Green tea polyphenol epigallocatechin-3-gallate increases atherosclerotic plaque stability in apolipoprotein E-deficient mice fed a high-fat diet

Background: Epigallocatechin-3-gallate (EGCG), which is the principal component of green tea, has been shown to prevent atherosclerosis. However, the effect of EGCG on atherosclerotic plaque stability remains unknown. Aim: This study aimed to assess whether EGCG can enhance atherosclerotic plaque stability and to investigate the underlying mechanisms. Methods: Apolipoprotein E-deficient mice fed a high-fat diet were injected intraperitoneally with EGCG (10 mg/kg) for 16 weeks. Cross sections of the brachiocephalic arteries were stained with haematoxylin and eosin for morphometric analyses or Masson’s trichrome for collagen content analyses. Immunohistochemistry was performed to evaluate the percentage of macrophages and smooth muscle cells (SMCs). Protein expression and matrix metalloproteinase (MMP) activity were assayed by Western blot and gelatin zymography, respectively. Serum inflammatory cytokine levels were quantified by enzyme-linked immunosorbent assays. Results: After 16 weeks of feeding the high-fat diet, there were clear atherosclerotic lesions in the proximal brachiocephalic artery segments according to HE staining. EGCG treatment significantly increased the thickness of the fibrous cap. In the atherosclerotic plaques of the EGCG group, the relative macrophage content was decreased, whereas the relative SMC and collagen contents were increased. The expression levels of MMP-2, MMP-9, and extracellular matrix metalloproteinase inducer (EMMPRIN) were significantly decreased by EGCG treatment. In addition, EGCG treatment decreased the circulat­ing tumour necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1, and interferon-γ levels in apolipoprotein E-deficient mice. Conclusions: EGCG promotes atherosclerotic lesion stability in apolipoprotein E-deficient mice. Potentially, these effects are mediated through the inhibition of inflammatory cytokine, MMPs and EMMPRIN expression

Association of admission serum calcium levels and in-hospital mortality in patients with acute ST-elevated myocardial infarction: an eight-year, single-center study in China.

OBJECTIVE: The relationship between admission serum calcium levels and in-hospital mortality in patients with acute ST-segment elevation myocardial infarction (STEMI) has not been well definitively explored. The objective was to assess the predictive value of serum calcium levels on in-hospital mortality in STEMI patients. METHODS: From 2003 to 2010, 1431 consecutive STEMI patients admitted to the First Affiliated Hospital of Nanjing Medical University were enrolled in the present study. Patients were stratified according to quartiles of serum calcium from the blood samples collected in the emergency room after admission. Between the aforementioned groups,the baseline characteristics, in-hospital management, and in-hospital mortality were analyzed. The association of serum calcium level with in-hospital mortality was calculated by a multivariable Cox regression analysis. RESULTS: Among 1431 included patients, 79% were male and the median age was 65 years (range, 55-74). Patients in the lower quartiles of serum calcium, as compared to the upper quartiles of serum calcium, were older, had more cardiovascular risk factors, lower rate of emergency revascularization,and higher in-hospital mortality. According to univariate Cox proportional analysis, patients with lower serum calcium level (hazard ratio 0.267, 95% confidence interval 0.164-0.433, p<0.001) was associated with higher in-hospital mortality. The result of multivariable Cox proportional hazard regression analyses showed that the Killip's class≥3 (HR = 2.192, p = 0.026), aspartate aminotransferase (HR = 1.001, p<0.001), neutrophil count (HR = 1.123, p<0.001), serum calcium level (HR = 0.255, p = 0.001), and emergency revascularization (HR = 0.122, p<0.001) were significantly and independently associated with in-hospital mortality in STEMI patients. CONCLUSIONS: Serum calcium was an independent predictor for in-hospital mortality in patients with STEMI. This widely available serum biochemical index may be incorporated into the current established risk stratification model of STEMI patients. Further studies are required to determine the actual mechanism and whether patients with hypocalcaemia could benefit from calcium supplement

In-hospital management and mortality of the STEMI patients according to serum calcium.

<p>Data are expressed as mean ± standard deviation for normally distributed data and percentage (%) for categorical variables. Revascularization  =  percutaneous coronary intervention; ACEI  =  angiotensin-converting enzyme inhibitors; ARB  =  angiotensin receptor blockers.</p

Distribution of baseline serum calcium levels at admission in 1,431 STEMI patients.

<p>The admission serum calcium levels were normally distributed with a mean admission calcium level of 2.25±0.21 (mmol/L).</p

Univariate and multivariable Cox regression analyses of factors associated in-hospital mortality.

<p>^aAdjusted for age, gender, Killip's class≥3, LVEF, neutrophil count, albumin, aspartate aminotransferase, serum calcium and emergency revascularization.</p

Comparisons of the baseline characteristics of the STEMI patients according to serum calcium.

<p>Data are expressed as mean ± standard deviation for normally distributed data, median (inter quartile range) for abnormally distributed data and percentage (%) for categorical variables. CK  =  Creatine kinase; LVEF  =  Left ventricular ejection fraction; LDL  =  Low density lipoprotein; HDL  =  High density lipoprotein; AST  =  Aspartate aminotransferase.</p

Kaplan-Meier curves for in-hospital cumulative mortality according to serum calcium of admission.

<p>Patients were stratified by quartiles of serum calcium. The comparisons among the groups were performed using the log rank test.</p