Inflammation in variant angina: Is there any evidence?

CARDIOPROTECTIVE ROLES OF THE CHINESE MEDICINAL FORMULA BAO-XIN-TANG ON ACUTE MYOCARDIAL INFARCTION IN RATS

Background:

Bao-Xin-Tang (BXT) is a traditional Chinese medicinal formula used for the treatment of coronary heart disease and known to have favorable therapeutic benefits. The current study was designed to determine whether BXT has a cardioprotective role for acute myocardial infarction. The underlying mechanisms were also explored.

Materials and Methods:

The Sprague-Dawley rat model of acute myocardial infarction was established by occluding the left anterior descending branch of the coronary artery. After a 3-h ischemic period, we determined the myocardial infarction size, inflammatory components, and antioxidant activities.

Results:

The data showed that BXT could reduce the infarction size and lower the levels of C-reactive protein, interleukin-6, and myeloperoxidase, and increase the activities of superoxide dismutase and the anti-inflammatory cytokine, interleukin-10. These results indicate that administration of BXT, following acute myocardial infarction, could reduce infarct size.

Conclusion:

The effects of BXT may be related to its anti-inflammatory and anti-oxidative properties.

Association of Genetic Polymorphisms on Vascular Endothelial Growth Factor and its Receptor Genes with Susceptibility to Coronary Heart Disease

Background

Coronary heart disease (CHD) is a cardiovascular disease characterized by high morbidity and mortality. Vascular endothelial growth factor (VEGF) and its receptor, named kinase insert domain-containing receptor (KDR, or VEGFR2), which are involved with angiogenesis and vascular repair, could partly contribute to the development of CHD. The aim of this study, therefore, was to investigate the potential correlations between genetic polymorphisms on VEGF and KDR and susceptibility to CHD, and the integrative role of SNPs combined on susceptibility to CHD were also studied.

Material/Methods

Venous blood samples gathered from 533 DCM patients and 533 healthy controls were used to genotype tag-SNPs of VEGF (rs699947, rs2010963, and rs3025010) and KDR (rs2071559, rs2305948, and rs1870377) by polymerase chain reaction (PCR) and SNaPshot assay. Investigations of potential haplotypes were conducted on the basis of SHEsis software. The odds ratio (ORs) and relevant 95% confidence intervals (95% CI) were used to estimate associations of SNPs/haplotypes with risk of CHD. Multivariate logistic regression was also performed, taking certain clinical characteristics (e.g., BMI, smoking, alcohol consumption, diabetes, and hypertension) into consideration. All statistical analyses were done with STATA Version 12.0 software.

Results

Our results suggest that rs699947 (T>C) on KDR are associated with susceptibility to CHD under the dominant model before (OR=1.35, 95% CI: 1.05–1.73, P=0.019) and after (OR=1.33, 95% CI: 1.01–1.76, P=0.044), allowing for clinical characteristics (e.g., BMI, smoking, alcohol consumption, diabetes, and hypertension). rs2305948 (G>A) and rs1870377 (A>T) on VEGF were also found to be associated with risk of CHD under the recessive model after adjustment with multivariate regression analyses (OR=1.21, 95% CI: 1.02–1.43, P=0.029; OR=2.54, 95% CI: 1.13–5.75, P=0.025); OR=2.83, 95% CI: 1.47–5.46, P=0.002, respectively). Additionally, haplotype analyses revealed that integration of 5 SNPs would either raise (e.g. C-C-T-G-T and T-G-T-G-T) or reduce (e.g. C-C-C-G-T, T-C-T-G-A, T-C-T-G-T, and T-G-T-G-A) risk of CHD.

Conclusions

Genetic polymorphisms on VEGF (rs699947) and KDR (rs2305948and rs1870377), as well as relevant haplotypes, may serve as genetic markers that might be useful in future investigations on the pathogenesis of CHD.

The association between soluble lectin-like oxidized low-density lipoprotein receptor-1 levels and patients with isolated coronary artery ectasia

Some evidence suggests that chronic inflammation plays a critical role in the development and progression of coronary artery ectasia. Lectin-like oxidized low-density lipoprotein receptor-1 is involved in multiple phases of vascular dysfunction, including endothelial dysfunction, atherogenesis, initiation of plaque rupture, and restenosis. The objectives was to study the purpose of the current study was to determine whether soluble lectin-like oxidized low-density lipoprotein receptor-1 is associated with isolated coronary artery ectasia patients. Forty-six patients with isolated coronary artery ectasia without stenosis and 46 control subjects with angiographically normal coronary arteries were included in this study. Lectin-like oxidized low-density lipoprotein receptor-1 levels were measured in serum by sandwich enzyme-linked immunosorbent assay. Baseline characteristics of the two groups were similar. Plasma levels of lectin-like oxidized low-density lipoprotein receptor-1 were significantly higher in the coronary artery ectasia group than normal coronary artery group (1.7 ± 0.8 ng/ml vs. 1.1 ± 0.3 ng/ml, P < 0.001, respectively). No correlation was found between plasma soluble lectin-like oxidized low-density lipoprotein receptor-1 levels and different types of ectasia in patients with coronary artery ectasia. In this study, we found significantly higher levels of soluble lectin-like oxidized low-density lipoprotein receptor-1 in coronary artery ectasia patients when compared to control subjects with normal coronary arteries, suggesting that soluble lectin-like oxidized low-density lipoprotein receptor-1 may be involved in the pathogenesis of coronary artery ectasia.

Expanded network of inflammatory markers of atherogenesis: where are we now?

Inflammatory biomarkers play a pivotal role in atherosclerotic lesions. The plasma levels of these markers are predictive of adverse outcomes such as myocardial infarction and cardiovascular death. The immune system is involved at all stages of atherogenesis via activation of monocytes/macrophages and T lymphocytes. Circulating proinflammatory cytokines and chemokines produced by these cells interact with specific receptors on various cells and activate specific signaling pathways, leading to inflammation-induced atherosclerotic lesions. Recent studies have focused on predictive value of inflammatory biomarkers such as C-reactive protein and interleukin-6. These biomarkers were shown to be associated with poor quality of life and predictive of adverse events in coronary atherosclerosis and left ventricular dysfunction. Vascular predictive value of other numerous inflammatory markers is being investigated. We herein analyze the role of several mediators of inflammation, affecting vascular functions and leading toward atherosclerotic lesions.

Expanded Network of Inflammatory Markers of Atherogenesis: Where Are We Now?

Inflammatory biomarkers play a pivotal role in atherosclerotic lesions. The plasma levels of these markers are predictive of adverse outcomes such as myocardial infarction and cardiovascular death. The immune system is involved at all stages of atherogenesisviaactivation of monocytes/macrophages and T lymphocytes.Circulating proinflammatory cytokines and chemokines produced by these cells interact with specific receptors on various cells and activate specific signaling pathways, leading to inflammation-induced atherosclerotic lesions. Recent studies have focused on predictive value of inflammatory biomarkers such as C-reactive protein and interleukin-6. These biomarkers were shown to be associated with poor quality of life and predictive of adverse events in coronary atherosclerosis and left ventricular dysfunction. Vascular predictive value of other numerous inflammatory markers is being investigated. We herein analyze the role of several mediators of inflammation, affecting vascular functions and leading toward atherosclerotic lesions.

Recent insights into the mechanisms of vasospastic angina

Coronary artery spasm plays an important role in the pathogenesis of many types of ischemic heart disease, not only in vasospastic angina but also in myocardial infarction and sudden death, particularly in the asian population. Patients with vasospastic angina are known to have defective endothelial function due to reduced nitric oxide bioavailability. Moreover, markers of oxidative stress and plasma levels of C-reactive protein are elevated. Smoking, polymorphysms of endothelial nitric oxide synthetase (eNOS), and low-grade inflammation have been regarded as the most important risk factors for vasospastic angina. The recent body of evidence indicates that RhoA and its down stream effector, ROCK/Rho-kinase, are associated with hypercontraction of vascular smooth muscle of the coronary artery and regulation of eNOS activity. Thus, endothelial dysfunction through abnormalities of eNOS and enhanced contractility of vascular smooth muscle in coronary artery segments are considered major mechanisms in vasospastic angina. However, the precise mechanisms for coronary vasospasm are not well understood. This article will review current understanding of the mechanism of coronary artery spasm.

The levels of tumor necrosis factor-alpha and interleukin-6 in patients with isolated coronary artery ectasia

Background/Aim. Coronary artery ectasia (CAE) is considered as a variant of atherosclerosis. Tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) are among the sensitive markers of systemic inflammation. The aim of this study was to evaluate the plasma levels of the cytokines; TNF-α and IL-6 in CAE patients. Methods. Plasma concentrations of TNF-α and IL-6 were measured in 36 patients with CAE (28 males, mean age: 58.2 ± 12 years), and results were compared with age and sex-matched controls (n = 32) without coronary artery ectasia. TNF-α and IL-6 concentrations in blood were assesed by enzyme-linked immunosorbent assay (ELISA). Results. Baseline characteristics of the two groups were similar. TNF-α and IL-6 levels were significantly higher in CAE group than controls (15.6 ± 11.2 pg/mL versus 7.8 ± 3.7 pg/mL, P < .001, and 17.2 ± 12.6 versus 7.6 ± 2.1 P < .0001, resp.). Conclusion. CAE patients showed increases in TNF-α and IL-6 levels compared to the controls. This study provides evidence for alterations in the proinflamatory cytokines which suggest the involvement of the immune system in the pathophysiology of CAE. Further placebo-controlled studies are needed to evaluate the clinical significance of this increase in TNF-α and IL-6 levels.

Histamine induces postprandial tachycardia through a direct effect on cardiac H2-receptors in pythons

The intrinsic heart rate of most vertebrates studied, including humans, is elevated during digestion, suggesting that a nonadrenergic-noncholinergic factor contributes to the postprandial tachycardia. The regulating factor, however, remains elusive and difficult to identify. Pythons can ingest very large meals, and digestion is associated with a marked rise in metabolism that is sustained for several days. The metabolic rise causes more than a doubling of heart rate and a fourfold rise in cardiac output. This makes the python an interesting model to investigate the postprandial tachycardia. We measured blood pressure and heart rate in fasting Python regius, and at 24 and 48 h after ingestion of a meal amounting to 25% of body wt. Digestion caused heart rate to increase from 25 to 56 min, whereas blood pressure was unchanged. The postprandial rise in heart rate was partially due to a doubling of intrinsic heart rate. The H2-antagonist did not affect heart rate of fasting snakes but decreased heart rate by 15–20 min at 24 h into digestion, whereas it had no effects at 48 h. Thus, the histaminergic tone on the heart rose from none to 30% at 24 h but vanished after 48 h. In anesthetized snakes, histamine caused a systemic vasodilatation and a marked increase in heart rate and cardiac output mediated through a direct effect on H2- receptors. Our study strongly indicates that histamine regulates heart rate during the initial phase of digestion in pythons. This study describes a novel regulation of the vertebrate heart.

The role of inflammation in coronary artery calcification

Vascular calcification is an age-dependent, common finding in human coronary arteries and begins as early as the second decade of life, just after fatty streak formation. Previous studies have showed that the severity of coronary calcification is closely related to atherosclerotic plaque burden and cardiac event rate. In the past few decades, coronary calcification has been considered passive and degenerative. With recent clinical and basic research, however, there is increasing recognition that coronary calcification is an active, regulated process. Current diagnostic methods for coronary artery calcification (CAC) are usually traditional coronary angiography, intravascular ultrasound (IVUS), electron beam computed tomography (EBCT) and multi-slice computed tomography (MSCT) while treatment for patients with calcified coronary arteries is troublesome. Several lines of evidence suggest that inflammation plays a major role in the development of atherosclerosis as well as its clinical manifestations. Recent study showed that inflammatory process might be also involved in coronary calcification. Accordingly, measurements of inflammatory markers such as C-reactive protein (CRP) may in part reflect indices of atherosclerosis, such as coronary calcification, and are likely to provide distinct information regarding cardiovascular risk. In this article, we review the current evidence of relationship between coronary calcification and inflammation for purpose of drawing the more attention on the inflammatory mechanism of coronary calcification, which may change our research as well as therapeutic strategies for coronary calcification in the future.