Ryuji Tsuburaya

Enhanced Rho-Kinase Activity in Circulating Neutrophils of Patients With Vasospastic Angina: A Possible Biomarker for Diagnosis and Disease Activity Assessment

OBJECTIVES The aim of this study was to examine whether Rho-kinase activity is systemically enhanced in patients with vasospastic angina (VSA) and, if so, whether a noninvasive diagnostic method could be developed to improve practice. BACKGROUND The activated Rho-kinase pathway plays a central role in the molecular mechanism of coronary vasospasm in animal models and patients with VSA. Recently, it has been reported that Rho-kinase activity in circulating leukocytes is associated with various diseases. METHODS Fifty-three consecutive patients with chest pain who underwent acetylcholine provocation testing for coronary spasm were examined. Patients were divided into 2 groups depending on their response to the test: VSA (n = 33) and non-VSA (n = 20) groups. Venous blood samples were collected to measure Rho-kinase activity in circulating neutrophils, determined by the extent of phosphorylation of myosin-binding subunit (MBS), a substrate of Rho-kinase. RESULTS Rho-kinase activity was significantly higher in the VSA group than in the non-VSA group (phosphorylated MBS/total MBS ratio 1.33 ± 0.37 vs. 0.95 ± 0.22, p < 0.001). In the VSA group, no correlation was noted between Rho-kinase activity and high-sensitivity C-reactive protein, smoking, or accumulated number of coronary risk factors. After the 3-month medical treatment, Rho-kinase activity in the VSA group was significantly decreased to 1.08 ± 0.31 (p < 0.001). On receiver-operating characteristic curve analysis, a phosphorylated MBS ratio of 1.18 was identified as the best cutoff level to predict the diagnosis of VSA. CONCLUSIONS These results indicate that Rho-kinase activity in circulating neutrophils is enhanced in patients with VSA and may be a useful biomarker for diagnosis and disease activity assessment of the vasospastic disorder.

Cardiac shock wave therapy ameliorates left ventricular remodeling after myocardial ischemia–reperfusion injury in pigs in vivo

ObjectivesLeft ventricular (LV) remodeling after acute myocardial infarction (AMI) is associated with a poor prognosis and an impaired quality of life. We have shown earlier that low-energy extracorporeal cardiac shock wave (SW) therapy improves chronic myocardial ischemia in pigs and humans and also ameliorates LV remodeling in a pig model of AMI induced by permanent coronary ligation. However, in the current clinical setting, most of the patients with AMI receive reperfusion therapy. Thus, in this study we examined whether our SW therapy also ameliorates LV remodeling after myocardial ischemia–reperfusion (I/R) injury in pigs in vivo. MethodsPigs were subjected to a 90-min ischemia and reperfusion using a balloon catheter and were randomly assigned to two groups with or without SW therapy to the ischemic border zone (0.09 mJ/mm2, 200 pulses/spot, 9 spots/animal, three times in the first week) (n=15 each). ResultsFour weeks after I/R, compared with the control group, the SW group showed significantly ameliorated LV remodeling in terms of LV enlargement (131±9 vs. 100±7 ml), reduced LV ejection fraction (28±2 vs. 36±3%), and elevated left ventricular end-diastolic pressure (11±2 vs. 4±1 mmHg) (all P<0.05, n=8 each). The SW group also showed significantly increased regional myocardial blood flow (−0.06±0.11 vs. 0.36±0.13 ml/min/g, P<0.05), capillary density (1.233±31 vs. 1.560±60/mm2, P<0.001), and endothelial nitric oxide synthase activity (0.24±0.03 vs. 0.41±0.05, P<0.05) in the ischemic border zone compared with the control group (n=7 each). ConclusionThese results indicate that our SW therapy is also effective in ameliorating LV remodeling after myocardial I/R injury in pigs in vivo.

Association of Adventitial Vasa Vasorum and Inflammation With Coronary Hyperconstriction After Drug-Eluting Stent Implantation in Pigs In Vivo

BACKGROUND The importance of adventitial inflammation has been implicated for the pathogenesis of coronary artery disease. However, the roles of adventitial changes in drug-eluting stent (DES)-induced coronary hyperconstriction remain largely unknown. In the present study, this issue in pigs in vivo with a special reference to adventitial vasa vasorum (VV) formation and Rho-kinase activation, a central mechanism of coronary vasospasm, was examined. METHODS AND RESULTS Each animal received a sirolimus-eluting stent (SES) and a biolimus A9-eluting stent (BES), one in the left anterior descending and another in the left circumflex coronary arteries in a randomized manner (n=18). After 1, 3 and 6 months, coronary vasomotion was examined. At 1 month, coronary vasoconstriction to serotonin was significantly enhanced at the SES edges as compared with the BES edges (SES, 52±7% vs. BES, 22±3%, P<0.01), which was equally prevented by a selective Rho-kinase inhibitor, hydroxyfasudil. A significant difference in vasoconstriction between SES and BES was sustained for 6 months. A micro-CT showed VV augmentation at the SES site, extending to the proximal and distal edges. Immunostainings demonstrated that VV formation, macrophage infiltration in the adventitia and Rho-kinase expressions/activation were significantly enhanced at the SES edges as compared with the BES edges. CONCLUSIONS The DES with durable polymers enhances VV formation and inflammation in the adventitia, associating with the pathogenesis of DES-induced coronary hyperconstriction through Rho-kinase activation in pigs in vivo.

Increased Coronary Perivascular Adipose Tissue Volume in Patients With Vasospastic Angina

BACKGROUND Recent studies have suggested that coronary perivascular adipose tissue (PVAT) impairs coronary vasomotion, so we examined whether PVAT is increased at the spastic coronary segment in patients with vasospastic angina (VSA). METHODSANDRESULTS PVAT volume in the left anterior descending (LAD) coronary arteries on CT coronary angiography was significantly increased in 48 VSA patients with LAD spasm compared with 18 controls (30.7±2.0 vs. 21.0±3.2 cm(3), P=0.01), whereas that of total epicardial adipose tissue was comparable between the 2 groups. CONCLUSIONS The results suggested an important role of PVAT in the pathogenesis of coronary spasm. (Circ J 2016; 80: 1653-1656).

Enhanced Adventitial Vasa Vasorum Formation in Patients With Vasospastic Angina: Assessment With OFDI.

Coronary artery spasm plays important roles in the pathogenesis of a wide range of ischemic heart disease. Recent studies have demonstrated that coronary spasm is frequently noted in Caucasians as in Asians [(1)][1]. We previously demonstrated that vascular smooth muscle cell hypercontraction

Accuracy of Optical Frequency Domain Imaging for Evaluation of Coronary Adventitial Vasa Vasorum Formation After Stent Implantation in Pigs and Humans – A Validation Study –

BACKGROUND Coronary adventitia harbors a wide variety of components, such as inflammatory cells and vasa vasorum (VV). Adventitial VV initiates the development of coronary artery diseases as an outside-in supply route of inflammation. We have recently demonstrated that drug-eluting stent implantation causes the enhancement of VV formation, with extending to the stent edges in the porcine coronary arteries, and also that optical frequency domain imaging (OFDI) is capable of visualizing VV in humans in vivo. However, it remains to be fully validated whether OFDI enables the precise measurement of VV formation in pigs and humans. METHODS AND RESULTS In the pig protocol, a total of 6 bare-metal stents and 12 drug-eluting stents were implanted into the coronary arteries, and at 1 month, the stented coronary arteries were imaged by OFDI ex vivo. OFDI data including the measurement of VV area at the stent edge portions were compared with histological data. There was a significant positive correlation between VV area on OFDI and that on histology (R=0.91, P<0.01). In the human protocol, OFDI enabled the measurement of the VV area at the stent edges after coronary stent implantation in vivo. CONCLUSIONS These results provide the first direct evidence that OFDI enables the precise measurement of the VV area in coronary arteries after stent implantation in pigs and humans.

Clinical Characteristics of Patients With Acute Myocardial Infarction Who Did Not Undergo Primary Percutaneous Coronary Intervention – Report From the MIYAGI-AMI Registry Study –

BACKGROUND In the current era of primary percutaneous coronary intervention (PCI), some patients with acute myocardial infarction (AMI) still do not undergo primary PCI. METHODSANDRESULTS To examine the clinical characteristics of AMI patients who did not undergo primary PCI, we analyzed patients enrolled between 2002 and 2010 in the MIYAGI-AMI Registry Study, in which all AMI patients in the Miyagi prefecture have been prospectively registered. Among a total of 8,640 patients, 1,879 (21.7%) did not undergo primary PCI and their in-hospital mortality was significantly worse compared with those who did (21.4% vs. 6.4%, P<0.01). Multivariate analysis demonstrated that female sex was significantly associated with non-performance of primary PCI [odds ratio (95% confidence interval): 1.40 (1.22-1.61), P<0.001], along with age [1.01 (1.01-1.02), P<0.001] and heart failure on admission [2.69 (2.29-3.16), P<0.001]. When dividing by age, the non-performance rate of primary PCI in females showed a U-shaped prevalence, whereas it simply increased with aging in males. Importantly, female patients aged <80 years had a significantly higher non-performance rate of primary PCI compared with male patients, regardless of the severity of AMI. CONCLUSIONS These results indicate that in the current PCI era, various factors, including aging, heart failure on admission and sex differences, are associated with non-performance of primary PCI, which remain to be resolved in order to further improve critical care of AMI.

Beneficial effects of long-acting nifedipine on coronary vasomotion abnormalities after drug-eluting stent implantation: The NOVEL study

AIMS It is widely known that drug-eluting stents (DES) induce coronary vasomotion abnormalities. We have previously demonstrated that chronic treatment with long-acting nifedipine suppresses coronary hyperconstricting responses induced by the first-generation DES (e.g. sirolimus- and pacritaxel-eluting stents) through inhibition of vascular inflammation in pigs. To examine whether this is also the case with the second-generation DES (everolimus-eluting stents, EES) in humans, the most widely used DES in the world, we conducted a prospective, randomized, multicentre trial, termed as the NOVEL Study. METHODS AND RESULTS We evaluated 100 patients with stable angina pectoris who underwent scheduled implantation of EES in the left coronary arteries. They were randomly assigned to receive either conventional treatments alone or additionally long-acting nifedipine (10-60 mg/day) (n = 50 each). After 8-10 months, 37 patients in the control and 38 in the nifedipine group were examined for coronary vasoreactivity to intracoronary acetylcholine (ACh) by quantitative coronary angiography after 48-h withdrawal of nifedipine. Coronary vasoconstricting responses to ACh were significantly enhanced at the distal edge of EES compared with non-stented vessel (P = 0.0001) and were significantly suppressed in the nifedipine group compared with the control group (P = 0.0044). Furthermore, the inflammatory profiles were also improved only in the nifedipine group, which evaluated by serum levels of high-sensitivity CRP (P = 0.0001) and adiponectin (P = 0.0039). CONCLUSIONS These results indicate that DES-induced coronary vasomotion abnormalities still remain an important clinical issue even with the second-generation DES, for which long-acting nifedipine exerts beneficial effects associated with its anti-inflammatory effects. TRIAL REGISTRATION This study is registered at the UMIN Clinical Trial Registry (UMIN-CTR; ID=UMIN000015147).

Plasma concentration of serotonin is a novel biomarker for coronary microvascular dysfunction in patients with suspected angina and unobstructive coronary arteries

Aims Although the importance of coronary microvascular dysfunction (CMD) has been emerging, reliable biomarkers for CMD remain to be developed. We examined the potential usefulness of plasma concentration of serotonin to diagnose CMD in patients with suspected angina and unobstructive coronary arteries. Methods and results We enrolled 198 consecutive patients (M/F 116/82, 60.2 ± 13.3 years old) who underwent acetylcholine provocation test and measured plasma serotonin concentration. Coronary microvascular dysfunction was defined as myocardial lactate production without or prior to the occurrence of epicardial coronary spasm during acetylcholine provocation test. Although no statistical difference in plasma concentration of serotonin [median (inter-quartile range) nmol/L] was noted between the vasospastic angina (VSA) and non-VSA groups [6.8 (3.8, 10.9) vs. 5.1 (3.7, 8.4), P = 0.135], it was significantly higher in patients with CMD compared with those without it [7.7 (4.5, 14.2) vs. 5.6 (3.7, 9.3), P = 0.008]. Among the four groups classified according to the presence or absence of VSA and CMD, serotonin concentration was highest in the VSA with CMD group. Importantly, there was a positive correlation between plasma serotonin concentration and baseline thrombolysis in myocardial infarction frame count (P = 0.001), a marker of coronary vascular resistance. The classification and regression trees analysis showed that plasma serotonin concentration of 9.55 nmol/L was the first discriminator to stratify the risk for the presence of CMD. In multivariable analysis, serotonin concentration greater than the cut-off value had the largest odds ratio in the prediction of CMD [odds ratio (95% confidence interval) 2.63 (1.28–5.49), P = 0.009]. Conclusions Plasma concentration of serotonin may be a novel biomarker for CMD in patients with angina and unobstructive coronary arteries.

Focal Vasa Vasorum Formation in Patients With Focal Coronary Vasospasm – An Optical Frequency Domain Imaging Study –

Coronary adventitia has attracted much attention as a source of inflammation because it harbors nutrient blood vessels, oronary artery spasm plays important roles in the pathogenesis of a wide range of ischemic heart disease, not only in vasospastic angina (VSA) but also in other forms of ischemic heart disease.1 Although VSA is believed to be more prevalent in Asian compared with Caucasian subjects,2 it has been recently suggested that the prevalence of VSA could be similar in both populations.3 Thus, coronary spasm is an emerging issue in the world. Furthermore, given C