Treatment of asymptomatic adults with elevated coronary calcium scores with atorvastatin, vitamin C, and vitamin E: the St. Francis Heart Study randomized clinical trial

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.

Bayesian model averaging in meta-analysis: vitamin E supplementation and mortality

CONTEXT

The strength and relevance of a meta-analysis depends on the validity of the statistical methods used. Of special importance is appropriately assessing different sources of variability. Many studies including meta-analyses have evaluated the efficacy and safety of vitamin E and have yielded varying results. Illuminating and resolving these disparities requires addressing study variability and model uncertainty.

OBJECTIVE

To describe Bayesian meta-analysis methods for combining data from clinical trials, using recent studies that analyzed the relationship between vitamin E dose and all-cause mortality.

DATA SOURCES

Studies used in a previously published meta-analysis appended by studies identified by a search of MEDLINE from August 2004 to December 2005 using the MeSH terms vitamin e and alpha tocopherol.

STUDY SELECTION

INCLUSION CRITERIA

men and nonpregnant women; use of vitamin E alone or in combination with other vitamins or minerals; random allocation of participants to either vitamin E or a placebo or other control group; intervention and follow-up duration greater than 1 year; 10 or more deaths.

DATA EXTRACTION

Independent data extraction by one author was reviewed and confirmed by a second author. Corresponding authors of the original publications were contacted when questions arose.

DATA SYNTHESIS

Data collection included the number of patients and deaths, percent men, use of other vitamins or minerals, mean age, and length of follow-up. We combined study results using Bayesian hierarchical model averaging. Analyses used Markov chain Monte Carlo computational techniques.

CONCLUSIONS

Vitamin E intake is unlikely to affect mortality regardless of dose. The Bayesian meta-analyses presented here are ideal for incorporating disparate sources of variability, including trial effect and model uncertainty.

Vascular calcifications as a marker of increased cardiovascular risk: a meta-analysis

Background:

Several imaging techniques may reveal calcification of the arterial wall or cardiac valves. Many studies indicate that the risk for cardiovascular disease is increased when calcification is present. Recent meta-analyses on coronary calcification and cardiovascular risk may be confounded by indication. Therefore, this meta-analysis was performed with extensive subgroup analysis to assess the overall cardiovascular risk of finding calcification in any arterial wall or cardiac valve when using different imaging techniques.

Methods and results:

A meta-analysis of prospective studies reporting calcifications and cardiovascular end-points was performed. Thirty articles were selected. The overall odds ratios (95% confidence interval [CI]) for calcifications versus no calcifications in 218,080 subjects after a mean follow-up of 10.1 years amounted to 4.62 (CI 2.24 to 9.53) for all cause mortality, 3.94 (CI 2.39 to 6.50) for cardiovascular mortality, 3.74 (CI 2.56 to 5.45) for coronary events, 2.21 (CI 1.81 to 2.69) for stroke, and 3.41 (CI 2.71 to 4.30) for any cardiovascular event. Heterogeneity was largely explained by length of follow up and sort of imaging technique. Subgroup analysis of patients with end stage renal disease revealed a much higher odds ratio for any event of 6.22 (CI 2.73 to 14.14).

Conclusion:

The presence of calcification in any arterial wall is associated with a 3–4-fold higher risk for mortality and cardiovascular events. Interpretation of the pooled estimates has to be done with caution because of heterogeneity across studies.

Progression of coronary atherosclerosis after heart transplantation on electron-beam computed tomography

RATIONALE AND OBJECTIVES

Cardiac transplant vasculopathy is the most important long-term complication of heart transplantation, with overlapping features with conventional, atherosclerotic coronary artery disease. The aim of this study was to determine the progression of coronary artery disease after heart transplantation by measuring total coronary calcium load.

MATERIALS AND METHODS

After heart transplantation, 185 patients were serially examined using electron-beam computed tomography for coronary calcium load for clinical reasons. The mean time between the initial examination and the follow-up scan was 566 days (range, 126-1,436). Coronary calcium load was measured by the Agatston method, and the total calcium scores at both examinations were compared between patients taking and those not taking lipid-lowering medications (statins).

RESULTS

Patients not taking statins (n = 94) displayed a median annualized percentage increase in total calcium score of 0 Agatston units, whereas patients taking at least the lowest recommended daily dose of a statin (n = 84) displayed an annualized percentage decrease of 11 Agatston units. The difference was not statistically significant (Wilcoxon's rank-sum test, P = .35). Only 17 patients had increases of > 24 Agatston units, and eight of them were taking statins (chi(2) test, P = .99).

CONCLUSION

The annual rate of progression of coronary calcium load after heart transplantation is low. In this investigation, no beneficial effects of statins could be detected.

Insights into atherosclerosis from invasive and non-invasive imaging studies: Should we treat subclinical atherosclerosis?

Although atherosclerosis is associated with the elderly, young adults with hypercholesterolemia and other cardiovascular risk factors may have subclinical atherosclerotic disease. In many cases, when two or more risk factors are present, conventional risk assessment using the Framingham score, that was not designed to detect atherosclerotic plaques, may significantly underestimate the extent of atherosclerosis. Several non-invasive imaging technologies now make it possible to identify subclinical atherosclerosis before symptoms appear or major vascular events occur. These include B-mode ultrasound to measure carotid intima-media thickness, computed tomography to measure coronary artery calcification, and high-resolution magnetic resonance imaging to evaluate plaque size and composition. On the basis of available evidence, assessment of subclinical atherosclerosis should be considered in persons judged to be at intermediate risk by Framingham score, because test results may influence risk stratification and, consequently, the intensity of therapeutic intervention. Patients with significant subclinical atherosclerosis are at high risk and, like other high-risk individuals, should receive treatment designed to achieve aggressive low-density lipoprotein cholesterol targets. Clinical studies show that statin therapy may delay atherosclerosis progression and that intensive therapy with rosuvastatin may actually reverse the atherosclerotic process.

Computed tomography imaging, coronary calcium and atherosclerosis

Coronary calcium score measured by electron beam tomography provides an indication of current atherosclerotic burden in the coronary arteries. It correlates with conventional risk factors, but less so with Type 2 diabetes. Measurement of coronary calcium score has been shown to be a powerful predictor of coronary heart disease events in the general population, in different racial groups, and in Type 2 diabetes. It adds incremental value to conventional risk factors and risk scores. Its role in monitoring therapy remains to be proven.

Amplification of atherosclerotic calcification and Mönckeberg's sclerosis: a spectrum of the same disease process

Autopsy studies have shown the near universal presence of fatty streaks and fibroatheromas in the general population from which chronic kidney disease (CKD) patients arise. The vast majority of CKD patients have multiple conventional cardiovascular risk factors. Atherosclerosis, once present, can predominantly manifest as medial calcification, which has been previously termed Mönckeberg's sclerosis. This term has also been used in rare cases to describe vascular calcinosis not related to CKD. This clarification is critical to advance the field in terms of pathological diagnosis and treatment of CKD bone and mineral disorder. Factors that appear to promote the osteoblastic transformation of vascular smooth muscle cells and enhance deposition of calcium hydroxyapatite crystals include phosphorus activation of the Pit-1 receptor, bone morphogenic proteins 2 and 4, leptin, endogenous 1,25 dihydroxy vitamin D, vascular calcification activating factor, and measures of oxidative stress. These entities work to accelerate the atherosclerotic process in CKD patients and may be future targets for diagnosis and treatment. Although conventional atherosclerotic risk factors should be optimally managed, it should be noted that trials of hydroxymethylglutaryl-CoA reductase inhibitors have failed to attenuate the rate of progressive vascular calcification as measured by computed tomography scans.

Vitamins and cardiovascular disease

CVD is a major cause of mortality and morbidity in the Western world. In recent years its importance has expanded internationally and it is believed that by 2020 it will be the biggest cause of mortality in the world, emphasising the importance to prevent or minimise this increase. A beneficial role for vitamins in CVD has long been explored but the data are still inconsistent. While being supported by observational studies, randomised controlled trials have not yet supported a role for vitamins in primary or secondary prevention of CVD and have in some cases even indicated increased mortality in those with pre-existing late-stage atherosclerosis. The superiority of combination therapy over single supplementation has been suggested but this has not been confirmed in trials. Studies have indicated that beta-carotene mediates pro-oxidant effects and it has been suggested that its negative effects may diminish the beneficial effects mediated by the other vitamins in the supplementation cocktail. The trials that used a combination of vitamins that include beta-carotene have been disappointing. However, vitamin E and vitamin C have in combination shown long-term anti-atherogenic effects but their combined effect on clinical endpoints has been inconsistent. Studies also suggest that vitamins would be beneficial to individuals who are antioxidant-deficient or exposed to increased levels of oxidative stress, for example, smokers, diabetics and elderly patients, emphasising the importance of subgroup targeting. Through defining the right population group and the optimal vitamin combination we could potentially find a future role for vitamins in CVD.

Accelerated atherosclerotic calcification and Monckeberg's sclerosis: a continuum of advanced vascular pathology in chronic kidney disease

Autopsy studies have demonstrated the near universal presence of fatty streaks and fibroatheromas in the general population from which patients with chronic kidney disease (CKD) arise. The vast majority of patients with CKD have multiple conventional cardiovascular risk factors. Vascular atherosclerotic calcification develops in most patients as they transition from the general population to significant CKD as part of cholesterol crystallization within atherosclerotic lesions. Once present, however, atherosclerotic medial calcification can become prominent and has been previously identified as Mönckeberg's sclerosis. A unifying concept supported by the preponderance of pathologic evidence contends that Mönckeberg's sclerosis is a manifestation of accelerated atherosclerosis in patients with CKD. The term has also been used in rare cases to describe vascular calcinosis not related to CKD. This clarification is critical to advance the field in terms of pathologic diagnosis and treatment of CKD bone and mineral disorder. Factors that seem to promote the osteoblastic transformation of vascular smooth muscle cells and enhance deposition of calcium hydroxyapatite crystals include phosphorus activation of the Pit-1 receptor, bone morphogenic proteins 2 and 4, leptin, endogenous 1,25 dihydroxyvitamin D, vascular calcification activating factor, and measures of oxidative stress. These entities work to accelerate the atherosclerotic process in patients with CKD and may be future targets for diagnosis and treatment because randomized trials with hydroxymethylglutaryl-CoA reductase inhibitors have failed to attenuate the rate of progressive vascular calcification.

Expert review on coronary calcium

While there is no doubt that high risk patients (those with >20% ten year risk of future cardiovascular event) need more aggressive preventive therapy, a majority of cardiovascular events occur in individuals at intermediate risk (10%–20% ten year risk). Accurate risk assessment may be helpful in decreasing cardiovascular events through more appropriate targeting of preventive measures. It has been suggested that traditional risk assessment may be refined with the selective use of coronary artery calcium (CAC) or other methods of subclinical atherosclerosis measurement. Coronary calcification is a marker of atherosclerosis that can be quantified with the use of cardiac CT and it is proportional to the extent and severity of atherosclerotic disease. The published studies demonstrate a high sensitivity of CAC for the presence of coronary artery disease but a lower specificity for obstructive CAD depending on the magnitude of the CAC. Several large clinical trials found clear, incremental predictive value of CAC over the Framingham risk score when used in asymptomatic patients. Based on multiple observational studies, patients with increased plaque burdens (increased CAC) are approximately ten times more likely to suffer a cardiac event over the next 3–5 years. Coronary calcium scores have outperformed conventional risk factors, highly sensitive C-reactive protein (CRP) and carotid intima media thickness (IMT) as a predictor of cardiovascular events. The relevant prognostic information obtained may be useful to initiate or intensify appropriate treatment strategies to slow the progression of atherosclerotic vascular disease. Current data suggests intermediate risk patients may benefit most from further risk stratification with cardiac CT, as CAC testing is effective at identifying increased risk and in motivating effective behavioral changes. This article reviews information pertaining to the clinical use of CAC for assessing coronary atherosclerosis as a useful predictor of coronary artery disease (CAD) in certain population of patients.

Drugs for cardiovascular disease prevention in women: implications of the AHA Guidelines--2007 Update

Lifestyle interventions constitute the initial strategy for the primary and secondary prevention of cardiovascular disease in women. However, pharmacotherapy is often indicated for control of major cardiovascular risk factors, and abundant clinical trial data support the morbidity and mortality benefit of a number of categories of drug therapy following a coronary event. Although women have increasingly been enrolled in clinical trials of pharmacotherapy, under representation of women in most research studies limits the gender-specific assessment of outcomes. Equally importantly, recent randomized clinical trial data have highlighted inappropriate preventive therapies for women (i.e. those lacking effectiveness and potentially imparting harm). Decision-making data for drug therapy for women also derive from a number of clinical trials conducted solely in women. The drug classes reviewed in this article include omega-3 fatty acids, aspirin, ACE inhibitors and angiotensin II receptor antagonists or blockers, beta-adrenoceptor antagonists (beta-blockers), aldosterone antagonists, antioxidants, folic acid and vitamins B(6) and B(12), and menopausal hormone therapy and selective estrogen-receptor modulators. Information is sparse regarding specific cardiovascular pharmacotherapies for elderly women, and women of racial and ethnic minorities. Owing to the under representation of the subset of women in many trials, analysis by age, race and ethnicity is not appropriate. This information gap presents a major challenge for future studies, as these subgroups constitute populations of women at high cardiovascular risk.

Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases

BACKGROUND

Animal and physiological research as well as observational studies suggest that antioxidant supplements may improve survival.

OBJECTIVES

To assess the effect of antioxidant supplements on mortality in primary or secondary prevention randomised clinical trials.

SEARCH STRATEGY

We searched The Cochrane Library (Issue 3, 2005), MEDLINE (1966 to October 2005), EMBASE (1985 to October 2005), and the Science Citation Index Expanded (1945 to October 2005). We scanned bibliographies of relevant publications and wrote to pharmaceutical companies for additional trials.

SELECTION CRITERIA

We included all primary and secondary prevention randomised clinical trials on antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, and selenium) versus placebo or no intervention. Included participants were either healthy (primary prevention trials) or had any disease (secondary prevention trials).

DATA COLLECTION AND ANALYSIS

Three authors extracted data. Trials with adequate randomisation, blinding, and follow-up were classified as having a low risk of bias. Random-effects and fixed-effect meta-analyses were performed. Random-effects meta-regression analyses were performed to assess sources of intertrial heterogeneity.

MAIN RESULTS

Sixty-seven randomised trials with 232,550 participants were included. Forty-seven trials including 180,938 participants had low risk of bias. Twenty-one trials included 164,439 healthy participants. Forty-six trials included 68111 participants with various diseases (gastrointestinal, cardiovascular, neurological, ocular, dermatological, rheumatoid, renal, endocrinological, or unspecified). Overall, the antioxidant supplements had no significant effect on mortality in a random-effects meta-analysis (relative risk [RR] 1.02, 95% confidence interval [CI] 0.99 to 1.06), but significantly increased mortality in a fixed-effect model (RR 1.04, 95% CI 1.02 to 1.06). In meta-regression analysis, the risk of bias and type of antioxidant supplement were the only significant predictors of intertrial heterogeneity. In the trials with a low risk of bias, the antioxidant supplements significantly increased mortality (RR 1.05, 95% CI 1.02 to 1.08). When the different antioxidants were assessed separately, analyses including trials with a low risk of bias and excluding selenium trials found significantly increased mortality by vitamin A (RR 1.16, 95% CI 1.10 to 1.24), beta-carotene (RR 1.07, 95% CI 1.02 to 1.11), and vitamin E (RR 1.04, 95% CI 1.01 to 1.07), but no significant detrimental effect of vitamin C (RR 1.06, 95% CI 0.94 to 1.20). Low-bias risk trials on selenium found no significant effect on mortality (RR 0.91, 95% CI 0.76 to 1.09).

AUTHORS' CONCLUSIONS

We found no evidence to support antioxidant supplements for primary or secondary prevention. Vitamin A, beta-carotene, and vitamin E may increase mortality. Future randomised trials could evaluate the potential effects of vitamin C and selenium for primary and secondary prevention. Such trials should be closely monitored for potential harmful effects. Antioxidant supplements need to be considered medicinal products and should undergo sufficient evaluation before marketing.

Progression of calcified coronary atherosclerosis: Relationship to coronary risk factors and carotid intima-media thickness

BACKGROUND

The determinants of coronary artery calcium (CAC) progression are not well understood. Prior studies have shown a limited relationship between CAC progression and traditional coronary risk factors. We hypothesized that the extent of non-calcified atherosclerosis detected using carotid intima-media thickness (CIMT) would predict progression of calcified atherosclerosis.

METHODS

One hundred and eighty healthy male participants (mean age 47.9) with CAC from the Prospective Army Coronary Calcium (PACC) project volunteered to undergo a second EBCT scan, risk factor assessment, lab testing, and CIMT assessment 4.2+/-1.3 years after their original scan. All results were independently examined, blinded to baseline data. A change in CAC score >or=15% per year was defined as clinically significant progression.

RESULTS

CAC progression occurred in 60.2%. Compared to participants without progression, those with progression had higher triglycerides, LDL and total cholesterol and Framingham risk scores, but similar blood pressure, HDL cholesterol, blood glucose, C-reactive protein, fibrinogen, and body mass index. CIMT was significantly higher among those with versus without CAC progression (0.660 mm versus 0.603 mm; P=0.001). Each quintile of increasing CIMT was independently associated with a 35% increase in the odds of CAC progression (P=0.01), after controlling for the Framingham risk score and C-reactive protein.

CONCLUSION

Among middle-aged men with coronary calcium, increasing extent of non-calcified atherosclerosis is strongly associated with coronary artery calcium progression over 4 years.

Antioxidants and Cardioprotection

Limiting myocardial ischemia-reperfusion (IR) injury is essential for preventing contractile dysfunction and limiting morbidity and mortality associated with ischemic heart disease. Over the last few decades, it has become clear that during IR insults, myocardial oxygen radical formation is accelerated and plays a critical role in mediating cellular damage and dysfunction. This review provides a brief summary of a variety of approaches that have been undertaken to alleviate the oxidant stress associated with myocardial IR, and a summary of the data demonstrating the potential therapeutic value of oxidant scavenging in limiting IR-induced myocardial damage. Included is a review of investigations using novel free radical scavengers, antioxidant extracts from a variety of plants, polyphenolic compounds from foods such as cocoa, soy, grapes, and wine, as well as vitamin E, vitamin C, and beta-carotene. Also reviewed is the evidence that exercise-induced increases in endogenous antioxidants may be an important change contributing to cardioprotection. One must conclude from this brief review that current evidence suggests that enhancing oxidant-scavenging capacity protects against some of the cardiomyocyte disturbances during IR and helps salvage myocardial tissue. Data in cultured cell and animal models are convincing; trials in humans are significantly more conflicting, but still promising.

Implications of C-reactive protein or coronary artery calcium score as an adjunct to global risk assessment for primary prevention of CHD

BACKGROUND

C-reactive protein (CRP) or coronary artery calcium (CAC) score have been suggested to identify a higher risk subset of intermediate-risk individuals, who potentially could be considered for more aggressive therapy. In the Multi-Ethnic Study of Atherosclerosis (MESA), we estimated the proportion of intermediate-risk participants whose risk status might change based on additional testing using CRP and/or CAC score.

METHODS

Framingham 10-year CHD risk scores (FRS) were calculated and cross tabulations were used to determine the percent of individuals at intermediate-risk by FRS with a CRP >3mg/L and/or CAC score >100 AU. Similar analyses were performed using the gender-specific 75th percentile for CRP and CAC.

RESULTS

Of the 30% of participants (N=1450) classified as intermediate-risk by FRS, 30% had a CRP >3mg/L and 33% had a CAC score >100 AU. Among intermediate-risk women, 49% had a CRP >3mg/L compared to 27% of intermediate-risk men (p<0.0001) while the same percent of intermediate-risk women and men (33%) had a CAC score >100 AU. Eleven percent or less of men or women had both a high CRP and CAC score whether conventional or gender-specific cut points were used. When the percent of intermediate-risk individuals with an elevated CRP and/or CAC score in MESA were applied to NHANES III data, over a million intermediate-risk individuals would move to high risk status if CRP or CAC screening directed treatment strategies were uniformly adopted in the U.S.

CONCLUSION

There were differences in the number of intermediate-risk individuals reclassified as high risk depending on the screening test used, the cut points selected, and the demographics of the individuals being screened. These data highlight current limitations of broadly using risk markers such as CRP and CAC score in an intermediate-risk population.

Effect of simvastatin (80 mg) on coronary and abdominal aortic arterial calcium (from the coronary artery calcification treatment with zocor [CATZ] study)

We tested the hypothesis that, compared with placebo, simvastatin would reduce the progression of coronary artery calcium (CAC) and abdominal aortic calcium (AAC) levels in participants asymptomatic for vascular disease. Total CAC and AAC were measured with multidetector cardiac computed tomography. Inclusion criteria were a CAC score of >or=50 Agatston units, high-density lipoprotein (HDL) cholesterol level<or=50 mg/dl, low-density lipoprotein (LDL) cholesterol level between 100 and 160 mg/dl, and >or=2 other risk factors. Diabetes and history of vascular disease were exclusion criteria. Participants were randomized to receive 80 mg simvastatin (n=40) or matching placebo (n=40) for 12 months. Lipids were measured at 3-month intervals, and CAC and AAC measurements were repeated at 6 and 12 months. Total cholesterol, triglycerides, and LDL decreased significantly with simvastatin treatment (p<0.0001 for all comparisons, adjusted for baseline levels), whereas lipids remained unchanged for subjects randomized to receive placebo. Total CAC volume increased from baseline in both treatment groups. For subjects in the active treatment group, CAC volume increased by 9%, whereas in the placebo group, plaque volume increased by 5% (p=0.12 for treatment effect). AAC volume also increased in both treatment groups (p=0.15 for treatment effect). In conclusion, simvastatin treatment does not reduce progression of CAC or AAC compared with placebo.

Implications of recent statin trials for primary care practice

3-Hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors (statins) are the first-line treatment for dyslipidemia and the results of large statin trials have a significant impact on guidelines for cardiovascular disease (CVD) management, such as those set by the National Cholesterol Education Program Adult Treatment Panel. The benefit of statin therapy in CVD prevention has traditionally been demonstrated in clinical trials by the superior efficacy of statins vs placebo in lowering low-density lipoprotein cholesterol (LDL-C) and preventing hard coronary heart disease (CHD) outcomes including myocardial infarction and CHD death. However, due to earlier and improved treatment of CVD, the clinical manifestations of atherosclerosis are changing and other forms of CVD are now thought to predominate (such as revascularization and stroke). These changes in how CVD manifests in the patient population may have consequences for selection of endpoints when designing future clinical trials. Recent statin trials have also demonstrated the early and improved clinical benefit of lowering LDL-C beyond traditional goals with intensive statin therapy vs more moderate lipid-lowering therapy. This review assesses the impact of early statin trials on current CVD management guidelines, summarizes results of recent landmark statin trials, and evaluates the potential implications of these studies for future clinical trials and CVD management guidelines.

Psoriasis: a possible risk factor for development of coronary artery calcification

BACKGROUND

Psoriasis is a chronic inflammatory skin disorder affecting about 2% of white-skinned individuals. Epidemiological data on the prevalence and degree of coronary artery calcification (CAC) as an indicator for cardiovascular diseases in patients with psoriasis are contradictory.

OBJECTIVES

To study the prevalence and degree of CAC as an indicator for cardiovascular diseases in 32 patients with psoriasis matched for age, sex and risk factors to an equally sized control population.

METHODS

Noncontrast-enhanced 16-row spiral computed tomography was performed in patients and controls.

RESULTS

We found a significantly increased prevalence (59.4% vs. 28.1%, P = 0.015) and severity (CAC score according to Agatston 3.7 vs. 0.0, P = 0.019) of CAC in patients with psoriasis. Multiple linear regression calculations identified psoriasis as a likely independent risk factor for CAC.

CONCLUSIONS

Our results point towards the potentially systemic nature of the inflammatory processes underlying the pathogenesis of psoriasis, which may therefore be considered a potentially severe systemic disease.

Lack of correlation between coronary artery calcium and myocardial perfusion imaging

BACKGROUND

Coronary artery calcium (CAC) provides evidence of coronary atherosclerosis and has significant prognostic power. Although prior studies have documented a relationship between CAC and hemodynamically significant coronary artery stenosis, the results have not been conclusive.

METHODS AND RESULTS

We evaluated 126 consecutive patients who underwent electron beam computed tomography CAC scoring by use of the Agatston method and stress myocardial perfusion imaging (MPI) within 3 months of each other. The analysis revealed no correlation between absolute CAC score and age- and gender-adjusted CAC scores with MPI. Overall, 18% of patients had abnormal MPI results irrespective of their CAC.

CONCLUSION

CAC scoring and stress MPI should be thus considered complementary approaches rather than exclusionary in the evaluation of the patient at risk for coronary artery disease.

Micronutrients and their supplementation in chronic cardiac failure. An update beyond theoretical perspectives

Physicians' use of micronutrients to improve symptoms or outcomes in chronic illness has until recently been guided by limited data on the actions of individual agents in vitro or in animal studies. However several recently published clinical trials have provided information about which groups of patients are likely to benefit from which combination of micronutrients. Patients with chronic cardiac failure (CCF), particularly elderly individuals, have several reasons to be deficient in micronutrients including reduced intake, impaired gastrointestinal absorption and increased losses on the background of increased utilisation due for example to increased oxidative stress. Studies of nutritional supplementation in CCF patients have usually concentrated on specific agents. However given that many micronutrients have synergistic influences upon metabolic processes this strategy might merely lead to a shifting of a limiting step. Rather, a strategy of increasing the availability of multiple agents at once might be more logical. The aim of this article is to briefly review the experimental rationale for each of the micronutrients of potential benefit in chronic heart failure and examine the current clinical trial evidence supporting their use.

The clinical trial of Women On the Move through Activity and Nutrition (WOMAN) study

The Women On the Move through Activity and Nutrition (WOMAN) study is the first randomized clinical trial of nonpharmacological intervention designed to modify lipoproteins, weight loss and exercise among postmenopausal women using noninvasive measures of atherosclerosis as the primary endpoint. The trial was initially designed to test whether intervention as compared to health education would be more effective in slowing progression of subclinical atherosclerosis among women on hormone therapy (HT), estrogen or estrogen+progestin. It was designed and implemented prior to the results of the Women's Health Initiative (WHI). The trial was since modified to include women who had been on HT but went off after the results of the WHI were reported. Eligible women were between the ages of 52-62, had waist circumference>or=80 cm, low density lipoprotein cholesterol between 100-160 mg% and controlled blood pressure. The intervention is low in total and saturated fat, trans fats, higher in fiber and promotes loss of 7-10% of body weight and includes at least 150 min of physical activity per week. The study has recruited 508 women. The primary endpoints are change in extent of carotid intima-media wall thickness as measured by carotid ultrasound, pulse wave velocity as a measure of vascular stiffness and coronary artery calcium using electron beam computed tomography. Body composition is measured by dual-energy X-ray absorptiometry.

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.

Vitamin-mineral supplementation and the progression of atherosclerosis: a meta-analysis of randomized controlled trials

BACKGROUND

Laboratory and observational studies suggest that antioxidant and B vitamin supplementation may prevent atherosclerosis. Although trials have not shown a benefit of these supplements on clinical cardiovascular events, it is unknown whether they affect the progression of atherosclerosis as measured by imaging techniques.

OBJECTIVE

The objective was to perform a meta-analysis of randomized controlled trials of the effect of vitamin-mineral supplementation on atherosclerosis progression.

DESIGN

We searched the MEDLINE, EMBASE, and CENTRAL databases for relevant studies. No language restrictions were applied. We separately analyzed trials using antioxidants (vitamins E and C, beta-carotene, or selenium) and trials using B vitamins (folate, vitamin B-6, or vitamin B-12). The progression of atherosclerosis was evaluated by B-mode ultrasound, intravascular ultrasound, or angiography. Effect sizes were calculated for the difference in slope of atherosclerosis progression between participants assigned to supplements and those assigned to the control group.

RESULTS

In trials not involving percutaneous transluminal coronary angioplasty, the pooled effect size was -0.06 (95% CI: -0.20, 0.09; 7 trials) for antioxidants and -0.93 (95% CI: -2.11, 0.26; 4 trials) for B vitamins. In trials involving percutaneous transluminal coronary angioplasty, the pooled relative risk of restenosis was 0.82 (95% CI: 0.54, 1.26; 3 trials) for antioxidants and 0.84 (95% CI: 0.34, 2.07; 2 trials) for B vitamins.

CONCLUSION

Our meta-analysis showed no evidence of a protective effect of antioxidant or B vitamin supplements on the progression of atherosclerosis, thus providing a mechanistic explanation for their lack of effect on clinical cardiovascular events.

Statins in the treatment of chronic heart failure: a systematic review

BACKGROUND

The efficacy of statin therapy in patients with established chronic heart failure (CHF) is a subject of much debate.

METHODS AND FINDINGS

We conducted three systematic literature searches to assess the evidence supporting the prescription of statins in CHF. First, we investigated the participation of CHF patients in randomized placebo-controlled clinical trials designed to evaluate the efficacy of statins in reducing major cardiovascular events and mortality. Second, we assessed the association between serum cholesterol and outcome in CHF. Finally, we evaluated the ability of statin treatment to modify surrogate endpoint parameters in CHF. Using validated search strategies, we systematically searched PubMed for our three queries. In addition, we searched the reference lists from eligible studies, used the "see related articles" feature for key publications in PubMed, consulted the Cochrane Library, and searched the ISI Web of Knowledge for papers citing key publications. Search 1 resulted in the retrieval of 47 placebo-controlled clinical statin trials involving more than 100,000 patients. CHF patients had, however, been systematically excluded from these trials. Search 2 resulted in the retrieval of eight studies assessing the relationship between cholesterol levels and outcome in CHF patients. Lower serum cholesterol was consistently associated with increased mortality. Search 3 resulted in the retrieval of 18 studies on the efficacy of statin treatment in CHF. On the whole, these studies reported favorable outcomes for almost all surrogate endpoints.

CONCLUSIONS

Since CHF patients have been systematically excluded from randomized, controlled clinical cholesterol-lowering trials, the effect of statin therapy in these patients remains to be established. Currently, two large, randomized, placebo-controlled statin trials are under way to evaluate the efficacy of statin treatment in terms of reducing clinical endpoints in CHF patients in particular.

Risk scoring in the assessment of cardiovascular risk

PURPOSE OF REVIEW

Cardiovascular risk scoring is incorporated in guidelines and recommended for targeting preventive treatment. Evidence is required on the most appropriate method, its accuracy in a given population, and its effectiveness in favourably influencing clinical behaviour and health outcomes.

RECENT FINDINGS

Recent risk scores address inaccuracies that arise when methods are transferred between populations, and specific methods and recalibrations are described for use in low-risk populations. Ethnic and social differences in risk are also recognized in the context of cardiovascular risk scoring. More sensitive measures of known risk factors and numerous emerging risk factors are reported and new statistical methods and sources of data suggested. Little emphasis has been placed on evaluation of the clinical effectiveness of cardiovascular risk scores. Education in cardiovascular risk assessment may help improve uptake of methods by healthcare professionals.

SUMMARY

Numerous risk scoring methods are available to the healthcare professional but use is patchy. Accuracy varies between populations and methods have been developed to compensate for some of this variability. If risk scoring methods are to be widely used in general practice, evidence is required on both the accuracy of methods in appropriate populations and their effectiveness in improving health outcomes.

Thematic review series: Patient-Oriented Research. Imaging atherosclerosis: state of the art

The ability to image obstructive arterial disease brought about a revolution in clinical cardiovascular care; the development of newer technologies that image arterial wall thicknesses, areas, volumes, and composition allows valid imaging of atherosclerosis for the first time. Development of noninvasive imaging of atherosclerosis has further led to a quantum shift in research in the field by enabling the study of asymptomatic populations and thus allowing investigators to focus on preclinical disease without the many biases associated with the study of symptomatic patients. These noninvasive investigations have broad implications for clinical care as well. Coronary angiography, computed tomographic (CT) imaging of coronary calcium, intravascular ultrasound, multidetector CT angiography, B mode ultrasound of the carotid arteries, and MRI of the carotid arteries all have unique strengths and weaknesses for imaging atherosclerosis. Certain of these techniques are extremely useful as outcome variables for clinical trials, and others are uniquely useful as predictors of the risk of cardiovascular disease. All are informative in one way or another with regard to the role of plaque remodeling and composition in disease causation. CT and MRI technology are advancing very rapidly, and research and clinical uses of these imaging modalities promise to further advance our understanding of atherosclerosis and its prevention.

Coronary artery calcium scanning: Clinical paradigms for cardiac risk assessment and treatment

BACKGROUND

Coronary artery calcium (CAC) scanning is being increasingly used for cardiac risk assessment in asymptomatic patients, particularly in those with a Framingham 10-year risk of 10% to 20%. Physician awareness of this technology and its appropriate uses and limitations is crucial to appropriate use.

METHODS

With the goal of establishing clinical paradigms, this document integrates the results of key published articles, Framingham Risk Score, National Cholesterol Education Program Adult Treatment Plan III guidelines, American College of Cardiology/American Heart Association exercise testing and angiographic guidelines, and the authors' extensive clinical experience.

RESULTS

Coronary artery calcium scanning is best used in the asymptomatic population with a 10% to 20% risk of cardiac events over 10 years, with selected application in higher and lower risk categories. In the 10%-20% risk patient, coronary artery calcium scores >100 or >75th percentile for age and sex transform the moderately high-risk patient to higher risk status with the attendant recommendation for more aggressive therapy; scores from 11 to 100 and <75th percentile are consistent with the 10%-20% 10-year risk status and scores from 0 to 10 and <75th percentile convert the patient to lesser risk categories. If stress testing is planned in the asymptomatic patient, it should be preceded by coronary artery calcium scanning and performed only for scores >400; it should always precede coronary angiography in these patients.

CONCLUSIONS

Coronary artery calcium scanning is an important risk assessment tool with direct clinical applications; it is of particular utility in the Framingham 10%-20% 10-year risk population.

Assessing drug risks and benefits: lessons from postmenopausal hormone therapy studies

The issue of safety standards for new drugs remains unsettled. Limitations of biomarker or observational studies for assessing global safety and efficacy of postmenopausal hormone therapy are highlighted by contrast with randomized clinical trial results. On the other hand, requiring large-scale, long-term outcome trials for every new drug might not be practical. Randomized trials with intermediate outcomes such as coronary angiography, coronary or carotid ultrasound, or coronary calcification present attractive alternatives. Trials with intermediate outcomes can be conducted with much smaller sample sizes and shorter duration, but the adequacy of these types of trials for assessment of safety and efficacy remains a topic of ongoing discussion in the scientific and regulatory communities.

Atherosclerotic Plaque Characterization by Multidetector Row Computed Tomography Angiography

Multidetector row computed tomography angiography (MDCTA) is seen as a potential alternative to current imaging methods for the assessment of vessel anatomy and atherosclerotic plaque composition/morphology in a great variety of arterial beds. Recent advances represented by the increase in gantry speed to <500 ms per rotation and in the number of detector rows from 4 to 64, in addition to the decrease in slice thickness to submillimetric levels, brought significant improvement in diagnostic accuracy by coronary MDCTA. In general, it has a good correlation with both intravascular ultrasound (IVUS) and histopathology for discrimination between soft, intermediate, and calcified plaques. Plaque area and volume tend to be underestimated by 12-detector row MDCTA and overestimated by 16-detector row MDCTA, but the number of patients studied so far is relatively small. However, it seems that 64-detector row MDCTA can measure plaque area and volume with greater accuracy. Plaque remodeling is overestimated in small vessels by 12-detector row MDCTA, whereas 16- and 64-detector row MDCTA show a good correlation with IVUS. Although still under development, the potential of MDCTA to characterize atherosclerotic plaque composition as well as to precisely determine plaque area, volume, and remodeling in the future is quite promising.

Progressive coronary calcification despite intensive lipid-lowering treatment: a randomised controlled trial

OBJECTIVES

To evaluate the effect of intensive lipid-lowering treatment on coronary artery calcification in a substudy of a trial recruiting patients with calcific aortic stenosis.

METHODS

In a double blind randomised controlled trial, 102 patients with calcific aortic stenosis and coronary artery calcification were randomly assigned by the minimisation technique to atorvastatin 80 mg daily or matched placebo. Coronary artery calcification was assessed annually by helical computed tomography.

RESULTS

48 patients were randomly assigned to atorvastatin and 54 to placebo with a median follow up of 24 months (interquartile range 24-30). Baseline characteristics and coronary artery calcium scores were similar in both groups. Atorvastatin reduced serum low density lipoprotein cholesterol (-53%, p < 0.001) and C reactive protein (-49%, p < 0.001) concentrations whereas there was no change with placebo (-7% and 17%, p > 0.95 for both). The rate of change in coronary artery calcification was 26%/year (0.234 (SE 0.037) log arbitrary units (AU)/year; n = 39) in the atorvastatin group and 18%/year (0.167 (SE 0.034) log AU/year; n = 49) in the placebo group, with a geometric mean difference of 7%/year (95% confidence interval -3% to 18%, p = 0.18). Serum low density lipoprotein concentrations were not correlated with the rate of progression of coronary calcification (r = 0.05, p = 0.62).

CONCLUSION

In contrast to previous observational studies, this randomised controlled trial has shown that, despite reducing systemic inflammation and halving serum low density lipoprotein cholesterol concentrations, statin treatment does not have a major effect on the rate of progression of coronary artery calcification.

Current and future status on cardiac computed tomography imaging for diagnosis and risk stratification

Computed tomography (CT) permits cross-sectional imaging with high spatial resolution and has, during the past years, undergone tremendous development mainly concerning the temporal resolution. By use of multidetector spiral technology, as well as electrocardiography-gated image acquisition and reconstruction techniques, 16- and 64-slice CT permits visualization of cardiac morphology and function. In this context, however, CT imaging does not play a major clinical role because other imaging methods (mainly echocardiography) usually provide all necessary information. Under certain conditions, multidetector CT also permits visualization of the coronary arteries. Detection of coronary calcification, as well as coronary CT angiography, can provide clinically useful information if applied to suitable patient groups. It is foreseeable that CT angiography will become part of the routine workup in some subsets of patients with suspected coronary artery disease, either alone or in combination with other imaging techniques. Among the limitations of cardiac CT are the requirement of a regular (and preferably low) heart rate, the associated x-ray exposure, and the need for an iodinated contrast agent for most applications. It is important to note that reliable and accurate results will require use of the most advanced CT scanner technology, optimal image quality, and sufficient experience in the acquisition and interpretation of cardiac CT data sets.

Effect of intensive versus standard lipid-lowering treatment with atorvastatin on the progression of calcified coronary atherosclerosis over 12 months: a multicenter, randomized, double-blind trial

BACKGROUND

Recent clinical trials have suggested that intensive versus standard lipid-lowering therapy provides for additional benefit. Electron-beam computed tomography provides the opportunity to quantify the progression of coronary artery calcification (CAC) in serial measurements.

METHODS AND RESULTS

In a multicenter, randomized, double-blind trial, 471 patients (age 61+/-8 years) who had no history of coronary artery disease and no evidence of high-grade coronary stenoses (>50% diameter reduction) were randomized if they had > or =2 cardiovascular risk factors and moderate calcified coronary atherosclerosis as evidenced by a CAC score > or =30. Patients were assigned to receive 80 mg or 10 mg of atorvastatin per day over 12 months. Progression of CAC volume scores could be analyzed in 366 patients. After pretreatment with 10 mg of atorvastatin for 4 weeks, 12 months of study medication reduced LDL cholesterol from 106+/-22 to 87+/-33 mg/dL in the group randomized to receive 80 mg of atorvastatin (P<0.001), whereas levels remained stable in the group randomized to receive 10 mg (108+/-23 at baseline, 109+/-28 mg/dL at the end of the study, P=NS). The mean progression of CAC volume scores, corrected for the baseline CAC volume score, was 27% (95% CI 20.8% to 33.1%) in the 80-mg atorvastatin group and 25% (95% CI 19.1% to 30.8%) in the 10-mg atorvastatin group (P=0.65). CAC progression showed no relationship with on-treatment LDL cholesterol levels.

CONCLUSIONS

We did not observe a relationship between on-treatment LDL cholesterol levels and the progression of calcified coronary atherosclerosis. Over a period of 12 months, intensive atorvastatin therapy was unable to attenuate CAC progression compared with standard atorvastatin therapy. The possibility remains that the time window was too short to demonstrate an effect.

Diagnostic and clinical perspectives of fusion imaging in cardiology: is the total greater than the sum of its parts?

Positron emission tomography, cardiovascular magnetic resonance and multislice computed tomography have contributed to changing our pathophysiological understanding of many conditions. Clinically, they have provided new tools for the identification of preclinical disease and a better understanding of how disease progresses. The application of these imaging modalities to preclinical disease and the use of these techniques in patients with overt cardiovascular disease are reviewed.

Plasma homocysteine predicts progression of atherosclerosis

MINI ABSTRACT: Three emerging risk factors potentially useful in predicting future cardiac events are electron-beam computed tomography (EBT), homocysteine(HCY), and C-reactive Protein (CRP). We evaluated a cohort of 133 serial asymptomatic patients, who underwent two consecutive EBT scans (8-84 months apart) and a comprehensive cardiac risk factor assessment, including measurements for lipids, ultrasensitive CRP and homocysteine. Individuals with elevated HCY (> or =12 micromol/L) demonstrated a mean increase in CC progression of 35% per year, while those with HCY <12 micromol/L (median) progressed at 17% per year (p = 0.0008). Patients with a level equal to or lower than the median value of CRP (0.8 mg/L) had a median yearly progression of 22%, compared to 21% for those with CRP value = 0.9-11 mg/L (p = ns). Presence of elevated HCY (>12 micromol/L) strongly and independently predicts progression of coronary plaque burden.

BACKGROUND

Despite the availability of effective preventive therapies, coronary artery disease (CAD) remains the leading cause of morbidity and mortality. Use of traditional cardiovascular risk factors is imprecise and predicts less than one half of future cardiovascular events. Three 'emerging risk factors', as potential means of identifying subclinical atherosclerosis and predicting future cardiovascular events, are electron-beam computed tomography, homocysteine, and C-reactive protein. Given the evidence that HCY and CRP are involved in atherogenesis, we hypothesized that significant progression of EBT calcium score (a measure of atherosclerotic plaque burden) is associated with higher levels of these markers.

METHODS

We evaluated 133 asymptomatic patients (100 men, 33 women; mean age was 61 +/- 9 years) who underwent previous EBT calcium score testing at Harbor-UCLA 8-80 months prior to enrollment (mean follow-up 20 months). Exclusion criteria included those with known or symptomatic CAD and chronic renal disease. During enrollment, we measured risk factors, serum HCY, serum lipids, ultrasensitive-CRP, and repeat EBT calcium scan. Statistical analysis was performed using probable Chi square method, and Student's t-test.

RESULTS

Individuals with elevated HCY (> or =12 micromol/L) demonstrated a mean increase in CC progression of 35% per year, while those with HCY <12 micromol/L (median) progressed at 17% per year (p = 0.0008). Patients with a level equal to or lower than the median value of CRP (0.8 mg/L) had a median yearly progression of 22%, compared to 21% for those with CRP value = 0.9-11 mg/L (p = ns). Neither cholesterol values, body mass index, gender, age nor presence of individual risk factors predicted progression of coronary calcium.

CONCLUSION

Presence of elevated HCY (>12 micromol/L) strongly and independently predicts progression of coronary plaque burden.

Catalysis in abiotic structured media: an approach to selective synthesis of biopolymers

Micro- and nanoenvironments formed by amphiphile self-assembled structures, water-ice lattices and minerals have well-defined, repeating, chemical and physical properties that can be used for selective synthesis of biopolymers, such as RNAs and proteins. The advances made in the development of polymerization supported by these micro- and nanosystems are reviewed here. In particular, it is shown that these systems promote non-enzymatic biopolymerization, yielding long polymers whose sequence composition is determined by the interactions between monomers and the supporting environment. When used to compartmentalize enzymatic biopolymerization, micro- and nanostructures allow the implementation of molecular selection and evolution schemes, which are difficult in homogeneous medium, yielding very active molecules. Thus, micro- and nanoenvironment approaches to the synthesis and selection of biopolymers could be developed into a new biotechnological tool for the production of biopolymers with novel functions.