Enhanced Coronary Calcification Determined by Electron Beam CT Is Strongly Related to Endothelial Dysfunction in Patients With Suspected Coronary Artery Disease

Association between cardiovascular risk profile and impaired microvascular function in a Swedish middle-aged cohort (the SCAPIS study)

AIMS

The aim was to investigate the relationship between microvascular function, cardiovascular risk profile, and subclinical atherosclerotic burden.

METHODS AND RESULTS

The study enrolled 3809 individuals, 50-65 years old, participating in the population-based observational cross-sectional Swedish CArdioPulmonary bioImage Study. Microvascular function was assessed in forearm skin using an arterial occlusion and release protocol determining peak blood oxygen saturation (OxyP). Cardiovascular risk was calculated using the updated Systematic Coronary Risk Evaluation [SCORE2; 10-year risk of fatal and non-fatal cardiovascular disease (CVD) events]. The OxyP was compared with coronary artery calcification score (CACS) and to plaques in the carotid arteries. Individuals with OxyP values in the lowest quartile (Q1; impaired microvascular function) had a mean SCORE2 of 5.8% compared with 3.8% in those with the highest values of OxyP (Q4), a relative risk increase of 53%. The risk of having a SCORE2 > 10% was five times higher for those in Q1 (odds ratio: 4.96, 95% confidence interval: 2.76-8.93) vs. Q4 when adjusting for body mass index and high-sensitivity C-reactive protein. The OxyP was lower in individuals with CACS > 0 and in those with both carotid plaques and CACS > 0, compared with individuals without subclinical atherosclerotic burdens (87.5 ± 5.6% and 86.9 ± 6.0%, vs. 88.6 ± 5.8%, P < 0.01).

CONCLUSION

In a population without CVD or diabetes mellitus, impaired microvascular function is associated with cardiovascular risk profiles such as higher SCORE2 risk and CACS. We suggest that OxyP may serve as a microcirculatory functional marker of subclinical atherosclerosis and CVD risk that is not detected by structural assessments.

The association between C-reactive protein and coronary artery calcification: a systematic review and meta-analysis

BACKGROUND

While coronary artery calcification (CAC) is recognized as a reliable marker for coronary atherosclerosis, the relationship between the concentration of C-reactive protein (CRP) and the incidence and progression of CAC remains controversial.

METHOD

PubMed, Embase, Web of Science, and Scopus were systematically searched to identify relevant observational studies until October 2023. The methodological quality of the included studies was evaluated using the Newcastle-Ottawa Scale (NOS). A random-effects meta-analysis was employed to calculate pooled odd ratios (OR) and corresponding 95% confidence intervals, considering heterogeneity among the studies.

RESULTS

Out of the 2545 records, 42 cross-sectional and 9 cohort studies were included in the systematic review. The meta-analysis on 12 eligible cross-sectional studies revealed no significant association between CAC and CRP [pooled OR: 1.03 (1.00, 1.06)]. Additionally, an insignificant association was found between CAC and CRP through meta-analysis on three eligible cohort studies [pooled OR: 1.05 (0.95, 1.15)] with no considerable heterogeneity across studies. Sensitivity analyses indicated that the meta-analysis models were robust. There was no evidence of publication bias.

CONCLUSION

Based on the meta-analysis findings, elevated levels of CRP did not emerge as a valuable prognostic maker for CAC incidence and progression prediction.

Resting Pd/Pa correlates with fractional flow reserve but not angiographic severity in calcified coronary arteries

OBJECTIVE

Study the effect of coronary artery calcium (CAC) on resting coronary physiological indices.

BACKGROUND

Prior studies found no correlation between angiographic stenosis and fractional flow reserve (FFR) in heavily calcified arteries.

METHODS

Two hundred consecutive patients undergoing whole-cycle resting Pd/Pa and FFR evaluation of a single lesion of intermediate severity (40-80%) had CAC quantified based upon radiopacities at the site of the stenosis, where 0 = none or mild calcium, 1 = moderate calcium, and 2 = severe calcium.

RESULTS

Mean age was 61 ± 11 years and 34% were female. The mean degree of stenosis, FFR, and resting Pd/Pa were 60 ± 12%, 0.83 ± 0.08, and 0.93 ± 0.05, respectively. Resting Pd/Pa correlated with degree of angiographic diameter stenosis (DS) as determined by quantitative coronary angiography (QCA) or visual estimation in arteries with calcium score of 0 or 1, but there was no correlation in severely calcified arteries. The diagnostic accuracy of DS ≥70% by QCA to predict hemodynamic significance was 68% with calcium scores of 0/1, but only 43% with calcium score = 2. Resting Pd/Pa was highly correlated with FFR irrespective of the degree of CAC (R² = 0.68, p < .001) and the sensitivity of resting Pd/Pa ≤0.91 for predicting an FFR ≤0.80 was 0.67 in arteries with calcium scores of 0 or 1 and 0.69 in arteries with a calcium score of 2.

CONCLUSIONS

There was no correlation between angiographic stenosis and either resting Pd/Pa or FFR in heavily calcified coronary artery lesions.

The relationship between endothelial function and aortic valve calcification: Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Aortic valve calcification (AVC) may be associated with atherogenic processes arising from endothelial dysfunction (ED). Limited data is available about the relationship between ED, defined by flow mediated dilation (FMD%) and biomarkers, and the prevalence and progression of AVC in a multiethnic population.

METHODS

A sample of 3475 individuals from the Multi-Ethnic Study of Atherosclerosis (MESA), with both initial and repeat CT scans at a mean of 2.65 ± 0.84 years and FMD% and serologic markers of ED [ C-reactive protein (CRP), Von Willebrand factor (vWF), Plasminogen Activator Inhibitor (PAI), fibrinogen, Interleukin 6 (IL6), E-selectin and ICAM-1 (Intercellular Adhesion Molecule 1)], were analyzed. Multivariate modeling evaluated the association between ED and the prevalent AVC and AVC progression.

RESULTS

The median levels of FMD% was lower and vWF%, fibrinogen, IL6 and ICAM-1 were significantly higher in the AVC prevalence group versus no AVC prevalence (all p < 0.001). In the fully adjusted model for established risk factors, decreasing FMD% or increasing biomarkers was not independently associated with AVC prevalence [OR FMD% 1.028 (0.786, 1.346), CRP 0.981 (0.825, 1.168), vWF 1.132 (0.559, 2.292), PAI 1.124 (0.960, 1.316), fibrinogen 1.116 (0.424, 2.940), IL6 1.065 (0.779, 1.456), E-selectin 0.876 (0.479, 1.602) and ICAM-1 1.766 (0.834, 3.743)]. In the AVC progression group, FMD%, vWF%, fibrinogen and IL6 were significantly different (p < 0.05). After adjusting for cardiac risk factors, AVC progression was not independently associated with decreasing FMD% or increasing biomarkers [OR FMD% 1.105 (0.835, 1.463), CRP 1.014 (0.849, 1.210), vWF% 1.132 (0.559, 2.292), PAI 1.124 (0.960, 1.316), fibrinogen 0.909 (0.338, 2.443), IL6 1.061 (0.772, 1.459), E-selectin 0.794 (0.426, 1.480) and ICAM-1 0.998 (0.476, 2.092)].

CONCLUSIONS

Endothelial dysfunction by FMD% and biomarkers is not significantly associated with the prevalence or progression of aortic valve calcification after adjustment for cardiac risk factors.

Distribution of ABO Blood Groups and Coronary Artery Calcium

BACKGROUND

ABO blood groups have been confirmed to be associated with cardiovascular diseases such as coronary artery disease. However, whether ABO blood group is correlated with coronary artery calcium (CAC) is still unknown.

METHOD

301 patients with coronary artery calcium score (CACS) assessed by computed tomography were consecutively enrolled and divided into two groups: with calcium group (CACS>0, n=104) and without calcium group (CACS=0, n=197). Distribution of ABO blood groups was evaluated between the two groups.

RESULTS

The percentage of A blood type was significantly higher (p=0.008) and O blood type was significantly lower (p=0.037) in the calcium group. Univariate regression analysis showed that age, total cholesterol, low density lipoprotein cholesterol, high-sensitivity C-reactive protein, A blood type were positively correlated with CAC, and O blood type was inversely associated with CAC. Multivariate regression analysis showed that A blood type was independently associated with CAC (odds ratio: 2.217, 95% confidence interval: 1.260-3.900, p=0.006) even after further adjustment for variables that were clearly different between the two groups.

CONCLUSIONS

Our data has suggested for the first time that A blood type was an independent risk marker for CAC.

Endothelial function predicts 1-year adverse clinical outcome in patients hospitalized in the emergency department chest pain unit

BACKGROUND

Endothelial function is a marker for cardiovascular risk. Thus, abnormal endothelial function may be associated with adverse 1-year outcome in patients presenting to the emergency department chest pain unit (CPU).

METHODS

Following endothelial function testing, using EndoPAT 2000 in 300 consecutive subjects with chest pain and no history of coronary artery disease (CAD) presenting to CPU, patients underwent coronary computerized tomographic angiography (CCTA) or single-photon emission computed tomography according to availability.

RESULTS

Mean 10-year Framingham risk score (FRS) was 6.6±5.9%, median reactive hyperemia index (RHI) as a measure of endothelial function 2.08 and mean was 2.0±0.4. During a 1-year follow-up, the 20 (6.6%) patients who developed major adverse cardiovascular end-points (MACE), including all-cause mortality, non-fatal myocardial infarction, hospitalization for heart failure or angina pectoris, stroke, coronary artery bypass grafting and percutaneous coronary interventions, had higher 10-year FRS (10.5±8.2% vs 6.3±5.7%; p<0.001), lower baseline RHI (1.43±0.41 vs 2.10±0.44; p<0.001) and a greater extent of coronary atherosclerosis lesions (70% vs 3.9%, p<0.001) in the CPU CCTA, compared to those without MACE. RHI≤the median was associated with higher 1-year MACE (13% vs 0.7%, p<0.001) compared to RHI>the median. Multivariate analysis demonstrated that RHI≤the median is an independent predictor of coronary atherosclerosis lesions in the CPU CCTA (OR 5.98, 95% CI 03.29-10.88; p<0.001) and 1-year MACE (OR 15.207, 95% CI 2.00-115.33; p<0.01).

CONCLUSIONS

Our findings suggest that non-invasive endothelial function testing may have clinical utility in triaging patients in the CPU and in predicting 1-year MACE.

Asymmetric dimethyl-arginine and coronary artery calcification in young adults entering middle age: the CARDIA Study

BACKGROUND

Normal endothelial function depends on nitric oxide (NO) release by endothelial cells. Asymmetric dimethylarginine (ADMA), by competing with L-arginine, inhibits NO production and may lead to endothelial dysfunction and atherosclerotic development. Our aim was to ascertain the association between ADMA and coronary artery calcification (CAC), a marker of atherosclerotic coronary disease burden.

DESIGN

A nested case-control study within the Coronary Artery Risk Development in Young Adults (CARDIA) cohort, an observational study among young adults residing in four US cities.

METHODS

Participants were 263 white and black male and female cases with the presence of CAC and 263 sex and race-matched controls without evidence of CAC by computed tomography, 33-47 years old in 2000-2001.

RESULTS

The median level (range) of ADMA was significantly higher in cases (0.55; 0.20-2.22 micromol/l) than in controls (0.53; 0.32-1.30 micromol/l; P=0.03). In conditional logistic regression adjusting for age, field center, educational attainment, smoking status, alcohol consumption, body mass index, waist circumference, hypertension, diabetes, low-density lipoprotein and high-density lipoprotein-cholesterol, triglycerides, renal function and C-reactive protein, the highest tertile of ADMA, compared with the lowest tertile, was associated with 1.80 (95% confidence interval 1.03-3.15) increased odds of the presence of any CAC. By linear regression, a significant independent relationship was also found between ADMA and the degree of CAC.

CONCLUSION

These results support a role for ADMA as a biochemical marker of CAC.

Association of Big Endothelin-1 with Coronary Artery Calcification

BACKGROUND

The coronary artery calcification (CAC) is clinically considered as one of the important predictors of atherosclerosis. Several studies have confirmed that endothelin-1(ET-1) plays an important role in the process of atherosclerosis formation. The aim of this study was to investigate whether big ET-1 is associated with CAC.

METHODS AND RESULTS

A total of 510 consecutively admitted patients from February 2011 to May 2012 in Fu Wai Hospital were analyzed. All patients had received coronary computed tomography angiography and then divided into two groups based on the results of coronary artery calcium score (CACS). The clinical characteristics including traditional and calcification-related risk factors were collected and plasma big ET-1 level was measured by ELISA. Patients with CAC had significantly elevated big ET-1 level compared with those without CAC (0.5 ± 0.4 vs. 0.2 ± 0.2, P<0.001). In the multivariate analysis, big ET-1 (Tertile 2, HR = 3.09, 95% CI 1.66-5.74, P <0.001, Tertile3 HR = 10.42, 95% CI 3.62-29.99, P<0.001) appeared as an independent predictive factor of the presence of CAC. There was a positive correlation of the big ET-1 level with CACS (r = 0.567, p<0.001). The 10-year Framingham risk (%) was higher in the group with CACS>0 and the highest tertile of big ET-1 (P<0.01). The area under the receiver operating characteristic curve for the big ET-1 level in predicting CAC was 0.83 (95% CI 0.79-0.87, p<0.001), with a sensitivity of 70.6% and specificity of 87.7%.

CONCLUSIONS

The data firstly demonstrated that the plasma big ET-1 level was a valuable independent predictor for CAC in our study.

BMP type I receptor inhibition attenuates endothelial dysfunction in mice with chronic kidney disease

The molecular mechanisms of endothelial dysfunction and vascular calcification have been considered independently and potential links are currently unknown in chronic kidney disease (CKD). Bone morphogenetic protein (BMP) receptor signaling mediates calcification of atherosclerotic plaques. Here we tested whether BMP receptor signaling contributes to endothelial dysfunction, as well as to osteogenic differentiation of vascular smooth muscle cells (VSMCs), in a model of short-term CKD. In C57BL/6 mice, subtotal nephrectomy activated BMP receptor and increased phosphatase-and-tensin homolog (PTEN) protein in the endothelial cells and medial VSMCs without vascular remodeling in the aorta. In the endothelial cells, PTEN induction led to inhibition of the Akt-endothelial nitric oxide synthase (eNOS) pathway and endothelial dysfunction. In VSMCs, the PTEN increase induced early osteogenic differentiation. CKD-induced inhibition of eNOS phosphorylation and the resultant endothelial dysfunction were inhibited in mice with endothelial cell-specific PTEN ablation. Knockout of the BMP type I receptor abolished endothelial dysfunction, the inhibition of eNOS phosphorylation, and VSMC osteogenic differentiation in mice with CKD. A small molecule inhibitor of BMP type I receptor, LDN-193189, prevented endothelial dysfunction and osteogenic differentiation in CKD mice. Thus, BMP receptor activation is a mechanism for endothelial dysfunction in addition to vascular osteogenic differentiation in a short-term CKD model. PTEN may be key in linking BMP receptor activation and endothelial dysfunction in CKD.

Epicardial adipose tissue thickness as a predictor of impaired microvascular function in patients with non-obstructive coronary artery disease

OBJECTIVE

To determine if increased epicardial adipose tissue (EAT) measured by cardiac CT could be associated with impaired myocardial flow reserve (MFR) in patients with non-obstructive coronary artery disease (CAD).

BACKGROUND

Studies have shown that EAT volume is related to epicardial obstructive CAD, myocardial ischemia and major adverse cardiac events. However, the association between EAT with coronary microvascular dysfunction and impaired MFR has not been well clarified.

METHODS

Consecutive patients who underwent Rb-82 positron emission tomography (PET), coronary artery calcium (CAC) scoring and non-invasive coronary computed tomography angiography (CCTA) were screened. PET scans were analysed for standard myocardial perfusion (MPI) and MFR. CCTA results were analysed and only patients with non-obstructive CAD (<50% luminal diameter stenosis) were included. EAT thickness and volumes were measured from CT scans.

RESULTS

Of 137 patients without obstructive CAD by CCTA and with normal Rb-82 PET relative MPI, 26 (19.0%) patients had impaired MFR < 2 and 87 (64%) patients had CAC. EAT(thickness), EAT(volume) and CAC values were higher in patients with impaired MFR < 2 than those with normal MFR ≥ 2 (6.7 ± 1.6 mm vs 4.4 ± 1.0 mm, P < .0001; 119.0 ± 25.3 cm(3) vs 105.8 ± 30.5 cm(3), P < .04 and 508.9 ± 554.3 vs 167.8 ± 253.9, P < .0001, respectively). However, EAT(thickness) had a stronger negative correlation with MFR than EAT(volume) and CAC (r = -0.78 vs r = -0.25 and ρ = -0.32, P < .0001). With multivariable logistic regression analysis, only EAT(thickness) was independently associated with impaired MFR (OR 20.7, 95% CI 4.9-87.9, P < .0001). Importantly, the receiver-operator characteristic (ROC) curves demonstrated a superior performance of EAT(thickness) vs EAT(volume) and EAT(thickness) vs CAC in detecting impaired MFR (AUC: 0.945 vs 0.625, difference between AUC: 0.319, P < .0001; AUC: 0.945 vs 0.710, difference between AUC: 0.235, P < .0006, respectively). On ROC curve analysis, an EAT(thickness) cut-off value > 5.6 mm was optimal in detecting impaired MFR with a sensitivity and specificity of 81% and 92%, respectively.

CONCLUSIONS

Increased EAT appears to be associated with impaired MFR. This parameter may help improve detection of patients at risk of microvascular dysfunction.

Plasma fetuin-A is associated with endothelial dysfunction and subclinical atherosclerosis in subjects with nonalcoholic fatty liver disease

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD), a hepatic manifestation of metabolic syndrome (MetS) is closely associated with an increased risk of cardiovascular disease. Fetuin-A is associated with MetS and NAFLD. We investigated the relationship of circulating fetuin-A level with markers of endothelial dysfunction and presence of carotid atherosclerosis in subjects with NAFLD.

METHODS

The consecutive 115 patients with NAFLD and age-matched 74 healthy subjects were enrolled. Plasma levels of fetuin-A and markers of endothelial dysfunction [asymmetric dimethyl arginine (ADMA) and adiponectin] were measured by ELISA method. Insulin sensitivity was determined by homeostasis model assessment of insulin resistance (HOMA-IR) index. Carotid artery intima-media thickness (cIMT) was assessed by high-resolution ultrasonography.

RESULTS

Fetuin-A and ADMA were higher and, adiponectin was lower in NAFLD group than the control group (P = 0·004, P < 0·001 and P < 0·001, respectively). In addition, NAFLD group had greater cIMT measurements than the controls (P < 0·001). However, no difference was found for fetuin-A, ADMA, adiponectin and cIMT between two groups when the findings were adjusted according to the glucose, lipids and HOMA-IR index. In correlation analysis, fetuin-A was found to be positively correlated with triglyceride (r = 0·23, P = 0·001), HOMA-IR (r = 0·29, P < 0·001), ADMA (r = 0·24, P = 0·001), cIMT (r = 0·3, P = 0·003) and, negatively correlated with HDL-C (r = -0·17, P = 0·02) and adiponectin (r = -0·19, P = 0·01) levels. Multiple linear regression analysis showed that fetuin-A was independently associated with ADMA and cIMT levels.

CONCLUSION

This study demonstrated for the first time that circulating fetuin-A in NAFLD is independently associated with endothelial dysfunction and subclinical atherosclerosis.

The importance of functional tests in personalized medicine

Cardiovascular disease is the most prevalent disease mainly in the Western society and becoming the leading cause of death worldwide. Standard methods by which healthcare providers screen for cardiovascular disease have only minimally reduced the burden of disease while exponentially increasing costs. As such, more specific and individualized methods for functionally assessing cardiovascular threats are needed to identify properly those at greatest risk, and appropriately treat these patients so as to avoid a fate such as heart attack, stroke, or death. Currently, endothelial function testing-in both the coronary and peripheral circulation-is well established as being associated with the disease process and future cardiovascular events. Improving such testing can lead to a reduction in the risk of future events. Combining this functional assessment of vascular fitness with other, more personalized, testing methods should serve to identify those at the greatest risk of cardiovascular disease earlier and subsequently reduce the affliction of such diseases worldwide.

Arteriovenous access failure: more than just intimal hyperplasia?

Haemodialysis vascular access patency is severely compromised by fistula non-maturation and access stenosis. Intimal hyperplasia (IH) is considered the culprit lesion in failed fistulas, resulting in luminal narrowing and stenosis. This review focuses on the biology and pathophysiology of fistula failure and highlights not only the classically associated IH but also some relatively neglected but potentially important contributors such as inadequate outward remodelling. In addition, the complex process and fragile balance of successful fistula maturation might be partially hindered by pre-existent chronic kidney disease-mediated vasculopathy. Further unravelling the (patho)physiology of outward remodelling and IH could contribute to novel therapies and enhance fistula patency.

Normal vascular function as a prerequisite for the absence of coronary calcification in patients free of cardiovascular disease and diabetes

BACKGROUND

The absence of coronary artery calcium (CAC) is a marker of very low cardiovascular risk. Endothelial cells may have an effect on the initiation and propagation of arterial calcification. We aimed to identify the relationship between the absence of CAC and endothelial function in individuals without cardiovascular disease and diabetes.

METHODS AND RESULTS

CAC was assessed using electron-beam computed tomography and the calcium score was then computed. Endothelial function was measured by assessing reactive hyperemia-induced vasodilation and expressed by the reactive hyperemia index (RHI). Of 82 patients, 39 had non-detectable calcium (CAC score=0) and 43 had a CAC score >0. In the CAC score=0 group, the prevalence of normal endothelial function was 84.6%, compared to 48.8% in the CAC score >0 group, P=0.001. The absence of CAC was highly correlated with normal endothelial function (γ=0.704, P<0.001). On average, endothelial function was significantly better in the CAC score=0 group than in the CAC score >0 group (RHI 2.2±0.6 vs. 1.8±0.5, P=0.002). In a multivariate logistic regression model, only normal endothelial function (odds ratio [OR] 5.03, 95% confidence interval [CI] 1.55-16.27, P=0.007) and age (years) (OR 0.91, 95% CI 0.86-0.96, P=0.002) were independently associated with the absence of CAC.

CONCLUSIONS

Normal functional status of the vasculature may be important for the prevention of coronary calcification and may partly account for the low cardiovascular risk of absent CAC.

Role of coronary artery calcification score on the decrease in GFR among subjects with CT coronary angiography

OBJECTIVE

Higher levels of coronary artery calcification score (CACS) are associated not only with an increased risk for cardiovascular death, but also with lower glomerular filtration rates (GFRs). However, its role in renal disease progression in patients has not been elucidated.

MATERIALS AND METHODS

We evaluated the change of estimated GFR in 279 nondialytic outpatients, who had undergone computed tomographic coronary angiography and follow-up over a period of 3 months.

RESULTS

The mean age of the participants was 57.7 ± 10.5 years, and the mean GFR was 88.2 ± 15.7 mL/min/1.73 m(2). Although there was no difference in baseline GFR between the CACS ≤ 200 AU group (n = 240) and the CACS > 200 AU group (n = 39), the latter group had a lower level of final GFR and higher annual reduction rate of GFR than the former group after an observation period of 13.1 ± 5.97 months. After adjusting for confounding variables, including age, gender, baseline GFR, albumin, and proteinuria, high levels of CACS showed an independent association with an annual reduction rate of GFR (r = -0.142, P = .048).

CONCLUSIONS

The results suggest that CACS was related to an annual decrease in GFR and may predict the faster decline in GFR in patients with symptoms requiring computed tomographic coronary angiography.

Endothelial function affects early carotid atherosclerosis progression in hypertensive postmenopausal women

OBJECTIVES

Endothelial dysfunction is known to be associated with atherosclerosis progression and cardiovascular events. Limited information exists regarding the importance of this topic in hypertensive postmenopausal women. In this particular population the influence of endothelial dysfunction on cardio-vascular end cerebro-vascular events is well demonstrated. Therefore, we investigated, in a prospective study, the influence of endothelial-dependent vasodilation on carotid intima-media thickness (IMT) progression in our population of hypertensive postmenopausal women.

METHODS

In addition to common risk factors and pharmacological therapy, we measured carotid IMT and flow-mediated dilation (FMD) of the brachial artery at baseline and after 1 year of follow-up.

RESULTS

Baseline and follow-up data were available for 618 hypertensive postmenopausal women with an age of 55 ± 8 years. The mean IMT at baseline was 754 ± 161 μm [interquartile range (IQR) from 600 to 838 μm]. The mean FMD at baseline was 5.8 ± 3.9% (IQR from 3.2 to 8.2%). There was a significant correlation between baseline FMD and carotid IMT (r = -0.16; P = 0.003). Mean IMT progression resulted in 103 μm (range from -250 to 567 μm; IQR from 0 to 200 μm) per year. Baseline FMD, FMD change and the amount of SBP reduction during follow-up remained the independent predictors of IMT progression in multivariable analysis.

CONCLUSIONS

In this prospective study we observed a significant interaction between baseline FMD, FMD change during follow-up and IMT progression in our population of hypertensive postmenopausal women. These results are in accordance with the suggestion that endothelial dysfunction is associated with enhanced atherosclerosis development. This hypothesis could provide a pathophysiological explanation for the increase in cardio-vascular and cerebro-vascular episodes recorded in hypertensive postmenopausal women with endothelial dysfunction.

Does uremia cause vascular dysfunction?

Vascular dysfunction induced by uremia has 4 main aspects. (1) Atherosclerosis is increased. Intima-media thickness is increased, and animal studies have established that uremia accelerates atherosclerosis. Uremic toxins are involved in several steps of atherosclerosis. Leukocyte activation is stimulated by guanidines, advanced glycation end products (AGE), p-cresyl sulfate, platelet diadenosine polyphosphates, and indoxyl sulfate. Endothelial adhesion molecules are stimulated by indoxyl sulfate. Migration and proliferation of vascular smooth muscle cells (VSMC) are stimulated by local inflammation which could be triggered by indoxyl sulfate and AGE. Uremia is associated with an increase in von Willebrand factor, thrombomodulin, plasminogen activator inhibitor 1, and matrix metalloproteinases. These factors contribute to thrombosis and plaque destabilization. There is also a decrease in nitric oxide (NO) availability, due to asymmetric dimethylarginine (ADMA), AGE, and oxidative stress. Moreover, circulating endothelial microparticles (EMP) are increased in uremia, and inhibit the NO pathway. EMP are induced in vitro by indoxyl sulfate and p-cresyl sulfate. (2) Arterial stiffness occurs due to the loss of compliance of the vascular wall which induces an increase in pulse pressure leading to left ventricular hypertrophy and a decrease in coronary perfusion. Implicated uremic toxins are ADMA, AGE, and oxidative stress. (3) Vascular calcifications are increased in uremia. Their formation involves a transdifferentiation process of VSMC into osteoblast-like cells. Implicated uremic toxins are mainly inorganic phosphate, as well as reactive oxygen species, tumor necrosis factor and leptin. (4) Abnormalities of vascular repair and neointimal hyperplasia are due to VSMC proliferation and lead to severe reduction of vascular lumen. Restenosis after coronary angioplasty is higher in dialysis than in nondialysis patients. Arteriovenous fistula stenosis is the most common cause of thrombosis. Uremic toxins such as indoxyl sulfate and some guanidine compounds inhibit endothelial proliferation and wound repair. Endothelial progenitor cells which contribute to vessel repair are decreased and impaired in uremia, related to high serum levels of β(2)-microglobulin and indole-3 acetic acid. Overall, there is a link between kidney function and cardiovascular risk, as emphasized by recent meta-analyses. Moreover, an association has been reported between cardiovascular mortality and uremic toxins such as indoxyl sulfate, p-cresol and p-cresyl sulfate.

Quantitative relationship between coronary calcium content and coronary flow reserve as assessed by integrated PET/CT imaging

PURPOSE

To evaluate the relationship between coronary artery calcium (CAC) and coronary vasodilator function.

METHODS

We evaluated 136 patients without known coronary artery disease (CAD) undergoing vasodilator stress (82)Rb PET/CT and CAC scoring who showed normal myocardial perfusion. The CAC score, resting and hyperemic myocardial blood flow (MBF), coronary flow reserve (CFR) and coronary vascular resistance were analyzed.

RESULTS

Global and regional CAC scores showed significant but weak inverse correlations with hyperemic MBF (r=-0.31 and r=-0.26, p< or =0.0002 respectively) and CFR (r=-0.28 and r=-0.2, p< or =0.001 respectively). With increasing CAC score, there was a modest stepwise decline in CFR on a per-patient basis (1.8+/-0.5 vs 1.7+/-0.5 vs 1.5+/-0.4, p=0.048, with total CAC=0, 1-400 and >400, respectively) and on a per-vessel basis. In multivariable modeling only body mass index and CAC score were predictive of CFR.

CONCLUSION

In patients with an intermediate likelihood of, but without overt, CAD, there is a statistically significant but weak inverse correlation between CAC content and coronary vasodilator function. The strength of this association weakens after adjusting CAC scores for age, gender and coronary risk factors. This suggests that CAC and coronary vasodilator function provide biologically different information regarding atherosclerosis.

Usefulness of combined high-sensitive C-reactive protein and N-terminal-probrain natriuretic peptide for predicting cardiovascular events in patients with suspected coronary artery disease

OBJECTIVE

We examined whether the combined use of high-sensitive C-reactive protein (hsCRP) and N-terminal-probrain natriuretic peptide (NT-proBNP) could increase the predictive value for future cardiovascular events.

BACKGROUND

hsCRP and NT-proBNP both have been shown to be strong predictors of cardiovascular events in patients with coronary artery disease. Few data are, however, available to assess whether combined use of these two distinct biomarkers improves the risk stratification in predicting cardiovascular events.

METHODS

A total of 205 participants with suspected coronary artery disease referred for coronary angiography were enrolled in the study. Plasma levels of hsCRP and NT-proBNP were measured before coronary angiography. Cox regression analyses were conducted for the 205 participants, with cardiovascular events being defined as nonfatal myocardial infarction, percutaneous coronary intervention, coronary artery bypass grafting, and ischemic stroke.

RESULTS

All patients were divided into four groups by using median values of hsCRP (1.1 mg/l) and NT-proBNP (472.6 fmol/ml): group 1, low hsCRP/low NT-proBNP (n=60); group 2, high hsCRP/low NT-proBNP (n=42); group 3, low hsCRP/high NT-proBNP (n=42); and group 4, high hsCRP/high NT-proBNP (n=61). During a median follow-up of 4 years, there were 84 cardiovascular events (41%): 11 events (18%) in group 1, 13 events (31%) in group 2, 20 events (48%) in group 3, and 40 events (66%) in group 4 (P<0.001). Patients with cardiovascular event had significantly attenuated flow-mediated vasodilation (3.6+/-3.4 vs. 5.3+/-3.5%, P=0.001) and increased plasma levels of NT-proBNP (627+/-330 vs. 458+/-196 fmol/ml, P<0.001). Simple linear regression analysis on all studied participants demonstrated significant associations between levels of hsCRP and NT-proBNP (hsCRP vs. NT-proBNP: r=0.354, P<0.001). Cox regression hazards model showed that combined use of NT-proBNP and hsCRP significantly increased predictive value for future cardiovascular events [hazard ratio (HR) 4.922, 95% confidence interval (CI), 2.519-9.617; P<0.0001 for high hsCRP/high NT-proBNP vs. low hsCRP/low NT-proBNP].

CONCLUSION

These findings demonstrated that a simple combination of distinct biomarkers of hsCRP and NT-proBNP might provide additional information for predicting cardiovascular events.

Short-term treatment with sevelamer increases serum fetuin-a concentration and improves endothelial dysfunction in chronic kidney disease stage 4 patients

BACKGROUND AND OBJECTIVES

Vascular calcification and endothelial dysfunction contribute to the development of cardiovascular disease in patients with chronic kidney disease (CKD). Sevelamer, a non-calcium-based phosphate binder, has been shown to attenuate cardiovascular calcification in CKD patients, although the exact mechanism has not been clarified. This study was designed to investigate the effect of short-term sevelamer treatment on both serum fetuin-A concentrations and endothelial dysfunction seen in CKD patients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Fifty nondiabetic stage 4 CKD patients whose phosphate levels were > or =5.5 mg/dl were enrolled in this 8-wk randomized prospective study. Thirty-six healthy volunteers served as matched controls. Patients were treated with either sevelamer (n = 25, 12 males) or calcium acetate (n = 25, 13 males). Fetuin-A, high-sensitivity C-reactive protein, Ca x PO4 product, flow-mediated dilation (FMD), insulin, and homeostasis model assessment (HOMA) were obtained at baseline and after the treatment period.

RESULTS

As expected, CKD patients had significantly lower levels of fetuin-A and FMD, and significantly higher levels of intact parathyroid hormone, Ca x PO4 product, and high-sensitivity C-reactive protein than controls (P < 0.001 for all). The use of sevelamer led to a significant increase in the fetuin-A concentration with improvement in FMD, whereas no significant difference was observed in the calcium acetate group. In a multiple regression analysis, FMD levels were independently related to fetuin-A both before (beta = 0.63, P < 0.001) and after (beta = 0.38, P = 0.004) treatment.

CONCLUSIONS

This small, randomized, prospective study shows that short-term sevelamer treatment significantly increases fetuin-A levels and improves FMD in nondiabetic stage 4 CKD patients.

Intracranial artery calcification: a newly identified risk factor of ischemic stroke

BACKGROUND AND PURPOSE

Calcification in cerebral arteries is understudied, although frequently observed on computed tomography of the brain (CT brain). We aimed to assess the incidence of intracranial artery calcification in ischemic stroke patients and to evaluate its correlation with ischemic stroke.

METHODS

Our study included ischemic stroke patients and age-gender-matched nonischemic stroke patients referred for CT brain.

RESULTS

One hundred and seventy-five ischemic stroke patients and 182 controls were enrolled. The highest prevalence of calcification was seen in intracranial internal carotid artery (IICA) (80.4%), and less commonly in the vertebral artery (35.6%). There was a higher prevalence of intracranial artery calcification in ischemic stroke patients than controls (92.6% vs. 76.4%, P < .001). Hypertension (OR = 2.056, 95% CI: 1.129 approximately 3.745), diabetes (OR = 2.483, 95% CI: 1.233 approximately 5.001), smoking (OR = 2.844, 95% CI: 1.542 approximately 5.243), intracranial artery calcification (OR = 3.172, 95% CI: 1.252 approximately 8.036), hyperlipidemia (OR = 6.714, 95% CI: 3.302 approximately 13.650), and atrial fibrillation (OR = 7.941, 95% CI: 2.790 approximately 22.599) were found to be independently associated with ischemic stroke.

CONCLUSIONS

We demonstrated a higher incidence of intracranial artery calcification in ischemic stroke patients. Besides traditional risk factors, intracranial artery calcification was found to be an independent risk factor of ischemic stroke.

Relation of coronary artery calcium to flow-mediated dilation and C-reactive protein levels in asymptomatic patients with heterozygous familial hypercholesterolemia

The extent of coronary artery calcium (CAC) is correlated with coronary artery disease prognosis. However, the relation of CAC to endothelial function and high-sensitivity C-reactive protein (hs-CRP) in patients with asymptomatic heterozygous familial hypercholesterolemia (FH) requires clarification. The study aim was to investigate the relations among CAC, endothelial function, and hs-CRP in patients with asymptomatic heterozygous FH. Thirty-two patients with asymptomatic heterozygous FH (mean age 42 years) and 34 healthy control subjects (mean age 36 years) were enrolled. We measured CAC by electron-beam computed tomography and endothelial function by flow-mediated dilation of the brachial artery. A higher percentage of patients with FH had a positive CAC score compared with the control group. Comparing the FH group with detectable CAC (CAC score >0) and undetectable CAC (CAC score of 0), we found higher hs-CRP levels (0.29 +/- 0.23 vs 0.07 +/- 0.08 mg/dl, p = 0.001) and reduced flow-mediated dilation (0.04 +/- 0.03 vs 0.08 +/- 0.03, p = 0.005) in the detectable CAC group. Multivariate analysis showed an independent correlation of hs-CRP with detectable CAC (relative risk 5.034, 95% confidence interval 1.525 to 16.613, p = 0.04). In conclusion, FH subjects with positive CAC scores have decreased flow-mediated dilation and increased hs-CRP levels. Furthermore, hs-CRP level is the only independent predictor of the presence of CAC.

Endothelial dysfunction and fetuin A levels before and after kidney transplantation

BACKGROUND

Endothelial dysfunction (ED) has a major role in the cardiovascular outcome of patients with chronic kidney disease (CKD). The aim of this study was to investigate the relation between fetuin A levels and ED in kidney transplant recipients.

METHODS

Forty-two living donor kidney transplant recipients, 21 (11 male) on cyclosporine A and 21 (10 male) on tacrolimus-based regimes, were studied. Forty-two (21 male) healthy subjects were enrolled as controls. Fetuin A, highly sensitive C-reactive protein (hsCRP) levels, brachial artery endothelium-dependent vasodilatation (FMD), nitroglycerine mediated dilatation (NMD), and carotid intima-media thickness (CIMT) were measured before transplantation and on the 30th and 90th days posttransplant.

RESULTS

Pretransplantation serum fetuin A concentrations and FMD values of patients were significantly lower than those of the controls (P<0.001 for both). These were significantly increased in the 30th and 90th days posttransplantation There was a significant positive correlation between Fetuin A and FMD levels both before and after kidney transplantation (r=0.534, r=0.576; respectively, P<0.001 for both). Carotid intima-media thickness and hsCRP levels decreased after transplantation (P<0.001 for all). According to the regression analysis, fetuin A, intact parathyroid hormone, and hsCRP levels were the independent determinants of FMD.

CONCLUSION

The results of the present study suggest that low serum fetuin A levels in CKD may contribute to impaired endothelial functions in CKD. Future studies should clarify the role of fetuin A levels in cardiovascular outcomes of CKD.

Clinical Outcomes After Both Coronary Calcium Scanning and Exercise Myocardial Perfusion Scintigraphy

OBJECTIVES

The purpose of this work was to assess the prognosis in patients undergoing both coronary artery calcium (CAC) scanning and exercise myocardial perfusion scintigraphy (MPS).

BACKGROUND

Whereas the prognostic effectiveness of MPS is well established, recent studies indicate that quantification of CAC also predicts cardiac outcomes. However, prognostic information is not yet available upon which to guide the management of patients who have had both tests.

METHODS

We assessed the frequency of cardiac death and myocardial infarction over a mean follow-up of 32 +/- 16 months in 1,153 patients undergoing both CAC scanning and MPS. Results were compared with those from a referent cohort of 9,308 patients who had earlier undergone MPS only.

RESULTS

The frequency of myocardial ischemia rose with increasing CAC scores (p < 0.001), but ischemia was present in only 64 patients. Among the 1,089 nonischemic patients, of which only 3 (0.3%) underwent early revascularization, the annualized cardiac event rate was <1% in all CAC subgroups, including those with CAC scores >1,000. Kaplan-Meier analysis revealed similarly low cardiac event rates among nonischemic patients with CAC scores >1,000 and nonischemic patients with Bayesian coronary artery disease likelihood > or =85%. Late myocardial revascularization rates were also similar in these 2 groups.

CONCLUSIONS

Among patients with nonischemic MPS studies, high CAC scores do not confer an increased risk for cardiac events. Thus, although patients with high CAC scores may be considered for intensive medical therapy to prevent future coronary artery disease events, a normal MPS study in such patients suggests no need for more aggressive interventions.

Brachial artery diameter and vasodilator response to nitroglycerine, but not flow-mediated dilatation, are associated with the presence and quantity of coronary artery calcium in asymptomatic adults

In the present study, we investigated whether measures of brachial artery reactivity were associated with the presence and extent of subclinical coronary atherosclerosis in asymptomatic adults. Electron beam computed tomography was employed to assess the presence and quantity of CAC (coronary artery calcium) in 441 participants (mean age, 61 years; 49% men) without prior history of CHD (coronary heart disease) or stroke, and CAC score was calculated using the method described by Agatston and co-workers [(1990) J. Am. Coll. Cardiol. 15, 827-832] High-resolution ultrasound was employed to measure BAD (brachial artery diameter), FMD (flow-mediated dilatation) and NMD (nitroglycerine-mediated dilatation). CAC score and FMD were log-transformed after adding 1 to reduce skewness. Multivariable logistic and linear regression models based on generalized estimating equations were used to assess whether BAD, FMD and NMD were each independently associated with the presence and quantity of CAC after adjustment for CHD risk factors and use of statin and hypertension medication. CAC was detectable in 64% of participants. After adjustment for age and sex, FMD was not correlated (r=-0.06; P=0.27), BAD was positively correlated (r=0.16; P=0.004) and NMD was inversely correlated in a borderline significant manner (r=-0.10; P=0.084) with log(CAC+1). In multivariable logistic regression analyses, FMD was not associated, whereas higher BAD (P=0.021) and lower NMD (P=0.030) were independently associated with the presence of CAC. In multivariable linear regression analyses, higher BAD (P=0.004) and lower NMD (P=0.016), but not FMD, were independently associated with log(CAC+1). We conclude that greater diameter of the brachial artery and lower vasodilator response to nitroglycerine, but not FMD, are associated with subclinical coronary atherosclerosis.

Corneal arcus as coronary artery disease risk factor

Corneal arcus is a lipid-rich and predominantly extracellular deposit that forms at the corneoscleral limbus. It represents the most common peripheral corneal opacity and is not associated with tissue breakdown but rather with the deposition of lipids. The deposition of cholesterol in the peripheral cornea and arterial wall are similar in that both are accelerated by elevated serum levels of atherogenic lipoproteins, such as low-density lipoproteins (LDL). Corneal arcus is more prevalent in men than in women and in Blacks than in Whites. Its prevalence increases with advancing age. It has been associated with hypercholesterolemia, xanthelasmas, alcohol, blood pressure, cigarette smoking, diabetes, age, and coronary heart disease. Nevertheless, it is not clear whether or not corneal arcus is an independent risk factor for coronary heart disease (CHD). The present systematic review examines the relationship of corneal arcus and CHD to determine if corneal arcus is an independent CHD risk factor. We conclude that there is no consensus that corneal arcus is an independent risk factor. The presence of corneal arcus in a young person should prompt a search for lipid abnormalities. Also, because corneal arcus represents physical evidence of early lipid deposition, its presence suggests the need for aggressive lipid therapy.

Plasma soluble osteopontin concentrations are increased in patients with rheumatic mitral stenosis and associated with the severity of mitral valve calcium

Although the severity of valvular calcification is an important prognostic indicator, the cellular mechanisms of the calcification process are unknown. Osteopontin modulates inflammation and biomineralization, and increased osteopontin expression has been demonstrated in calcified degenerative or rheumatic cardiac valves. The present study evaluated soluble plasma osteopontin in 32 patients with echocardiographically determined rheumatic mitral stenosis and compared the results to those of a control group of 22 healthy patients. Patients were evaluated with routine echocardiographic techniques, Wilkins scoring, and 2-dimensional echocardiographic calcium scoring. Patients with rheumatic involvement other than in the mitral valve were excluded. Plasma osteopontin and high-sensitivity C-reactive protein levels in patients with mitral stenosis were significantly higher those of the control group (p = 0.006 and p = 0.0001, respectively). A significant correlation was found between plasma osteopontin levels and the severity of mitral valve calcification (p = 0.003) and also between high-sensitivity C-reactive protein levels and Wilkins score (p = 0.009). There was a stepwise and statistically significant increase in soluble plasma osteopontin levels in association with the severity of mitral valve calcification. In conclusion, increased osteopontin levels were correlated with the severity of mitral valve calcification in patients with rheumatic mitral stenosis, suggesting an important role of osteopontin in the modulation of valvular calcification. Elevated levels of high-sensitivity C-reactive protein concentrations suggest the presence of ongoing inflammation in those patients.

Decreased heparin cofactor II activity is associated with impaired endothelial function determined by brachial ultrasonography and predicts cardiovascular events

BACKGROUND

Heparin cofactor II (HCII) could inactivate thrombin after binding to dermatan sulfate at injured arterial walls, and has been shown to be a novel and independent antiatherosclerotic factor. However, the relation between plasma HCII activity and peripheral vascular endothelial function remains unclear.

METHODS

A total of 199 patients (mean age, 63+/-14 years) were enrolled and followed up for a median period of 24 months. Endothelial function was assessed using brachial ultrasonography to determine endothelium dependent flow-mediated vasodilation (FMD). Cox regression analyses were conducted for the 199 subjects, with cardiovascular events being defined as myocardial infarction (MI), percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), ischemic stroke, and peripheral artery revascularization.

RESULTS

A total of 31 patients (16%) had cardiovascular events. Patients with cardiovascular events had significantly lower HCII activity (112+/-34 versus 127+/-34%, p=0.027) and lower antithrombin III (ATIII) activity (82+/-12 versus 88+/-13%, p=0.014) than those without events. By multivariate analysis, age (p=0.012), hsCRP (p=0.020) and HCII activity (p=0.035) were correlated with FMD. Kaplan-Meier analysis was performed and showed plasma HCII (p=0.036) and ATIII activities (p=0.005) were predictors of cardiovascular events. By Cox regression analysis, plasma HCII activity (p=0.026) could be an independent predictor of future cardiovascular events, but not ATIII.

CONCLUSIONS

The present study demonstrates that plasma HCII activity is positively correlated with endothelial vasodilator function. Furthermore, plasma HCII activity could be a predictor of future cardiovascular events in patients with suspected coronary artery disease, suggesting its role in atherosclerosis.