Nobukiyo Tanaka

Aims Renal dysfunction in patients with chronic heart failure predicts a poor prognosis. Tolvaptan has a diuretic effect in patients with chronic kidney disease and heart failure without adverse effects on renal function. We aimed to determine the effects of tolvaptan and predictors of worsening renal function in patients with heart failure. Metho...

Introduction: Previous trials showed that tolvaptan improves acute heart failure (HF). However, the optimal timing for administering tolvaptan to achieve the best outcome remains unclear. Therefore, the current study investigated the relationship between the timing of tolvaptan treatment initiation and clinical outcomes in patients with acute deco...

Aims: Our aim was to evaluate the safety and efficacy of intracoronary (IC) nicorandil as an alternative choice of hyperaemic agent for invasive physiologic studies. Methods and results: A total of 480 intermediate coronary lesions from 429 patients enrolled from six Japanese and Korean centres were analysed. IC nicorandil showed earlier achievemen...

Warfarin, dabigatran, and apixaban are used for preventing ischemic stroke due to non-valvular atrial fibrillation (NVAF). However, it is often challenging to select the appropriate anticoagulant. We present the case of a 70-year-old male patient with persistent NVAF who developed pulmonary thromboembolism (PTE), deep vein thrombosis (DVT), and lef...

Background Fractional flow reserve (FFR) is useful for determining the functional significance of epicardial coronary stenosis and may facilitate clinical decision making in patients with an equivocal coronary stenosis for coronary revascularization. Therefore, determining an efficient and safe method to achieve hyperemia is important for evaluatin...

Left atrial appendage (LAA) thrombosis is an important cause of cardiogenic cerebral thromboembolism. Apixaban is a member of the class of novel oral anticoagulants (NOAC) and is superior to warfarin in preventing stroke or systemic embolism, causes less bleeding, and results in lower mortality in patients with atrial fibrillation. There are few re...

Coronary artery spasm has recently been reported as a complication of the ablation of atrial fibrillation (AF). It may be induced by cardiac autonomic nervous dysfunction during radiofrequency catheter ablation of AF. However, the underlying mechanism is not clear. We hypothesized that patients with paroxysmal AF coincidentally exhibit coronary art...

Background: The relationship between the anatomical location of right ventricular pacing site and paced QRS duration is unclear. In this study, we aimed to investigate the relationship between right ventricular pacing site and paced QRS duration using cardiac angiography. Methods: Fifty patients were implanted with pacemakers. The right ventricu...

Cigarette smoking is a strong risk factor for atherosclerotic disease; however, it remains unclear whether the impact of other risk factors differs by smoking status. The aim of this study was to investigate this issue, especially with regard to low-density and high-density lipoprotein (LDL/HDL) levels. In total, 448 healthy, middle-aged men (aged...

To elucidate the associations between Lp(a) levels and coronary and aortic atherosclerosis, we performed aortic MRI in 143 patients undergoing coronary angiography. Severity of aortic atherosclerosis was represented as plaque scores. Of the 143 patients, 104 had coronary artery disease (CAD). Thoracic and abdominal aortic plaques were found in 89 a...

We recently reported that the endogenous ATP-binding cassette transporter (ABC) A7 strongly associates with phagocytosis, being regulated by sterol regulatory element binding protein 2. We therefore examined the effect of statins on phagocytosis in vitro and in vivo through the SREBP-ABCA7. Phagocytosis was found to be enhanced by pravastatin, rosu...

A 72-year-old man with drug-resistant persistent AF was admitted to our institution for LA catheter ablation. The patient had no history of coronary arterial disease, ischemia related symptoms. After obtaining written informed consent, LA catheter ablation was performed. Two decapolar catheters were placed within the ipsilateral superior and inferi...

ATP-binding cassette transporter (ABC) A7 is an ABC family protein that is a so-called full-size ABC transporter, highly homologous to ABCA1, which mediates the biogenesis of high-density lipoprotein (HDL) with cellular lipid and helical apolipoproteins. ABCA7 mediates the formation of HDL when exogenously transfected and expressed; however, endoge...

Resistin is an adipocytokine that may link inflammation and atherosclerosis.We studied the associations of resistin levels with cardiovascular events and restenosis. We measured pre-procedural serum resistin levels in 140 patients with coronary artery disease undergoing elective percutaneous coronary intervention (PCI), of whom 97 had a stent. Rest...

We previously reported that the endogenous ATP-binding cassette transporter (ABC)A7 strongly associates with phagocytic function rather than biogenesis of high-density lipoprotein (HDL), being regulated by sterol-regulatory element binding protein (SREBP)2. Phagocytic activity was found enhanced by apolipoprotein (apo)A-I and apoA-II more than twic...

To investigate the interaction of ATP-binding cassette transporter A1 (ABCA1) with calmodulin in relation to its calpain-mediated degradation because many calpain substrates bind calmodulin to regulate cellular functions. The activity of ABCA1 is regulated through proteolysis by calpain. An immunoprecipitation and glutathione S-transferase pull-dow...

Limited correlations between C-reactive protein (CRP) and coronary artery disease (CAD) have been reported. Recently, MRI became a useful tool for non-invasively evaluating atherosclerotic plaques in thoracic and abdominal aortas. To elucidate the associations between plasma CRP levels and the severities of coronary and aortic atherosclerosis, we p...

Matrix metalloproteinases (MMPs) play a role in collagen breakdown, leading to plaque instability. High levels of MMPs mRNA and proteins, especially MMP-1, MMP-2, MMP-8, MMP-9, and MMP-13, were shown in human atherosclerotic plaques. However, among various MMPs, only MMP-1, MMP-8 and MMP-13, so-called interstitial collagenases, can initiate collage...

Using MRI, we reported plaque regression in thoracic aorta and retardation of plaque progression in abdominal aorta by 1-year atorvastatin. However, association between serial plaque changes and LDL-cholesterol levels was not fully elucidated. A prospective, randomized, open-label trial. We investigated the long-term effect of 20 versus 5-mg atorva...

Osteopontin (OPN) mRNA is highly expressed in atherosclerotic plaques and plasma OPN levels are high in patients with coronary artery disease and in those with restenosis. OPN-overexpressing transgenic mice show markedly increased neointimal formation after arterial injury. The prognostic significance of the preprocedural plasma OPN level was inves...

Fibrates reduce triglycerides (TG) and increase HDL-cholesterol levels, but there was no report showing plaque regression by fibrates. Using MRI, we investigated the effects of bezafibrate on aortic plaques in 22 dyslipidemic patients. All patients were asked to receive 400mg bezafibrate, but 8 who declined to have bezafibrate became the control gr...

The association between coronary artery disease (CAD) and thoracic aortic plaques has often been reported using transesophageal echocardiography. However, studies showing the association between CAD and abdominal aortic plaques are scarce. CMR can visualize plaques in both the thoracic and abdominal aortas. Using CMR, we investigated the associatio...

Osteopontin (OPN) mRNA was shown to be highly expressed in atherosclerotic plaques. We reported plasma OPN levels to be high in patients (pts) with coronary artery disease. Moreover, OPN levels were recently shown to be high in acute coronary syndrome. Increased OPN mRNA expression was also shown in rat arteries after balloon injury. OPN transgenic...

ATP-binding cassette transporter A1 (ABCA1) is a rate-limiting factor for high-density lipoprotein (HDL) biogenesis. The ABCA1 gene expression is known to be upregulated by various transcriptional factors. However, negative regulation factors would be better targets for pharmacological modulation of HDL biogenesis. Doxazosin, an alpha(1)-adrenocept...

The ATP binding cassette transporters A1 and G1 (ABCA1/G1) and scavenger receptor class B type I (SR-BI) are key molecules in cholesterol efflux and atherogenesis. These genes are regulated by peroxisome proliferator-activated receptor gamma (PPARgamma) and liver X receptor (LXR). Telmisartan is an angiotensin type 1 receptor blocker which has been...

Coronary artery fistulas are uncommon entities with communication between the coronary artery and cardiac structure. We encounter a 70-year-old, asymptomatic woman with a large right coronary artery to left ventricle fistula. Non-invasive echocardiogram was helpful in detecting an enlarged right coronary that drained from the aorta into the left ve...

Inhibition of matrix metalloproteinases (MMPs) would be expected to suppress atherosclerotic neointimal proliferation and thus limit atheromatous plaque progression, but this has not yet been demonstrated morphologically in atherosclerotic intimal hyperplasia induced by cholesterol loading in experimental animals. We therefore investigated whether...

A 61-year-old man was admitted with angina pectoris. Coronary angiography (CAG) showed a 65% diameter and 9 mm-length stenosis in the distal left anterior descending artery. A Cypher™ stent (2.5 x 18 mm) was implanted without residual stenosis. This patient remained asymptomatic. Follow-up CAG at 6-months after stenting showed complete fracture at...

To the Editor High levels of osteopontin (OPN) mRNA and proteins were reported in atherosclerotic plaques.1,2 OPN-transgenic mice developed marked atherosclerosis.3 We reported plasma OPN levels to be high in patients with coronary artery disease (CAD) and to correlate with the severity of CAD.4 We also reported high plasma levels of OPN in patien...

Coronary plaque instability causes myocardial infarction (MI). Angiographic lesions with such instability are complex lesions. Complex carotid plaques were reported to be prevalent in unstable angina. We investigated associations between coronary plaque instability, such as MI and angiographic complex coronary lesions, and aortic plaques. Aortic MR...

The ATP-binding cassette transporter-A1 (ABCA1) regulates cholesterol efflux from cells and is involved in high-density lipoprotein metabolism and atherogenesis. The objective of this study was to investigate the effect of dexamethasone (Dex) and other glucocorticoid receptor (GR) ligands on apolipoprotein AI-mediated cholesterol efflux from macrop...