von Willebrand factor and soluble E-selectin in the prediction of cardiovascular disease progression in hyperlipidaemia

von Willebrand factor, C-reactive protein, nitric oxide, and vascular endothelial growth factor in a dietary reversal model of hypercholesterolemia in rabbit

AIMS

Endothelial dysfunction is considered a sign of the early vascular changes preceding atherosclerosis. We studied the alteration of von Willebrand Factor (vWF), C - reactive protein (CRP), nitrite and Vascular Endothelial Growth Factor (VEGF) in a dietary reversal model of hypercholesterolemia in rabbit.

METHODS

This project was designed in two phases. In phase I, male rabbits (n = 11) were fed a 1% high cholesterol diet for 30 days. Then the diet was replaced with normal rabbit chow for other 30 days (cholesterol withdrawal phase, phase II). To compare the fatty streak formation with normal condition, a control group (n = 6) received normal diet during the study. The serum lipid levels, vWF, CRP, nitrite, and VEGF were measured before the experiment and by the end of each phase. Fatty streak formation in the walls of the aortas in both groups (high cholesterol diet and control group) was determined using intima thickness/media thickness (IMT) ratio.

RESULTS

The results indicate that the level of cholesterol, Low Density Lipoproteins (LDL), vWF and CRP increased significantly in phase I, and decreased after hypercholesterolemic diet withdrawal (p < 0.05). No statistically significant changes were found in VEGF levels but the serum level of nitrite increased significantly during both phases of the study (p < 0.05). The IMT ratio in the walls of aortas was significantly different between the groups in both phases of studies (p < 0.05). There was a significant correlation between nitrite and cholesterol levels in both phases (r = 0.62 and r = 0.98, p < 0.05). Nitrite concentration also correlated with IMT ratio in both phases of the study (r = 0.75 and r = -0.99, p < 0.05). vWF did not correlate with cholesterol but it correlated with IMT ratio in both phases of the study (r = 0.87 and r = 0.84, p < 0.05). CRP only correlated with cholesterol in the first phase (r = 0.91, p < 0.05).

CONCLUSIONS

Among the endothelial biomarkers, vWF was found to be a biological marker for identifying the risk of developing atherosclerosis; however a single biomarker may not provide appropriate information.

ABO(H) blood groups and vascular disease: a systematic review and meta-analysis

BACKGROUND

Associations between vascular disease and ABO(H) blood groups have a long history, but no consensus exists regarding its magnitude and significance, or whether it relates to all disorders equally. An accurate calculation of risk would allow direct assessment of whether the effects of non-O status on thrombosis risk are of the magnitude predicted by its effect on von Willebrand factor/FVIII levels.

METHODS AND RESULTS

We conducted a systematic review and meta-analysis of studies reporting associations with non-O blood groups. This gave pooled odds ratios of 1.25 [95% confidence interval (CI) 1.14-1.36] for myocardial infarction (MI), 1.03 (95% CI 0.89-1.19) for angina, 1.45 (95% CI 1.35-1.56) for peripheral vascular disease, 1.14 (95% CI 1.01-1.27) for cerebral ischemia of arterial origin, and 1.79 (95% CI 1.56 to 2.05) for venous thromboembolism (VTE). However, restriction to prospective MI studies only did not confirm the association (OR 1.01; 95% CI 0.84-1.23), although these studies may have failed to capture early-onset disease. For VTE, using a combined group of OO/A(2)A(2)/A(2)O as index, the combination of A(1)A(1)/A(1)B/BB gave an OR of 2.44 (95% CI 1.79-3.33) and A(1)O/ BO/A(2)B an OR of 2.11 (95% CI 1.66-2.68).

CONCLUSIONS

This study confirms the historical impression of linkage between some vascular disorders and non-O blood group status. Although the odds ratios are similar to those predicted by the effect of ABO(H) on von Willebrand factor levels, further work is required to assess risk prospectively and to refine the effect of reducing O(H) antigen expression on thrombosis. However, as non-O and particularly A(1)A(1), A(1)B, BB constitute a significant proportion of the population attributable fraction of VTE, there may be a role for more widespread adoption of ABO(H) typing in testing strategies.

Effects of non-oral postmenopausal hormone therapy on markers of cardiovascular risk: a systematic review

OBJECTIVE

To review the effects of non-oral administration of postmenopausal hormone therapy (HT) on risk markers for atherosclerotic and venous thromboembolic disease.Non-oral postmenopausal HT appears not to increase venous thromboembolic risk, whereas the effect on coronary heart disease risk is less clear.

DESIGN

Systematic review of literature obtained from MEDLINE, EMBASE, and CENTRAL databases from 1980 until and including April 2006. Terms for "postmenopausal hormone therapy" and for "non-oral administration" were combined in the search.

SETTING

Randomized clinical trials.

PATIENT(S)

Postmenopausal women, both healthy and with established cardiovascular disease or specified cardiovascular risk factors

INTERVENTION(S)

Non-oral HT (e.g., transdermal or intranasal) compared with oral HT or no treatment/placebo.

MAIN OUTCOME MEASURE(S)

Lipoprotein(a), homocysteine, C-reactive protein (CRP), cell adhesion molecules, markers of endothelial dysfunction, coagulation, and fibrinolysis.

RESULT(S)

Seventy-two studies investigating either transdermal or intranasal administration were included. For non-oral HT, decreases in lipoprotein(a), cell adhesion molecules, and factor VII generally were significant, resistance to activated protein C (APCr) was slightly increased, and other markers including CRP and homocysteine did not change. Compared with oral HT, changes in CRP and APCr were smaller, changes in cell adhesion molecules and some fibrinolytic parameters tended to be smaller, whereas changes in other factors including lipoprotein(a) and homocysteine did not differ.

CONCLUSION(S)

Potentially unfavorable changes seen with oral HT on two important markers, CRP and APCr, are substantially smaller with non-oral HT. Non-oral HT has minor effects on the other cardiovascular risk markers studied. Therefore, compared with oral HT, non-oral HT appears be safer with respect to atherosclerotic and venous thromboembolic disease risk.

Circulating markers of endothelial function in cardiovascular disease

Endothelial dysfunction is a key event in cardiovascular disease. Measurement of endothelial dysfunction in vivo presents a major challenge, but has important implications since it may identify the clinical need for therapeutic intervention, specifically in primary prevention. Several biological markers have been used as indicators of endothelial dysfunction. The soluble adhesion molecules sICAM-1 and sVCAM-1 lack specificity and are increased in inflammatory processes. Both markers are increased in coronary artery disease. sICAM-1 level predicts the risk for cardiovascular disease or diabetes mellitus in healthy individuals. sE-selectin is specific for the endothelium and is increased in coronary artery disease and diabetes mellitus. sE-selectin is also associated with diabetic risk. The endothelium-specific marker, soluble thrombomodulin, is associated with severity of coronary artery disease, stroke or peripheral occlusive arterial disease and is not increased in healthy or asymptomatic subjects. Interestingly, thrombomodulin decreases during treatment of hypercholesterolemia or hyperhomocysteinemia. In contrast, von Willebrand factor is the best endothelial biomarker and predicts risk for ischemic heart disease or stroke.

Age and sex modulate metabolic and cardiovascular risk markers of patients after 1 year of highly active antiretroviral therapy (HAART)

OBJECTIVE

Primary aim: To evaluate the modulating effects of age and sex on changes in plasma lipid levels in the response to highly active antiretroviral therapy (HAART). Secondary aim: To study insulin, leptin, adiponectin, E-selectin and P-selectin levels and their relation to demographics.

DESIGN

Comparative, longitudinal, open cohort-study.

SETTING

Tertiary care center at a University Hospital.

METHODS

Eighty-two consecutive HIV-seropositive patients of either sex were enrolled in the study. Subjects were between 19 and 60 years of age and naive to HAART. Patients were treated with nucleoside reverse transcriptase inhibitors (NRTIs) and protease inhibitor(s) (PIs) or reverse transcriptase inhibitors (RTIs) only. Subjects were evaluated at baseline and after 3, 6 and 12 months.

RESULTS

Total cholesterol levels increased in all patients. The greatest increase was seen in patients of older age treated with PI. Male gender was another risk factor for higher cholesterol but also for higher triglyceride levels. Therapy with protease inhibitors and/or stavudine had a negative influence on plasma triglyceride levels. Selectins, adipokines and insulin were less influenced by HAART.

CONCLUSION

Based on the results of this study selection of therapy regimen according to the demographic risk factors sex and age can offer an easy strategy to help to minimize lipid elevations.

Assessment of Endothelial Dysfunction: Focus on Atherothrombotic Disease

As the endothelium is crucial to cardiovascular disease, the accurate assessment of this organ is a valuable tool, especially if such assessments are clinically relevant. As functions of the endothelium focus on haemostasis and the maintenance of correct vascular tone, and dysfunction results in changes that promote thrombosis and hypertension, thus assessment of endothelial function therefore follows these processes. Foremost in the plasma markers of vascular function is von Willebrand factor, a molecule that interacts with platelets. Lack of nitric oxide results in poor blood pressure control that can be quantified by impaired flow mediated dilatation. More recently, increased numbers of circulating endothelial cells have been described that indicate severe damage to the endothelium. Unsurprisingly, these three markers correlate with each other and former two predict adverse outcome in long-term follow up studies. The assessment of vascular damage is becoming recognised as having an increasingly prominent part in the pathophysiology of cardiovascular disease.

Novel predictors of acute coronary syndrome outcomes

Morbidity and mortality rates among patients with acute coronary syndrome (ACS) remain high, and it is difficult to determine which patients will progress satisfactorily and which patients will have poor outcomes. Research has indicated that the inflammatory process is involved in coronary disease. There is great interest within the research community in determining if inflammatory markers could be used to determine the severity of the disease process and therefore serve as a prognostic tool for clinicians. This article describes the inflammatory process in ACS and provides a review of the current diagnostic studies of endothelial inflammatory markers (EIMs) in heart disease. Although research results of EIMs have not all been significant in determining outcomes, there is some evidence that they may be more specific than other generalized inflammatory markers, such as C-reactive protein. Future research of EIMs in patients with ACS might provide evidence of easy-to-measure and economically feasible markers that are sound prognosticators.

Raloxifene, conjugated oestrogen and endothelial function in postmenopausal women

OBJECTIVES

To study the long-term effects of raloxifene, a potential designer oestrogen, and oestrogen monotherapy on endothelial function in healthy postmenopausal women.

DESIGN

A 2-year double-blind, randomized and placebo-controlled study in an Academic Medical Center. Fifty-six hysterectomized but otherwise healthy postmenopausal women randomly received raloxifene hydrochloride 60 mg day-1 (n = 15) or 150 mg day-1 (n = 13), conjugated equine oestrogen (CEE) 0.625 mg day-1 (n = 15), or placebo (n = 13).

MAIN OUTCOME MEASURES

Endothelial function as estimated from brachial artery flow-mediated, endothelium-dependent vasodilation and nitroglycerine-induced endothelium-independent vasodilation, and plasma levels of the endothelium-derived regulatory proteins, von Willebrand factor (vWF) and endothelin (ET).

RESULTS

Raloxifene 60 mg did not significantly affect endothelial function. As compared with placebo, at 6 months of therapy, raloxifene 150 mg and CEE were associated with a mean increase in vWF of 25.5% point (95% CI 3.6-47.3) and 26.6% point (95% CI 6.9-46.3), respectively. At 24 months of therapy, raloxifene 150 mg was associated with a mean decrease in ET of 0.96 pg mL-1 (95% CI -1.57 to -0.36). Raloxifene nor CEE significantly affected endothelium-dependent and/or -independent vasodilation.

CONCLUSIONS

Our results suggest that long-term therapy with raloxifene or oral CEE does not affect endothelium-dependent vasodilation in healthy postmenopausal women. Raloxifene 150 mg day-1 might have both positive and negative effects on endothelium. The clinical significance of these findings remains to be investigated.

The importance of von Willebrand factor level and heart rate changes in acute coronary syndromes: a comparison with chronic ischemic conditions

The pathogenesis of acute coronary syndrome (ACS) and transient myocardial ischemia (TMI) is not completely understood. Therefore, the authors studied the biological indicators of thrombogenesis and sympathetic activity. The study was conducted on 50 patients with acute coronary syndrome and 30 patients with stable angina pectoris. Treatment was standardized with low-molecular-weight heparin and 300 mg aspirin/day but with no IIb/IIIa inhibitors, an oral beta-blocker, diltiazem 60 mg tid, glyceryl trinitrate i.v. in patients with ACS but with mononitrates orally and low-molecular-weight heparin in patients with stable angina. Twenty-four-hour continuous ECG monitoring and ST segment analysis were performed on day 2 of admission and heart rate analysis was performed 10, 5, and 1 minute before and during the myocardial ischemia periods. Blood sampling for von Willebrand factor (vWf) determination was performed through a peripheral vein at 8 AM, noon, 6 PM and 10 PM and half an hour after the description of angina. The patients with ACS were grouped as transient myocardial ischemia positive (n = 20) and negative (n = 30). The patients with stable angina were designated as the control group (n = 30). The detected vWf levels at 4 different daytime periods in patients with ACS were significantly higher than those in patients with stable angina. At the 6 PM to 10 PM period, the vWf level increase was significantly higher in patients with TMI than in the patients without TMI. At the 8 AM to noon period, the detected vWf levels decreased significantly in both TMI groups. During the nocturnal ischemia periods, the increase in vWf levels immediately after angina was significantly more apparent than the detected changes during daytime ischemia. Analysis showed that heart rates before the ischemia during stable angina episodes were significantly higher than those in TMI (-) (silent) angina. The heart rate difference between 10 minutes before and during the ischemia in the angina group was significantly different from that during TMI (-) (silent) ischemia. The heart rates at the times related to ischemia in the nocturnal period were significantly lower than those in the daytime period. The heart rate differences between the ischemia-related times and during the ischemia were significantly higher in daytime ischemic attacks than in nocturnal ischemic attacks. The study confirms that the vWf level, which is an indicator of thrombogenesis, was significantly increased in patients with ACS. Nocturnal ischemia is associated with thrombogenesis. Daytime ischemia is associated with increased sympathetic activity, and symptomatic ischemia is usually associated with increased sympathetic activity.

Effects of alcohol intake on endothelial function in men: a randomized controlled trial

BACKGROUND

Regular light consumption of alcohol appears to reduce the risk of cardiovascular disease, whereas in heavier drinkers the opposite effect is seen. This biphasic relationship could partly be due to contrasting actions of low and high alcohol intake on endothelial function.

OBJECTIVE

To determine whether reducing alcohol intake in moderate-to-heavy drinkers (40-110 g/day) would improve conduit artery endothelial function as assessed by post-ischaemic brachial artery flow-mediated dilatation (FMD).

METHODS

In a two-way cross-over study, 16 healthy men either substituted their usual alcohol intake with a 0.9% alcohol beer or maintained their usual alcohol intake during sequential 4-week periods. At the end of each period of FMD and glyceryl trinitrate-induced brachial artery dilatation, blood pressure, plasma lipids, homocysteine and biomarkers of alcohol consumption (gamma-glutamyl transpeptidase) and endothelial function (E-selectin, von Willebrand factor, endothelin-1) were assessed.

RESULTS

The participants reduced their alcohol intake from 72.4 to 7.9 g/day. This self-reported reduction in alcohol intake was corroborated by significant decreases in gamma-glutamyl transpeptidase (24%). The decrease in alcohol intake resulted in reductions in total cholesterol (5%), high-density lipoprotein cholesterol (17%), homocysteine (9%) and systolic and diastolic blood pressure [5 mmHg (P = 0.01) and 4 mmHg (P = 0.003), respectively]. There was no effect of alcohol on FMD (6.23 +/- 0.75% compared with 6.24 +/- 0.71%, P = NS), glyceryl trinitrate-induced vasodilatation, E-selectin, endothelin-1 and von Willebrand factor.

CONCLUSION

Substantial reduction in alcohol intake in healthy moderate-to-heavy drinkers does not improve endothelial function as measured by post-ischaemic flow-mediated dilatation of the brachial artery or biomarkers of endothelial function.

Oral conjugated equine estrogen increases plasma von Willebrand factor in postmenopausal women

OBJECTIVES

We sought to test whether one month of daily oral conjugated equine estrogen (CEE) or transdermal estradiol alters hemostatic factors in postmenopausal subjects.

BACKGROUND

Estrogen replacement therapy and hormonal replacement therapy (HRT) effect an early increase in cardiovascular events in postmenopausal women. Circulating plasma von Willebrand factor (vWF) antigen is a marker of generalized endothelial dysfunction and atherothrombosis.

METHODS

Thirty-eight healthy postmenopausal women (average 59 +/- 7 years) were randomized to receive daily oral CEE, 0.625 mg (n = 21); transdermal estradiol, 0.1 mg/day (n = 7); or oral placebo (n = 10) for one month. Blood samples were collected at baseline and after two weeks and four weeks of therapy for measurement of circulating plasma hormones, lipid concentrations, and hemostatic factors.

RESULTS

Oral CEE decreased total cholesterol (p < 0.01) and low-density lipoprotein cholesterol (p < 0.01), although it increased both triglycerides (p < 0.05) and high-density lipoprotein cholesterol (p < 0.01). Transdermal estradiol had no significant effect on lipids. Plasminogen activator inhibitor-1 antigen declined in both oral CEE and transdermal estradiol users, but did not achieve statistical significance. Fibrin D-dimer antigen did not vary significantly in any group. However, oral CEE users had a significant increase in vWF from baseline to four weeks (p < 0.03) and a decrease in tissue-type plasminogen activator antigen from baseline to four weeks (p < 0.004), which was significantly different from the change observed in the transdermal estradiol group (p < 0.05).

CONCLUSIONS

These data suggest that the oral CEE-mediated increase in plasma vWF may have clinical relevance given the early atherothrombotic effects of HRT in postmenopausal women.

Endothelial markers and adhesion molecules in acute ischemic stroke--sequential change and differences in stroke subtype

The progress of a stroke concerns the activation of endothelial cells and platelets. We measured the plasma activities of von Willebrand factor (vWf) and the serum levels of soluble thrombomodulin (sTM) as endothelial markers, and the plasma concentrations of soluble P-selectin (sP-selectin) and soluble E-selectin (sE-selectin) as adhesion molecules during the acute (within 48 h from onset) and subacute (after 1 month from the onset) phases of 52 consecutive patients with acute ischemic stroke and 86 age-matched control subjects. The plasma vWf activities and levels of sP-and sE-selectins in stroke patients were significantly elevated compared with those in controls during both the acute and subacute phases. The serum levels of sTM in stroke patients were significantly higher than those in controls only during the subacute phase. In atherothrombotic infarction, the vWf activities and the levels of sP-selectin, markers for endothelial and platelet activation, remained higher until the subacute phase compared with controls, and the concentrations of sTM, a marker for endothelial injury, were increased during the subacute phase compared with during the acute phase. In lacunar infarction, the levels of sTM and sE-selectin of patients were higher only during the acute phase than controls. These findings suggest that the endothelial cell damage might be maintained until the subacute phase in atherothrombotic infarction, whereas it is remarkable only during the acute phase in lacunar infarction. The evaluation of endothelial markers and adhesion molecules would represent the pathophysiological states of stroke and may provide useful information for the treatment of the ischemic infarction.

Inflammatory cytokine release in patients with unstable angina after coronary angioplasty

The aim of the present study was to investigate inflammatory cytokine release and the interaction with platelets in patients with unstable angina (UA) after coronary angioplasty. In 50 patients with stable angina (SA) and 58 patients with UA, serial venous blood samples were obtained immediately before, and 30 minutes, 4, 12, 24, 48 and 72 hours, and 7 days after coronary angioplasty. Plasma concentrations of IL-8 and vWF were determined by immunoassay, while the expression of CD11 b/CD18 on monocytes and the expression of CD41 on platelets were assessed by flow cytometry. Differences in the baseline plasma concentrations of IL-8, vWF and CD11b/CD18, CD41 were found in the UA and SA groups before angioplasty (101.1 +/- 31.28 pg/mL to 55.8 +/- 17.24 pg/mL, 137.67 +/- 38.14% to 107.40 +/- 28.67% and 318.67 +/- 36.85 MFI to 240.72 +/- 28.43 MFI, 147.5 +/- 23.18 MFI to 104.43 +/- 26.68 MFI all p < 0.05). The peak plasma levels of IL-8 (172.24 +/- 37.82 pg/mL at 12 hours) and vWF (256 +/- 42.32% at 4 hours) significantly increased after coronary angioplasty (both p < 0.01), and were associated with significant time course increases in surface expression of CD11b/CD18 (p < 0.01) and CD41 (p < 0.01). The levels of plasma IL-8 and vWF were significantly higher pre- and post-procedure in UA patients with lesion type C compared to types A or B (p < 0.05), but there were no differences for pre-procedure in the SA group patients with different lesion types (p > 0.05). There were significant correlations between plasma IL-8 and monocyte CD11b/CD18, vWF and CD41 in the UA group (r = 0.5248, r = 0.6240 both p < 0.01, respectively). The findings demonstrate increases in plasma IL-8 and CD11b/CD18 as inflammatory mediators, vWF and CD41 as the abnormal coagulation activity may therefore yield a rationale for pharmacological anticytokines in patients with UA after coronary angioplasty.

Why is soluble intercellular adhesion molecule-1 related to cardiovascular mortality?

Increased plasma levels of soluble adhesion molecules are associated with an increased risk of atherothrombosis. The pathophysiological mechanisms responsible for these associations are not known. The aim of the present study was to investigate the association of soluble intercellular adhesion molecule-1 (sICAM-1) concentration and risk of cardiovascular and all-cause mortality among individuals with and without type 2 diabetes. In addition, we assessed potential pathophysiological mechanisms by which sICAM-1 may promote mortality. Six hundred and thirty-one subjects taken from a general population of the middle-aged and elderly participated in this prospective cohort study. Baseline data collection was performed from 1989 to 1992; subjects were followed until 1 January 2000. Subjects who died had higher levels of sICAM-1 than those who survived (506(164) vs. 477(162) ng mL(-1), respectively). After adjustment for age, gender and glucose tolerance status, subjects with sICAM-1 levels in the upper quartile (> or =550 ng mL(-1)) had a relative risk of cardiovascular mortality of 2.05 (95% confidence interval, 1.10-3.81) compared to subjects with sICAM-1 levels in the other quartiles. Further adjustment for classical cardiovascular risk factors or indicators of (sub)clinical atherosclerosis, endothelial dysfunction, inflammation and renal function did not materially alter this relative risk. A high sICAM-1 level was more frequent in subjects with type 2 diabetes than in subjects with a normal glucose tolerance (33.3 vs. 17.8%). Individuals with a plasma concentration of sICAM-1 higher than 550 ng mL(-1) had a cardiovascular mortality risk that was twice that of individuals with a lower concentration. Classical cardiovascular risk factors (sub)clinical atherosclerosis, endothelial dysfunction and inflammation do not explain this excess risk.

Soluble adhesion molecules and prediction of coronary heart disease: a prospective study and meta-analysis

BACKGROUND

Previous studies have suggested that circulating concentrations of soluble adhesion molecules are useful predictors of risk of coronary heart disease (CHD). Larger studies are needed, however, to test this hypothesis.

METHODS

We measured serum concentrations of four soluble cell adhesion molecules (intercellular adhesion molecule-1 [ICAM-1], vascular cell adhesion molecule-1 [VCAM-1], E-selectin, and P-selectin) in the stored baseline serum samples of 643 men with coronary heart disease and 1278 controls nested in a prospective sutdy of 5661 men who were monitored for 16 years. We also did a meta-analysis of previous relevant studies to place our findings in context.

RESULTS

Concentrations of soluble adhesion molecules were significantly associated with one another, with other markers of inflammation, and with some classic coronary risk factors. For ICAM-1, the odds ratio for CHD was 1.68 (95% CI 1.32-2.14) in a comparison of men in the top third with those in the bottom third of baseline measurements after adjustments for age and town. This decreased to 1.11 (0.75-1.64) after adjustment for some classic coronary risk factors and indicators of socioeconomic status. For the three other cell adhesion molecules, the odds ratios for CHD, first adjusted for age and town only, and then additionally adjusted for other risk factors, were: VCAM-1: 1.26 (0.99-1.61) and 0.96 (0.66-1.40); E-selectin: 1.27 (1.00-1.61) and 1.13 (0.78-1.62); and P-selectin: 1.23 (0.96-1.56) and 1.20 (0.81-1.76).

INTERPRETATION

The measurement of these adhesion molecules is unlikely to add much predictive information to that provided by more established risk factors.

Circulating N-terminal brain natriuretic peptide precursor and endothelin levels in patients with syndrome X and left bundle branch block with preserved systolic function

BACKGROUND

Deterioration of left ventricular function during follow-up was reported in some patients with syndrome X and concomitant left bundle branch block. The patients with syndrome X and left bundle branch block has been frequently presented with elevated Endothelin-1 (ET-1) level while brain natriuretic peptide (BNP) (a sensitive marker of left ventricular dysfunction) has not been measured in patients with syndrome X.

METHODS

The purpose of the present study was to assess left ventricular diastolic function, levels of N-terminal Brain Natriuretic Peptide (NT-proBNP) precursor and biochemical parameters of endothelial function in patients with syndrome X complicated by left bundle branch block but preserved left ventricular systolic function (group A, n=8). The echocardiographic and neurohormonal measures in these patients were compared to those in patients with syndrome X without left bundle branch block (group B, n=13), and controls (group C, n=15).

RESULTS

At rest and after exercise the serum concentration of NT-proBNP was significantly higher in group A than in the controls (at rest: 232+/-96 vs. 133+/-23 fmol/ml, P=0.03; after exercise: 313+/-96 vs. 180+/-33 fmol/ml, P=0.02). The highest concentration of endothelin-1 was also found in group A, being significantly higher than in the controls (6.81 vs. 4.52 pg/ml, P<0.05). Mitral flow abnormalities were detected in left bundle branch block patients. Accordingly, the lowest E/A ratio was in group A and it differed significantly from that in group C (0.85 vs. 1.1, P<0.05). E/A ratio inversely correlated with plasma NT-proBNP concentration in patients with left bundle branch block (r=-0.48, P=0.02).

CONCLUSIONS

Elevated NT-proBNP and endothelin-1 plasma concentrations were demonstrated in patients with syndrome X complicated by left bundle branch block even when left ventricular systolic function was still preserved. In this subgroup the magnitude of left ventricular diastolic dysfunction correlated with the increase of BNP level which reflects neurohormonal activation.

Sex differences in HAART-associated dyslipidaemia

OBJECTIVES

Because female sex protects against dyslipidaemia and atherosclerosis in normal subjects, we aimed to reveal potential sex differences in metabolic side-effects of a newly initiated highly active antiretroviral therapy (HAART) regimen, and to relate these changes to endothelial cell activation as measured by levels of circulating E-selectin (cE-selectin).

DESIGN

Prospective longitudinal cohort study.

SETTING

Tertiary care centre at a University Hospital.

METHODS

HIV-seropositive male (n = 27) and female patients (n = 13) with a plasma viral load of > or = 10 000 copies/ml and 35 healthy controls were enrolled in the study. All participants were weight stable, free of acute opportunistic infections, and had not taken any protease inhibitors before. Serum levels of lipids, insulin, leptin, and cE-selectin were measured before initiation of HAART, and at 3 and 6 months thereafter.

RESULTS

HAART increased serum levels of triglycerides, leptin, and low-density lipoprotein (LDL) cholesterol; these effects were more distinct in women. Fasting insulin levels and the LDL : high density lipoprotein (HDL) ratio increased only in female HIV-infected patients (P < 0.02 versus men). In contrast, endothelial activation, as measured by cE-selectin, decreased more in men (P < 0.02) than in women. As a consequence, women had higher triglycerides and leptin levels after therapy than did men, and the LDL : HDL ratio and cE-selectin levels, which were initially higher in men, were no longer different between the sexes.

CONCLUSIONS

Metabolic adverse effects during HAART are more pronounced in women than in men. Hence, female HIV-infected patients seem to loose part of their natural protection from atherosclerosis during antiretroviral therapy.

Effects of heparin and aspirin on circulating P-selectin, E-selectin and von Willebrand Factor levels in healthy men

As thrombin stimulates P-selectin expression on platelets and its release into plasma, we hypothesized that enhancing antithrombin activity by unfractionated heparin (UFH) could decrease plasma levels of circulating (c)P-selectin, (c)E-selectin, and von Willebrand Factor (vWF). Hence the effect of UFH and aspirin were examined on these activation markers in healthy volunteers. UFH decreased cP-selectin levels by -10% (CI: -16 - (-4%); P = 0.005) at 24 h, but did not change levels of vWF-Ag. In contrast, aspirin did not affect cP-selectin levels but decreased vWF-Ag levels by -12% (CI: -18 - (-7%); P = 0.005) at 24 h. Neither drug affected cE-selectin levels. Thus, UFH decreases cP-selectin levels, which may reflect decreased platelet activation in vivo. An increase in cP-selectin under UFH therapy should alert the clinician to look for platelet destruction.

Differences in free and total tissue factor pathway inhibitor, and tissue factor in peripheral artery disease compared to healthy controls

Tissue factor (TF) is one of the major initiators of coagulation and raised plasma levels have been found in various cardiovascular diseases. TF activity is, however, regulated by tissue factor pathway inhibitor (TFPI), and alteration in levels of TF and/or TFPI may thus relate to thrombogenesis and atherogenesis. To investigate possible abnormalities in TF and free TFPI (i.e. unbound to TF) and total TFPI among patients with peripheral artery disease (PAD), we studied 42 patients (mean age 57, 35 men) with objectively proven (by ABPI/Doppler) disease and 42 age- and sex- matched healthy controls. TF, free TFPI and total TFPI were measured in citrated plasma by ELISA. TF was higher in the patients with PAD compared to controls (275+/-122 pg/ml versus 158+/-60, P<0.0001) but levels of total TFPI were lower in the patients (43+/-10 ng/ml versus 50+/-15, P=0.021). There was no significant difference in levels of free TFPI between patients and controls (7.2+/-1.5 ng/ml in controls, 7.5+/-1. 6 among patients, P=0.39). Within the control patients, levels of free and total TFPI were significantly correlated (Spearman r=0.51, P=0.001) but in the patients with PAD this correlation was poor (r=0. 21, P=0.178). We suggest that reduced levels of total TFPI and raised levels of TF may contribute to the process of atherogenesis and the increased risk of thrombosis among patients with cardiovascular disease.

Serum homocysteine is weakly associated with von Willebrand factor and soluble vascular cell adhesion molecule 1, but not with C-reactive protein in type 2 diabetic and non-diabetic subjects - The Hoorn Study

BACKGROUND

Hyperhomocysteinaemia may constitute an independent risk factor for cardiovascular disease, but it is still unclear by which pathophysiological mechanisms homocysteine (tHcy) may promote atherothrombosis. The aim of this study was firstly to examine whether tHcy is associated with endothelial dysfunction, increased adherence of leukocytes, and/or chronic low-grade inflammation, as estimated from plasma levels of von Willebrand factor (vWf), soluble vascular cell adhesion molecule 1 (sVCAM-1) and C-reactive protein (CRP), respectively. Secondly we investigated whether the presence of type 2 diabetes modifies these associations.

MATERIALS AND METHODS

Six hundred and ten subjects of a general population of middle-aged and elderly subjects, 170 of whom had type 2 diabetes, participated in this cross-sectional study. Linear regression analyses were used to study whether tHcy was associated with vWf, sVCAM-1 and CRP, and whether the presence of diabetes modified these associations.

RESULTS

After adjustment for confounders, tHcy was significantly but weakly associated with vWf (beta = 0.15, P = 0.05) and sVCAM-1 (beta = 0.082, P = 0.04). tHcy was not significantly associated with CRP (beta = 0.02, P = 0.91). The presence of diabetes did not significantly modify these associations.

CONCLUSIONS

This study provides evidence that tHcy is, at most, weakly associated with endothelial dysfunction as estimated from plasma vWf, and with leukocyte adhesion as estimated from plasma sVCAM-1. tHcy was not significantly associated with chronic low-grade inflammation as estimated from plasma CRP. Our data thus suggest that the link between tHcy and atherothrombosis cannot be explained by associations of tHcy with vWf, sVCAM-1 or CRP.

Release of endothelin 1 and angiotensin II induced by percutaneous transluminal coronary angioplasty

Endothelial injury plays critical roles in acute and chronic complications after percutaneous transluminal coronary angioplasty (PTCA). We investigated coronary endothelial injury and the release of vasoactive substances induced by PTCA. We examined 44 patients with ischemic heart disease who underwent elective PTCA to isolated stenotic lesions in left coronary arteries. Eleven patients received balloon angioplasty (BA), 14 percutaneous transluminal rotational atherectomy (PTRA), and 19 stent implantation. Blood samples were drawn from the coronary sinus immediately before and after as well as 4 hr and 24 hr after PTCA. Plasma levels of endothelin (ET) 1, angiotensin (ANG) II, von Willebrand factor (vWF), and thrombomodulin (TM) were measured. Seven control subjects who underwent diagnostic coronary angiography (CAG) were used as controls. In all patients, ET-1 levels in the coronary sinus blood significantly increased immediately after PTCA. ANG II levels and vWF activity showed significant increases 4 hr after PTCA. Changes in levels of these markers were similar among the BA, PTRA, and stent groups. TM levels were elevated in all groups of patients, including those simply undergoing diagnostic CAG. Changes in ET-1, ANG II, and vWF levels in the coronary sinus reflect coronary endothelial injury induced by PTCA.

Endothelial cell dysfunction correlates differentially with survival in primary and secondary pulmonary hypertension

BACKGROUND

Plasma von Willebrand factor antigen (vWF:Ag) has been used as a marker of endothelial perturbation in a number of vascular disorders. In this study, vWF:Ag was determined as an attempt to evaluate the severity of endothelial cell dysfunction in primary pulmonary hypertension (PPH) and congenital heart disease-associated pulmonary hypertension (CHD-PH) comparatively and to determine its impact on short-term survival.

METHODS AND RESULTS

Clinical, hemodynamic, and biochemical data were obtained from 11 patients with PPH and 24 with CHD-PH. Patient groups were similar in terms of age and pulmonary artery pressure. vWF:Ag was measured by electroimmunodiffusion. Patients were followed up for 1 year and at that time, data collected at the beginning of the study were subjected to univariate and multivariate analyses. vWF:Ag was increased in patients (normal reference value 87% +/- 23% activity, mean +/- SD), with higher levels in the PPH group (231% +/- 89%) in comparison with the CHD-PH group (127% +/- 68%) (P <.001). Multivariate analysis showed that survival was influenced by the underlying cause of pulmonary hypertension and vWF:Ag levels but not by patient age, sex, or pulmonary artery pressure. Seven of 10 nonsurvivors but only 4 of 25 survivors had PPH (P =.007). vWF:Ag was 255% +/- 90% in the nonsurvivor group and 121% +/- 54% in the survivors (P <.001).

CONCLUSIONS

Our findings suggest that short-term survival is related to the severity of endothelial cell dysfunction in pulmonary hypertension. In addition, exceedingly high vWF:Ag levels in PPH might reflect a particular pattern of endothelial cell dysfunction that could be associated with decreased short-term life expectancy in this disorder compared with secondary forms of pulmonary hypertension.

Partial inhibition of nitric oxide synthase primes the stimulated pathway of vWF-secretion in man

Increased release of von Willebrand factor (vWF) has been linked to the pathogenesis of atherosclerosis. For this complex disease, impairment of endothelium-derived, nitric oxide production and impaired vascular relaxation has also been reported. Since endothelially produced nitric oxide (NO) is known to inhibit secretion of the Weibel-Palade bodies in animals, we hypothesized that NO could mitigate vWF secretion. In a randomized, placebo controlled cross-over trial, eight male volunteers received N-monomethyl-L-arginine (LNMMA) to block endothelial NO production or placebo, and vWF release was stimulated by infusing desmopressin in three cumulative doses (0.05, 0.15, 0.4 microg/kg) in both periods. At a threshold dose of 0.l5 microg/kg desmopressin, concomitant partial blockade of NO production resulted in 20% higher levels of vWF (P<0.04). However, maximal vWF release after 0.4 microg/kg desmopressin was unaffected by L-NMMA (Delta7% between periods, P=0.88). These data show the dampening effect of NO production on vWF release in response to threshold concentrations of secretagogues. This may in part explain the higher vWF levels in cardiovascular diseases associated with impaired endothelial NO generation.

von Willebrand factor, C-reactive protein, and 5-year mortality in diabetic and nondiabetic subjects: the Hoorn Study

Increased levels of von Willebrand factor (vWf) and C-reactive protein (CRP) predict cardiovascular mortality in selected populations. It is uncertain whether vWf and CRP predict mortality in a general population and whether vWf and CRP predict mortality through similar pathways. This study investigated the association of vWf and CRP with cardiovascular and all-cause mortality among diabetic and nondiabetic subjects. An age-, sex-, and glucose tolerance-stratified sample (n=631) of a population-based cohort aged 50 to 75 years was followed prospectively for 5 years. After 5 years of follow-up, 58 subjects had died (24 of cardiovascular causes). vWf (>1.56 IU/mL) and CRP (>2.84 mg/L) levels in the upper tertile were associated with, respectively, a 3- and 2-fold increase in cardiovascular mortality after adjustment for age, sex, and glucose tolerance status. Analyses in nondiabetic and diabetic subjects separately gave similar results. After further adjustment for hypertension, levels of HDL cholesterol and triglyceride, smoking habits, ischemic heart disease, and peripheral arterial disease, the relative risks (RRs) were 3.0 (95% CI 1.2 to 7.9) for vWf and 1.4 (95% CI 0.6 to 3.5) for CRP. When both vWf and CRP were included in the latter multivariate analysis, the RRs were 3.0 (95% CI 1.1 to 7.9) for vWf and 1.3 (95% CI 0.5 to 3.4) for CRP. The association between vWf and risk of cardiovascular mortality was independent of blood group (O versus non-O) and, moreover, similar among subjects with different blood groups. Repeating the analyses for all-cause mortality gave similar results for CRP. For vWf, the RR was 2.0 (95% CI 1.1 to 3.5) after adjustment for all other risk factors. Increased levels of vWf are independently associated with cardiovascular and all-cause mortality in both diabetic and nondiabetic subjects. The association between increased levels of CRP and cardiovascular mortality was partly explained by other risk factors. Mutual adjustment of vWf and CRP did not markedly change the results, favoring the hypothesis that vWf and CRP predict mortality through different pathways.

Short-term hormone replacement therapy: reduced plasma levels of soluble adhesion molecules

BACKGROUND

Epidemiological data have suggested that the use of hormone replacement therapy (HRT) is associated with a decreased risk of cardiovascular disease. Vascular endothelium and adhesion molecules play an important role in the initiation and progression of atherosclerosis.

MATERIAL AND METHODS

Prospective, randomized, placebo-controlled 12-week study. Sixty healthy, normotensive postmenopausal women received either micronised oestradiol 2 mg alone (n = 16, E2 group), or sequentially combined with a progestagen; E2 + P groups trimegestone 0.5 mg (E2 + T, n = 14) or dydrogesterone 10 mg (E2 + D group, n = 14) or placebo (n = 16). Data were collected at baseline and at 4 and 12 weeks.

RESULTS

Twelve weeks of treatment with E2 or E2 + P was associated with a significant decrease in the plasma concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), and thrombomodulin (sTM). The average decrease in these markers was about 9%. In women treated with trimegestone the decreases were larger than in those treated with dydrogesterone; for sICAM-1 (-15% vs. -2%; P < 0.0001), sVCAM-1 (-15% vs. +3%; P = 0. 003) and sTM (-9% vs. -4%; P = 0.11). Plasma levels of endothelin-1 (ET-1) decreased (by 13%) only in women treated with E2 + P. In the E2 group, flow-mediated, endothelium-dependent vasodilatation increased by 6 percentage points after 12 weeks (P = 0.07 vs. baseline, P = 0.02 vs. E2 + P, and P = 0.17 vs. placebo).

CONCLUSION

Short-term treatment with E2 or E2 + trimegestone reduces plasma levels of sICAM-1, sVCAM-1 and sTM. ET-1 decreased only in the E2 + P groups. Different types of progestagens may differentially affect sICAM-1, sVCAM-1 and sTM levels, which may be relevant for the choice of type HRT.

Intimal deposition of functional von Willebrand factor in atherogenesis

During the formation of intimal thickening in normocholesterolemic rabbits, von Willebrand factor (vWF) is increased in the endothelial cells (ECs) and deposited in the intima. We investigated whether this also occurs during cholesterol-induced plaque formation, whether the synthesis of vWF increases, and whether this influences platelet adhesion. Rabbits were fed a cholesterol-rich (0.3%) diet for 26 weeks. Thereafter, half of the animals received a normal diet for another 26 weeks (cholesterol withdrawal). To induce intimal thickening in normocholesterolemic rabbits, collars were positioned around the carotid artery. Arterial segments were studied using immunohistochemistry, reverse transcription-polymerase chain reaction, electron microscopy, and platelet adhesion tests. Cholesterol treatment induced plaque formation in the aorta. The ECs had a cuboidal aspect, showed a dense immunoreactivity for vWF, a pronounced rough endoplasmic reticulum, and numerous Weibel-Palade bodies. There were subendothelial vWF deposits in the plaques and vWF mRNA was significantly increased as compared with controls. Similar changes were seen after collar-induced intimal thickening. After cholesterol withdrawal, both vWF mRNA and the ultrastructural morphology of the ECs normalized, and the vWF deposits disappeared from the plaque. Perfusion studies with anticoagulated rabbit blood over cross-sections of atherosclerotic aortas revealed increased vWF-mediated platelet adhesion in the subendothelial plaque region. Whereas rabbit platelets perfused through the lumen adhered to the same extent to de-endothelialized aortas of normocholesterolemic and atherosclerotic rabbits, vWF mediated platelet adhesion to endothelium was observed in atherosclerotic but not in normal aortas. Our results show an increased synthesis and (sub)endothelial presence of vWF after vascular injury, with functional consequences for platelet deposition on the vessel wall.

Plasma Homocysteine Is Weakly Correlated with Plasma Endothelin and von Willebrand Factor but not with Endothelium-dependent Vasodilatation in Healthy Postmenopausal Women

Background: Hyperhomocysteinemia is an independent cardiovascular risk factor, possibly through the induction of endothelial dysfunction. The postmenopausal state is associated with increased plasma homocysteine. We examined whether increased homocysteine is associated with impaired endothelial function.

Methods: Sixty-three hysterectomized but otherwise healthy postmenopausal women (54.8 ± 3.5 years) participated in this study. Fasting total plasma homocysteine (tHcy) was measured as free plus protein-bound homocysteine. Endothelial function was assessed by measuring plasma concentrations of the endothelium-derived proteins endothelin (ET), von Willebrand factor (vWF), and plasminogen activator inhibitor type 1 (PAI-1) as well as brachial artery flow-mediated, endothelium-dependent vasodilatation (FMD).

Results: Plasma tHcy was 9.6 ± 2.5 μmol/L. After adjustment for possible confounders, a 1 μmol/L increase in tHcy was associated with an increase in ET of 0.08 ng/L (P = 0.045) and an increase in vWF of 4.2% (P = 0.05). No statistically significant association was present between tHcy and PAI-1 or FMD.

Conclusions: Increased fasting homocysteine in postmenopausal women may impair some aspects of endothelial function. It is of clinical interest to study whether homocysteine lowering can improve endothelial function and thus cardiovascular morbidity and mortality in postmenopausal women.

Long-term effects of combined hormone replacement therapy on markers of endothelial function and inflammatory activity in healthy postmenopausal women

OBJECTIVE

To study the effects of combined hormone replacement therapy on markers of endothelial function and inflammatory activity.

DESIGN

Prospective, randomized, controlled study.

SETTING

Academic hospital.

PATIENT(S)

Healthy postmenopausal women with an intact uterus.

INTERVENTION(S)

For the first 12 months, the hormone replacement therapy group (n = 14) received oral E2, 1 mg daily, sequentially combined with 5 or 10 mg of dydrogesterone. Thereafter, they received oral E2, 2 mg daily, sequentially combined with 10 mg of dydrogesterone. The control group (n = 13) received no treatment. Data were collected at baseline and at 3, 12, and 15 months.

MAIN OUTCOME MEASURE(S)

Parameters of endothelial function and inflammatory activity.

RESULT(S)

During 12 months of follow-up, we observed decreases of 15% in plasma levels of endothelin-l, of 21% in soluble thrombomodulin, of 14% in von Willebrand factor, and of 12% in clottable fibrinogen in the hormone replacement therapy group compared with the control group. There was a 5% decrease in soluble E-selectin tevels. All significant changes were observed by 3 months and sustained after 15 months. Brachial artery flow-mediated vasodilatation and C-reactive protein levels did not change significantly.

CONCLUSION(S)

Long-term combined hormone replacement therapy with E2 and dydrogesterone in healthy women was associated with sustained improvement in some aspects of endothelial function and in clottable fibrinogen levels.

The role of adhesion molecules in atherosclerosis

The progression of atherosclerosis is currently believed to involve the interaction of monocytes with the vascular endothelium. Within the last decade, the cell-surface proteins thought to control these interactions have been investigated. This review seeks to describe the nature of these interactions through what are known as adhesion molecules and their role in atherogenesis. It begins with the stages of atherogenesis from the movement of the monocyte to the endothelium, followed by the migration of smooth muscle cells from the media to the intima, and subsequently to the later stages of fibrofatty plaque formation and potential complications due to thrombosis and/or plaque fissure and embolism. The different structural classifications of the adhesion molecules, such as integrins, cadherins, selectins, and members of the immunoglobulin gene superfamily, are outlined, and interaction of binding domains are highlighted. The vascular endothelium and the basic role of adhesion molecules in dysfunction are considered. Discussion of the role of adhesion molecules in atherogenesis focuses on interactions of the endothelium, monocytes, and leukocytes, as well as the influences of cytokines, oxidized low-density lipoproteins, and genetic determinants. Finally, epidemiological risk factors associated with atherosclerosis such as hypertension and dyslipidemia are considered in light of their effects on adhesion molecule expression.