Endothelial function, arterial stiffness and lipid lowering drugs

Arterial Stiffness and its Impact on Cardiovascular Health

PURPOSE OF REVIEW

Cardiovascular diseases are the leading cause of mortality globally. Identifying patients at risk is important to initiate preventive strategies. Over the last few decades, the role of the endothelium and its impact on arterial stiffness have been recognised as playing a pivotal role in cardiovascular disease. This review will focus on the effect of arterial stiffness in different patient cohorts with regard to cardiovascular morbidity and mortality, as well as its use in clinical practice.

RECENT FINDINGS

Arterial stiffness is associated with a range of cardiovascular risk factors and is an independent predictor of cardiovascular mortality. The gold standard for evaluating arterial stiffness is pulse wave velocity. Recently, cardio-ankle vascular index has been implemented as an easy and highly reproducible measure of arterial stiffness. Moreover, certain pharmacologic agents may modify arterial stiffness and alter progression of cardiovascular disease. The endothelium plays an important role in cardiovascular disease. Implementing assessment of arterial stiffness in clinical practice will improve stratification of patients at risk of cardiovascular disease and help modify disease progression.

Assessment of vascular stiffness using different modalities in patients with systemic lupus erythematosus: a case control study

Background

Cardiovascular disease is a major cause of morbidity and mortality in systemic lupus erythematosus (SLE) patients. Accurate risk stratification would require a simple, non-invasive index integrating all traditional and emerging risk factors. Vascular stiffness fulfills these requirements and has better predictive value for cardiovascular events than traditional risk factors in hypertensives and patients with coronary artery disease. Our aim was to determine whether arterial stiffness is increased in SLE patients compared to healthy controls and to correlate the arterial stiffness in SLE patients with cardiovascular risk factors, namely, hypertension and diabetes mellitus.

Results

This study included 50 SLE patients and 50 age- and gender-matched healthy individuals. SLE patients had higher median aortic stiffness index (SI) and lower strain and distensibility, compared to controls (p value for all < 0.001). SLE patients had significantly impaired flow-mediated dilation (FMD) compared to controls: the median (range) in SLE patients was 8.82 (2.5–21.87), compared to 19 (12–37.5) in controls (z = − 7.695, p ˂ 0.001). Regarding quality arterial stiffness (QAS) parameters, SLE patients had significantly lower median carotid distension, distensibility coefficient, and compliance coefficient, with higher median carotid SI, carotid pulse wave velocity (PWV), and augmentation index (AI), compared to controls (p value for all ≤ 0.001). SLE patients had a higher median cf-PWV 6.5 m/s (4.8–11.8), compared to a median of 4.6 m/s (3.8–6.9) in controls (z = − 8.193, p ˂ 0.001). Linear regression analysis to adjust for hypertension and diabetes mellitus yielded a statistically significant difference between both groups for all of the above parameters (p = 0.014 for maximum carotid intima media thickness (IMT) and < 0.001 for remaining parameters), with the exception of the maximum carotid augmentation index (p = 0.184).

Conclusion

SLE patients have significantly increased arterial stiffness and impaired FMD compared to healthy controls. This is true even after adjusting for hypertension and diabetes mellitus, highlighting the fact that SLE could be an independent cardiovascular risk factor. These findings emphasize the need for early management of SLE together with aggressive risk factor modification.

Favorable Pulse Wave Augmentation Indices and Left Ventricular Diastolic Profile in β-Thalassemia Minor

β-Thalassemia minor (β-Τm) is associated with rheological and biochemical alterations that can affect cardiovascular function. We aimed to evaluate the elastic arterial properties and the pulse wave augmentation indices in a population of patients with β-Τm. Seventy-five individuals with β-Τm (age 55.5 [42.75-65.25], women 48%) and 127 controls (age 57 years [48-63], women 55.1%) underwent comprehensive echocardiographic evaluation and applanation tonometry of the radial and femoral artery. Pulse wave analysis revealed that augmentation pressure, augmentation index (AIx), and heart rate-corrected AIx were significantly lower (median [interquartile range]: 8.75 [4.625-13] vs 11 [6.5-14.5], P = .017; 26.5 [17.5-33.375] vs 30.5 [20.75-37.5], P = .014; and 22.25 [15.125-29.5] vs 27 [20.5-33], P = .008, respectively) in the β-Τm group compared to controls. The left atrial active emptying volume was significantly lower and the isovolumic relaxation time was shorter in the β-Τm group compared to the control group (10.2 [7.4-14.4] vs 12.0 [8.6-15.8], P = .040 and 78 [70-90] vs 90 [70-104], P = .034, respectively). β-Thalassemia minor is associated with favorable pulse wave augmentation indices and left ventricular diastolic function profile in asymptomatic individuals with cardiovascular risk factors.

Aortic Elastic Properties and Myocardial Performance Index Are Impaired in Patients with Lichen Planus

OBJECTIVES

The aim of this study was to investigate the elastic properties of the aorta and the myocardial performance index of the left ventricle (LV) in patients with lichen planus (LP).

SUBJECTS AND METHODS

A total of 54 patients with LP and 50 controls were enrolled in the study. The 2 groups were well-matched regarding age, gender, body mass index, any smoking history, diabetes mellitus and systolic and diastolic blood pressure (SBP and DBP). The echocardiographic examination was performed on the study subjects and the controls. Aortic elasticity parameters and the myocardial performance index of the LV were calculated. The Student t test, the x03C7;2 test and multiple linear regression were used for the statistical analysis.

RESULTS

Aortic strain (AS, 4.77 ± 1.81 vs. 8.95 ± 2.22; p < 0.001) and aortic distensibility (AD, 0.25 ± 0.009 vs. 0.42 ± 0.120; p < 0.001) were significantly lower, and aortic stiffness index β (ASIβ, 3.65 ± 1.03 vs. 2.70 ± 0.91; p < 0.001) was significantly higher in the LP group than in the controls. The myocardial performance index (Tei index) was significantly higher in the LP group than in the control group (p = 0.001). The duration of the LP was negatively correlated with AS (r = -0.364, p < 0.001) and AD (r = -0.279, p = 0.006), and positively correlated with the Tei index (r = 0.324, p = 0.001) and ASIβ (r = 0.364, p < 0.001). After adjustment for relevant confounders (age, male gender, smoking, SBP, DBP, diabetes mellitus and low- and high-density lipoprotein cholesterol), LP and its duration were still associated with AS, AD and ASIβ.

CONCLUSION

In this study, AS and AD were lower and ASIβ and myocardial performance index higher in LP patients than in controls.

Association between polyvascular atherosclerosis and estimated glomerular filtration rate in patients with ischaemic stroke: data analysis of the patients in the Chinese National Stroke Registry

OBJECTIVES

This study evaluated the prevalence of chronic kidney disease (CKD) in ischemic stroke (IS) patients with polyvascular disease (PolyVD) and analysed the relationship between PolyVD and estimated glomerular filtration rate (eGFR) in IS patients.

METHODS

Data from 9152 consecutive IS patients from the China National Stroke Registry were analysed. PolyVD was defined as patients with IS and coronary artery disease (CAD) and/or peripheral arterial disease (PAD). Chronic kidney disease was defined as eGFR < 60 mL/minute/1.73 m(2).The prevalence of CKD in IS patients with PolyVD was calculated. Logistic regression was used to estimate the correlation between PolyVD and eGFR between the monovascular group (IS alone) and the PolyVD group after adjusting for age, current or previous smoking, moderate or heavy drinking, body mass index, hypertension, dyslipidemia, diabetes mellitus, atrial fibrillation, previous stroke, and National Institutes of Health Stroke Scale scores.

RESULTS

PolyVD was observed in 1387 of 9152 patients (15.16%). Among these patients, 1351 (14.76%) had CAD, 56 (0.61%) had PAD, and 20 (0.22%) had CAD and PAD in addition to IS. The prevalence of CKD in IS patients with PolyVD and IS alone was 29.56 and 16.28%, respectively (P < 0.0001). The PolyVD group had a significantly higher risk of lower eGFR (OR: 1.414, 95% CI: 1.202-1.665, P < 0.0001) compared with patients with IS alone.

DISCUSSION

IS patients with PolyVD had a high prevalence of CKD, and PolyVD was independently associated with a low eGFR.

Aortic arterial stiffness is a moderate predictor of cardiovascular disease in patients with psoriasis vulgaris

Psoriasis is associated with an increased risk of atherosclerosis. Endothelial dysfunction is the critical early step in the process of atherogenesis, and it is commonly investigated by measuring arterial stiffness. We aimed to investigate the relationship between arterial stiffness and high-sensitivity C-reactive protein (hsCRP) in patients with psoriasis. A total of 32 patients with psoriasis and 35 patients with other skin diseases were included in the study. The hsCRP levels and arterial stiffness measurements were compared. Arterial stiffness was significantly different between the 2 groups (P = .01). Arterial stiffness was not associated with the duration of the disease or the disease activity (P = .34 and .64, respectively). In patients with psoriasis, arterial stiffness correlated positively with age, sex, body mass index, diastolic blood pressure, and hsCRP level (P < .05). These findings provide further evidence of a link between inflammation, premature atherosclerosis, and psoriasis.

Association of serum lipids with arterial stiffness in a population-based study in Beijing

BACKGROUND

Some cardiovascular risk factors such as age, hypertension and diabetes have been confirmed to be positively correlated with arterial stiffness. However, the relationship between serum lipids and arterial stiffness is incompletely understood. Recent studies have been far from conclusive and consistent data were not obtained. We investigated the relationship between serum lipids and pulse wave velocity (PWV) in community-dwelling individuals in Beijing, China.

METHODS

This was a population-based, cross-sectional sample of adults (n = 2375; 48·1% men; age range, 40-96 years) from two communities in Beijing. A questionnaire was used for the risk factors of arterial stiffness. Anthropometry, blood pressure and heart rate were measured. Values of fasting plasma glucose (FPG), serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and uric acid were measured. Carotid-femoral PWV (cfPWV) and carotid-radial PWV (crPWV) were assessed non-invasively.

RESULTS

Carotid-femoral pulse wave velocity was significantly positively related to TC (r = 0·221; P < 0·0001), LDL-C (r = 0·193; P < 0·0001) and inversely related to HDL-C (r = -0·240; P < 0·0001), but not with TG (r = 0·073; P = 0·6721). crPWV was inversely related to HDL-C (r = -0·272; P < 0·0001), but not with TC (r = 0·007; P = 0·4781), LDL-C (r = 0·021; P = 0·6393) or TG (r = 0·008; P = 0·2498). The multiple regression analysis showed that LDL-C was independently associated with cfPWV and that HDL-C was inversely associated with cfPWV and crPWV. TC and TG were not independently related to cfPWV and crPWV.

CONCLUSIONS

These data show the correlation between some of the parameters of serum lipids and arterial stiffness. LDL-C was independently associated with aortic stiffness, and HDL-C was independently inversely associated with aortic stiffness and peripheral stiffness.

Is vascular stiffness a target for therapy?

BACKGROUND

Early cardiovascular disease starts in the endothelium leading to functional changes in the vasculature. These changes can be depicted by assessment of arterial stiffness or elasticity. There are several techniques to assess arterial stiffness. Increased arterial stiffness or decreased arterial elasticity has been associated with cardiovascular risk factors. There is now evidence that small artery elasticity is a strong predictor for arterial hypertension. Moreover arterial elasticity provides extra prognostic information beyond arterial blood pressure measurement. Arterial stiffness attenuation may reflect the true reduction of arterial wall damage.

RESULTS

ACE-inhibitors, angiotensin II receptor blockers, aldosterone antagonists and calcium antagonists have favorable effects in improving arterial elasticity, while beta-blockers have an inverse effect. Diuretics have not been evaluated. Lipid lowering therapy, some antidiabetic therapy have shown to reduce arterial stiffness. Inflammatory and infectious diseases have been associated with vascular inflammation and consequently increase in arterial stiffness. The effect of anti-inflammatory agents and antiretroviral therapy on arterial stiffness is under investigation.

CONCLUSIONS

Measurement of arterial stiffness will not only be helpful in the detection of early vascular disease but also as a tool in the selection and follow-up monitoring of therapeutic strategies aimed at preventing or delaying progression of vascular disease.

Production of Omega-3 Triacylglycerol Concentrates using a New Food Grade Immobilized Candida antarctica Lipase B

Triacylglycerol concentrates of eicosapentaenoic and docosahexaenoic omega-3 fatty acids were synthesized either via transesterification or esterification of glycerol with the corresponding ethyl ester or free fatty acid concentrates, respectively. A newly developed food grade immobilized Candida antarctica lipase B system using an Amberlite FPX-66 hydrophobic matrix, was compared with a commercially available non-food grade commercial system, for their ability to catalyze these reactions. For either system, the transesterification required higher temperature (90°C) than esterification (70°C) to achieve maximum triacylglycerol yields. The newly developed immobilized system efficiently catalyzes the esterification of free fatty acids with glycerol and differs from the existing commercial system in that it is food grade and has a more uniform and larger particle distribution. The new system significantly improves flow in a packed bed reactor, enabling multiple reuse of the catalyst for up to 80 repeats.

Omega-3 fatty acids: how can they be used in secondary prevention?

Omega-3 fatty acids (FAs) are divided into long-chain fatty acids (eicosapentaenoic acid and docosahexaenoic acid ), which are found in fatty fish, and intermediate-chain FAs (alpha-linolenic acid), which are found in vegetable oils. Omega-3 FAs favorably modulate a variety of vascular risk factors and also exert antiarrhythmic effects. Epidemiologic data suggest that increased consumption of marine omega-3 FAs is associated with reduced coronary heart disease (CHD) mortality. Randomized controlled studies also show that supplementation with EPA and DHA reduces CHD risk, primarily in the secondary prevention setting. Data are more limited on the efficacy of marine omega-3 FAs for the primary prevention of CHD and on the role of alpha-linolenic acid. Increased intake of EPA and DHA represents a valuable tool for vascular disease prevention and should be recommended in all patients with CHD.

Role of xanthine oxidoreductase in cardiac nitroso-redox imbalance

Emerging evidence supports the importance of nitroso-redox balance in the cardiovascular system. Xanthine oxidoreductase (XOR) is a major oxidative enzyme and increased XOR activity, leading to both increased production of reactive oxygen species and uric acid, is implicated in heart failure. Within the heart, XOR activity stimulates cardiomyocyte hypertrophy, apoptosis, and impairs matrix structure. The underpinnings of these derangements can be linked not solely to oxidative stress, but may also involve the process of nitroso-redox imbalance. In this regard, XOR interacts with nitric oxide signaling at numerous levels, including a direct protein-protein interaction with neuronal nitric oxide synthase (NOS1) in the sarcoplasmic reticulum. Deficiency or translocation of NOS1 away from this microdomain leads to increased activity of XOR, which in turn impairs excitation-contraction coupling and myofilament calcium sensitivity. There is a mounting abundance of preclinical data supporting beneficial effects of inhibiting XOR, but translation to the clinic continues to be incomplete. A growing understanding of XOR and its role in nitroso-redox imbalance has great potential to lead to improved pathophysiologic insights and possibly therapeutic advances.

Assessment of arterial stiffness, a translational medicine biomarker system for evaluation of vascular risk

AIMS

Stiffening of the large arteries is a common feature of aging and is exacerbated by a number of disorders such as hypertension, diabetes, and renal disease. Arterial stiffening is recognized as an important and independent risk factor for cardiovascular events. This article will provide a comprehensive review of the recent advance on assessment of arterial stiffness as a translational medicine biomarker for cardiovascular risk.

DISCUSSIONS

The key topics related to the mechanisms of arterial stiffness, the methodologies commonly used to measure arterial stiffness, and the potential therapeutic strategies are discussed. A number of factors are associated with arterial stiffness and may even contribute to it, including endothelial dysfunction, altered vascular smooth muscle cell (SMC) function, vascular inflammation, and genetic determinants, which overlap in a large degree with atherosclerosis. Arterial stiffness is represented by biomarkers that can be measured noninvasively in large populations. The most commonly used methodologies include pulse wave velocity (PWV), relating change in vessel diameter (or area) to distending pressure, arterial pulse waveform analysis, and ambulatory arterial stiffness index (AASI). The advantages and limitations of these key methodologies for monitoring arterial stiffness are reviewed in this article. In addition, the potential utility of arterial stiffness as a translational medicine surrogate biomarker for evaluation of new potentially vascular protective drugs is evaluated.

CONCLUSIONS

Assessment of arterial stiffness is a sensitive and useful biomarker of cardiovascular risk because of its underlying pathophysiological mechanisms. PWV is an emerging biomarker useful for reflecting risk stratification of patients and for assessing pharmacodynamic effects and efficacy in clinical studies.

Statin treatment, carotid atherosclerotic plaque macrophage infiltration and circulating inflammatory markers

BACKGROUND

Statin treatment is considered as first line therapy in patients with atherosclerotic disease. We evaluated the effect of pre-treatment with statins on carotid plaque infiltration by macrophages and on the circulating levels of proinflammatory cytokines in patients who underwent carotid endarterectomy.

PATIENTS AND METHODS

One hundred fourteen patients were enrolled; 89 men and 25 women (mean age 67+/-8 years; range 42-83 years). Fifty three patients (46%) were on statin treatment at least 3 months before endarterectomy and 61 (54%) had never received statin treatment. The serum levels of high sensitivity C reactive protein (hsCRP), serum amyloid A (SAA), tumor necrosis factor alpha (TNFalpha), interleukin (IL)-1beta and IL-6 were evaluated preoperatively. The intensity of macrophage infiltration was evaluated by immunochemistry, using the monoclonal antibody CD 68. The area of the plaque covered by macrophages was measured as a proportion of the whole plaque area, using a custom designed image tool analysis.

RESULTS

Patients on statins had lower serum total cholesterol levels (172+/-50 vs 194+/-35 mg/dl, p= 0.014), lower low density cholesterol levels (103+/-44 vs 123+/-31 mg/dl, p= 0.010) and lower serum hsCRP levels (1.8 [1.1-3.4] vs 3.4 [1.3-4.9] mg/l, p= 0.03), while SAA, TNFalpha, IL-6 and IL-1beta levels did not differ between the 2 groups. The infiltration of atherosclerotic plaque by macrophages was similar in statin treated patients and in controls (0.55+/-0.15% vs 0.49+/-0.19%, p= 0.21).

CONCLUSION

Patients on statins have similar macrophage accumulation in their carotid atherosclerotic plaques compared with patients not on statins. Inflammatory markers were also similar in both groups except for hsCRP which was significantly lower in those taking statins.

Statin discontinuation: an underestimated risk?

Statin treatment is essential for the prevention of vascular disease. Despite the established benefits of statins, discontinuation of these agents is frequent. Whether statin discontinuation leads to adverse outcomes is still debated and the most convincing evidence is mainly restricted to patients who experienced an acute vascular event. It is important to establish if this phenomenon extends to other populations, like those without vascular disease but with a high calculated risk. Overall, it appears that even a brief discontinuation of statins might be harmful. Therefore, statin treatment should not be interrupted except if there is a very good reason. Moreover, patients should be instructed as to why they must adhere to their medication. Adherence should be monitored regularly.

Fluvastatin Treatment and Withdrawal: Effects on Endothelial Function

Fluvastatin lowers lipids and protects endothelial function. This study investigated how 2 preparations of fluvastatin would affect endothelial function after treatment and early after its discontinuation. Twenty-seven patients received 80 mg extended-release fluvastatin every day, 40 mg immediate-release fluvastatin twice a day, or placebo for 5 weeks. Fasting lipids and flow-mediated dilation were measured at baseline and after each treatment period. In 21 patients, flow-mediated vasodilation was also measured 24 hours after discontinuation of therapy. Both forms of fluvastatin improved flow-mediated vasodilation (extended release: P < .037 and immediate release: P < .001). However, this improvement occurred preferentially in patients with low baseline flow-mediated vasodilation (<5%). Twenty-four hours after treatment discontinuation, the flow-mediated vasodilation deteriorated again to baseline (extended release and immediate release: P < .001). Fluvastatin improved flow-mediated vasodilation only in patients with low baseline values. Twenty-four hours after discontinuation, the flow-mediated vasodilation deteriorated again, surprisingly irrespective of prior improvement.

Plasma Total Antioxidant Activity in Comparison with Plasma NO and VEGF Levels in Patients with Metabolic Syndrome

Introduction

The aim of our study was to estimate plasma antioxidant activity as well as plasma nitric oxide (NO) and vascular endothelial growth factor levels in patients with metabolic syndrome compared with healthy participants.

Material and Methods

Fifty patients (24 women and 26 men, mean age 55.9 ± 11.8 years) with metabolic syndrome were compared with 25 healthy participants (12 women and 13 men, mean age 54.2 ± 12.8 years). Plasma total antioxidant activity and plasma levels of NO and VEGF were determined in all participants.

Results

In the patients with metabolic syndrome, plasma total antioxidant activity, nitric oxide, and vascular endothelial growth factor were significantly lower ( P < .001) than that observed in healthy participants (3.2 ± 1.6 vs 6.4 ± 2.1 mM/L), (6.3 ± 2.2 vs 9.8 ± 2.7 μM/L), and 71.0 ± 16.9 vs 137.5 ± 12.6 pg/mL), respectively.

Conclusions

Decreased plasma total antioxidant activity, NO, and VEGF levels in patients with metabolic syndrome reflect significant endothelial dysfunction. This suggests that oxidation–reduction balance disorders might play an important role in this process

Cardiorenal anemia syndrome: do erythropoietin and iron therapy have a place in the treatment of heart failure?

The cardiorenal anemia syndrome in congestive heart failure (CHF) is an independent risk factor for vascular morbidity and mortality. Several factors play a role in the pathogenesis of anemia in CHF, including inflammation, impaired renal function, use of certain antihypertensive or cardioprotective agents, and gastrointestinal or urinary losses of essential hemopoietic factors. Several trials evaluated the effects of administering erythropoietin (EPO) and/or iron to patients with CHF. Even though most of them were uncontrolled studies, their results suggest that EPO treatment might be beneficial in CHF. Nevertheless, more studies are needed and certain issues should be resolved, particularly the optimal hemoglobin level, before EPO can become part of the treatment of patients with CHF.

C-reactive protein (CRP): more than just an innocent bystander?

This editorial discusses whether measuring C-reactive protein (CRP) levels can be used as a predictor of vascular risk. The agents that reduce CRP levels and the evidence for a possible causative role of CRP in the pathogenesis of coronary events and atherosclerosis are also considered. There is a need to further elucidate the role of CRP, as well as the clinical relevance, if any, of CRP-lowering agents.