The Prevalence and Predictors of Atherosclerotic Coronary Artery Disease in Rheumatic and Non-rheumatic Valvular Heart Disease Patients.

OBJECTIVES: The paradox of concurrent coronary artery disease (CAD) among patients with rheumatic and non-rheumatic valvular heart disease (RVHD; non-RVHD) is unclear. We aimed to evaluate the impact of the RVHD and non-RVHD on the prevalence of CAD and various risk factors, assess the number of diseased coronaries, clinical profile and the possible predictors of CAD in these patients, which may clarify the paradox and provide an insight for the prevention of CAD. METHODS: The records of 106 valvular heart disease patients who had undergone valve replacement surgery at the King Faisal Cardiac Centre from January 2014 to October 2019 were evaluated. The clinical data and established risk factors were compared and logistic regression analyses were performed to identify plausible predictors of CAD. RESULTS: Transthoracic echocardiographic diagnosis of 106 patients confirmed, 43 had RVHD (56.4 ± 8 years), of whom six (13.9%) had CAD with the highest mitral valve regurgitation (p < 0.01), and 63 had non-RVHD (60.0 ± 12 years). Of these, 31 patients showed the highest CAD (49.2%). Single- and triple-vessel disease was most common in RVHD and non-RVHD patients with concurrent CAD (33.3%; 41.9%, respectively), while non-RVHD patients also had quadruple vessel disease. The mean age of the RVHD and non-RVHD patients with coexisting CAD was significantly higher (66.7 ± 5; 66.7 ± 8 years) than those without CAD (46.1 ± 12.0; 54.7 ± 20, respectively). RVHD patients showed a significantly lower prevalence of diabetes, dyslipidaemia, hypertension, inflammatory cells, hepatorenal function markers, ejection fraction, and regional wall motion abnormality compared to RVHD patients with coexisting CAD (p < 0.01). Bivariate analysis indicated white blood cells, monocytes, neutrophils, gamma-glutamyl-transferase (GGT), bilirubin and blood urea nitrogen (BUN) to be significantly lower in RVHD patients. Predictors of high risk of CAD were BUN and hyperlipidaemia for RVHD and BUN, creatinine and GGT for non-RVHD patients. CONCLUSIONS: The prevalence of CAD in Saudi RVHD patients was significantly lower than in the Western countries, whereas non-RVHD was higher. The low prevalence may partly be attributed to age, reduced mitral regurgitation, and low frequency of risk and inflammatory factors.

The Impact of Natural Antioxidants on the Regenerative Potential of Vascular Cells.

With advances in technology, the impact of natural antioxidants on vascular cell regeneration is attracting enormous attention as many current studies are now exploring the clinical potential of antioxidants in regenerative medicine. Natural antioxidants are an important step for improving future treatment and prevention of various diseases such as cardiovascular, cancer, neurodegenerative, and diabetes. The use of natural antioxidants which have effects on several types of stem cells with the potential to differentiate into functional endothelium and smooth muscle cells (known as vascular progenitors) for vascular regeneration might override pharmaceutical and surgical treatments. The natural antioxidant systems comprise of several components present in fruits, vegetables, legumes, medicinal plants, and other animal-derived products that interact with reactive free radicals such as oxygen and nitrogen species to neutralize their oxidative damaging effects on vascular cells. Neutralization by antioxidants involves the breaking down of the oxidative cascade chain reactions in the cell membranes in order to fine-tune the free radical levels. The effect of natural antioxidants on vascular regeneration includes restoration or establishment of new vascular structures and functions. In this review, we highlight the significant effects of natural antioxidants on modulating vascular cells to regenerate vessels, as well as possible mechanisms of action and the potential therapeutic benefits on health. The role of antioxidants in regenerating vessels may be critical for the future of regenerative medicine in terms of the maintenance of the normal functioning of vessels and the prevention of multiple vascular diseases.

Increased expression of phosphorylated forms of heat-shock protein-27 and p38MAPK in macrophage-rich regions of fibro-fatty atherosclerotic lesions in the rabbit.

We aimed to assess the expression and distribution of Hsp27, pHsp27 (Ser82), p38MAPK and p-p38MAPK in fibro-fatty atherosclerotic lesions and the myocardium of hypercholesterolaemic rabbits. Male New Zealand white rabbits were fed a high-cholesterol diet for 18 weeks, maintaining serum cholesterol at approximately 20 mmol/l over this period. Aortic arch and myocardial tissues were analysed by Western blot, immunohistochemistry and double immunofluorescence. Plasma Hsp27 levels were measured by ELISA. There was a significant increase in the expression of monomeric and dimeric forms of Hsp27, together with pHsp27 (Ser82), p38MAPK and p-p38MAPK in the fibro-fatty atherosclerotic lesions (P < 0.01; P < 0.05; P < 0.001; and P < 0.001, respectively) and the myocardial tissues (P < 0.001) from the cholesterol-fed rabbits compared with equivalent tissues from controls when the plasma concentration was low. Immunohistochemical analysis of the fibro-fatty lesions showed marked increases in Hsp27 and pHsp27 (Ser82) immunoreactivity. Double immunostaining showed intense expression of pHsp27 and p-p38MAPK in regions that were rich in macrophages, suggesting a close association with these inflammatory cells, whereas, in regions rich in smooth muscle cells, only p-p38MAPK was found to be strongly expressed. An increased expression of pHsp27 (Ser82) was spatially associated with increased p-p38MAPK within fibro-fatty atherosclerotic lesions and was colocalized to regions rich in macrophages. The initial increase in plasma Hsp27 levels may reflect the increase in systemic inflammation and oxidative stress in the early phases of disease. The falling concentrations subsequently may be coincident with the development of the advanced atherosclerotic lesions.

Altered antioxidant and trace-element status in adolescent female gymnasts.

Physical activity is associated with the generation of reactive oxygen species and may lead to decreased levels of plasma antioxidants and increased oxidant stress. Some studies have reported that antioxidant supplements can reduce the consequences of oxidative stress during exercise. In this study the authors aimed to assess the chronic effects of exercise on endogenous serum antioxidant enzyme concentrations. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity were measured in adolescent girls who were either competitive gymnasts or sedentary controls. The relationship between age, body-mass index, dietary intake, trace-element status, and serum GPx and SOD was determined. The participants in the study were part of a 3-yr longitudinal investigation of exercise and peak bone-mass development in 38 competitive gymnasts and 40 healthy sedentary adolescent females 8-17 yr of age. Serum GPx and SOD were measured using colorimetric assays, and trace elements were measured using inductively coupled plasma mass spectrometry. The mean serum GPx concentrations were significantly higher in the gymnasts than in the sedentary females (157 ± 11.1 vs. 126 ± 8.8 U/ml, p < .05). In contrast, serum SOD concentrations were significantly lower in the gymnasts than in the sedentary group (7.24 ± 2.6 vs. 8.57 ± 2.3 U/ml, p < .05). Serum selenium, zinc, and copper were higher in the physically active group than in the inactive group (0.89 ± 0.03, 10.86 ± 0.39, 14.50 ± 0.50 vs. 0.81 ± 0.03, 10.32 ± 0.28, and 14.38 ± 0.42 µmol/L, respectively), although only serum selenium reached statistical significance (p < .05). The findings show that young female gymnasts have an altered antioxidant enzyme profile compared with their less physically active peers.

Insulin sensitivity (Si) assessment in lean and overweight subjects using two different protocols and updated software.

BACKGROUND: The standard frequently-sampled intravenous glucose tolerance test (FSIVGTT) is an alternative procedure to the clamp technique for estimating the insulin sensitivity (Si) parameter. The goal of this study was to compare Si in lean and overweight individuals in addition to assessing intra-individual reproducibility using two different protocols and updated software. METHODS: FSIVGTT was carried out in 14 lean (BMI 25 kg/m(2)) subjects using two different protocols; full (29 samples) and short (12 samples). For reproducibility assessment four normal subjects (triplicate on three and twice on one) were recruited to undergo the same procedure at 1-week intervals. Data analysis was performed using COMAL and Minmod Millennium software. RESULTS: Mean Si (10(-4)min(-1)[pmol/l](-1)) values were significantly different between lean and overweight subjects (p < 0.001) but not between the two protocols using both software packages. For the full and short protocols, Si values were more closely related in lean versus overweight subjects using either COMAL (r = 0.98, p < 0.001), (r = 0.89, p < 0.001) or Minmod Millennium (r = 0.99, p < 0.001), (r = 0.85, p < 0.001) software respectively. The intra-individual reproducibility (%CV) of Si (COMAL) in full versus short protocol was 18.3 +/- 11.1% and 13.7 +/- 1.9% respectively. Reproducibility values for Si (Minmod Millenium) in full versus short protocols were 14.3 +/- 3.8 and 14.9 +/- 1.9% respectively. CONCLUSIONS: Si can be assessed accurately by a short protocol FSIVGTT in normal individuals. The short protocol may give less acceptable results for insulin sensitivity in individuals who have normal glucose tolerance but high BMI.

Serum insulin-like growth factor binding protein-1 (IGFBP-1) phosphorylation status in subjects with and without ischaemic heart disease.

BACKGROUND: Insulin-like growth factor binding protein-1 (IGFBP-1) modulates the activity of IGF-I. It exists in serum as phosphorylated and less phosphorylated forms. We wished to measure serum levels of both these forms of IGFBP-1, using a novel assay, in subjects with, or without ischaemic heart disease (IHD). METHODS: We measured serum concentrations of the phosphorylated and less phosphorylated forms of IGFBP-1 in 75 subjects (36 with and 39 without IHD). Two immunoassays were used, one which detects non-, and less-phosphorylated forms (LpIGFBP-1), and another which specifically detects the serine phosphorylated form of IGFBP-1 (pIGFBP-1). RESULTS: LpIGFBP-1 concentrations were significantly higher in subjects without IHD than in those with IHD (5.3+/-0.5 microg/L vs. 2.7+/-0.4 microg/L, p<0.001). pIGFBP-1 levels were also significantly higher in subjects without IHD compared to those with IHD (33.3+/-2.0 microg/L vs. 25.3+/-2.2 microg/L, p<0.01). The correlation between LpIGFBP-1 and pIGFBP-1 for all subjects was (r=0.71, p<0.001). This association was stronger in subjects without IHD (r=0.76, p<0.001) than for those with IHD (r=0.60, p<0.001). A significant negative association was observed between IGF-I and the ratio between the two forms (r=-0.45, p<0.0001). Receiver-Operating Characteristic (ROC) curve showed the highest area under the curve for LpIGFBP-1 (0.75) [95% CI: 0.63-0.86] and optimum cut-off value of 2.83 microg/L with 75% sensitivity and 74% specificity. CONCLUSIONS: We propose that low serum concentrations of IGFBP-1 forms could be a marker of coronary risk, and the LpIGFBP-1:pIGFBP-1 ratio may be an index of biologically active IGF-I.

Markers of inflammation, endothelial activation and autoimmunity in adolescent female gymnasts.

High levels of physical activity have been linked to benefits in cardiovascular and bone health by affecting, in part, changes in proinflammatory profile. Therefore, we have aimed to assess the effects of intensive training on markers of inflammation, endothelial activation and auto-immunity in the absence of the potential confounding effects of incident atherosclerosis. The subjects comprised 25 competitive gymnasts and 19 healthy sedentary adolescent females, aged 8-17 years. Serum soluble intercellular adhesion molecule 1 (sICAM-1), high sensitivity C-reactive protein (hsCRP), heat shock protein 27 (Hsp27) and Hsp27 antibody titres were measured by ELISAs in a sample of adolescent girls who were either physically active (competitive gymnasts) or sedentary. The association between age, body mass index (BMI), dietary intake, serum hsCRP, sICAM-1 and Hsp27 antigen and antibody titres were determined. The mean serum sICAM-1 concentrations were significantly higher in the gymnasts compared to the sedentary females (0.29 ± 0.02 versus 0.23 ± 0.01 mg·L(-1), p < 0.01). In contrast serum hsCRP concentrations were substantially lower in the gymnasts compared to the sedentary adolescent females (0.49 ± 0.03 versus 1.38 ± 0.19 mg·L(-1), p < 0.001). Differences remained significant after adjustment for anthropometric factors. We also found that serum Hsp27 antigen concentrations were determined by dietary saturated fat intake (p < 0.001), and antibody titres to Hsp27 were determined by dietary PUFA (p < 0.001) after adjustment for BMI. Our findings show that young female gymnasts have an altered profile of inflammatory markers and endothelial activation compared to their less physically active peers. Key pointsResults showed that adolescent young female gymnasts have an altered serum inflammatory markers and endothelial activation, compared to their less physically active peers.Physical activities improved immune system.Differences in these biochemical data kept significant after adjustment for body weight and height.

Periadventitial delivery of anti-EGF receptor antibody inhibits neointimal macrophage accumulation after angioplasty in a hypercholesterolaemic rabbit.

Monocyte recruitment and their differentiation into macrophages are both early events in native and accelerated atherosclerosis that follows angioplasty. We have investigated the putative functional role of the epidermal growth factor receptor (EGFR) present on rabbit monocytes/macrophages. The impact of periadventitial delivery of an EGFR-specific, blocking monoclonal antibody (ICR62, which inhibits EGF-binding to its receptor) was investigated in a rabbit model of accelerated atherosclerosis induced by a combination of carotid injury and 4 weeks of a 2% cholesterol-diet. Two weeks after the initiation of the diet, a balloon-catheter angioplasty of the left common carotid artery was performed and a collar placed around the injured carotid artery immediately, for the delivery of ICR62 antibody, isotype-matched antibody or saline control. Monocyte/macrophage accumulation, cell proliferation and neointimal thickening were determined 2 weeks after the delivery of the antibodies. The function of the EGFR on rabbit monocytes was also investigated in vitro, using chemotaxis assays. Treatment with ICR62 was associated with a significant reduction in macrophage accumulation and neointimal thickening and a 76% reduction in neointimal area of the vessel wall compared with controls. In vitro ICR62 inhibited macrophage and smooth muscle cell migration towards EGFR ligands including EGF and HB-EGF. These findings suggest that EGFR ligation may be important in the development of early atherosclerotic lesions following balloon-catheter angioplasty, and periadventitial delivery may provide a feasible approach for administration of the inhibitors of EGFR-binding such as ICR62.

Anti-heat shock protein-27 (Hsp-27) antibody levels in patients with chest pain: association with established cardiovascular risk factors.

BACKGROUND: Antibody titres to several heat shock proteins (Hsps) have been shown to be associated with risk factors for cardiovascular disease (CVD), but there are no data for Hsp-27. We developed an ELISA for total IgG antibody concentrations, applying this to individuals with and without acute coronary syndrome, and have assessed the relationship between antibody levels and individual coronary risk factors. METHODS: Blood was collected from 63 healthy controls without a history of chest pain or CVD and 60 patients admitted to hospital with acute cardiac chest pain on admission and approximately 12 h after the acute event. RESULTS: Patients with chest pain had significantly higher Hsp-27 antibody levels than controls [median 0.16 (range 0.01-0.51) vs. 0.10 (range 0.00-0.32); p<0.001]. Furthermore, Hsp-27 antibody concentrations showed strong associations with age and hypertension (Standardised beta coefficient=0.343, p<0.001 and = -0.235, p<0.016, respectively), but not with other established cardiovascular risk factors. Logistic regression analysis showed age and diabetes were significant predictors of risk of CVD with OR 1.29 (95% CI 1.16 to 1.42, p=0.001) and 25.9 (95% CI 2.14>312, p=0.01) respectively. CONCLUSIONS: Raised antibody levels to Hsp-27 were associated only with age and hypertension.

Yin Yang-1 inhibits vascular smooth muscle cell growth and intimal thickening by repressing p21WAF1/Cip1 transcription and p21WAF1/Cip1-Cdk4-cyclin D1 assembly.

Vascular injury initiates a cascade of phenotype-altering molecular events. Transcription factor function in this process, particularly that of negative regulators, is poorly understood. We demonstrate here that the forced expression of the injury-inducible GLI-Krüppel zinc finger protein Yin Yang-1 (YY1) inhibits neointima formation in human, rabbit and rat blood vessels. YY1 inhibits p21(WAF1/Cip1) transcription, prevents assembly of a p21(WAF1/Cip1)-cdk4-cyclin D1 complex, and blocks downstream pRb(Ser249/Thr252) phosphorylation and expression of PCNA and TK-1. Conversely, suppression of endogenous YY1 elevates levels of p21(WAF1/Cip1), PCNA, pRb(Ser249/Thr252) and TK-1, and increases intimal thickening. YY1 binds Sp1 and prevents its occupancy of a distinct element in the p21(WAF1/Cip1) promoter without YY1 itself binding the promoter. Additionally, YY1 induces ubiquitination and proteasome-dependent degradation of p53, decreasing p53 immunoreactivity in the artery wall. These findings define a new role for YY1 as both an inducer of p53 instability in smooth muscle cells, and an indirect repressor of p21(WAF1/Cip1) transcription, p21(WAF1/Cip1)-cdk4-cyclin D1 assembly and intimal thickening.

Heat shock protein 27: its potential role in vascular disease.

Heat shock proteins are molecular chaperones that have an ability to protect proteins from damage induced by environmental factors such as free radicals, heat, ischaemia and toxins, allowing denatured proteins to adopt their native configuration. Heat shock protein-27 (Hsp27) is a member of the small Hsp (sHsp) family of proteins, and has a molecular weight of approximately 27 KDa. In addition to its role as a chaperone, it has also been reported to have many additional functions. These include effects on the apoptotic pathway, cell movement and embryogenesis. In this review, we have focused on its possible role in vascular disease.

Placental growth factor promotes atherosclerotic intimal thickening and macrophage accumulation.

BACKGROUND: Placental growth factor (PlGF) has been implicated in the pathophysiological angiogenesis and monocyte recruitment that underlie chronic inflammatory disease, but its role in atherosclerosis has not been examined. We investigated the effects of exogenous PlGF, delivered by adenoviral gene transfer, on atherogenic intimal thickening and macrophage accumulation induced by collar placement around the rabbit carotid artery and examined the effects of PlGF deficiency on atherosclerosis in apolipoprotein E-deficient (apoE(-/-)) mice. METHODS AND RESULTS: Periadventitial transfer of PlGF2-encoding adenoviruses significantly increased intimal thickening, macrophage accumulation, endothelial vascular cell adhesion molecule-1 expression, and adventitial neovascularization in the collared arteries of hypercholesterolemic rabbits and increased the intima-to-media ratio in rabbits fed a normal diet. Neointimal macrophages were associated with increased expression of the PlGF receptor Flt-1. The size and macrophage content of early atherosclerotic lesions were reduced in mice deficient in both apoE and PlGF compared with apoE-deficient mice. CONCLUSIONS: Local adenoviral PlGF2 delivery promotes atherogenic neointima formation in hypercholesterolemic rabbits, and PlGF is required for macrophage infiltration in early atherosclerotic lesions in apoE(-/-) mice. These findings support a novel role for PlGF in the pathogenesis of atherosclerotic disease.

Vascular endothelial growth factor gene transfer inhibits neointimal macrophage accumulation in hypercholesterolemic rabbits.

OBJECTIVE: This study aims to determine the effects of periadventitial vascular endothelial growth factor (VEGF) gene transfer on neointima formation and macrophage accumulation induced by collar placement around the carotid artery in hypercholesterolemic rabbits. METHODS AND RESULTS: Collar placement around the carotid artery in cholesterol-fed rabbits induced intimal thickening with increased neointimal macrophage content. Liposome-mediated VEGF gene transfer, confirmed by transgene-specific RT-PCR, caused a marked inhibition of both intimal thickening and macrophage accumulation compared with a lacZ control gene. VEGF gene transfer was not accompanied by a significant increase in adventitial neovascularization. Collaring of carotid arteries in hypercholesterolemic rabbits also upregulated endothelial VCAM-1 expression. Inhibition of neointimal macrophage infiltration in VEGF-transduced, collared arteries was associated with decreased endothelial VCAM-1. CONCLUSIONS: VEGF gene transfer inhibits collar-induced intimal thickening, macrophage accumulation, and VCAM-1 expression in cholesterol-fed rabbits. These findings support the concept that low-level VEGF expression can exert arterioprotective effects in the presence of high blood cholesterol.

Long-term low-dose treatment with reserpine of cholesterol-fed rabbits reduces cholesterol in plasma, non-high density lipoproteins and arterial walls.

The effects of long-term low-dose treatment with reserpine on plasma lipoproteins and arterial cholesterol were determined in cholesterol-fed rabbits. Hepatic low-density lipoprotein (LDL) receptors; uptake of LDL by liver, heart, and kidneys; plasma fibrinogen; blood pressure; and heart rate were also determined. Reserpine at 43 microg/kg. d was continuously infused subcutaneously via implanted minipumps for 6 weeks into conscious unrestrained male New Zealand White rabbits (n = 5) fed a 0.2% cholesterol-enriched diet. Compared with controls, reserpine (n = 4) significantly reduced the elevated levels of plasma total cholesterol and esterified and unesterified cholesterol throughout the study, and at 6 weeks of treatment these reductions were 42, 41, and 49%, respectively. The increased cholesterol in the aortic walls (n = 5) produced by the atherogenic diet was reduced by 73% (p < 0.004) and 125I-tyramine cellobiose-labeled LDL by 67 to 86% (0.05 < p <0.004), respectively. The aortic intimal-medial thickness ratio was reduced by 70%. The decrease in elevated plasma total cholesterol was mainly due to cholesterol reductions in both LDL (41%) and non-high density lipoprotein (HDL) of density < 1.019 g/ml (51%). HDL cholesterol and triglyceride levels were unchanged. Reserpine had no significant effects on the clearance of 125I-tyramine cellobiose-LDL from plasma and there was a trend towards an increase in hepatic LDL receptor expression. Heart rate was decreased by 28%. There were no significant effects on blood pressure, liver and heart lipids, hematocrit, or plasma fibrinogen. The results suggest that treatment of cholesterol-fed rabbits with reserpine at a low dose over a long period prevents increases in plasma atherogenic lipoproteins. Reserpine decreases the cholesterol in aortic walls and the intima-media thickness ratio. This anti-atherosclerotic effect of reserpine may have therapeutic implication.