac sympathetic activity and prevents early left ventricular remodeling in rats with myocardial infarction. In the present study, we evaluated the effect of ghrelin on autonomic nerve activity in healthy human subjects. An intravenous bolus of human synthetic ghrelin (10μg/kg) was administered to 10 healthy men (mean age, 33 years). Holter monitoring assessment was performed before and during 2h after the ghrelin therapy. The standard deviation of normal RR intervals (SDNN), square root of the mean of the sum of the squares of differences between adjacent RR intervals (rMSSD), high-frequency power (HF), and low-frequency power (LF) were analyzed. Blood samples were also obtained before and after the therapy. A single administration of ghrelin decreased both heart rate and blood pressure. Interestingly, ghrelin significantly decreased the LF and LF/HF ratio of heart rate variability and increased the SDNN, rMSSD, and HF. Ghrelin also elicited a marked increase in circulating GH, but not insulin-like growth factor-1. These data suggest that ghrelin might suppress cardiac sympathetic nerve activity and stimulate cardiac parasympathetic nerve activity.

Platypnea‐Orthodeoxia Syndrome Associated with Patent Foramen Ovale and Aortic Ectasia

A 59‐year‐old man was admitted for dyspnea on exertion and edema. The patient did not have any pulmonary diseases that could cause dyspnea. Transesophageal echocardiography on the tilting bed with contrast infusion revealed a right‐to‐left shunt through the patent foramen ovale. Therefore, he was diagosed as platypnea‐orthodeoxia syndrome due to the patent foramen ovale. Surgical closure was done and all of his symptoms had improved.

Serial imaging changes during treatment of Takayasu arteritis with pulmonary artery stenosis

Most cases of chronic stenosis or occlusive lesions of the pulmonary arteries are attributed to thromboembolism, and pulmonary arteritis is extremely rare as the primary cause of these entities. We report a case of pulmonary stenosis and occlusion caused by Takayasu arteritis. The patient was a 54-year-old woman who presented with dyspnea. Total occlusion of the left pulmonary artery and significant stenosis of the right pulmonary artery caused by Takayasu arteritis were confirmed by various imaging modalities including pulmonary angiography, 18fluorodeoxyglucose-positron emission tomography, magnetic resonance imaging and real-time three-dimensional transesophageal echocardiography. After 6 weeks of steroid therapy, follow-up imaging studies showed that the stenotic lesion had resolved.

Diagnostic utility of cardiac magnetic resonance for detection of cardiac involvement in female carriers of Duchenne muscular dystrophy

Background Cardiac involvement is a recognised complication in female carriers of Duchenne muscular dystrophy (DMD). Since segmental or global left ventricle (LV) wall motion abnormalities in DMD carriers can arise even without apparent muscle weakness, it is difficult to differentiate cardiac involvement of a DMD carrier from other heart diseases in a non-invasive manner. Cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE) enables assessment of regional wall motion abnormality and myocardial damage with high spatial resolution. Objective To assess the utility of CMR for detection of myocardial damage in female carriers of DMD. Methods and results Gadolinium-enhanced CMR was performed in seven female DMD carriers. Physical examination, electrocardiography, chest radiograph, measurements of total creatinine kinase and brain natriuretic peptide levels, and two-dimensional echocardiography were also performed. Four (57%) of the seven carriers had LGE, and LGE was frequently observed at the subepicardial layer in the inferolateral segment. Two carriers had a focal LGE at the LV inferolateral wall without LV dilation or wall motion abnormalities. Conclusion CMR findings of DMD carriers were characterised by subepicardial LGE, which was localised at inferolateral segments. CMR may be a useful modality for detecting cardiac involvement in DMD carriers.

Acute hemodynamic effects of adaptive servo ventilation in patients with pulmonary hypertension

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