Social Support, Sense of Coherence, and Self-Management among Hemodialysis Patients.

Self-management is essential for patients who require regular hemodialysis treatment. This study aimed to explore the relationships between social support, sense of coherence (SOC), and self-management in hemodialysis patients and to examine whether SOC plays a mediating role. In a cross-sectional study, 402 hemodialysis patients from four tertiary hospitals were recruited. Data were analyzed using structural equation modeling. Social support, SOC, and self-management were significantly correlated with each other. The proposed model provided a good fit to the data. Social support had a direct effect on self-management and SOC, partially mediated the effect of social support on self-management (ß = 0.248, p = 0.001). Social support and SOC explained 69% of the variance in self-management. Our findings indicate that health care providers can enhance social support with an emphasis on strengthening SOC strategies to better improve self-management in hemodialysis patients.

Correlates of Symptom Burden of Hemodialysis Patients.

This cross-sectional study assessed the overall symptom burden, including the prevalence, frequency, severity, and distress of symptoms among hemodialysis patients, and explored the relationship between demographic characteristics, clinical variables, self-management, sense of coherence, social support, and symptom burden in these patients. Herein, a regression analysis was performed to determine associations with symptom burden. The mean score of symptom burden among the participants (n = 382) was 74.12, with an average number of 12 symptoms. The analysis revealed that self-management, sense of coherence, and social support were negatively associated with the overall symptom burden. The multiple regression model showed that 48.6% of the variance in symptom burden was explained by meaningfulness, emotional management, daily urine output, subjective support, gender, and manageability. These findings contribute to the knowledge of symptom burden among hemodialysis patients and some new predictors (self-management, sense of coherence, and social support) of their symptom burden.

Epigallocatechin-3-Gallate (EGCG)-Inducible SMILE Inhibits STAT3-Mediated Hepcidin Gene Expression.

Hepatic peptide hormone hepcidin, a key regulator of iron metabolism, is induced by inflammatory cytokine interleukin-6 (IL-6) in the pathogenesis of anemia of inflammation or microbial infections. Small heterodimer partner-interacting leucine zipper protein (SMILE)/CREBZF is a transcriptional corepressor of nuclear receptors that control hepatic glucose and lipid metabolism. Here, we examined the role of SMILE in regulating iron metabolism by inflammatory signals. Overexpression of SMILE significantly decreased activation of the Janus kinase 2-signal transducer and activator of transcription 3 (STAT3)-mediated hepcidin production and secretion that is triggered by the IL-6 signal in human and mouse hepatocytes. Moreover, SMILE co-localized and physically interacted with STAT3 in the nucleus in the presence of IL-6, which significantly suppressed binding of STAT3 to the hepcidin gene promoter. Interestingly, epigallocatechin-3-gallate (EGCG), a major component of green tea, induced SMILE expression through forkhead box protein O1 (FoxO1), as demonstrated in FoxO1 knockout primary hepatocytes. In addition, EGCG inhibited IL-6-induced hepcidin expression, which was reversed by SMILE knockdown. Finally, EGCG significantly suppressed lipopolysaccharide-induced hepcidin secretion and hypoferremia through induction of SMILE expression in mice. These results reveal a previously unrecognized role of EGCG-inducible SMILE in the IL-6-dependent transcriptional regulation of iron metabolism.

Analysis of Plaque Composition in Coronary Chronic Total Occlusion Lesion Using Virtual Histology-Intravascular Ultrasound.

BACKGROUND AND OBJECTIVES: Success rates of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have recently been reported to range from 80% to 90%. A better understanding of the pathologic characteristics of the CTO lesion may helpful to improving CTO PCI success rates. We evaluated the CTO lesion in patients with stable angina (SA) by virtual histology-intravascular ultrasound (VH-IVUS). SUBJECTS AND METHODS: The study population consisted of 149 consecutive patients with SA underwent VH-IVUS examination. We analyzed demographic and VH-IVUS findings in 22 CTO patients (17 males; mean, 62.3 years old) compared with 127 non-CTO patients (82 males; mean, 61.3 years old). RESULTS: A significantly lower ejection fraction (57.6±13.0% vs. 65.4±8.8%, p=0.007) was detected in the CTO group compared with the non-CTO group. Reference vessel lumen area of the proximal and distal segment was significantly less in CTO group than in non-CTO group. The lesion length of the CTO group was significantly longer than those of the non-CTO group (24.4±9.6 mm vs. 17.2±7.4 mm, p<0.001). Total atheroma volume (224±159 mm(3) vs. 143±86 mm(3), p=0.006) and percent atheroma volume (63.2±9.6% vs. 55.8±8.5%, p=0.011) of the CTO group were also significantly greater than those of non-CTO group. However, the lesion length adjusted plaque composition of the CTO group was not significantly different compared with that of the non-CTO group. CONCLUSION: CTO lesions had a longer lesion length and greater plaque burden than the non-CTO lesion in patients with SA. However, lesion length adjusted plaque composition showed similar between the two groups. These results support that plaque characteristics of CTO lesions are similar to non-CTO lesions in patients with SA.

Analysis of Carotid Ultrasound Findings on Cardiovascular Events in Patients with Coronary Artery Disease during Seven-Year Follow-Up.

BACKGROUND AND OBJECTIVES: Both carotid intima-media thickness (CIMT) and carotid plaque are important factors in the primary prevention of cardiac disease. However, it is unclear which one is more important for prognosis, especially in patients with coronary artery disease (CAD). SUBJECTS AND METHODS: In total, 1426 consecutive CAD patients, proven by angiography, were followed-up for a mean of 85 months. The study population was divided into four groups depending on the CIMT (≥0.83 mm, >95 percentile in Korea) and the presence or absence of carotid plaque. RESULTS: Patients with carotid plaque and thick CIMT (n=237, 16.6%) had a higher prevalence of hypertension, diabetes mellitus, and dyslipidemia than those had plaque and thin CIMT (n=213, 14.9%), those without plaque and thick CIMT (n=265, 18.6%) and those without plaque and thin CIMT (n=711, 49.9%). The patients with carotid plaque and thick CIMT group had a higher cardiac mortality rate (20.7% vs. 13.1%, 9.4% and 3.9%, respectively, p<0.001) and higher major adverse cardiovascular events (MACE) including death, acute myocardial infarction, and stroke (27.8% vs. 18.8%, 15.5% and 9.3%, respectively, p<0.001) than any other groups. Multivariate Cox regression analysis showed that the presence of carotid plaque with thick CIMT had the highest hazard ratio (HR) compared to other groups (HR 2.23 vs. 1.81, 2.01) for cardiac mortality. Also, carotid plaque had a higher HR than CIMT for mortality (HR 1.56 vs. 1.37) and MACE (HR 1.54 vs. 1.36) in the total study population. CONCLUSION: Carotid plaque is a more important prognostic factor than CIMT in patients with CAD, and adding a thick CIMT to carotid plaque increases the prognostic power for cardiac events.

Impact of plaque composition on long-term clinical outcomes in patients with coronary artery occlusive disease.

BACKGROUND AND OBJECTIVES: It is unclear which plaque component is related with long-term clinical outcomes in patients with coronary artery occlusive disease (CAOD). We assessed the relationship between plaque compositions and long-term clinical outcomes in those patients. SUBJECTS AND METHODS: The study subjects consisted of 339 consecutive patients (mean 61.7±12.2 years old, 239 males) who underwent coronary angiogram and a virtual histology-intravascular ultrasound examination. Major adverse cardiac and cerebrovascular events (MACCE), including all-cause death, non-fatal myocardial infarction, cerebrovascular events, and target vessel revascularization were evaluated during a mean 28-month follow-up period. RESULTS: Patients with high fibrofatty volume (FFV, >8.90 mm(3), n=169) had a higher incidence of MACCE (25.4% vs. 14.7%, p=0.015), male sex (75.7% vs. 65.3%, p=0.043), acute coronary syndrome (53.3% vs. 35.9%, p=0.002), multivessel disease (62.7% vs. 41.8%, p<0.001) and post-stent slow flow (10.7% vs. 2.4%, p=0.002) than those with low FFV (FFV≤8.90 mm(3), n=170). Other plaque composition factors such as fibrous area/volume, dense calcified area/volume, and necrotic core area/volume did not show any impact on MACCE. Cardiogenic shock {hazard ratio (HR)=8.44; 95% confidence interval (CI)=3.00-23.79; p<0.001} and FFV (HR=1.85; 95% CI=1.12-3.07; p=0.016) were the independent predictors of MACCE by Cox regression analysis. Thin-cap fibroatheroma, necrotic core area, and necrotic core volume were not associated with MACCE. CONCLUSION: FFV of a culprit lesion was associated with unfavorable long-term clinical outcomes in patients with CAOD.

The impact of glucose control on coronary plaque composition in patients with diabetes mellitus.

BACKGROUND: Patients with diabetes mellitus (DM) are known to have large necrotic core in their coronary plaque compared to non-DM patients. We assessed coronary plaque composition in patients with angina and with/without DM according to glucose control. METHODS: Study subjects consisted of 114 non-DM patients, 14 well-controlled DM patients (hemoglobin A1c [HbA1c] <7.0%), and 37 poorly controlled DM patients (HbA1c ≥ 7%) who underwent virtual histology intravascular ultrasound (VH-IVUS) examinations of culprit lesions. RESULTS: The DM patients had longer lesion length (20.2 ± 7.8 mm vs 17.0 ± 7.3 mm; P=.013) than non-DM patients. The plaque volume was highest in the poorly-controlled DM patients (188.9 ± 92.6 mm(3)) compared with the non-DM patients (144.1 ± 92.3 mm(3); P=.011) and the well-controlled DM patients (151.7 ± 82.4 mm(3); P=.194). The well-controlled DM patients had less dense calcium (0.33 ± 0.14 mm(3)/mm vs 0.71 ± 0.60 mm(3)/mm; P=.020) and less necrotic core (0.71 ± 0.48 mm(3)/mm vs 1.30 ± 0.94 mm(3)/mm; P=.029) than the poorly-controlled DM patients and had similar amounts of dense calcium and necrotic core with non-DM patients, whereas fibrous and fibro-fatty volume showed no significant differences among the groups. CONCLUSION: Coronary plaque composition and plaque volume in well-controlled DM patients are similar to those in non-DM patients and both groups had less dense calcium and necrotic core volume than the poorly-controlled DM patients. These findings suggest hyperglycemia control is important in DM patients with angina.

Hypercholesterolemia and in-vivo coronary plaque composition in patients with coronary artery disease: a virtual histology - intravascular ultrasound study.

BACKGROUND AND OBJECTIVES: Hypercholesterolemia is a key factor in the development of atherosclerosis. We sought to evaluate the relation between hypercholesterolemia and plaque composition in patients with coronary artery disease. SUBJECTS AND METHODS: Study subjects consisted of 323 patients (mean 61.5 years, 226 males) who underwent coronary angiography and virtual histology-intravascular ultrasound examination. Patients were divided into two groups according to total cholesterol level: hypercholesterolemic group (≥200 mg/dL, n=114) and normocholesterolemic group (<200 mg/dL, n=209). RESULTS: Hypercholesterolemic patients were younger (59.7±13.3 years vs. 62.6±11.5 years, p=0.036), than normocholesterolemic patients, whereas there were no significant differences in other demographics. Hypercholesterolemic patients had higher corrected necrotic core volume (1.23±0.85 mm(3)/mm vs. 1.02±0.80 mm(3)/mm, p=0.029) as well as percent necrotic core volume (20.5±8.5% vs. 18.0±9.2%, p=0.016) than normocholesterolemic patients. At the minimal lumen area site, percent necrotic core area (21.4±10.5% vs. 18.4±11.3%, p=0.019) and necrotic core area (1.63±1.09 mm(2) vs. 1.40±1.20 mm(2), p=0.088) were also higher than normocholesterolemic patients. Multivariate linear regression analysis showed that total cholesterol level was an independent factor of percent necrotic core volume in the culprit lesion after being adjusted with age, high density lipoprotein-cholesterol , hypertension, diabetes mellitus, smoking and acute coronary syndrome (beta 0.027, 95% confidence interval 0.02-0.053, p=0.037). CONCLUSION: Hypercholesterolemia was associated with increased necrotic core volume in coronary artery plaque. This study suggests that hypercholesterolemia plays a role in making plaque more complex, which is characterized by a large necrotic core, in coronary artery disease.

Carotid plaque is associated with increased cardiac mortality in patients with coronary artery disease.

BACKGROUND: It is still controversial whether carotid plaque is associated with cardiovascular events in patients with coronary artery disease (CAD). The aim of the present study is to evaluate the impact of carotid plaque on long term clinical outcomes especially in patients with CAD. METHODS: The study population consisted of 1390 consecutive patients with angiographically proven CAD. All subjects underwent carotid scanning 1 day before or after coronary angiogram and were followed up for major adverse cardiovascular events (MACE; death, myocardial infarction, stroke, revascularization, restenosis and hospitalization for heart failure) during a mean of 54.2 ± 23.9 months. RESULTS: Patients with carotid plaque (n=433) were older, had higher prevalence of cardiovascular risk factors and acute coronary syndrome (34.2% vs. 24.6%, p<0.001) than those without carotid plaque (n=957). On univariate analysis, the presence of carotid plaque was a predictor of cardiac death, hard MACE (death, myocardial infarction and stroke) and total MACE, whereas carotid intima-media thickness (CIMT) was a predictor of total MACE. Multivariate analysis revealed that carotid plaque was associated with cardiac death (HR 6.99, 95% CI 1.88-25.95, p=0.004), hard MACE (HR 1.89, 95% CI 1.18-3.04, p=0.008) and total MACE (HR 1.47, 95% CI 1.13-1.90, p=0.004), whereas CIMT was associated only with total MACE (HR 1.39, 95% CI 1.06-1.81, p=0.017). CONCLUSIONS: Carotid plaque is a strong predictor of future cardiac death and MACE in patients with CAD. This study suggests that carotid plaque has additional value for secondary prevention and more important prognostic factor than CIMT in patients with CAD.

Discrepancy of calcium detection between gray scale intravascular ultrasound and spectral analysis of radiofrequency data.

BACKGROUND: We evaluated discrepancy of calcium detection between gray scale intravascular ultrasound (IVUS) and virtual histology (VH)-IVUS and the association between coronary calcium and plaque composition. METHODS: Study population consisted of 162 consecutive patients who underwent percutaneous coronary intervention with VH-IVUS study. Subjects were divided into 3 groups based on gray scale IVUS findings; No calcification group (n=50), spotty group (n=56) who had a lesion containing only small calcium deposits within an arc <90° and diffuse group (n=56) who had a diffuse calcified lesion with an arc ≥ 90° in ≥ 1 cross-sectional image of the lesion. RESULTS: No calcification group was younger than spotty and diffuse groups (54.4 ± 13.0 years vs. 61.1 ± 10.7 years and 64.2 ± 9.9 years, p=0.011 and p<0.001, respectively). No calcification group had some degree of dense calcium (5. 7 ± 6.9 mm(3)) by VH-IVUS analysis. Furthermore, calcified volume by VH-IVUS in no calcification group was similar to those in spotty group (5.7 ± 6.9 mm(3) vs. 5.4 ± 4.4mm(3)). Dense calcium volume was correlated directly with plaque volume (r=0.65, p<0.001), fibrous volume (r=0.54, p<0.001), fibro-fatty volume (r=0.29, p<0.001) and lipid core volume (r=0.77, p<0.001). In multiple regression analysis, lipid core volume (ß=0.287, 95% confidence interval (CI) 0.187-0.388, p<0.001) was an independent predictor of dense calcium volume. CONCLUSIONS: This study showed that coronary calcium can be present even if invisible in gray scale IVUS and associated with lipid core volume, which is a characteristic of plaque vulnerability.

Positive Vascular Remodeling in Culprit Coronary Lesion is Associated With Plaque Composition: An Intravascular Ultrasound-Virtual Histology Study.

BACKGROUND AND OBJECTIVES: The relationship between the positive remodeling (PR) of a coronary artery and plaque composition has been studied only in a relatively small number of study population or non-culprit lesion. We evaluated the association between coronary plaque composition and coronary artery remodeling in a relatively large number of culprit lesions. SUBJECTS AND METHODS: The study population consisted of 325 consecutive patients with coronary artery disease that underwent intravascular ultrasound-virtual histology examination in a culprit lesion. The remodeling index (RI) was calculated as the lesion external elastic membrane (EEM) area divided by the average reference EEM area. RESULTS: The lesions with PR (RI>1.05, n=97, mean RI=1.19±0.12) had a higher fibrous volume/lesion length (3.85±2.12 mm(3)/mm vs. 3.04±1.79 mm(3)/mm, p=0.003) and necrotic core volume/lesion length (1.26±0.89 mm(3)/mm vs. 0.90±0.66 mm(3)/mm, p=0.001) than those with negative remodeling (NR) (RI<0.95, n=132, mean RI=0.82±0.09). At the minimal luminal area site, the lesions with PR had a higher fibrous area (5.81±3.17 mm(2) vs. 3.61±2.30 mm(2), p<0.001), dense calcified area (0.73±0.69 mm(2) vs. 0.46±0.43 mm(2), p=0.001), and necrotic core area (1.93±1.33 mm(2) vs. 1.06±0.91 mm(2), p<0.001) than those with NR. RI showed significant positive correlation with fibrous volume/lesion length (r=0.173, p=0.002), necrotic core volume/lesion length (r=0.188, p=0.001), fibrous area (r=0.347, p<0.001), fibrofatty area (r=0.111, p=0.036), dense calcified area (r=0.239, p<0.001), and necrotic core area (r=0.334, p<0.001). Multivariate analysis showed that the independent factor for PR was the necrotic core volume/lesion length (beta=0.130, 95% confidence interval; 0.002-0.056, p=0.037) over the entire lesion. CONCLUSION: This study suggests that PR in a culprit lesion is associated with the necrotic core volume in the entire lesion, which is a characteristic of vulnerable plaque.

Fibro-Fatty Component is Important for the Long-Term Clinical Events in Patients Who Have Undergone Primary Percutaneous Coronary Intervention.

BACKGROUND AND OBJECTIVES: We evaluated which plaque components are associated with long-term clinical events in patients who underwent primary percutaneous coronary intervention (PCI). SUBJECTS AND METHODS: The study subjects consisted of 57 consecutive patients (mean age, 58.5±14.5 years; 45 males) who underwent primary PCI and a virtual histology-intravascular ultrasound examination. Major adverse cardiac events (MACEs) including death, acute myocardial infarction, stroke, and revascularization were evaluated during the mean 28 month follow-up period. RESULTS: Patients with high fibro-fatty volume (FFV >13.4 mm(3), n=29; mean age, 61.3 years) had a lower ejection fraction (52.7% vs. 59.4%, p=0.022), a higher incidence of multi-vessel disease (69.0% vs. 28.6%, p=0.002), larger plaque area (25.7 mm(2) vs. 15.9 mm(2), p<0.001), and larger plaque volume (315 mm(3) vs. 142 mm(3), p<0.001) than those with a low FFV (≤13.4 mm(3), n=28; mean age, 55.6 years). Patients with high FFV had a significantly higher incidence (32.1% vs. 8.3%, p=0.036) of MACE than those with low FFV. When we divided the study population according to the necrotic core volume (NCV), fibrous volume, or dense calcified volume, no significant findings in terms of demographics and MACE rates were observed. A Cox regression analysis revealed that the independent factor for MACE was FFV (hazard ratio, 6.748; 95% confidence interval, 1.168-38.971, p=0.033) in this study population. CONCLUSION: The coronary plaque component, particularly FFV, but not NCV, was important in long-term clinical outcomes in patients who underwent primary PCI.

Evaluation of CVD diamond coating layer using leaky Rayleigh wave.

In the present study, the possibility of using leaky Rayleigh waves as a nondestructive tool for the evaluation of CVD diamond coating layer is explored experimentally. For this purpose, a set of CVD diamond coated specimens are prepared and the leaky Rayleigh waves are measured in an immersion, pulse-echo setup. For the proper analysis of the acquired signals we propose a novel signal analysis approach, namely the "time trace angular scan (TTAS)" image. Then, the proposed approach together with the backward radiation profiles are applied for the analysis of signals acquired in the initial experiments. The TTAS image shows the entire information on both time-of-arrival and angle of incidence of the signals for the proper "time-angle windowing." Then, the backward radiation profile of the windowed signals provides adequate parameters from which nondestructive evaluation of the coated specimens is carried out.