Effect of hydroxymethylglutaryl coenzyme a reductase inhibitors on the progression of calcific aortic stenosis

Ongoing clinical trials of the pleiotropic effects of statins

BACKGROUND

The multiple effects (ie, pleiotropic effects of statins) have received increasing recognition and may have clinical applicability across a broad range of cardiovascular and noncardiovascular conditions.

OBJECTIVE

To determine the relevance and significance of ongoing clinical trials of the pleiotropic effects of statins, focusing on nonlipid effects.

METHOD

Ongoing trials were identified through personal communication, reports presented at scientific meetings (2000-2004), and queries made to AstraZeneca, Bristol-Myers Squibb Co, Merck & Co, Novartis, and Pfizer, manufacturers of the currently marketed statins. Published trials and other source material were identified through electronic searches on MEDLINE (1990-2003), abstract books, and references identified from bibliographies of pertinent articles. Eligible studies were the clinical trials of statins currently under way in which primary or secondary outcomes included the statins' nonlipid (ie, pleiotropic) effect(s). Data were extracted and trial quality was assessed by the authors.

RESULTS

Of the 22 ongoing trials of the nonlipid effects of statins identified, 10 assessed inflammatory markers and plaque stabilization, 4 assessed oxidized low density lipoprotein/vascular oxidant stress, 3 assessed end-stage renal disease, 3 assessed fibrinogen/viscosity, 2 assessed endothelial function, 2 assessed acute coronary syndrome, 2 assessed aortic stenosis progression, and 1 each assessed hypertension, osteoporosis, ischemic burden, Alzheimer's disease, multiple sclerosis, and stroke (outcomes often overlapped).

CONCLUSION

Given the excellent safety and tolerability of statins as a class, full exploration of their pleiotropic effects has the potential to provide additional benefits to many patients.

Indications for aortic valve replacement in aortic stenosis

Aortic stenosis is a common condition, particularly in the elderly. The treatment is surgical, and any patient with symptomatic severe aortic stenosis should be considered for aortic valve replacement. Aortic stenosis causes an increase in afterload to the left ventricle, which when severe can lead to hemodynamic instability. Although the therapy of aortic stenosis is valve replacement, determining whether a patient has symptoms and accurately assessing the severity of stenosis can be difficult. The management of patients with severe aortic stenosis in the intensive care unit setting can be very challenging, particularly when comorbid medical conditions make aortic valve replacement difficult. This article reviews the diagnosis of aortic stenosis, methods of assessing symptoms and severity, and management of severe symptomatic stenosis, particularly in the intensive care unit setting. Components of the history that suggest symptomatic aortic stenosis are presented. The role of physical examination is discussed, as are the echocardiographic means of determining stenosis severity. Other means of assessing severity are addressed, as are circumstances in which there can be difficulty in interpretation, such as severe aortic stenosis and left ventricular dysfunction. Management of patients, focusing on the intensive care unit setting, is reviewed, with a focus on the timing of aortic valve replacement.

A high association of aortic valve sclerosis detected by transthoracic echocardiography with coronary arteriosclerosis

OBJECTIVE

To examine whether aortic valve sclerosis (AVS) detected by transthoracic echocardiography (TTE) has a high association with coronary arteriosclerosis.

METHODS

Clinical and angiographic features and TTE findings were retrospectively analyzed in a blinded fashion for 138 consecutive patients, of whom 58 had AVS and 80 had non-AVS diseases. Both histological and immunohistochemical studies were performed on frozen aortic valve sections obtained at autopsy from 7 AVS and 3 non-AVS patients.

RESULTS

AVS and coronary artery disease (CAD) had similar clinical risk factors. The AVS group had a higher positive rate of coronary angiography and a higher incidence rate of multivessel CAD than the non-AVS group. The sensitivity, specificity, positive predictive value and negative predictive value of AVS in diagnosing CAD were 63.8, 71.3, 61.7 and 73.1%, respectively. Early lesions of AVS were characterized by accumulation of lipid and infiltration of macrophages and T lymphocytes as indicated by immunohistochemical staining. Late lesions were characterized by formation of calcific plaques, proliferation of fibrous connective tissue and immunohistochemical staining identifying a few macrophages or T lymphocytes and little lipid accumulation on the surface of aortic valve leaflets. Late lesions in the basement of aortic valve leaflets were characterized by hyperplastic granulation tissues. Three aortic valve leaflets from the non-AVS group were characterized by nonspecific thickened tips, increased collagen, no calcification, no lipid accumulation and no inflammatory cells.

CONCLUSIONS

There were significant similarities in clinical risk factors, histopathological alterations of AVS and coronary atherosclerosis. AVS detected by TTE had a high association with coronary arteriosclerosis.

Correlation of high sensitivity C-reactive protein and calcific aortic valve disease

OBJECTIVE

To determine whether a difference exists in the levels of high sensitivity C-reactive protein (Hs-CRP) in patients with and without calcific aortic valve disease (CAVD).

PATIENTS AND METHODS

This cross-sectional study consisted of 110 patients who had undergone echocardiographic examination from January 2005 to February 2006 at our institution. Information on demographic variables, coronary risk factors, and medications was obtained. More than 200 patients were excluded on the basis of any evidence of infection, active connective tissue disorder, rheumatoid arthritis, recent episodes of bleeding, acute fractures, bowel obstruction, or acute coronary syndrome or use of corticosteroids, nonsteroidal anti-inflammatory drugs, or antibiotic treatment. The values of Hs-CRP, total cholesterol, and erythrocyte sedimentation rate were included.

RESULTS

Of the 110 study subjects, 38 patients had aortic sclerosis, 36 patients had aortic stenosis, and 36 were controls. The mean Hs-CRP level in the control group was significantly lower (4.84 +/- 6.9 mg/L) compared with the levels in the groups with aortic sclerosis (14.9 +/- 19.6 mg/L) and aortic stenosis (13.6 +/- 17.3 mg/L) (P = -.01). No statistically significant difference was found between the patients in the aortic sclerosis and aortic stenosis groups. Among the patients with aortic stenosis, no significant correlation existed between Hs-CRP levels and aortic stenosis severity.

CONCLUSIONS

The Hs-CRP seems to have a significant association with CAVD during its early stage. The study findings did not have sufficient evidence to suggest the use of Hs-CRP as a marker of progression of calcific aortic stenosis. The Hs-CRP may have a role in identifying patients in the early stages of CAVD and in whom medical treatment may be beneficial to halt the progression to irreversible aortic valvular calcification and stenosis.

Rosuvastatin affecting aortic valve endothelium to slow the progression of aortic stenosis

OBJECTIVES

The objective of this study was to test the effect of a 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitor on the progression of moderate to severe aortic stenosis as measured by echocardiography.

BACKGROUND

Recent retrospective studies support the hypothesis that statins slow the progression of aortic stenosis.

METHODS

We performed an open-label, prospective study evaluating 121 consecutive patients with asymptomatic moderate to severe aortic stenosis (aortic valve area > or = 1.0 cm2; mean age 73.7 +/- 8.9 years; 57 men and 64 women), treated with and without rosuvastatin according to the National Cholesterol Education Program Adult Treatment Panel III guidelines. Echocardiographic, serum lipid, and inflammatory markers were measured at baseline and every 6 months for 18 months.

RESULTS

Sixty-one patients (50.4%) with elevated LDL (159.7 +/- 33.4 mg/dl), aortic valve velocity (3.65 +/- 0.64 m/s), and aortic valve area (1.23 +/- 0.42 cm2) received rosuvastatin (20 mg/day), and 60 (49.6%) with a normal LDL (118.6 +/- 37.4 mg/dl), aortic valve velocity (3.62 +/- 0.61 m/s), and aortic valve area (1.20 +/- 0.35 cm2) received no statin. During a mean follow-up of 73 +/- 24 weeks, the change in aortic valve area in the control group was -0.10 +/- 0.09 cm2/year versus -0.05 +/- 0.12 cm2/year in the rosuvastatin group (p = 0.041). The increase in aortic valve velocity was 0.24 +/- 0.30 m/s/year in the control group and 0.04 +/- 0.38 m/s/year in the rosuvastatin group (p = 0.007). There was significant improvement in serum lipid and echocardiographic measures of aortic stenosis in the statin group.

CONCLUSIONS

Prospective treatment of aortic stenosis with rosuvastatin by targeting serum LDL slowed the hemodynamic progression of aortic stenosis. This is the first prospective study that shows a positive effect of statin therapy for this disease process. (Rosuvastatin Affecting Aortic Valve Endothelium; http://www.clinicaltrials.gov/ct/show/NCT00114491?order = 1; NCT0014491).

Age-related changes in hemodynamics affecting valve performance

Degenerative processes result in changes in both the aortic and mitral valves. For example, degenerative changes may lead to significant aortic stenosis or myxomatous mitral valves. Flows through each valve are determined not only by the properties of the valve itself, but also by the properties of proximal and distal chambers, which also undergo changes with age and diseases associated with the elderly, such as hypertension and coronary artery disease. Assessment of valvular performance should consider the effects of atrial-ventricular coupling (for the mitral valve) or ventricular-arterial coupling (for the aortic valve). Design of therapy or intervention should accordingly consider effects on the system as a whole.

Interventional therapies for heart failure in the elderly

The aging of a population replete with risk factors for heart failure(HF) (coronary heart disease, diabetes, and hypertension) coupled with a declining age-adjusted mortality rate for coronary artery and hypertensive heart diseases has created, and will continue to create, a literal explosion in the prevalence of HF in the United States. Despite advances in maximal medical therapy, however, most patients who have symptomatic HF can expect functional impairment, interludes of worsening symptomatology, and a shortened lifespan. This article updates the use of interventional therapies for the treatment of elderly patients who have HF caused by coronary artery disease, valvular heart disease, congenital heart disease, myocardial disease, and renal vascular disease.

A medical therapy for aortic valve sclerosis and aortic valve stenosis? Rationale of the ASSIST study (Asymptomatic aortic Sclerosis/Stenosis: Influence of STatins): a large, observational, prospective, multicenter study of the Italian Society of Cardiovascular Echography

Progression of sclerosis and stenosis is substantially unpredictable in the individual patient: in some cases it is very slow, in others it is accelerated. In addition, different patterns of progression (linear and non-linear) are possible. It has been suggested that the aortic valve lesion can be considered a form within the spectrum of the same atherosclerotic disease. In this context it seemed reasonable to hypothesize that targeted medical therapy could retard the progression of the disease. In particular HMG-CoA reductase inhibitors (statins) and angiotensin-converting enzyme inhibitors have been tested. The first experimental and clinical studies are now available, even though they are not conclusive to date. Large, prospective, randomized trials are ideally needed, but they are quite difficult, if not even impossible, to realize in practice. The ASSIST study (Asymptomatic aortic Sclerosis/Stenosis: Influence of STatins) of the Italian Society of Cardiovascular Echography aims to create a large, prospective, observational investigation, involving many centers of echocardiography and thousands of patients, in order to provide from the real clinical world at least some of the answers to this unsolved question.

Approach to the patient with bicuspid aortic valve and ascending aorta aneurysm

Bicuspid aortic valve (BAV) disease is a common congenital heart valve abnormality accounting for a large number of valve replacements in the United States. Although still incompletely understood, the natural history of BAV disease is severe aortic stenosis and associated ascending aortic dilatation. In addition to the increased risk of endocarditis, aortic dissection and severe aortic valve dysfunction are responsible for most fatal complications. Thus, early and precise recognition of this condition is mandatory. The new American College of Cardiology/American Heart Association recommendations highlight the role of MRI and CT as complimentary tools to echocardiography for the diagnosis and surveillance of the morphology of the aortic valve and ascending aorta. Moreover, better understanding of the cellular mechanisms, including inflammation, bone formation, atherosclerotic-like processes, and aortic wall abnormalities, as well as the heritability and genetic predisposition for the disease, will define the potential for targeted medical therapies in the future. Currently, the treatment of this condition is primarily surgical. Although combined valve and ascending aorta replacement has been the most common surgical approach in the past, the increased cumulative risk of thrombotic and embolic events among these young patients has led to more conservative approaches. Several valve-sparing approaches with comparable mid-term results compared with the classic procedures have recently been reported. However, longer follow-up studies will be helpful to better define the advantages of these new surgical options. After a quick overview of the natural history of the BAV, this article provides an updated approximation of the current knowledge of the pathophysiology as well as the recommendations for the management and treatment of this disease.

Potential role of statin therapy in heart failure, atrial fibrillation and aortic stenosis

3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, or statins, are widely prescribed throughout the world, and considerable evidence has indicated their powerful effects in ischemic forms of cardiovascular disease. Recently, several trials have demonstrated that statins have pleiotropic effects beyond their lipid-lowering capacities. These findings may play a role in the use of statins to manage forms of cardiovascular disease that may or may not have an ischemic etiology: congestive heart failure, atrial fibrillation and aortic stenosis.

C-reactive protein in aortic valve disease

Aortic Valve Disease, includes a range of disorder severity from mild leaflet thickening without valve obstruction, "aortic sclerosis", to severe calcified aortic stenosis. It is a slowly progressive active process of valve modification similar atherosclerosis for cardiovascular risk factors, lipoprotein deposition, chronic inflammation, and calcification. Systemic signs of inflammation, as wall and serum CRP, similar to those found in atherosclerosis, are present in patients with degenerative aortic valve stenosis and may be expression of a common disease, useful in monitoring of stenosis progression.

Association of lipid profile with echocardiographic Wilkins score in patients with moderate to severe mitral stenosis: possible impact on prognosis

BACKGROUND

Association of valvular heart disease and lipid profile might be important as in the case of aortic stenosis. However, it has not been so far considered in detail the probable association of other valvular diseases, particularly of mitral stenosis (MS) with lipid profile. In our study, we aimed to search possible association of echocardiographic mitral valve score, evaluated according to Wilkins score, with lipid parameters in a group of patients with mitral stenosis, who were referred for possible percutaneous balloon valvuloplasty.

MATERIAL AND METHOD

We retrospectively reviewed 401 patients (316 female, 85 male), who were referred as possible candidates for PMBV, with moderate to severe MS of predominantly rheumatic origin. Mitral valve was evaluated according to Wilkins score by an experienced author as indicated.

RESULTS

Mean age of all patients was 36.6+/-11.3 years, and was not different in both genders. Mean mitral valve area was 1+/-0.1 mm2. Considering all patients, total Wilkins score was significantly, but mildly correlated with ratio of total/HDL cholesterol ratio (r=0.174, p=0.02). Presence of more than one recurrent attack of rheumatic fever, narrow mitral valve area, high total/HDL cholesterol and being male were independent predictors of poor echocardiographic Wilkins score (>8).

CONCLUSION

We think that Wilkins echocardiographic score of mitral stenosis, particularly of leaflet thickening, might well be associated with serum lipids, probably as the same extent does aortic stenosis.

Chemically modified tetracyclines (CMT-3 and CMT-8) enable control of the pathologic remodellation of human aortic valve stenosis via MMP-9 and VEGF inhibition

OBJECTIVE

Tetracycline derivatives affect many cellular functions relevant to chronic cardiovascular pathologies, including cell proliferation, migration and matrix remodelling. Accordingly, we sought to determine whether they may modulate the pathologic characteristics known to be significantly involved in human aortic valve stenosis, such as gelatinase production, apoptosis, expression of vascular endothelial growth factor (VEGF) and tumour necrosis factor-alpha (TNF-alpha).

METHODS

The effects of tetracycline derivatives (tetracycline and CMTs-3, -5, -8) on MMP-2 and -9 and their endogenous tissue inhibitor (TIMP-1 and -2) production profiles in explanted human aortic valve pieces were examined by means of gelatine zymography and reverse zymography. Chemiluminescent ELISA was performed to assess VEGF and TNF-alpha concentrations in the medium, and in order to evaluate programmed cell death, in situ labelling of the 3'-ends of the DNA fragments generated by apoptosis-associated endonucleases was performed.

RESULTS

CMT-3 and -8 lowered the MMP-9 and VEGF levels significantly in a drug-, dose-, and time-dependent manner. MMP-2 and TIMPs remained unchanged, emphasizing the specificity of CMTs to MMP-9 production on the one hand and restoring the beneficial equilibrium of MMP-9 and TIMPs on the other. Tetracycline was the only drug with a significant impact on net gelatinolytic activity, suggesting that the effect of tetracycline is more extensive concerning total MMP activity.

CONCLUSIONS

Tetracycline derivatives may have therapeutic effects on the pathologic remodellation of advanced human aortic stenosis through the inhibition of MMP-9 and VEGF production.

Degeneration of native and tissue prosthetic valve in aortic position: do statins play an effective role in prevention?

Degenerative aortic valve stenosis is a common disease in western countries. When it becomes severe, it confers significant morbidity and mortality. Aortic stenosis has been recognized as a complex inflammatory and highly regulated process with histological and immunochemical similarities with the process of atherosclerosis. Hypertension, smoking and diabetes mellitus have consistently been linked to the development of aortic stenosis. Endothelial injury or other processes that contribute to coronary disease may play a role in calcific aortic stenosis. Several observational studies suggests that the key factors of aortic stenosis are lipoproteins and that medical therapies with cholesterol lowering drugs may retard its progression. Similarly, it has been suggested that the process of degeneration of the tissue heart valve has been associated with the same risk factors of atherosclerosis and shares many histological and molecular characteristics. Assuming all this concept, and evaluating the results of a retrospective study it has been suggested to use statin also as medical therapy able to prevent tissue valve degeneration. Randomized controlled clinical trials will be needed to demonstrate the role of lipid intervention to prevent the progression of aortic stenosis and the degeneration of tissue heart valves.

Is there a role of statins in the prevention of aortic biological prostheses degeneration

It has been recently observed that statins might slow the progression of aortic stenosis or sclerosis. Preliminary reports suggested a similar positive effect in reducing the degeneration of aortic valve bioprostheses even though this hypothesis should be further proven and supported by new data. In this review the present evidences of the possible effects of statins in this field are discussed.

C-reactive protein in degenerative aortic valve stenosis

Degenerative aortic valve stenosis includes a range of disorder severity from mild leaflet thickening without valve obstruction, "aortic sclerosis", to severe calcified aortic stenosis. It is a slowly progressive active process of valve modification similar to atherosclerosis for cardiovascular risk factors, lipoprotein deposition, chronic inflammation, and calcification. Systemic signs of inflammation, as wall and serum C-reactive protein, similar to those found in atherosclerosis, are present in patients with degenerative aortic valve stenosis and may be expression of a common disease, useful in monitoring of stenosis progression.

Metabolic Syndrome Negatively Influences Disease Progression and Prognosis in Aortic Stenosis

OBJECTIVES

This study sought to examine the association between the metabolic syndrome (MS) and the progression of aortic stenosis (AS).

BACKGROUND

It has been suggested that aortic valve sclerosis and its progression to AS are caused by an atherosclerotic process. Metabolic syndrome is associated with a higher risk of vascular atherosclerosis. Thus, we hypothesized that the atherogenic features of MS could negatively influence disease progression and prognosis in patients with AS.

METHODS

We retrospectively analyzed the data of 105 consecutive patients (age 69 +/- 12 years, 64 men) with at least moderate AS. Of these patients, 40 (38%) had MS identified according to the modified clinical criteria proposed by the National Cholesterol Education Program-Adult Treatment Panel III. The hemodynamic progression of AS was assessed by the measurement of the annualized decrease in valve area during the follow-up period of the study, which averaged 28 +/- 13 months. Event-free survival was defined as the absence of death or aortic valve replacement during follow-up.

RESULTS

The hemodynamic progression of the stenosis was twice as fast (-0.14 +/- 0.13 cm2/year vs. -0.08 +/- 0.08 cm2/year, p = 0.008) and the three-year event-free survival was markedly lower (44 +/- 8% vs. 69 +/- 6%, p = 0.002) among patients with MS. In multivariate analysis, MS was found to be a strong independent predictor of both stenosis progression (p = 0.006) and event-free survival (odds ratio 3.85, 95% CI 1.96 to 7.58, p < 0.001).

CONCLUSIONS

The present study is the first to report that MS is associated with a faster disease progression and worse outcome in patients with AS. Such findings open new avenues of research and provide a strong impetus for the elaboration of additional prospective studies focusing on this association.

Emerging medical treatments for aortic stenosis: statins, angiotensin converting enzyme inhibitors, or both?

Aortic stenosis is the most common adult heart valve condition seen in the Western world and its incidence continues to rise. No established disease modifying treatments retard progression of the stenotic process. Recent insights into the pathogenesis of calcific aortic stenosis suggest that the disease mimics atherosclerosis. The natural history and progression of calcific aortic stenosis are described with particular emphasis on new and emerging medical treatments that may modify the disease process. In particular, statins and angiotensin converting enzyme inhibitors appear to hold promise but definitive evidence from large clinical trials is awaited.

A review of the application of propensity score methods yielded increasing use, advantages in specific settings, but not substantially different estimates compared with conventional multivariable methods

OBJECTIVE

Propensity score (PS) analyses attempt to control for confounding in nonexperimental studies by adjusting for the likelihood that a given patient is exposed. Such analyses have been proposed to address confounding by indication, but there is little empirical evidence that they achieve better control than conventional multivariate outcome modeling.

STUDY DESIGN AND METHODS

Using PubMed and Science Citation Index, we assessed the use of propensity scores over time and critically evaluated studies published through 2003.

RESULTS

Use of propensity scores increased from a total of 8 reports before 1998 to 71 in 2003. Most of the 177 published studies abstracted assessed medications (N=60) or surgical interventions (N=51), mainly in cardiology and cardiac surgery (N=90). Whether PS methods or conventional outcome models were used to control for confounding had little effect on results in those studies in which such comparison was possible. Only 9 of 69 studies (13%) had an effect estimate that differed by more than 20% from that obtained with a conventional outcome model in all PS analyses presented.

CONCLUSIONS

Publication of results based on propensity score methods has increased dramatically, but there is little evidence that these methods yield substantially different estimates compared with conventional multivariable methods.

Quantification of Aortic Valve Calcification Using Multislice Spiral Computed Tomography

OBJECTIVES

Multislice spiral computed tomography (MSCT) allows the in vivo detection of valvular calcification. The aim of this study was to validate the quantification of aortic valve calcification (AVC) by MSCT with in vitro measurements by atomic absorption spectroscopy.

METHODS

In 18 patients with severe aortic stenosis, 16 detector row MSCT (SOMATOM Sensation 16, Siemens, Forchheim, Germany with scan parameters as follows: 420 milliseconds tube rotation time, 12 x 0.75 mm collimation, tube voltage 120 KV) was performed before aortic valve replacement. Images were reconstructed at 60% of the RR interval with an effective slice thickness of 3 mm and a reconstruction increment of 2 mm. AVC was assessed using Agatston AVC score, mass AVC score, and volumetric AVC score. After valve replacement, the calcium content of the excised human stenotic aortic valves was determined in vitro using atomic absorption spectroscopy.

RESULTS

The mean Agatston AVC score was 3,842 +/- 1,790, the mean volumetric AVC score was 3,061 +/- 1,406, and mass AVC score was 888 +/- 492 as quantified by MSCT. Atomic absorption spectroscopy showed a mean true calcification mass (Ca5(PO4)3OH) of 19 +/- 8 mass%. There was a significant correlation between in vivo AVC scores determined by MSCT and in vitro mean true calcification mass (r = 0.74, P = 0.0004 for mass AVC score, r = 0.79, P = 0.0001 for volumetric AVC score and r = 0.80, P = 0.0001 for Agatston AVC score) determined by atomic absorption spectroscopy. Linear regression analysis showed a significant association between the degree of hydroxyapatite (given in mass%) in the aortic valve and the degree of AVC (R = 0.74, F = 19.6, P = 0.0004 for mass AVC score, R = 0.80, F = 29.3, P = 0.0001 for Agatston AVC score and R = 0.79, F = 27.3, P = 0.0001 for volumetric AVC score) assessed by MSCT.

CONCLUSION

MSCT allows accurate in vivo quantification of aortic valve calcifications.

APOE alleles are not associated with calcific aortic stenosis

OBJECTIVES

To analyse the association of APOE alleles with aortic stenosis (AS) in a large study population.

METHODS

Patients with AS (n = 538) and a control group of the same age without heart disease (n = 536) were recruited. Left heart catheterisation was performed and mean gradient, aortic valve area, presence of stenotic coronary artery disease (CAD) and cardiovascular risk factors (hypercholesterolaemia, hypertension, smoking, diabetes mellitus and family history of CAD) were assessed. The frequency of the APOE major alleles e2, e3 and e4 was assessed by genotyping the polymorphisms APOE334 and APOE472 with a 5' exonuclease assay (TaqMan).

RESULTS

Mean gradient across the aortic valve in cases was 50 (SD 20) mm Hg corresponding to a mean aortic valve area of 0.84 (SD 0.34) cm(2). 270 patients with AS had stenotic CAD. Among patients with AS, the prevalence of hypercholesterolaemia (64% v 40%, p < 0.001), smoking (43% v 27%, p < 0.001), diabetes (27% v 17%, p < 0.01), family history of CAD (30% v 21%, p </= 0.05), and male sex (65% v 44%, p < 0.001) was higher in those with than in those without CAD. The frequency of the major alleles was not different between cases and controls (APOE e2: 104 (19.3%) v 94 (17.5%); APOE e3: 319 (59.3%) v 332 (61.9%); APOE e4: 115 (21.3%) v 110 (20.5%); all p > 0.10).

CONCLUSION

APOE e4 is not associated with AS, reflecting the different genetic backgrounds of CAD and AS.

Increased prevalence of coronary artery disease, silent myocardial ischemia, complex ventricular arrhythmias, atrial fibrillation, left ventricular hypertrophy, mitral annular calcium, and aortic valve calcium in patients with chronic renal insufficiency

Cardiovascular morbidity and mortality is high in patients with chronic renal insufficiency. Patients with chronic renal insufficiency have an increased prevalence of coronary artery disease, silent myocardial ischemia, complex ventricular arrhythmias, atrial fibrillation, left ventricular hypertrophy, mitral annular calcium, and aortic valve calcium than patients with normal renal function. These risk factors for cardiovascular morbidity and mortality contribute to the increased incidence of cardiovascular morbidity and mortality seen in patients with chronic renal insufficiency.

Treating dyslipidemia in the elderly

PURPOSE OF REVIEW

The treatment of dyslipidemia has been dynamic over the past several years. Of special importance is the impact of recent clinical trial data on management strategies of dyslipidemia in the elderly. People 65 years and older are living longer and are the fastest growing subset of the US population, necessitating more attention to chronic disease conditions that manifest in this age group. This review addresses guidelines of lipid management, discusses data that support their use, and examines the benefits of lipid-lowering therapy in the elderly with attention to the chronic conditions that are common in this population.

RECENT FINDINGS

Clinical trials completed since the publication of the 2001 National Cholesterol Education Program (NCEP) Adult Treatment Panel III guidelines support the use of lipid-lowering therapy in the elderly population. Lipid-lowering therapy has not only proven to be generally safe in the elderly, but has also proven effective in helping manage the chronic disease conditions that are common in this age group.

SUMMARY

The elderly segment of our population continues to grow. Along with this growth in population is a growth in incidence of cardiovascular disease, the metabolic syndrome, chronic kidney disease, cerebrovascular disease, and diabetes mellitus. There is no known panacea for managing these chronic disease conditions; however, lipid-lowering therapy has been shown to prevent or delay the progression of these diseases and the mortality and morbidity that accompanies them.

A high fat/high carbohydrate diet induces aortic valve disease in C57BL/6J mice

OBJECTIVES

The purpose of this study was to compare aortic valve function and morphology in adult wild-type (WT) mice and in low-density lipoprotein receptor-deficient (LDLr-/-) mice fed or not fed a high-fat/high-carbohydrate (HF/HC) diet.

BACKGROUND

Observations suggest a link between degenerative aortic valve stenosis (AS) and atherosclerosis. Aortic valve stenosis has been successfully induced in animal models of extreme hypercholesterolemia, but these models are less relevant to humans. It is not known if a proatherogenic HF/HC diet without added cholesterol could have the same negative impacts.

METHODS

Forty C57BL/6J mice were divided into four groups: WT + normal diet, WT + HF/HC diet, LDLr-/- with a normal diet, and LDLr-/- with a HF/HC diet. Aortic valve function and histology were evaluated by echocardiography after four months.

RESULTS

Wild-type mice on a HF/HC diet became mildly hypercholesterolemic, obese, and hyperglycemic. As expected, LDLr-/- mice became severely hypercholesterolemic. Both WT and LDLr-/- mice on a HF/HC diet displayed smaller valve areas and higher transvalvular velocities (p < 0.01) after four months. Aortic valve leaflets were thicker and infiltrated with lipids and macrophages in both HF/HC groups.

CONCLUSIONS

A HF/HC diet in mice results in significant aortic valve abnormalities. Putting WT mice on a HF/HC diet reproduced a combination of atherogenic factors (obesity, mild dyslipidemia, and hyperglycemia) more commonly encountered in humans than isolated severe hypercholesterolemia. Severe hypercholesterolemia was not a prerequisite in our model. This experimental model suggests that AS development is multifactorial and that hypercholesterolemia should not be the only target in this disease.

Statin therapy of calcific aortic stenosis: hype or hope?

Calcific aortic stenosis, with a prevalence of 3-9%, is the most frequent heart valve disease and the main cause for valve replacement in patients over 60 years of age. Once thought to be caused by a passive calcium precipitate within the aortic valve leaflets, there is now increasing evidence that development and progression of calcific aortic valve disease may be triggered by underlying genetic and cardiovascular risk factors, and is regulated by an active cellular process involving inflammatory pathways. Targeted drug therapy to prevent the progression of calcific aortic valve disease should ideally be based on the knowledge of risk factors and the molecular pathogenesis of the disease. Conflicting data exists on the potency of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (i.e. statins) to influence both risk factors and inflammatory pathways by lowering lipid levels and exerting anti-inflammatory properties, respectively. In this review, various aspects of the molecular pathogenesis of calcific aortic stenosis will be summarized and connected with recent experimental and clinical studies that address the potential benefit of the targeted drug therapy by statins in order to prevent the progression of the disease.

Management of hyperlipidemia with statins in the older patient

Numerous randomized, double-blind, placebo-controlled studies and observational studies have demonstrated that statins decrease mortality and major cardiovascular events in older high-risk persons with hypercholesterolemia. The Heart Protection Study found that statins decreased mortality and major cardiovascular events in high-risk persons regardless of the initial level of serum lipids, age, or gender. The updated National Cholesterol Education Program (NCEP) III guidelines state that in very high-risk patients, a serum low-density lipoprotein (LDL) cholesterol level of < 70 mg/dl is a reasonable clinical strategy, regardless of age. When a high-risk person has hypertriglyceridemia or low serum high-density lipoprotein cholesterol, consideration can be given to combining a fibrate or nicotinic acid with an LDL cholesterol-lowering drug. For moderately high-risk persons (2 or more risk factors and a 10-year risk for coronary heart disease of 10% to 20%), the serum LDL cholesterol should be decreased to < 100 mg/dl. When LDL cholesterol-lowering drug therapy is used to treat high-risk persons or moderately high-risk persons, the serum LDL cholesterol should be decreased at least 30% to 40%.

Relation of circulating C-reactive protein to progression of aortic valve stenosis

C-reactive protein (CRP) is a marker of inflammation and predicts outcome in apparently healthy subjects and patients with coronary artery disease. Systemic inflammation is present in patients with aortic valve stenosis (AS). The aim of this prospective study was to assess whether CRP levels predict the progression of AS severity. Blood samples for high-sensitivity CRP measurements and echocardiographic data were obtained in 43 patients (70% men; mean age 73 +/- 8 years) with asymptomatic degenerative AS at study entry. On the basis of repeat echocardiographic assessment at 6 months, patients were grouped as (1) slow progressors (a decrease in aortic valve area [AVA] <0.05 cm2 and/or an increase in aortic peak velocity <0.15 m/s) and (2) rapid progressors (a decrease in AVA > or =0.05 cm2 and/or an increase in aortic peak velocity > or =0.15 m/s). Plasma CRP levels were significantly higher in rapid progressors than slow progressors (median 5.1 [range 2.3 to 11.3] vs 2.1 [range 1.0 to 3.1] mg/L, p = 0.007). In multivariate analysis, CRP levels >3 mg/L were independently associated with rapid AS progression (odds ratio 9.1, 95% confidence interval 2.2 to 37.3). In conclusion, CRP levels are higher in patients with degenerative AS who show rapid valve disease progression. These findings suggest that inflammation may have a pathogenic role in degenerative AS.

Managing Hyperlipidaemia in the Elderly

Numerous randomised, double-blind, placebo-controlled studies and observational studies have shown that HMG-CoA reductase inhibitors (statins) reduce mortality and major cardiovascular events in elderly high-risk persons with hypercholesterolaemia. The Heart Protection Study showed that statins reduced mortality and major cardiovascular events in elderly high-risk patients regardless of the initial level of serum lipids, age or sex. The updated National Cholesterol Education Program III guidelines state that in very high-risk individuals, a target serum low-density lipoprotein cholesterol (LDL-C) level of <70 mg/dL (1.8 mmol/L) is a reasonable clinical strategy. When a high-risk patient has hypertriglyceridaemia or low high-density lipoprotein-cholesterol, consideration can be given to combining a fibric acid derivative or nicotinic acid with an LDL-C-lowering drug. For moderately high-risk patients (two or more risk factors and a 10-year risk for coronary artery disease of 10-20%), the serum LDL-C should be reduced to <100 mg/dL (2.6 mmol/L). When LDL-C-lowering drug therapy is used to treat high-risk patients or moderately high-risk patients, the serum LDL-C should be reduced by at least 30-40%.

Tissue resident C reactive protein in degenerative aortic valves: correlation with serum C reactive protein concentrations and modification by statins

OBJECTIVE

To assess aortic valve probes for valvar C reactive protein (CRP) presence, the relation between valvar and serum CRP, and a possible modification of CRP by statin medication.

SETTING

Tertiary referral centre.

PATIENTS AND DESIGN

End stage, degenerative valve tissue was taken from 81 patients, 57 with non-rheumatic aortic valve stenosis (AS) and 24 with degenerative aortic valve bioprosthesis (BP). Five non-stenosed valves served as controls. Tissue from four non-implanted bioprostheses was also examined. The presence and location of CRP was analysed by use of immunostaining and morphometry. Serum CRP concentrations were measured preoperatively.

RESULTS

The majority of AS and BP valves exhibited CRP labelled cells, predominantly localised to the valvar fibrosa. The expression of CRP was much higher in BP than in AS (by a factor of 3.7, p = 0.03). Notably, non-stenosed aortic valves and non-implanted bioprostheses did not have CRP signalling. Serum CRP was also increased with BP (by a factor of 2.5, p = 0.02) and was significantly correlated with valvar CRP expression (r = 0.54, p < 0.001). The main finding in patients with (n = 26) and without statin treatment (n = 55) was that both valvar CRP expression (p = 0.02) and serum CRP concentrations (p = 0.04) were lower in the statin treated group.

CONCLUSIONS

CRP was found in a large series of degenerative aortic valves, more often in bioprostheses than in native cusps. Serum CRP concentrations may reflect inflammatory processes within the aortic valve. The association of statin treatment with decreases in both valvar and serum CRP concentrations may explain known pleiotropic effects of statins in patients with aortic stenosis.

Impact of vitamin E and C supplementation on serum adhesion molecules in chronic degenerative aortic stenosis: a randomized controlled trial

BACKGROUND

An inflammatory component has been identified in degenerative aortic stenosis (AS). The combination of vitamins E and C has been shown to have anti-inflammatory properties. The aim of this study was to determine the impact of the combination of vitamins C and E or vitamin C only on serum levels of cell adhesion molecules and C-reactive protein in patients with chronic degenerative AS, with or without concomitant coronary artery disease.

METHODS AND RESULTS

One hundred patients with asymptomatic or mildly symptomatic moderate AS were randomized in 2:2:1 format in an open-label trial. Forty-one patients received vitamin E (400 IU) and vitamin C (1000 mg) daily, 39 patients received vitamin C (1000 mg) only, and 20 patients were followed as controls. Serum intracellular adhesion molecule (ICAM-1), E selectin, P selectin, vascular-cellular adhesion molecule (VCAM-1), C-reactive protein, and alpha-tocopherol (vitamin E) were measured by enzyme-linked immunosorbent assay at baseline and 6 months postsupplementation. Half of the patients from each of the 2 active groups were followed for further 6 months to determine any changes after cessation of therapy. In the vitamin E and C, group there was reduction in serum ICAM-1 (298 +/- 12 to 272 +/- 12 ng/mL at 6 months, P = .0015) with a return to base line 6 months after cessation of therapy. In the vitamin C only group, there was a reduction in serum P selectin (134 +/- 10 to 118 +/- 10 ng/mL at 6 months, P = .033). All the inflammatory markers were unchanged in control group over 6 months of follow-up.

CONCLUSION

Vitamin E and C supplementation had modest anti-inflammatory effect in chronic degenerative AS. The clinical relevance of this would require further clarification.

[When should one operate for severe asymptomatic aortic stenosis?]

The most common cause of aortic stenosis is degenerative and progression of the disease is slow. Deciding to proceed to aortic valve replacement in an asymptomatic patient is always difficult. Only a minority will require valve replacement after repeated work-ups including stress testing and serial echographic examinations. In the future, stress echocardiography and BNP measurements may prove helpful in decision making.

Is it time to prescribe statins to patients with calcified aortic stenosis?

Aortic stenosis (AS) is a common disease especially in the older population. It is associated with high mortality and morbidity. Recent data suggest that coronary artery disease and AS share common risk factors. Retrospective studies suggest that statins might slow the progression of AS but there are no randomized clinical trial data available. It would seem that statins can be considered for medical treatment of AS; however, this needs to be investigated in future randomized clinical trials.

Atherosclerosis of the aorta is common in patients with severe aortic stenosis: An intraoperative transesophageal echocardiographic study

OBJECTIVE

Several studies have recently reported an association between aortic valve calcification and atherosclerosis of the cardiovascular system, suggesting that aortic valve calcification might represent an atherosclerosis-like process. Hence the aim of the present study was to determine whether there is a similar association between aortic stenosis and aortic atheromas.

METHODS

We evaluated the records and echocardiographic videotapes of 91 consecutive patients with severe aortic stenosis who underwent intraoperative transesophageal echocardiography before aortic valve replacement to measure the presence and characteristics of aortic atheromas. There were 50 men (55%) and 41 women (45%). The mean age was 71.9 +/- 9.4 years (range, 34-91 years). These patients were compared with 91 sex-and age-matched patients without aortic stenosis who underwent transesophageal echocardiography for various indications. Aortic atheroma was defined as localized intimal thickening of 3 mm or larger. A lesion was considered complex if there was a plaque extending 5 mm or more into the aortic lumen; if the lesion was protruding, mobile, or ulcerated; or both.

RESULTS

The aortic stenosis group had significantly higher rates of aortic atheromas (85% vs 37%, P < .001) and complex atheromas (47% vs 9%, P < .001) compared with the control group. In the vast majority of patients in the aortic stenosis group, the aortic atheromas were localized in the aortic arch (60 [66%] patients, with 50% being complex aortic atheromas) and in the descending aorta (70 [77%] patients, with 45.7% being complex aortic atheromas); in only 4 (4.4%) patients, the aortic atheromas were localized in the ascending aorta (50% complex aortic atheromas).

CONCLUSIONS

There is a strong association between the presence of severe aortic stenosis and the presence and severity of aortic atheromas, suggesting that aortic stenosis might be a manifestation of the atherosclerotic process. These findings imply that (1) aggressive atherosclerotic risk-factor modification for patients with aortic stenosis might be advisable and (2) consideration of evaluation of the aorta by means of transesophageal echocardiography before aortic valve replacement in selected patients might be helpful.

A randomized trial of intensive lipid-lowering therapy in calcific aortic stenosis

BACKGROUND

Calcific aortic stenosis has many characteristics in common with atherosclerosis, including hypercholesterolemia. We hypothesized that intensive lipid-lowering therapy would halt the progression of calcific aortic stenosis or induce its regression.

METHODS

In this double-blind, placebo-controlled trial, patients with calcific aortic stenosis were randomly assigned to receive either 80 mg of atorvastatin daily or a matched placebo. Aortic-valve stenosis and calcification were assessed with the use of Doppler echocardiography and helical computed tomography, respectively. The primary end points were change in aortic-jet velocity and aortic-valve calcium score.

RESULTS

Seventy-seven patients were assigned to atorvastatin and 78 to placebo, with a median follow-up of 25 months (range, 7 to 36). Serum low-density lipoprotein cholesterol concentrations remained at 130+/-30 mg per deciliter in the placebo group and fell to 63+/-23 mg per deciliter in the atorvastatin group (P<0.001). Increases in aortic-jet velocity were 0.199+/-0.210 m per second per year in the atorvastatin group and 0.203+/-0.208 m per second per year in the placebo group (P=0.95; adjusted mean difference, 0.002; 95 percent confidence interval, -0.066 to 0.070 m per second per year). Progression in valvular calcification was 22.3+/-21.0 percent per year in the atorvastatin group, and 21.7+/-19.8 percent per year in the placebo group (P=0.93; ratio of post-treatment aortic-valve calcium score, 0.998; 95 percent confidence interval, 0.947 to 1.050).

CONCLUSIONS

Intensive lipid-lowering therapy does not halt the progression of calcific aortic stenosis or induce its regression. This study cannot exclude a small reduction in the rate of disease progression or a significant reduction in major clinical end points. Long-term, large-scale, randomized, controlled trials are needed to establish the role of statin therapy in patients with calcific aortic stenosis.

Principles for modeling propensity scores in medical research: a systematic literature review

PURPOSE

To document which established criteria for logistic regression modeling researchers consider when using propensity scores in observational studies.

METHODS

We performed a systematic review searching Medline and Science Citation to identify observational studies published in 2001 that addressed clinical questions using propensity score methods to adjust for treatment assignment. We abstracted aspects of propensity score model development (e.g. variable selection criteria, continuous variables included in correct functional form, interaction inclusion criteria), model discrimination and goodness of fit for 47 studies meeting inclusion criteria.

RESULTS

We found few studies reporting on the propensity score model development or evaluation of model fit.

CONCLUSIONS

Reporting of aspects related to propensity score model development is limited and raises questions about the value of these principles in developing propensity scores from which unbiased treatment effects are estimated.

The relation between homocysteine and calcific aortic valve stenosis

BACKGROUND

In patients diagnosed with calcific aortic valve stenosis, cardiac risk factors are similar to those of coronary artery disease; homocysteine concentration is an independent risk factor for coronary artery disease. The aim of this study was to investigate the correlation between plasma homocysteine levels and aortic valve stenosis and the influence of homocysteine levels on the coexistence of coronary artery disease in patients with moderate to severe aortic valve stenosis.

METHODS

Fifty-eight patients who had been diagnosed with moderate to severe aortic stenosis formed the test group of this study, and 47 healthy subjects without coronary artery disease or aortic valve stenosis formed the control group. The patients with aortic stenosis were divided into two groups according to the presence or absence of coronary artery disease in their coronary angiograms. After 12 h fasting venous blood samples were collected and total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides and homocysteine levels were measured and compared between the two groups.

MEASUREMENTS AND RESULTS

The mean blood homocysteine level was 10.8 +/- 3.3 micromol/l in patients with aortic valve stenosis and 8.1 +/- 4.7 micromol/l in the control group; the difference between these levels was statistically insignificant. The patients with aortic valve stenosis had significantly higher levels of total cholesterol and hypertension and were more likely to have a positive family history for coronary artery disease. When the two subgroups of patients with aortic valve stenosis were compared, mean blood homocysteine levels were 13.2 +/- 3.1 and 8.3 +/- 2.2 micromol/l, respectively, showing significantly higher levels in the group with coronary artery disease. In this comparison patients with coronary artery disease were also found to have significantly higher levels of total cholesterol and LDL and they were more likely to be smokers.

CONCLUSIONS

Although there was no relation between blood homocysteine levels and the existence of aortic valve stenosis, in cases with both coronary heart disease and aortic stenosis homocysteine levels were significantly higher than in the patients with pure aortic valve stenosis.