Coronary calcification score: the coronary-risk impact factor

Evidence Accumulates: Patients with Ascending Aneurysms Are Strongly Protected from Atherosclerotic Disease

Ascending thoracic aortic aneurysms may be fatal upon rupture or dissection and remain a leading cause of death in the developed world. Understanding the pathophysiology of the development of ascending thoracic aortic aneurysms may help reduce the morbidity and mortality of this disease. In this review, we will discuss our current understanding of the protective relationship between ascending thoracic aortic aneurysms and the development of atherosclerosis, including decreased carotid intima-media thickness, low-density lipoprotein levels, coronary and aortic calcification, and incidence of myocardial infarction. We also propose several possible mechanisms driving this relationship, including matrix metalloproteinase proteins and transforming growth factor-β.

Understanding the Stony Bridge between Osteoporosis and Vascular Calcification: Impact of the FGF23/Klotho axis

A relationship between osteoporosis (OP) and vascular calcification (VC) is now proposed. There are common mechanisms underlying the regulation of them. Fibroblast growth factor- (FGF-) 23 and Klotho are hormones associated with the metabolic axis of osteovascular metabolism. Most recently, it was suggested that the FGF23-klotho axis is associated with increasing incidence of fractures and is potentially involved in the progression of the aortic-brachial stiffness ratio. Herein, we discussed the potential role of the FGF23/Klotho axis in the pathophysiology of OP and VC. We want to provide an update review in order to allow a better understanding of the potential role of the FGF23/Klotho axis in comorbidity of OP and VC. We believe that a better understanding of the relationship between both entities can help in proposing new therapeutic targets for reducing the increasing prevalence of OP and VC in the aging population.

Study on the predictive effect of fibrinogen on vascular calcification

BACKGROUND

Fibrinogen, lipoprotein, and high-density lipoprotein levels were associated with vascular calcification, but their predictive capacity for a vascular calcification was not reported.

AIMS

The purpose of this study was to evaluate the predictive efficacy of fibrinogen, lipoprotein, and high-density lipoprotein by retrospective analysis of fibrinogen, lipoprotein, and high-density lipoprotein levels in patients with vascular calcification, to explore the effective predictive indexes of vascular calcification, to predict the occurrence and development of vascular calcification, and to provide a simple and effective method for the diagnosis and prevention of vascular calcification.Hypothesis: Fibrinogen is a good prediction of vascular calcification.

METHODS

Univariate and multivariate analyses were used to assess the effects of fibrinogen, lipoprotein, and high-density lipoprotein on the CV, and the ROC curve of the predictive model was used to assess its predictive effectiveness. We collected the relevant indicators of 462 patients admitted to the Department of Vascular Surgery of the First Hospital of Hebei Medical University from August 2018 to July 2020, including 189 patients with vascular calcification (40.9%) and 273 patients without vascular calcification (59.1%); 75% of the collected data is used for modeling (modeling group) and 25% for verification (verification group).

RESULTS

Results from the multivariate analysis showed fibrinogen, lipoprotein, and high-density lipoprotein to be independent predictors of vascular calcification. Next, the three-factor models are developed respectively. The area below the ROC curve in the fibrinogen, lipoprotein, and high-density lipoprotein forecast model was 0.8018, 0.7348, and 0.7019, respectively.

CONCLUSIONS

Fibrinogen is more predictive than high-density lipoprotein and lipoprotein in patients with arteriosclerosis.

Automated classification of coronary plaque calcification in OCT pullbacks with 3D deep neural networks

SIGNIFICANCE

Detection and characterization of coronary atherosclerotic plaques often need reviews of a large number of optical coherence tomography (OCT) imaging slices to make a clinical decision. However, it is a challenge to manually review all the slices and consider the interrelationship between adjacent slices.

APPROACH

Inspired by the recent success of deep convolutional network on the classification of medical images, we proposed a ResNet-3D network for classification of coronary plaque calcification in OCT pullbacks. The ResNet-3D network was initialized with a trained ResNet-50 network and a three-dimensional convolution filter filled with zeros padding and non-zeros padding with a convolutional filter. To retrain ResNet-50, we used a dataset of ∼4860 OCT images, derived by 18 entire pullbacks from different patients. In addition, we investigated a two-phase training method to address the data imbalance. For an improved performance, we evaluated different input sizes for the ResNet-3D network, such as 3, 5, and 7 OCT slices. Furthermore, we integrated all ResNet-3D results by majority voting.

RESULTS

A comparative analysis proved the effectiveness of the proposed ResNet-3D networks against ResNet-2D network in the OCT dataset. The classification performance (F1-scores  =  94  %   for non-zeros padding and F1-score  =  96  %   for zeros padding) demonstrated the potential of convolutional neural networks (CNNs) in classifying plaque calcification.

CONCLUSIONS

This work may provide a foundation for further work in extending the CNN to voxel segmentation, which may lead to a supportive diagnostic tool for assessment of coronary plaque vulnerability.

Diabetic cardiomyopathy: molecular mechanisms, detrimental effects of conventional treatment, and beneficial effects of natural therapy

ABSTARCT

Diabetic complications are among the largely exigent health problems currently. Cardiovascular complications, including diabetic cardiomyopathy (DCM), account for more than 80% of diabetic deaths. Investigators are exploring new therapeutic targets to slow or abate diabetes because of the growing occurrence and augmented risk of deaths due to its complications. Research on rodent models of type 1 and type 2 diabetes mellitus, and the use of genetic engineering techniques in mice and rats have significantly sophisticated for our understanding of the molecular mechanisms in human DCM. DCM is featured by pathophysiological mechanisms that are hyperglycemia, insulin resistance, oxidative stress, left ventricular hypertrophy, damaged left ventricular systolic and diastolic functions, myocardial fibrosis, endothelial dysfunction, myocyte cell death, autophagy, and endoplasmic reticulum stress. A number of molecular and cellular pathways, such as cardiac ubiquitin proteasome system, FoxO transcription factors, hexosamine biosynthetic pathway, polyol pathway, protein kinase C signaling, NF-κB signaling, peroxisome proliferator-activated receptor signaling, Nrf2 pathway, mitogen-activated protein kinase pathway, and micro RNAs, play a major role in DCM. Currently, there are a few drugs for the management of DCM and some of them have considerable adverse effects. So, researchers are focusing on the natural products to ameliorate it. Hence, in this review, we discuss the pathogical, molecular, and cellular mechanisms of DCM; the current diagnostic methods and treatments; adverse effects of conventional treatment; and beneficial effects of natural product-based therapeutics, which may pave the way to new treatment strategies. Graphical Abstract.

Mandatory Reporting of Coronary Artery Calcifications Incidentally Noted on Chest Multi-Detector Computed Tomography: A Multicentre Experience

BACKGROUND

Coronary Artery Calcifications (CACs) are associated with coronary atherosclerosis and Cardiovascular (CV) events. In "non-cardiovascular" settings, CACs can be easily detected on chest Multi-Detector Computed Tomography (MDCT). Their evaluation may help to better stratify CV risk in the general population, especially for primary prevention.

AIMS

We retrospectively evaluated the relationship between CAC distribution and CV risk, determined by Framingham Risk Score (FRS), in a cohort of patients who underwent chest MDCT performed for several clinical indications.

METHOD

We retrospectively recruited 305 patients (194 men, 111 women; mean age 70.5 years) from 3 different Italian centres. Patients with coronary stent, pacemaker and/or CV devices were excluded from the study. Circumflex Artery (LCX), Left Main Coronary Artery (LMCA), left Anterior Descending artery (LAD) and right coronary artery (RCA) were analysed.

RESULTS

From a total population of 305 patients, 119 (39%) had low FRS (<10%), 115 (38%) had intermediate FRS (10-20%), and 71 (23%) had high FRS (>20%). The study identified 842 CACs located in decreasing order as follows: RCA (34.5%), LAD (32.3%), LCX (28%) and LMCA (13%). Statistical two-step analysis subdivided patients into two clusters according to FRS (risk threshold = 12.38%): cluster I (mean 9.34) and cluster II (mean 15.09). A significant association between CAC distribution and cluster II was demonstrated. CACs were mostly detected in patients with intermediate FRS. All patients (100%) with the highest CV risk showed intermediate RCA and LMCA involvement.

CONCLUSION

Radiologists can note the distribution of CACs on a chest MDCT and should mandatorily record them in their reports. Depending on CAC presence and location, these findings may have important clinical implications, mostly in asymptomatic patients with intermediate FRS. This information may reclassify a patients' CV risk and improve clinical management.

The Role of Vitamin K in Chronic Aging Diseases: Inflammation, Cardiovascular Disease, and Osteoarthritis

Vitamin K is an enzyme cofactor required for the carboxylation of vitamin K dependent proteins, several of which have been implicated in diseases of aging. Inflammation is recognized as a crucial component of many chronic aging diseases and evidence suggests vitamin K has an anti-inflammatory action that is independent of its role as an enzyme co-factor. Vitamin K-dependent proteins and inflammation have been implicated in cardiovascular disease and osteoarthritis, which are leading causes of disability and mortality in older adults. The purpose of this review is to summarize observational studies and randomized trials focused on vitamin K status and inflammation, cardiovascular disease, and osteoarthritis. Although mechanistic evidence suggests a protective role for vitamin K in these age-related conditions, the benefit of vitamin K supplementation is controversial because observational data are equivocal and the number of randomized trials is few.

Osteoporosis Is Associated With High Risk for Coronary Heart Disease: A Population-Based Cohort Study

We employed a population-based cohort sample to explore the risk of coronary heart disease (CHD) in relation to osteoporosis in an Asian population.We designed a retrospective population-based cohort study from 2000 to 2010 with data obtained from Taiwan's Longitudinal Health Insurance Database. A total of 19,456 patients aged 45 years or older who had no history of CHD and had a diagnosis of osteoporosis were identified as the osteoporosis cohort. The patients in the comparison cohort were randomly selected and frequency matched according to age, sex, and year of index date at a 1:1 ratio. Both cohorts were followed from the index date until a new diagnosis of CHD was made. Baseline variables, comorbidities, and bisphosphonate and estrogen prescriptions were collected.The overall incidence of CHD was 23.5 (per 1000 person-years) for the osteoporosis cohort and 16.7 for the comparison cohort, with a mean follow-up of 6.54 years and 6.63 years, respectively. The hazard ratio (HR) for developing CHD during follow-up was 1.30 (95% confidence interval [CI], 1.23-1.38) for the osteoporosis cohort compared with the comparison cohort after adjusting for age, sex, comorbidities, and estrogen medication. Patients with osteoporosis who received treatment with bisphosphonates or with both bisphosphonates and estrogen exhibited a significantly lower risk for CHD (adjusted HR = 0.37 and 0.23) than those who did not receive either of these 2 medications.The results support an association between osteoporosis and CHD in Asian population.

Age and sex based reference values for incidental coronary artery and thoracic aorta calcifications on routine clinical chest CT: a powerful tool to appreciate available imaging findings

OBJECTIVE

To establish age and gender specific reference values for incidental coronary artery and thoracic aorta calcification scores on routine diagnostic CT scans. These reference values can aid in structured reporting and interpretation of readily available imaging data by chest CT readers in routine practice.

METHODS

A random sample of 1572 (57% male, median age 61 years) was taken from a study population of 12,063 subjects who underwent diagnostic chest CT for non-cardiovascular indications between January 2002 and December 2005. Coronary artery and thoracic aorta calcifications were graded using a validated ordinal score. The 25th, 50th and 75th percentile cut points were calculated for the coronary artery and thoracic aorta calcification scores within each age/gender stratum.

RESULTS

The 75th percentile cut points for coronary artery calcification scores were higher for men than for women across all age groups, with the exception of the lowest age group. The 75th percentile cut points for thoracic aorta calcifications scores were comparable for both genders across all age groups. Based on the obtained age and gender reference values a calculation tool is provided, that allows one to enter an individual's age, gender and calcification scores to obtain the corresponding estimated percentiles.

CONCLUSIONS

The calculation tool as provided in this study can be used in daily practice by CT readers to examine whether a subject has high calcifications scores relative to others with the same age and gender.

Breast arterial calcifications as a cardiovascular risk marker in women

Cardiovascular disease and breast cancer are the two main causes of mortality in women. Mammography as a screening test for breast cancer is recommended for all women from the age of 40 to 50 years. Mammographically detected breast arterial calcifications are currently considered an incidental finding without clinical importance, since they are not associated with an increased risk of breast cancer. However, recent studies have shown that breast arterial calcifications on mammograms have been associated with cardiovascular risk factors and atherosclerotic cardiovascular disease. These results suggest that breast arterial calcifications, detected during routine mammography, are a noteworthy finding that could be valuable in identifying asymptomatic women at increased cardiovascular risk.

Vitamin K status in chronic kidney disease

The purpose of this review is to summarize the research to date on vitamin K status in chronic kidney disease (CKD). This review includes a summary of the data available on vitamin K status in patients across the spectrum of CKD as well as the link between vitamin K deficiency in CKD and bone dynamics, including mineralization and demineralization, as well as ectopic mineralization. It also describes two current clinical trials that are underway evaluating vitamin K treatment in CKD patients. These data may inform future clinical practice in this population.

Atmospheric ultrafine particles promote vascular calcification via the NF-κB signaling pathway

Exposure to atmospheric fine particulate matter (PM(2.5)) is a modifiable risk factor of cardiovascular disease. Ultrafine particles (UFP, diameter <0.1 μm), a subfraction of PM(2.5), promote vascular oxidative stress and inflammatory responses. Epidemiologic studies suggest that PM exposure promotes vascular calcification. Here, we assessed whether UFP exposure promotes vascular calcification via NF-κB signaling. UFP exposure at 50 μg/ml increased alkaline phosphatase (ALP) activity by 4.4 ± 0.2-fold on day 3 (n = 3, P < 0.001) and matrix calcification by 3.5 ± 1.7-fold on day 10 (n = 4, P < 0.05) in calcifying vascular cells (CVC), a subpopulation of vascular smooth muscle cells with osteoblastic potential. Treatment of CVC with conditioned media derived from UFP-treated macrophages (UFP-CM) also led to an increase in ALP activities and matrix calcification. Furthermore, both UFP and UFP-CM significantly increased NF-κB activity, and cotreatment with an NF-κB inhibitor, JSH23, attenuated both UFP- and UFP-CM-induced ALP activity and calcification. When low-density lipoprotein receptor-null mice were exposed to UFP at 359.5 μg/m(3) for 10 wk, NF-κB activation and vascular calcification were detected in the regions of aortic roots compared with control filtered air-exposed mice. These findings suggest that UFP promotes vascular calcification via activating NF-κB signaling.

Role of coronary CT angiography in asymptomatic patients with type 2 diabetes mellitus

Diabetic patients with coronary artery disease are often asymptomatic, making appropriate care of such patients difficult. The purpose of this study was to investigate the prevalence of coronary lesions in asymptomatic diabetic patients. Coronary computed tomography (CT) angiography was performed in 120 consecutive diabetic patients (90 of whom were men, mean age 65, mean HbA1c 7.2%). Images from patients whose coronary artery calcium scores (CAC scores) were less than 400 were subjected to stenosis and plaque analysis. Significant stenosis was defined as coronary artery stenosis > 70%. High-risk plaque was defined as plaque having both a CT density < 30 Hounsfield Units (HU) and showing positive remodeling. Significant stenoses were identified in 30.5% of the patients. High-risk plaques were identified in 17.1% of the patients. Less than half of the high-risk plaques were obstructive plaques. There was a statistically significant association between significant stenosis and high-risk plaque by chi-square test (P = 0.022). We found significant stenosis even in patients whose CAC score = 0 at a rate of 5.0%. Using univariate logistic-regression analysis, we found that coronary risk factors associated with significant stenosis and high-risk plaque were dyslipidemia (P = 0.033) and current smoking (P = 0.030), respectively. We report for the first time, the prevalence of high-risk plaques in the arteries of patients with asymptomatic diabetes, as assessed by coronary CT angiography.

Vitamin K status and vascular calcification: evidence from observational and clinical studies

Vascular calcification occurs when calcium accumulates in the intima (associated with atherosclerosis) and/or media layers of the vessel wall. Coronary artery calcification (CAC) reflects the calcium burden within the intima and media of the coronary arteries. In population-based studies, CAC independently predicts cardiovascular disease (CVD) and mortality. A preventive role for vitamin K in vascular calcification has been proposed based on its role in activating matrix Gla protein (MGP), a calcification inhibitor that is expressed in vascular tissue. Although animal and in vitro data support this role of vitamin K, overall data from human studies are inconsistent. The majority of population-based studies have relied on vitamin K intake to measure status. Phylloquinone is the primary dietary form of vitamin K and available supplementation trials, albeit limited, suggest phylloquinone supplementation is relevant to CAC. Yet observational studies have found higher dietary menaquinone, but not phylloquinone, to be associated with less calcification. Vascular calcification is highly prevalent in certain patient populations, especially in those with chronic kidney disease (CKD), and it is plausible vitamin K may contribute to reducing vascular calcification in patients at higher risk. Subclinical vitamin K deficiency has been reported in CKD patients, but studies linking vitamin K status to calcification outcomes in CKD are needed to clarify whether or not improving vitamin K status is associated with improved vascular health in CKD. This review summarizes the available evidence of vitamin K and vascular calcification in population-based studies and clinic-based studies, with a specific focus on CKD patients.

Relationship between coronary artery calcium score by multidetector computed tomography and plaque components by virtual histology intravascular ultrasound

The aim of this study was to evaluate the relationship between coronary artery calcium score (CACS) assessed by multidetector computed tomography (MDCT) and plaque components assessed by virtual histology-intravascular ultrasound (VH-IVUS) in 172 coronary artery disease (CAD) patients with 250 coronary lesions. CACS was assessed according to Agatston scoring method by MDCT and patients were divided into four groups: Group I (CACS = 0 [n = 52]); Group II (CACS = 1-100 [n = 99]); Group III (CACS = 101-400 [n = 84]); and Group IV (CACS > 400 [n = 15]). Total atheroma volume was greatest in Group IV (152 ± 132 µL vs 171 ± 114 µL vs 195 ± 149 µL vs 321±182 µL, P < 0.001). The absolute dense calcium (DC) and necrotic core (NC) volumes were greatest, and relative DC volume was greatest in Group IV (5.5 ± 6.6 µL vs 11.0 ± 10.3 µL vs 15.6 ± 13.6 µL vs 36.6 ± 18.2 µL, P < 0.001, and 14.8 ± 18.2 µL vs 19.5 ± 18.9 µL vs 22.5 ± 19.1 µL vs 41.7 ± 27.9 µL, P < 0.001, and 6.4 ± 5.3% vs 11.0 ± 6.2% vs 14.0 ± 6.5% vs 20.0 ± 7.8%, P < 0.001, respectively). The absolute plaque and DC and NC volumes and the relative DC volume correlated positively with calcium score. CAD patients with high calcium score have more vulnerable plaque components (greater DC and NC-containing plaques) than those with low calcium score.

Relation between aortic knob calcium observed by simple chest x-ray or fluoroscopy and plaque components in patients with diabetes mellitus

We used virtual histology and intravascular ultrasound (VH-IVUS) to evaluate the relation between aortic knob calcium (AKC) and plaque components in diabetic patients. The presence of AKC was assessed by posteroanterior view of chest x-ray or fluoroscopy at the time of coronary angiography. A total of 137 de novo coronary culprit lesions in 137 consecutive diabetic patients were studied and coronary plaque components were analyzed using VH-IVUS according to the presence (n = 45) or absence (n = 92) of AKC. Patients with AKC were significantly older (68 +/- 8 vs 62 +/- 9 years, p <0.001) and had significantly higher high-sensitivity C-reactive protein levels (1.97 +/- 1.33 vs 0.48 +/- 1.35 mg/dl, p = 0.005) compared to patients without AKC. Absolute and percent necrotic core (NC) volumes (30 +/- 26 vs 20 +/- 19 mm(3), p = 0.003; 23.4 +/- 10.3% vs 17.4 +/- 8.9%, p = 0.005, respectively) and absolute and percent dense calcium (DC) volumes (17 +/- 12 vs 11 +/- 12 mm(3), p = 0.010; 13.3 +/- 7.3% vs 9.6 +/- 7.9%, p = 0.011, respectively) were significantly greater in lesions with AKC compared to those without AKC. Multivariable analysis showed that age (odds ratio [OR] 1.233, 95% confidence interval [CI] 1.121 to 1.355, p <0.001), high-sensitivity C-reactive protein (OR 1.871, 95% CI 1.090 to 2.943, p = 0.007), absolute DC volume (OR 1.020, 95% CI 1.050 to 1.178, p = 0.003), and absolute NC volume (OR 1.026, 95% CI 1.057 to 1.199, p <0.001) were independent predictors of AKC. In conclusion, diabetic patients with AKC were older, had greater NC- and DC-containing plaques, and higher inflammatory status compared to diabetic patients without AKC.

Myeloid CD34+CD13+ precursor cells transdifferentiate into chondrocyte-like cells in atherosclerotic intimal calcification

Chondrogenic differentiation is pivotal in the active regulation of artery calcification. We investigated the cellular origin of chondrocyte-like cells in atherosclerotic intimal calcification of C57BL/6 LDLr(-/-) mice using bone marrow transplantation to trace ROSA26-LacZ-labeled cells. Immunohistochemical costaining of collagen type II with LacZ and leukocyte defining surface antigens was performed and analyzed by high-resolution confocal microscopy. Chondrocyte-like cells were detected in medium and advanced atherosclerotic plaques accounting for 7.1 +/- 1.6% and 14.1 +/- 1.7% of the total plaque cellularity, respectively. Chimera analysis exhibited a mean of 89.8% LacZ(+) cells in peripheral blood and collagen type II costaining with LcZ revealed an average 88.8 +/- 7.6% cytoplasmatic LacZ(+) evidence within the chondrocyte-like cells. To examine whether hematopoietic stem cells contribute to the phenotype, stem cell marker CD34 and myeloid progenitor-associated antigen CD13 were analyzed. CD34(+) was detectable in 86.9 +/- 8.1% and CD13(+) evidence in 54.2 +/- 7.6% of chondrocyte-like cells, attributable most likely because of loss of surface markers during transdifferentiation. Chondrocyte differentiation factor Sox-9 was detected in association with chondrocyte-like cells, whereas Sm22alpha, a marker for smooth muscle cells, could not be demonstrated. The results show that the majority of chondrocyte-like cells were of bone marrow origin, whereas CD34(+)/CD13(+) myeloid precursors appeared to infiltrate the plaque actively and transdifferentiated into chondrocytes-like cells in the progression of atherosclerosis.

Familial tumoral calcinosis: from characterization of a rare phenotype to the pathogenesis of ectopic calcification

Familial tumoral calcinosis (FTC) refers to a heterogeneous group of inherited disorders characterized by the occurrence of cutaneous and subcutaneous calcified masses. Two major forms of the disease are now recognized. Hyperphosphatemic FTC has been shown to result from mutations in three genes: fibroblast growth factor-23 (FGF23), coding for a potent phosphaturic protein, KL encoding Klotho, which serves as a co-receptor for FGF23, and GALNT3, which encodes a glycosyltransferase responsible for FGF23 O-glycosylation; defective function of any one of these three proteins results in hyperphosphatemia and ectopic calcification. The second form of the disease is characterized by absence of metabolic abnormalities, and is, therefore, termed normophosphatemic FTC. This variant was found to be associated with absence of functional SAMD9, a putative tumor suppressor and anti-inflammatory protein. The data gathered through the study of these rare disorders have recently led to the discovery of novel aspects of the pathogenesis of common disorders in humans, underscoring the potential concealed within the study of rare diseases.

Vascular dysfunction and cardiovascular complications

PURPOSE OF REVIEW

Antiretroviral (ARV) therapy has altered the course of HIV disease and dramatically increased the lifespan of HIV-infected individuals. Accumulating evidence, however, suggests that prolonged ARV use contributes to metabolic and cardiovascular changes. Understanding the toxicities of ARV treatment and sequelae of long-term infection is critical. This review will examine recent evidence related to vascular dysfunction and cardiovascular complications in HIV infection.

RECENT FINDINGS

Recent studies investigating circulating markers of inflammation, surrogate markers of subclinical atherosclerotic disease, and novel imaging modalities suggest the presence of endothelial dysfunction in HIV-infected patients. In addition, data from several recently updated cohort studies confirm an association between ARV therapy and cardiovascular events.

SUMMARY

New data suggest that cardiovascular disease is increased among HIV-infected patients receiving highly active ARV therapy. The mechanisms of increased cardiovascular disease may relate to direct effects of the HIV virus and inflammation on the vasculature or to toxicities from specific ARV therapies, which may increase traditional cardiovascular risk factors. Understanding and modifying these risks and preventing cardiovascular events are critical to the long-term management of the HIV-infected patient.

The effects of calcium-based versus non-calcium-based phosphate binders on mortality among patients with chronic kidney disease: a meta-analysis

BACKGROUND

The effects of calcium compared with non-calcium-based phosphate binders on mortality, cardiovascular events and vascular calcification in patients with chronic kidney disease (CKD) are unknown.

METHODS

To address this question, we conducted a systematic review. We electronically searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and CINAHL. We identified 160 potential studies and included 8 randomized trials. Eligible studies, determined by consensus using predefined criteria, were reviewed, and data were extracted onto a standard from.

RESULTS

There was a trend towards a decrease in all-cause mortality among non-calcium-based versus calcium-based phosphate binders [relative risk (RR) 0.68; 95% CI 0.41-1.11] based upon eight randomized controlled trials and 2873 subjects. Two trials reported on cardiovascular events with a RR of 0.85 (95% CI 0.35-2.03) in patients receiving calcium-based versus non-calcium-based binders. Coronary artery calcification was reported in five trials involving 469 patients; the difference in the change in the calcium score from baseline to follow-up among subjects taking non-calcium-based binders versus calcium-based binders was -76.35 (95% CI -158.25-5.55).

CONCLUSION

Despite the trends observed, we did not find a statistically significant difference in cardiovascular mortality and coronary artery calcification in patients receiving calcium-based phosphate binders compared to non-calcium-based phosphate binders. However, the data are limited by the small number of studies and the confidence intervals do not exclude a potentially important beneficial effect. Therefore, further randomized trials are required.

Vitamin K supplementation and progression of coronary artery calcium in older men and women

BACKGROUND

Coronary artery calcification (CAC) is an independent predictor of cardiovascular disease. A preventive role for vitamin K in CAC progression has been proposed on the basis of the properties of matrix Gla protein (MGP) as a vitamin K-dependent calcification inhibitor.

OBJECTIVE

The objective was to determine the effect of phylloquinone (vitamin K1) supplementation on CAC progression in older men and women.

DESIGN

CAC was measured at baseline and after 3 y of follow-up in 388 healthy men and postmenopausal women; 200 received a multivitamin with 500 microg phylloquinone/d (treatment), and 188 received a multivitamin alone (control).

RESULTS

In an intention-to-treat analysis, there was no difference in CAC progression between the phylloquinone group and the control group; the mean (+/-SEM) changes in Agatston scores were 27 +/- 6 and 37 +/- 7, respectively. In a subgroup analysis of participants who were > or =85% adherent to supplementation (n = 367), there was less CAC progression in the phylloquinone group than in the control group (P = 0.03). Of those with preexisting CAC (Agatston score > 10), those who received phylloquinone supplements had 6% less progression than did those who received the multivitamin alone (P = 0.04). Phylloquinone-associated decreases in CAC progression were independent of changes in serum MGP. MGP carboxylation status was not determined.

CONCLUSIONS

Phylloquinone supplementation slows the progression of CAC in healthy older adults with preexisting CAC, independent of its effect on total MGP concentrations. Because our data are hypothesis-generating, further studies are warranted to clarify this mechanism. This trial was registered at clinicaltrials.gov as NCT00183001.

A method for calcium quantification by means of CT coronary angiography using 64-multidetector CT: very high correlation with Agatston and volume scores

To find out whether calcium scoring of the coronary arteries (CAC scoring) could be carried out with a CT angiography of the coronary arteries (CTCA) in a single CT data acquisition. The Agatston and V130 scores for 113 patients were assessed. A calcium volume score (V600 score) was compiled from the CTCA data sets. Intra- and interobserver correlations were excellent (rho > 0.97). The intra- and interobserver repeatability coefficients were extremely low, increasing in magnitude from the V600 score to the V130 and Agatston scores. The V600 score underestimates the coronary calcium burden. However, it has a linear relation to the Agatston and V130 scores. Thus, they are predictable from the values of the V600 score. The V600 score shows a linear relation to the classic CAC scores. Due to its extremely high reliability, the score may be a feasible alternative for classic CAC scoring methods in order to reduce radiation dosages.

Atherosclerotic and pleural calcifications are related among asbestos-exposed workers

METHODS

We studied the relationship between calcified chest atherosclerosis and pleural plaques among 505 construction workers with computed tomography. The extent and thickness of pleural plaques and the score of visceral pleural thickening were estimated, as was calcification of both pleural disease and chest atherosclerosis.

RESULTS

Adjusted for age, BMI, smoking, and asbestos exposure, pleural calcification was associated with calcification in coronary arteries (P<0.001) and in the aorta (P<0.001).

CONCLUSION

These associations may be due to susceptibility factors common to both conditions. Calcification in pleural plaques may be a hint of atherosclerosis at least among asbestos-exposed people.

Coronary artery calcium screening: current status and recommendations from the European Society of Cardiac Radiology and North American Society for Cardiovascular Imaging

Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multi-detector CT is discussed.

[Cardiovascular risk factors in workers at health centre in Beocin]

Most cardiovascular diseases are caused by atherosclerosis, which is a result of interactions between risk factors such as gender, age, blood lipid concentrations, blood pressure, glucose tolerance, adiposity, physical activity and cigarette smoking. Identification of risk factors is the first step in cardiovascular disease prevention. As health workers contribute significantly to cardiovascular morbidity, the aim of our study was to analyze prevalence of cardiovascular risk factors and to assess the level of mentioned risk in health workers employed in Health Centre Beocin. The study group consisted of 50 health workers. Obesity was evaluated according to BMI and body fat (BF%) values, while central obesity was defined using waist circumference. Serum lipid concentrations and glycaemia were used in metabolic profile definition. The level of physical activity was assessed using IPAQ, and information about smoking status and family history of cardiovascular diseases was obtained from self-report. Framingham point-scoring system was used to predict the risk for development of coronary heart disease in the 10-year period. Overweight was found in 36%, and obesity in 18% subjects. 42% of examined subjects had higher fat mass, while 24% of them had obesity. Central fat accumulation was observed in 50% subjects. We registered 56% smokers, 70% subjects with positive family history, 28% subjects with hypertension, and 56% subjects with dyslipidemia. According to IPAQ results 20% of examinated subjects were minimally active and 70% were insufficiently active. Estimated risk of coronary heart disease was 7.38%, and 10% subjects had risk over 20%. In spite of lower cardiovascular risk level, our results showed high prevalence of overweight, smoking and physical inactivity in health workers, which suggests take importance of their own lifestyle modification. It should be the first step in increasing motivation of their patients.

Mechanism of pi-induced vascular calcification

Vascular calcification is clinically important in the development of cardiovascular disease. It has been suggested that apoptosis is one of the processes regulating calcification in vascular smooth muscle cells (VSMC). In this review, we discuss the role of apoptosis in inorganic phosphate (Pi)- induced calcification, focusing on regulation of the survival pathway mediated by growth arrest- specific gene 6 (Gas6). Further, we mention the beneficial effect of statins mediated by inhibition of apoptosis which is accompanied by restoration of the Gas6-mediated survival pathway. These findings indicate that Gas6 is a novel target of statins' effects to prevent vascular calcification.

Adiponectin antagonizes stimulatory effect of tumor necrosis factor-alpha on vascular smooth muscle cell calcification: regulation of growth arrest-specific gene 6-mediated survival pathway by adenosine 5'-monophosphate-activated protein kinase

Adiponectin exhibits diverse protective effects against atherogenesis and antagonizes many effects of TNFalpha. Here, we investigated the effect of adiponectin and TNFalpha on vascular calcification, a critical event in the development and progression of vascular disease. In human aortic smooth muscle cells (HASMC), TNFalpha augmented inorganic phosphate (Pi)-induced calcification, whereas adiponectin significantly suppressed it and abolished the stimulatory effect of TNFalpha in a concentration-dependent manner. Similarly, adiponectin ameliorated the accelerating effect of TNFalpha on Pi-induced apoptosis, the essential process of HASMC calcification. Furthermore, these effects of TNFalpha and adiponectin were associated with AMP-activated protein kinase (AMPK)-dependent growth arrest-specific gene 6 (Gas6) expression and Akt signaling. The AMPK activator, 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR), induced phosphorylation of AMPK and significantly inhibited Pi-induced calcification in HASMC. Conversely, pharmacological inhibition of AMPK by compound C blocked both AMPK activation and the inhibitory effect of adiponectin on calcification, providing evidence that AMPK plays a regulatory role in vascular calcification. Reporter assay revealed that adiponectin restored Gas6 promoter activity decreased by TNFalpha, and the effect of adiponectin was abrogated by compound C. These results demonstrate that adiponectin antagonizes the stimulatory effect of TNFalpha on vascular calcification by restoration of the AMPK-dependent Gas6-mediated survival pathway.

Subclinical disease detection: advanced imaging applications

Coronary events are the leading cause of death in the United States, and sudden coronary death is often the first presenting symptom. Because there is such a large population at risk for coronary events and because many of these patients go undetected before presenting with a significant cardiovascular event or sudden death, there is great interest in better detection and characterization of subclinical disease before it causes morbidity and mortality. This chapter will focus on promising imaging-based methods for the evaluation of subclinical cardiovascular disease. Several imaging methods that are most likely to be useful for future screening and intervention studies for characterizing risk among asymptomatic persons will be presented.

Tumoral calcinosis: new insights for the rheumatologist into a familial crystal deposition disease

A growing body of evidence points to extraosseous calcification (calcification occurring in nonosseous tissues) as a major cause of morbidity and mortality in humans. The term familial tumoral calcinosis encompasses a number of rare recessive diseases, often associated with increased reabsorption of phosphate through the renal proximal tubule, which manifests with periarticular or acral calcium deposition. Recently, the molecular pathogenesis of this group of disorders has been elucidated, leading to the identification of several proteins playing pivotal roles in the regulation of extraosseous calcification. This report reviews these advances as well as the potential implications of these discoveries for the management of acquired conditions associated with abnormal calcification.

Retinal arteriolar narrowing and left ventricular remodeling: the multi-ethnic study of atherosclerosis

OBJECTIVES

This study sought to examine the relationships of retinal vascular signs with left ventricular (LV) mass, volume, and concentric remodeling.

BACKGROUND

Microvascular disease, reflected as retinopathy lesions, has been shown to predict clinical congestive heart failure. Whether these retinal vascular changes are related to early structural alterations and remodeling of the heart in asymptomatic individuals is unknown.

METHODS

A cross-sectional, population-based study of 4,593 participants ages 45 to 85 years, free of clinical cardiovascular disease. Retinal vascular calibers and retinopathy were graded from retinal photographs according to standardized protocols. The LV mass and volume were measured from cardiac magnetic resonance imaging. Extent of LV concentric remodeling was determined by the ratio of LV mass to end-diastolic volume (M/V ratio).

RESULTS

After controlling for age, gender, race, center, past and current systolic blood pressure, body mass index, smoking, antihypertensive medications, diabetes, diabetes duration, glycosylated hemoglobin, lipid profile, and C-reactive protein, narrower retinal arteriolar caliber was associated with concentric (highest quintile of M/V ratio) remodeling (odds ratio [OR] 2.06, 95% confidence interval 1.57 to 2.70). This association was seen in men and women, and was present even in those without diabetes, without hypertension, and without significant coronary calcification. In multivariate analysis, the presence of retinopathy (OR 1.31, 95% confidence interval 1.08 to 1.61) was also associated with concentric remodeling.

CONCLUSIONS

Narrower retinal arteriolar caliber is associated with LV concentric remodeling independent of traditional risk factors and coronary atherosclerotic burden, supporting the hypothesis that microvascular disease may contribute to cardiac remodeling.

Carotid intima–media thickness, carotid distensibility and mitral, aortic valve calcification: a useful diagnostic parameter of systemic atherosclerotic disease

BACKGROUND

Mitral (MAC) and aortic (AVC) calcification are observed more frequently in the elderly and are associated with coronary artery disease, aortic atheroma and peripheral arterial atherosclerotic disease. Common carotid intima-media thickness (cIMT) and distensibility (cDIST) are also independent predictors of adverse cardiovascular outcomes. We examined the relationship between the degree of MAC-AVC and cIMT and cDIST.

METHODS AND RESULTS

One hundred and forty-three patients referred for transthoracic echocardiography and carotid artery echo-Doppler were evaluated; the variables measured were: systemic blood pressure, pulse pressure; body mass index, traditional risk factors, cIMT, cDIST (cDIST = [(csD - cdD)/PP]/csD; where csD and cdD were systolic and diastolic carotid diameters, respectively). MAC and AVC score, based on acoustic densitometry, were: 1 = absence of annular/valvular (av) sclerosis/calcification; 2 = av sclerosis; 3 = av calcification; 4 = av calcification; 5 = av calcification with no recognition of the leaflets; the resulting score was the highest for either valvular annulus. Mean cIMT increased linearly with increasing valvular calcification score (P < 0.0001) whereas cDIST decreased for scores 1 to 5 (P < 0.0001). Distribution of cIMT quartiles showed that 75% of the patients in the lowest quartile had a score of 1 and 70% of patients in the highest quartile had a score of 5; 47% of the patients in the highest quartile of cDIST had a score of 1, whereas 60% of patients in the lowest quartile of cDIST had a score of 4.

CONCLUSIONS

The MAC and AVC score identifies subgroups of patients with different cIMT and cDIST. These data may confirm MAC-AVC as a useful important diagnostic parameter of systemic atherosclerotic disease.

Effect of particle size on hydroxyapatite crystal-induced tumor necrosis factor alpha secretion by macrophages

Macrophages may promote a vicious cycle of inflammation and calcification in the vessel wall by ingesting neointimal calcific deposits (predominantly hydroxyapatite) and secreting tumor necrosis factor (TNF)alpha, itself a vascular calcifying agent. Here we have investigated whether particle size affects the proinflammatory potential of hydroxyapatite crystals in vitro and whether the nuclear factor (NF)-kappaB pathway plays a role in the macrophage TNFalpha response. The particle size and nano-topography of nine different crystal preparations was analyzed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and gas sorbtion analysis. Macrophage TNFalpha secretion was inversely related to hydroxyapatite particle size (P=0.011, Spearman rank correlation test) and surface pore size (P=0.014). A necessary role for the NF-kappaB pathway was demonstrated by time-dependent I kappaB alpha degradation and sensitivity to inhibitors of I kappaB alpha degradation. To test whether smaller particles were intrinsically more bioactive, their mitogenic activity on fibroblast proliferation was examined. This showed close correlation between TNFalpha secretion and crystal-induced fibroblast proliferation (P=0.007). In conclusion, the ability of hydroxyapatite crystals to stimulate macrophage TNFalpha secretion depends on NF-kappaB activation and is inversely related to particle and pore size, with crystals of 1-2 microm diameter and pore size of 10-50 A the most bioactive. Microscopic calcific deposits in early stages of atherosclerosis may therefore pose a greater inflammatory risk to the plaque than macroscopically or radiologically visible deposits in more advanced lesions.

Vascular calcification and osteoporosis--from clinical observation towards molecular understanding

Patients with osteoporosis frequently suffer from vascular calcification, which was shown to predict both cardiovascular morbidity/mortality and osteoporotic fractures. Various common risk factors and mechanisms have been suggested to cause both bone loss and vascular calcification, including aging, estrogen deficiency, vitamin D and K abnormalities, chronic inflammation and oxidative stress. Major breakthroughs in molecular and cellular biology of bone metabolism and the characterization of knockout animals with deletion of bone-related genes have led to the concept that common signaling pathways, transcription factors and extracellular matrix interactions may account for both skeletal and vascular abnormalities. For example, mice that lack the cytokine decoy receptor osteoprotegerin or the hormone Klotho display a combined osteoporosis-arterial calcification phenotype. In this review, we summarize the current data and evaluate potential mechanisms of the osteoporosis-arterial calcification syndrome. We propose a unifying hypothesis of vascular calcification that combines both active and passive mechanisms of vascular mineralization with aspects of bone resorption and age-related changes.

Clinical significance of aortic knob width and calcification in unstable angina

BACKGROUND

Chest radiography is a routine examination evaluating those patients with chest pain. There are few data about the correlation between aortic knob width, calcification and coronary atherosclerosis.

METHODS AND RESULTS

The aortic knob width was measured and the presence of aortic knob calcification was assessed via a chest posteroanterior view in 178 consecutive patients. The aortic knob width and calcification were compared to the risk factor and the extent of coronary artery disease. Patient's age (69.5+/-7.95 vs 61.1+/-10.29 years, p=0.010), the prevalence of hypertension (65.9 vs 46.3%, p=0.024) and diabetes (43.2 vs 26.1%, p=0.033), the level of total cholesterol (196.8+/-63.21 vs 188.6+/-44.45 mg/dl, p=0.049) and the incidence of multi-vessel disease (65.9 vs 38.1%, p<0.001) were higher in patients with aortic knob calcification than in patients without calcification. The aortic knob width and the prevalence of aortic knob calcification were significantly correlated with the severity of coronary artery disease. Multivariate analysis demonstrated that aortic knob calcification and diabetes were independent factors for multi-vessel disease (p=0.018 and p=0.012).

CONCLUSIONS

The observation of aortic knob on a chest radiograph can provide important predictive information of coronary atherosclerosis.

Role of computed tomography in risk assessment for coronary heart disease

Coronary heart disease is the most common cause of death in Western countries, with a rising incidence in developing countries. It is part of the spectrum of cardiovascular diseases that have common end points of myocardial infarction, stroke and death. As these end points often occur suddenly and often in those with no known disease, identification of those people at high risk is important. Besides the known traditional risk factors, direct imaging of the calcified plaque as a marker for atherosclerotic disease has been extensively studied with electron beam computed tomography and now with multislice computed tomography. This review discusses the role of computed tomography in assessment of cardiovascular risk in both people with or without symptoms.

Quantification and characterization of carotid calcium with multi-detector CT-angiography

OBJECTIVE

The aim of this study was to assess the accuracy of CT-angiography for identification and measurement of calcification of carotid atherosclerotic plaques and to characterise the content and distribution pattern of mineral calcium (hydroxyapatite, Ca) in carotid bifurcations and investigate its relationship with neurological symptoms.

METHODS

Twenty-six patients with ICA stenosis > 60% (13 symptomatic, 13 asymptomatic) were selected for study. Ca was estimated from the weight of the ashed remnants of carotid endarterectomy (CEA) specimens in 11 patients. Calcium content (calcification volume (mm3),CV), and average calcium density (Hounsfield units (HU),CD), were determined by CT-angiography. The distribution pattern of calcium within the lesion (base (posterior), shoulder or luminal surface) was assessed in all cases.

RESULTS

CT-derived estimation of CV and Ca mass (modified Agatston Score, (mAS) = CV x CD) showed a good correlation with its direct measurement in CEA specimens (r = 0.911 and 0.993 respectively, p < 0,005). Asymptomatic patients with ICA stenosis > 60% showed statistically significant higher content of Ca than those who were symptomatic (mAS: 122.6 +/- 138.0 HU mm3 vs 42.8 +/- 59.1 HU mm3, p = 0.04). Calcification on the surface of the plaque was observed more commonly in asymptomatic patients (9/12 vs 3/15, p = 0.006). Non-calcified or plaques with posterior calcification were 12 times more likely to be symptomatic (OR: 12, 95%CI 1.5-91.1, p = 0.021).

CONCLUSIONS

CT-angiography permits the reliable quantification of calcification of carotid plaques. A lower content of calcium in carotid plaques, as well as its distribution in the base of the lesion, was associated with a greater prevalence of neurological symptoms. These parameters may be useful to identify those patients at higher risk of stroke.

[Assessment of cardiovascular risk in population groups. Comparison of Score system and Framingham in hypertensive patients]

INTRODUCTION AND OBJECTIVES

Calculation of cardiovascular risk in populations allows for developing and assessing of intervention programs and adapting health resources. While the Framingham System has been used in the past, a group of European researchers have proposed a different method called the Score project. The purpose of this paper is to compare the value of both methods for assessing cardiovascular risk.

METHODS

In 6,775 evaluable hypertensive patients distributed over the 17 Spanish autonomous communities (ACs), the 10-year risk of experiencing a coronary event (CR) was calculated using the Framingham equation, while risk of coronary death (RCD) and vascular death (RVD) was calculated using the Score project system, both at baseline and after one year of blood pressure control with amlodipine at the required dose. A comparison was made of the capacity to detect risk differences by both methods between populations with known different risks, and in the same population as a result of blood pressure control.

RESULTS

Both the Score and the Framingham systems detected the significant decrease in both CR and RCD or RVD at one year of application of the CORONARIA study protocol. Risk decrease measured by any of the two methods was significant (p < 0.05) overall, by genders, and by ACs. However, the Score System, unlike the Framingham system, could not detect the reported differences in the mortality risk for coronary and vascular disease between the ACs of the North and the South-East parts of Spain.

Sample size calculation for clinical trials using magnetic resonance imaging for the quantitative assessment of carotid atherosclerosis

PURPOSE

To provide sample size calculation for the quantitative assessment of carotid atherosclerotic plaque using non-invasive magnetic resonance imaging in multi-center clinical trials. METHODS. As part of a broader double-blind randomized trial of an experimental pharmaceutical agent, 20 asymptomatic placebo-control subjects were recruited from 5 clinical sites for a multi-center study. Subjects had 4 scans in 13 weeks on GE 1.5 T scanners, using TOF, T1-/PD-/T2- and contrast-enhanced Tl-weighted images. Measurement variability was assessed by comparing quantitative data from the index carotid artery over the four time points. The wall/outer wall (W/OW) ratio was calculated as wall volume divided by outer wall volume. The percent lipid-rich/necrotic core (%LR/NC) and calcification (%Ca) were measured as a proportion of the vessel wall. For %LR/NC and %Ca, only those subjects that exhibited LR/NC or Ca components were used in the analysis.

RESULTS

Measurement error was 5.8% for wall volume, 3.2% for W/OW ratio, 11.1% for %LR/NC volume and 18.6% for %Ca volume. Power analysis based on these values shows that a study with 14 participants in each group could detect a 5% change in W/OW ratio, 10% change in wall volume, and 20% change in %LR/NC volume (power = 80%, p < .05). The calculated measurement errors presume any true biological changes were negligible over the 3 months that subjects received placebo.

CONCLUSION

In vivo MRI is capable of quantifying plaque volume and plaque composition, such as %lipid-rich/necrotic core and %calcification, in the clinical setting of a multi-center trial with low inter-scan variability. This study provides the basis for sample size calculation of future MRI trials.

Prognostic value of coronary artery calcium screening in asymptomatic smokers and non-smokers

AIMS

To determine the extent and prognostic significance of coronary artery calcium in asymptomatic smokers and non-smokers. Population data are available on the prognostic impact of smoking on atherosclerotic imaging measurements of the carotid and peripheral arteries. Limited data are available on the impact of cigarette smoking on the prognostic value of coronary calcium.

METHODS AND RESULTS

A referred patient registry of 10,377 asymptomatic individuals (40% were current smokers) was followed for death from all-causes at 5 years. Univariable and multivariable Cox proportional hazard models were calculated to estimate time to all-cause mortality. Cumulative 5-year survival was 96.9 and 98.4% for smokers when compared with non-smokers (P < 0.0001). Using a stratified Cox proportional hazards survival analysis, survival for non-smokers ranged from 99.7 to 89.6% with calcium score of 0-10 and >1000 (P < 0.0001). In comparison, smokers had survival rates ranging from 99.5 to 81.4% for calcium score of 0-10 to >1000 (P < 0.0001). When further evaluating the effect of age on prognosis by coronary calcium, there was an additive relationship between age and calcium that was exacerbated with smoking, resulting in higher relative risk ratios for older smokers with coronary calcium (P < 0.0001). For smokers <50 years of age, a calcium score >1000 was associated with a relative risk ratio that was elevated 8.9-fold (P = 0.029). Thus, resulting in an expected reduction in life expectancy of 4.8 years for smokers <50 years of age with a calcium score >400 (P < 0.0001).

CONCLUSION

The prognostic value of coronary artery calcium scoring was accurate in identifying a high-risk cohort of asymptomatic smokers and non-smokers. Young smokers with high-risk calcium scores have a four- to nine-fold increased risk of dying when compared with similarly aged non-smokers. When prospectively applied, evidence of a high-risk calcium score may be useful in educating patients as to their expected risk of dying over the next 5 years.

[Impact of both cardiac-CT and cardiac-MR on the assessment of coronary risk]

Today's definition of coronary artery disease (CAD) comprises two forms: obstructive and non-obstructive CAD. The 31-72% chance of a life-threatening event-like a myocardial infarction-with non-obstructive CAD is well documented in numerous studies. The objective in modern strategies of diagnosis and therapy should therefore be expedient identification of patients at high risk for coronary events, who will benefit from a customized therapy. Before initiating diagnostic procedures of CAD, a well defined strategy should be pursued. There are two possible primary objectives: ASSESSMENT OF THE INDIVIDUAL RISK FOR A CORONARY EVENT: Assessment of the individual "absolute" risk for a coronary event is not possible using single traditional risk factors. The individual risk can be estimated by integrating several of the traditional risk factors into a scoring system. These so-called risk scores (e.g. Framingham score and Procam score), however, have been associated with shortcomings: insufficient discrimination of high-risk from low-risk individuals. The calcium score has therefore become increasingly established; this Agatston score is independent of the traditional risk factors, so there is no correlation between Agatston and Procam scores. Today, the calcium score is considered the superior test for identifying individuals at high risk for a coronary event and its use is recommended by the European Society of Cardiology (ESC) guidelines for prevention of cardiovascular diseases. PROOF OR EXCLUSION OF A HEMODYNAMICALLY SIGNIFICANT CORONARY STENOSIS: Another concept is the definitive proof or exclusion of a hemodynamically "significant" coronary narrowing. The probability of an obstructive CAD is traditionally assessed by the type of chest pain, age, gender and stress-ECG. In patients with a low probability of an obstructive CAD, cardiac catheterization is not indicated, whereas in patients with a high probability of a hemodynamically significant coronary stenosis, an invasive strategy should be performed. Since non-invasive coronary angiography (CTA) with cardiac-CT has been shown to provide a high negative predictive value, CTA (with good imaging quality) is suitable for ruling out a significant obstructive CAD in the group at intermediate risk for an obstructive CAD. Another approach could be a functional test to initially prove a relevant, inducible myocardial ischemia: In a large cohort it was shown that patients will only prognostically benefit from revascularization procedures if the ischemic myocardial area is greater than 10%. Therefore, the assessment of the extent of myocardial ischemia is the domain of modern stress imaging tests. Stress-echocardiography and myocardial scintigraphy have almost the same sensitivity (74-80%, 84-90%, respectively) and specificity (84-89%, 77-86%, respectively), which are considerably higher than for stress-ECG. Cardiac MR is most suitable for the assessment of myocardial perfusion, because it traces the first pass dynamics of gadolinium at rest and during stress in reproducible slices at an acceptable spatial and a high temporal resolution without ionizing radiation. Whether the non-invasive coronary angiography with cardiac-CT and the Adenosin-perfusion imaging with cardiac-MR will completely replace diagnostic cardiac catheterization and stress-echocardiography as well as myocardial scintigraphy remains to be evaluated in further studies.

Atherothrombosis and High-Risk Plaque

This second part of the review on atherothrombosis highlights the diffuse nature of the disease analyzing the feasibility and potential of the noninvasive imaging modalities, including computed tomography (electron-beam computed and multi-detector computed tomography) and magnetic resonance imaging for its detection and monitoring. These imaging modalities are being established as promising tools in high-risk cardiovascular patients for identification and/or management of coronary calcification, stenotic or obstructive disease, high-risk plaques (not necessarily stenotic), and overall burden of the disease. In addition, such technology facilitates the understanding of the processes involved in the development and progression of atherothrombosis responsible for coronary, cerebral, and peripheral ischemic events.

Osteoporosis and atherosclerosis: biological linkages and the emergence of dual-purpose therapies

Osteoporosis and atherosclerosis are both widely prevalent in an ageing population, and induce serious morbidities and death. There is growing evidence that in addition to their relationship to ageing, osteoporosis and atherosclerosis are also linked by biological associations. This article reviews their clinical interrelations, discusses the basic biology of bone and the arterial wall, and presents five examples that illustrate their biological linkages. Current therapeutic approaches emerging from these linkages, including statins, bisphosphonates, and the thiazolidinediones, have dual effects on bone and the vasculature. Additional therapies derived from experimental studies that enhance bone density and reduce atherogenesis hold further promise to diminish the morbidity and mortality of osteoporosis and atherosclerosis, with attendant benefits to society.

Proinflammatory Activation of Macrophages by Basic Calcium Phosphate Crystals via Protein Kinase C and MAP Kinase Pathways

Basic calcium phosphate (BCP) crystal deposition underlies the development of arterial calcification. Inflammatory macrophages colocalize with BCP deposits in developing atherosclerotic lesions and in vitro can promote calcification through the release of TNF alpha. Here we have investigated whether BCP crystals can elicit a proinflammatory response from monocyte-macrophages. BCP microcrystals were internalized into vacuoles of human monocyte-derived macrophages in vitro. This was associated with secretion of proinflammatory cytokines (TNFα, IL-1β and IL-8) capable of activating cultured endothelial cells and promoting capture of flowing leukocytes under shear flow. Critical roles for PKC, ERK1/2, JNK, but not p38 intracellular signaling pathways were identified in the secretion of TNF alpha, with activation of ERK1/2 but not JNK being dependent on upstream activation of PKC. Using confocal microscopy and adenoviral transfection approaches, we determined a specific role for the PKC-alpha isozyme. The response of macrophages to BCP crystals suggests that pathological calcification is not merely a passive consequence of chronic inflammatory disease but may lead to a positive feed-back loop of calcification and inflammation driving disease progression.