Case-controlled study to assess risk factors for aortic stenosis in congenitally bicuspid aortic valve

Identification of TNFα-mediated inflammation as potential pathological marker and therapeutic target for calcification progress of congenital bicuspid aortic valve

BACKGROUD

Congenital bicuspid aortic valve (cBAV) develops calcification and stenotic obstruction early compared with degenerative tricuspid aortic valve (dTAV), which requires surgical intervention. Here we report a comparative study of patients with cBAV or dTAV to identify risk factors associated with the rapid development of calcified bicuspid valves.

METHODS

A total of 69 aortic valves (24 dTAV and 45 cBAV) were collected at the time of surgical aortic valve replacement for comparative clinical characteristics. Ten samples were randomly selected from each group for histology, pathology, and inflammatory factors expression and comparison analyses. OM-induced calcification in porcine aortic valve interstitial cell cultures were prepared for illustrating the underlying molecular mechanisms about calcification progress of cBAV and dTAV.

RESULTS

We found that cBAV patients have increased cases of aortic valve stenosis compared with dTAV patients. Histopathological examinations revealed increased collagens deposition, neovascularization and infiltrations by inflammatory cells, especially T-lymphocytes and macrophages. We identified that tumor necrosis factor α (TNFα) and its regulated inflammatory cytokines are upregulated in cBAV. Further in vitro study indicated that TNFα-NFκB and TNFα-GSK3β pathway accelerate aortic valve interstitial cells calcification, while inhibition of TNFα significantly delays this process.

CONCLUSION

The finding of intensified TNFα-mediated inflammation in the pathological cBAV advocates the inhibition of TNFα as a potential treatment for patients with cBAV by alleviating the progress of inflammation-induced valve damage and calcification.

Anatomical and Clinical Factors Associated With Valvulopathy and Aortopathy in Mexican Patients With Bicuspid Aortic Valves

The bicuspid aortic valve (BAV) is associated with significant aortic valve dysfunction. We aimed to study Mexican patients with BAV to assess phenotypic expressions of BAV, and associations of valvulopathy and aortopathy and their predictors. A cross-sectional, retrospective study was designed. The patients were divided according to (1) normally or minimally dysfunctional BAV, (2) predominant aortic regurgitation (AR), and (3) predominant aortic stenosis (AS). A total of 189 patients were included with a high prevalence of males (68%). The overall median age was 42 (23 to 52) years. The distribution of fused BAV phenotypes was right-left fusion (77%), right noncoronary fusion (17%) and left noncoronary fusion (6%). AS-predominant group was the oldest with a high prevalence of hypertension, type 2 diabetes mellitus (T2DM), and raphe. In multivariable analysis T2DM (odds ratio [OR] 10.5 [95% confidence interval (CI) 2.1 to 52], p <0.01) and presence of raphe (OR 2.58 [95% CI 1.02 to 6.52], p = 0.04) were independently associated with AS. The AR-predominant group was composed mostly of males with significantly fewer cardiovascular risk factors. Male gender (OR 2.84 [95%CI 121 to 6.68], p = 0.01) and aortic dilatation (OR 3.58 [95% CI 1.73 to 7.39], p <0.01) were associated with AR-predominance in multivariable analysis. Aortic dilatation was associated with age (OR 1.03 [95% CI 1.008 to 1.05], p <0.01) and AR (OR 4.31 [95% CI 2.05 to 9.06], p <0.01). Independent factors associated with the root phenotype were male gender (OR 12.4 [95% CI 1.6 to 95], p <0.01) and AR (OR 5.25 [95% CI 2.18 to 12.6], p <0.01).In conclusion, in a mestizo population, the distribution of BAV-fused phenotypes was similar to European and North American populations, the presence of raphe and T2DM were independently associated with AS-predominance, and male gender and aortic dilatation were independently associated with AR-predominance.

Association between monocyte to high-density lipoprotein cholesterol ratio and bicuspid aortic valve degeneration

Background/aim

From a pathophysiological point of view, inflammation is thought to be more dominant in bicuspid aortic valve (BAV) stenosis than tricuspid aortic valve (TAV) stenosis. Our study aimed to determine the association between monocyte to high-density lipoprotein cholesterol (HDL-C) ratio (MHR), a new inflammatory marker, and the speed of progression of stenosis and pathophysiology of BAV stenosis.

Materials and methods

A total of 210 severe aortic stenosis patients (70 consecutive BAV patients, 140 matched TAV patients) were retrospectively enrolled in the study. Clinical and echocardiographic data and laboratory results related to our research were collected retrospectively from the patients’ records. MHR was measured as the ratio of the absolute monocyte count to the HDL-C value.

Results

Seventy BAV (mean age: 72.0 ± 9.1 years, 42.9% female) and 140 TAV patients (mean age: 77.9 ± 8.3 years, 51.4% female) with severe aortic stenosis were enrolled in this study. There was no difference between the two groups in terms of another baseline demographic or clinic findings except age (P < 0.001). Monocyte count, hemoglobin level, mean platelet volume was significantly higher, and HDL-C level was significantly lower in the BAV group, while other lipid and CBC parameters were found to be similar. In the multivariate analysis, MHR (P = 0.005, 95% CI: 0.90–0.98) and, as expected, age (P = 0.001, 95% CI: 1.02–1.11) were found to be significant as the independent predictor of BAV, after adjusting for other risk factors.

Conclusion

Our study showed a significant correlation between increased MHR and BAV. MHR was determined as a significant independent predictor for the speed of progression and diagnosis of severe BAV stenosis in multivariate analysis.

Quantitative three-dimensional echocardiographic analysis of the bicuspid aortic valve and aortic root: A single modality approach

BACKGROUND

Patients with bicuspid aortic valves (BAV) are heterogeneous with regard to patterns of root remodeling and valvular dysfunction. Two-dimensional echocardiography is the standard surveillance modality for patients with aortic valve dysfunction. However, ancillary computed tomography or magnetic resonance imaging is often necessary to characterize associated patterns of aortic root pathology. Conversely, the pairing of three-dimensional (3D) echocardiography with novel quantitative modeling techniques allows for a single modality description of the entire root complex. We sought to determine 3D aortic valve and root geometry with this quantitative approach.

METHODS

Transesophageal real-time 3D echocardiography was performed in five patients with tricuspid aortic valves (TAV) and in five patients with BAV. No patient had evidence of valvular dysfunction or aortic root pathology. A customized image analysis protocol was used to assess 3D aortic annular, valvular, and root geometry.

RESULTS

Annular, sinus and sinotubular junction diameters and areas were similar in both groups. Coaptation length and area were higher in the TAV group (7.25 ±  0.98 mm and 298 ± 118 mm² , respectively) compared to the BAV group (5.67 ± 1.33 mm and 177 ± 43 mm² ; P = .07 and P = .01). Cusp surface area to annular area, coaptation height, and the sub- and supravalvular tenting indices did not differ significantly between groups.

CONCLUSIONS

Single modality 3D echocardiography-based modeling allows for a quantitative description of the aortic valve and root geometry. This technique together with novel indices will improve our understanding of normal and pathologic geometry in the BAV population and may help to identify geometric predictors of adverse remodeling and guide tailored surgical therapy.

Clinical-pathological correlations of BAV and the attendant thoracic aortopathies. Part 1: Pluridisciplinary perspective on their hemodynamics and morphomechanics

Clinical BAV manifestations pertain to faulty aortic valve (AOV) function, the associated aortopathy, and other complications such as endocarditis, thrombosis and thromboembolism. BAV arises during valvulogenesis when 2 of the 3 leaflets/cusps of the AOV are fused together. Ensuing asymmetric BAV morphologies alter downstream ejection jet flow-trajectories. Based on BAV morphologies, ejection-flows exhibit different wall-impingement and scouring patterns in the proximal aorta, with excessive hydrodynamic wall-shear that correlates closely with mural vascular smooth muscle cell and extracellular matrix disruptions, revealing hemodynamic participation in the pathogenesis of BAV-associated aortopathies. Since the embryologic regions implicated in both BAV and aortopathies derive from neural crest cells and second heart field cells, there may exist a common multifactorial/polygenic embryological basis linking the abnormalities. The use of Electronic Health Records - encompassing integrated NGS variant panels and phenotypic data - in clinical studies could speed-up comprehensive understanding of multifactorial genetic-phenotypic and environmental factor interactions. This Survey represents the first in a 2-article pluridisciplinary work. Taken in toto, the series covers hemodynamic/morphomechanical and environmental (milieu intérieur) aspects in Part 1, and molecular, genetic and associated epigenetic aspects in Part 2. Together, Parts 1-2 should serve as a reference-milestone and driver for further pluridisciplinary research and its urgent translations in the clinical setting.

An Exploratory Look at Bicuspid Aortic Valve (Bav) Aortopathy: Focus on Molecular and Cellular Mechanisms

Bicuspid aortic valve (BAV) is the most common congenital heart malformation. BAV patients are at increased risk for aortic valve disease (stenosis/regurgitation), infective endocarditis, thrombi formation and, in particular, aortic dilatation, aneurysm and dissection. This review aims at exploring the possible interplay among genetics, extracellular matrix remodeling, abnormal signaling pathways, oxidative stress and inflammation in contributing to BAV-associated aortopathy (BAV-A-A). Novel circulating biomarkers have been proposed as diagnostic tools able to improve risk stratification in BAV-A-A. However, to date, the precise molecular and cellular mechanisms that lead to BAV-A-A remain unknown. Genetic, hemodynamic and cardiovascular risk factors have been implicated in the development and progression of BAV-A-A. Oxidative stress may also play a role, similarly to what observed in atherosclerosis and vulnerable plaque formation. The identification of common pathways between these 2 conditions may provide a platform for future therapeutic solutions.

Management of Patients With Aortic Valve Stenosis

With increased life expectancy and aging of the population, aortic stenosis is now one of the most common valvular heart diseases. Early recognition and management of aortic stenosis are of paramount importance because untreated symptomatic severe disease is universally fatal. The advent of transcather aortic valve replacement technologies provides exciting avenues of care to patients with this disease in whom traditional surgical procedures could not be performed or were associated with high risk. This review for clinicians offers an overview of aortic stenosis and updated information on the current status of various treatment strategies. An electronic literature search of PubMed, MEDLINE, EMBASE, and Scopus was performed from conception July 1, 2016, through November 30, 2017, using the terms aortic stenosis, aortic valve replacement, transcatheter aortic valve replacement (TAVR), transcatheter aortic valve insertion (TAVI), surgical aortic valve replacement, aortic stenosis flow-gradient patterns, low-flow aortic valve stenosis, natural history, stress testing, pathophysiology, bicuspid aortic valve, and congenital aortic valve disease.

Osteocardiology: Defining the Go/No-Go Time Point for Therapy

Recent epidemiological studies have revealed that the risk factors associated with coronary artery calcification (CAC), including male gender, smoking, hypertension, and elevated serum cholesterol, are similar to the risk factors associated with the development of calcific aortic valve disease (CAVD). The results of the experimental and clinical studies demonstrate that traditional risk factors initiate early atherosclerosis which over time differentiates to form bone in the heart causing clinical CAC and CAVD. Understanding the cellular mechanisms of cardiovascular calcification, the end-stage process of the atherosclerosis will help define the specific time point to modify this cellular process of bone formation in the heart termed osteocardiology. This time point between subclinical atherosclerosis and clinical calcification is the go/no-go time point, or the point of no return with severe clinical calcification in the heart. This review will summarize the development of bone formation in the heart termed osteocardiology, to define the go/no-go time point for therapy initiation to slow the progression of cardiovascular calcification.

Pathological Investigation of Congenital Bicuspid Aortic Valve Stenosis, Compared with Atherosclerotic Tricuspid Aortic Valve Stenosis and Congenital Bicuspid Aortic Valve Regurgitation

Background

Congenital bicuspid aortic valve (CBAV) is the main cause of aortic stenosis (AS) in young adults. However, the histopathological features of AS in patients with CBAV have not been fully investigated.

Methods and Results

We examined specimens of aortic valve leaflets obtained from patients who had undergone aortic valve re/placement at our institution for severe AS with CBAV (n = 24, CBAV-AS group), severe AS with tricuspid aortic valve (n = 24, TAV-AS group), and severe aortic regurgitation (AR) with CBAV (n = 24, CBAV-AR group). We compared the histopathological features among the three groups. Pathological features were classified using semi-quantitative methods (graded on a scale 0 to 3) by experienced pathologists without knowledge of the patients’ backgrounds. The severity of inflammation, neovascularization, and calcium and cholesterol deposition did not differ between the CBAV-AS and TAV-AS groups, and these four parameters were less marked in the CBAV-AR group than in the CBAV-AS (all p<0.01). Meanwhile, the grade of valvular fibrosis was greater in the CBAV-AS group, compared with the TAV-AS and CBAV-AR groups (both p<0.01). In AS patients, thickness of fibrotic lesions was greater on the aortic side than on the ventricular side (both p<0.01). Meanwhile, thickness of fibrotic lesions was comparable between the aortic and ventricular sides in CBAV-AR patients (p = 0.35).

Conclusions

Valvular fibrosis, especially on the aortic side, was greater in patients with CBAV-AS than in those without, suggesting a difference in the pathogenesis of AS between CBAV and TAV.

SALTIRE-RAAVE: targeting calcific aortic valve disease LDL-density-radius theory

SALTIRE and RAAVE were the first two studies to evaluate the use of statin therapy for impeding calcific aortic valve disease (CAVD). This review presents the findings of low-density lipoprotein (LDL)-density-radius theory as tested using the combined results from the SALTIRE and RAAVE studies. Patients who received statin therapy had a greater degree of LDL cholesterol lowering, seen as the % change in LDL (47 vs 2%, p = 0.012), which in itself was significantly associated with a lesser change in aortic valve area (AVA; p < 0.001 and R(2) = 0.27). The percent change in the AVA for the treated patients was 5% and 15% for the nontreated patients (p = 0.579 and R(2) = 0.03). In summary, these published findings suggest that when applying the LDL-density-radius theory, which combines the cellular biology and the hemodynamics as defined by the continuity equation for AVA, there may be a role for lipid-lowering therapy in contemporary patients with calcific aortic valve disease (CAVD).

Differing relationship between hypercholesterolemia and a bicuspid aortic valve according to the presence of aortic valve stenosis or aortic valve regurgitation

OBJECTIVES

To assess the difference in hyperlipidemia between patients with bicuspid aortic valve (BAV) and those with a normal aortic valve (NAV), and to compare aortic valve stenosis (AS), with aortic valve regurgitation (AR).

METHODS

Among 32 patients with BAV and 142 patients with NAV who underwent aortic valve replacement, 81 patients had AR and 91 patients had AS. The preoperative clinical characteristics were compared between the BAV and NAV patients. Patients with replacement of the ascending aorta were included, and those who underwent combined valvular surgery, coronary artery bypass grafting, or statin treatment were excluded.

RESULTS

The proportions of females patients (p = 0.42), patients with diabetes (p = 0.26) and patients on dialysis (p = 0.69) were similar in the two groups. Mean age was significantly lower, the mean diameter of the ascending aorta was significantly larger, and the rate of surgical intervention for the ascending aorta was significantly higher in the BAV group than in the NAV group (all p < 0.0001). The mean levels of low-density lipoprotein cholesterol (LDL) (p < 0.0001) and total cholesterol (TC) (p = 0.0003) were significantly higher in the BAV group than in the NAV group, in the analysis of only patients with AS, whereas these levels did not differ significantly between the groups, when only patients with AR were considered.

CONCLUSION

BAV with AS is associated with hypercholesterolemia. However, BAV with AR was not associated with hypercholesterolemia.

Acquired aortic stenosis

Aortic stenosis is the most commonly encountered valvular disease in the elderly, with approximately 2-3% of individuals over 65 years of age afflicted. The most common cause of acquired aortic stenosis is calcific degeneration, characterized by a slowly progressive, asymptomatic period which can last decades. Once symptomatic, the clinical manifestation of aortic stenosis is from functional obstruction of left ventricular outflow and the additional hemodynamic effects on the left ventricle and vasculature. With advances in echocardiography, individuals with aortic stenosis are increasingly diagnosed in the asymptomatic latent period. However, echocardiographic measures alone cannot identify clinically significant outflow obstruction as there is considerable overlap in hemodynamic severity between symptomatic and asymptomatic individuals. Current clinical guidelines predicate the timing of surgical valve replacement on the presence or absence of symptoms. Management for symptomatic, significant stenosis is surgical valve replacement as there are no current medical therapies reliably proven to decrease aortic stenosis severity or improve long-term outcomes. However, recent retrospective studies have demonstrated an association between atherosclerotic disease risk factors, such as hyperlipidemia and aortic stenosis. Given these findings, there are now advocates for prospective primary prevention trials for aortic stenosis in patients with mild or moderate valvular disease. The following paper will discuss etiology, diagnostic evaluation and therapeutic options of acquired aortic stenosis. This review will discuss etiology, diagnostic evaluation, and therapeutic options of acquired aortic stenosis.

Aortic stenosis at young adult age

Aortic stenosis at young adult age is usually the result of a stenotic bicuspid aortic valve, which is the most common cardiac congenital anomaly. In clinical practice, exercise and pregnancy are important topics. Furthermore, the timing of intervention is under debate, as little information is available on the natural history and outcome after aortic valve replacement in these young adults. In older patients, there is a trend towards earlier intervention. With the increased knowledge of the pathophysiology of aortic stenosis, studies have focused on the dilatation of the ascending aorta with risk of dissection. Recently, it has been suggested that pharmacologic treatment of aortic stenosis could be beneficial for these young adults.

Bicuspid aortic valve disease: recent insights in pathophysiology and treatment

Bicuspid aortic valve is a common congenital cardiac malformation with a broad spectrum of clinical outcomes. Bicuspid aortic valve may go undetected throughout an individual's lifetime or, alternatively, they may have devastating clinical consequences, resulting in death. Both clinicians and medical scientists have taken a renewed interest in the development, pathophysiology and treatment options for this subtle but often substantial clinical entity. Evidence is mounting to suggest that an underlying disease of the aorta is inherited with bicuspid aortic valve, although considerable controversy surrounds this theory. Novel molecular mechanisms underlying the valve and vascular pathologies, as well as new surgical therapies for these patients have been proposed in the past 10 years.

Bicuspid aortic valves undergo excessive strain during opening: a simulation study

OBJECTIVE

The objective of this study was to examine the influence of the morphologic characteristics of the bicuspid aortic valve on its disease progression by comparing the motion, stress/strain distribution, and blood flow of normal and stenotic tricuspid valves using simulation models.

METHODS

Bicuspid, stenotic tricuspid with commissural fusion or thickened leaflet, and normal aortic valves were modeled with internal blood flow. Blood flow and the motion of aortic valve leaflets were studied using fluid-structure interaction finite element analysis, and stress/strain (curvature) distributions were calculated during the cardiac cycle. To mimic disease progression, we modified the local thickness of the leaflet where the bending stress was above a threshold.

RESULTS

Transvalvular pressure gradient was greater in the bicuspid valve compared with the stenotic tricuspid valve with a similar valvular area. The bending strain (curvature) increased in both stenotic tricuspid and bicuspid valves, but a greater increase was observed in the bicuspid valve, and this was concentrated on the midline of the fused leaflets. During disease progression analysis, severity of the stenosis increased only in the bicuspid aortic valve model in terms of valvular area and pressure gradient.

CONCLUSIONS

The characteristic morphology of the bicuspid valve creates excessive bending strain on the leaflets during ventricular ejection. Such mechanical stress may be responsible for the rapid progression of this disease.

The role of Lrp5/6 in cardiac valve disease: LDL-density-pressure theory

Atherosclerosis and osteoporosis are the leading causes of mortality and morbidity in the World. Recent epidemiologic studies have demonstrated that these disease processes develop in parallel. Evidence indicates that hyperlipidemia plays a paradoxical role in both disease processes. However, the mechanism is not understood. This prospectus hypothesizes the role of lipids activate atherosclerosis within the bone and the heart to initiate the development of diseases in both of these tissues. The Prospectus on the Lrp 5/6 receptors provides a foundation for the mechanisms involved in the Lrp5/6 mediated disease biology. The LDL-Density-Pressure theory: the Role of Lrp5/6 provides a biological and a hemodynamic approach towards understanding the development of valvular heart disease and the implications in the field of bone molecular biology. This prospectus will review the current literature, provide a basis for the development of valve disease and indicate future therapeutic pathways for this disease process in the future.

Genetically alike Syrian hamsters display both bifoliate and trifoliate aortic valves

The bifoliate, or bicuspid, aortic valve (BAV) is the most frequent congenital cardiac anomaly in man. It is a heritable defect, but its mode of inheritance remains unclear. Previous studies in Syrian hamsters showed that BAVs with fusion of the right and left coronary leaflets are expressions of a trait, the variation of which takes the form of a phenotypic continuum. It ranges from a trifoliate valve with no fusion of the coronary leaflets to a bifoliate root devoid of any raphe. The intermediate stages are represented by trifoliate valves with fusion of the coronary aortic leaflets, and bifoliate valves with raphes. The aim of this study was to elucidate whether the distinct morphological variants rely on a common genotype, or on different genotypes. We examined the aortic valves from 1 849 Syrian hamsters belonging to a family subjected to systematic inbreeding by full-sib mating. The incidence of the different trifoliate aortic valve (TAV) and bifoliate aortic valve (BAV) morphological variants widely varied in the successive inbred generations. TAVs with extensive fusion of the leaflets, and BAVs, accounted for five-sixths of the patterns found in Syrian hamsters considered to be genetically alike or virtually isogenic, with the probability of homozygosity being 0.999 or higher. The remaining one-sixth hamsters had aortic valves with a tricuspid design, but in most cases the right and left coronary leaflets were slightly fused. Results of crosses between genetically alike hamsters, with the probability of homozygosity being 0.989 or higher, revealed no significant association between the valvar phenotypes in the parents and their offspring. Our findings are consistent with the notion that the BAVs of the Syrian hamster are expressions of a quantitative trait subject to polygenic inheritance. They suggest that the genotype of the virtually isogenic animals produced by systematic inbreeding greatly predisposes to the development of anomalous valves, be they bifoliate, or trifoliate with extensive fusion of the leaflets. We infer that the same underlying genotype may account for the whole range of valvar morphological variants, suggesting that factors other than genetic ones are acting during embryonic life, creating the so-called intangible variation or developmental noise, and playing an important role in the definitive anatomic configuration of the valve. The clinical implication from our study is that congenital aortic valves with a trifoliate design, but with fusion of coronary aortic leaflets, may harbour the same inherent risks as those already recognised for BAVs with fusion of right and left coronary leaflets.

Lipid lowering on progression of mild to moderate aortic stenosis: meta-analysis of the randomized placebo-controlled clinical trials on 2344 patients

BACKGROUND

Aortic stenosis (AS) is believed to develop through an inflammatory similar to the atherosclerosis process. Based on findings from animal studies and uncontrolled clinical studies, lipid-lowering therapy with a statin is postulated to slow this process. Randomized trials, however, reported neutral results. This meta-analysis of randomized lipid trials on patients with AS examined the effects of treatment on AS progression and clinical outcomes.

METHODS

Echocardiographic measures of AS (aortic valve jet velocity, peak and mean valve gradients, and aortic valve area) were pooled and clinical outcomes were evaluated in 4 randomized placebo controlled trials (N=2344).

RESULTS

Although active treatment with statin therapy was associated with highly significant 50% reduction in low-density lipoprotein cholesterol levels, there were no statistical differences between active and placebo groups in any of the echocardiographic indicators of AS severity: annual increase in AS velocity was 0.16±0.28 m/sec, and mean gradient was 2.8±3.0 mm Hg. Each trial reported no differences in clinical outcomes between the 2 treatment groups. Substantial events rates (6.6% aortic valve surgery and 1.2% cardiovascular deaths per year in SEAS with follow-up of 4.4 years and 5.8% aortic valve surgery and 0.7% cardiovascular deaths per year in ASTRONOMER over 3.5 years) were observed in these patients despite the relatively mild disease.

CONCLUSION

The current data do not support the hypothesis that statin therapy reduces AS progression. Patients with mild to moderate AS may require closer follow-up because despite the less severe disease in these trials, event rates remain substantial.

Effect of Lipid lowering with rosuvastatin on progression of aortic stenosis: results of the aortic stenosis progression observation: measuring effects of rosuvastatin (ASTRONOMER) trial

BACKGROUND

Aortic stenosis (AS) is an active process with similarities to atherosclerosis. The objective of this study was to assess the effect of cholesterol lowering with rosuvastatin on the progression of AS.

METHODS AND RESULTS

This was a randomized, double-blind, placebo-controlled trial in asymptomatic patients with mild to moderate AS and no clinical indications for cholesterol lowering. The patients were randomized to receive either placebo or rosuvastatin 40 mg daily. A total of 269 patients were randomized: 134 patients to rosuvastatin 40 mg daily and 135 patients to placebo. Annual echocardiograms were performed to assess AS progression, which was the primary outcome; the median follow-up was 3.5 years. The peak AS gradient increased in patients receiving rosuvastatin from a baseline of 40.8+/-11.1 to 57.8+/-22.7 mm Hg at the end of follow-up and in patients with placebo from 41.6+/-10.9 mm Hg at baseline to 54.8+/-19.8 mm Hg at the end of follow-up. The annualized increase in the peak AS gradient was 6.3+/-6.9 mm Hg in the rosuvastatin group and 6.1+/-8.2 mm Hg in the placebo group (P=0.83). Treatment with rosuvastatin was not associated with a reduction in AS progression in any of the predefined subgroups.

CONCLUSIONS

Cholesterol lowering with rosuvastatin 40 mg did not reduce the progression of AS in patients with mild to moderate AS; thus, statins should not be used for the sole purpose of reducing the progression of AS. Clinical Trial Registration Information- URL: http://www.controlled-trials.com/.

CLINICAL TRIAL REGISTRATION NUMBER

ISRCTN 32424163.

Mechanisms of aortic valve calcification: the LDL-density-radius theory: a translation from cell signaling to physiology

Recent epidemiologic studies have revealed the risk factors associated for vascular atherosclerosis, including the male sex, smoking, hypertension, and elevated serum cholesterol, similar to the risk factors associated with the development of AV stenosis. An increasing number of models of experimental hypercholesterolemia demonstrate features of atherosclerosis in the AV, which are similar to the early stages of vascular atherosclerotic lesions. Experimental and clinical studies demonstrate that the hypercholesterolemic AV develops an atherosclerotic lesion which is proliferative and expresses high levels of osteoblast bone markers which mineralize over time to form bone. Calcification, the end-stage process of the disease, is necessary to understand as a prognostic indicator in the modification of this cellular process before it is too late. In summary, these findings suggest that medical therapies may have a potential role in patients in the early stages of this disease process to slow the progression to severe aortic stenosis and to delay the timing of the need for surgery. The translation of these experimental studies to clinical practice will be important to understand the potential for medical therapy for this disease process.

Natural history of asymptomatic patients with normally functioning or minimally dysfunctional bicuspid aortic valve in the community

BACKGROUND

Bicuspid aortic valve is frequent and is reported to cause numerous complications, but the clinical outcome of patients diagnosed with normal or mildly dysfunctional valve is undefined.

METHODS AND RESULTS

In 212 asymptomatic community residents from Olmsted County, Minn (age, 32+/-20 years; 65% male), bicuspid aortic valve was diagnosed between 1980 and 1999 with ejection fraction > or =50% and aortic regurgitation or stenosis, absent or mild. Aortic valve degeneration at diagnosis was scored echocardiographically for calcification, thickening, and mobility reduction (0 to 3 each), with scores ranging from 0 to 9. At diagnosis, ejection fraction was 63+/-5% and left ventricular diameter was 48+/-9 mm. Survival 20 years after diagnosis was 90+/-3%, identical to the general population (P=0.72). Twenty years after diagnosis, heart failure, new cardiac symptoms, and cardiovascular medical events occurred in 7+/-2%, 26+/-4%, and 33+/-5%, respectively. Twenty years after diagnosis, aortic valve surgery, ascending aortic surgery, or any cardiovascular surgery was required in 24+/-4%, 5+/-2%, and 27+/-4% at a younger age than the general population (P<0.0001). No aortic dissection occurred. Thus, cardiovascular medical or surgical events occurred in 42+/-5% 20 years after diagnosis. Independent predictors of cardiovascular events were age > or =50 years (risk ratio, 3.0; 95% confidence interval, 1.5 to 5.7; P<0.01) and valve degeneration at diagnosis (risk ratio, 2.4; 95% confidence interval, 1.2 to 4.5; P=0.016; >70% events at 20 years). Baseline ascending aorta > or =40 mm independently predicted surgery for aorta dilatation (risk ratio, 10.8; 95% confidence interval, 1.8 to 77.3; P<0.01).

CONCLUSIONS

In the community, asymptomatic patients with bicuspid aortic valve and no or minimal hemodynamic abnormality enjoy excellent long-term survival but incur frequent cardiovascular events, particularly with progressive valve dysfunction. Echocardiographic valve degeneration at diagnosis separates higher-risk patients who require regular assessment from lower-risk patients who require only episodic follow-up.

The combined effects of balloon valvuloplasty and surgical weight loss in treatment of aortic stenosis

We report a case of a patient with a congenitally bicuspid aortic valve and extreme obesity who developed severe aortic stenosis. She dramatically improved after the combined use of balloon valvuloplasty and Roux en Y gastric bypass. Gastric bypass surgery has promise for patients with congenital cardiac disease whose treatment is complicated by extreme obesity.

Reassessment of statins to retard the progression of aortic stenosis

Aortic valve stenosis is the most common indication for surgical valve replacement in the United States and Europe. For years, this valve lesion was thought to be a passive degenerative disease. In the past decade there have been a number of studies indicating that the risk factors for valvular heart disease are the same as those for vascular atherosclerosis. This correlation with atherosclerosis and valvular heart disease indicates that medical therapy may have a role in slowing the progression of this disease process. Currently, the retrospective studies indicate that medical therapy slows the progression of this disease. The prospective data are currently conflicting in terms of the final outcomes for treating the disease process with medical therapy. This review outlines the growing number of clinical studies implicating the potential for medical therapy in this patient population.

Impact of blood pressure on the Doppler echocardiographic assessment of severity of aortic stenosis

OBJECTIVE

To investigate the impact of blood pressure (BP) on the Doppler echocardiographic (Doppler-echo) evaluation of severity of aortic stenosis (AS).

METHODS

Handgrip exercise or phenylephrine infusion was used to increase BP in 22 patients with AS. Indices of AS severity (mean pressure gradient (DeltaP(mean)), aortic valve area (AVA), valve resistance, percentage left ventricular stroke work loss (% LVSW loss) and the energy loss coefficient (ELCo)) were measured at baseline, peak BP intervention and recovery.

RESULTS

From baseline to peak intervention, mean (SD) BP increased (99 (8) vs 121 (10) mm Hg, p<0.001), systemic vascular resistance (SVR) increased (1294 (264) vs 1552 (372) dynexs/cm(5), p<0.001) and mean (SD) transvalvular flow rate (Q(mean)) decreased (323 (67) vs 306 (66) ml/s, p = 0.02). There was no change in DeltaP(mean) (36 (13) vs 36 (14) mm Hg, p = NS). However, there was a decrease in AVA (1.15 (0.32) vs 1.09 (0.33) cm(2), p = 0.02) and ELCo (1.32 (0.40) vs 1.24 (0.42) cm(2), p = 0.04), and an increase in valve resistance (153 (63) vs 164 (74) dynexs/cm(5), p = 0.02), suggesting a more severe valve stenosis. In contrast, % LVSW loss decreased (19.8 (6) vs 16.5 (6)%, p<0.001), suggesting a less severe valve stenosis. There was an inverse relationship between the change in mean BP and AVA (r = -0.34, p = 0.02); however, only the change in Q(mean) was an independent predictor of the change in AVA (r = 0.81, p<0.001).

CONCLUSIONS

Acute BP elevation due to increased SVR can affect the Doppler-echo evaluation of AS severity. However, the impact of BP on the assessment of AS severity depends primarily on the associated change in Q(mean), rather than on an independent effect of SVR or arterial compliance, and can result in a valve appearing either more or less stenotic depending on the direction and magnitude of the change in Q(mean).

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.

Bicuspid aortic valve: an innocent finding or a potentially life-threatening anomaly whose complications may be elicited by sports activity?

The bicuspid aortic valve is the most frequent congenital anomaly of the heart in adults. Since the 1970s, with the advent of two-dimensional echocardiography, the in-vivo diagnosis of bicuspid aortic valve has become easier and greater attention has been paid to this anomaly in normal young people, particularly in sportsmen because, from a theoretical point of view, physical exercise may stress the abnormal aortic valve, favouring an early deterioration of the valve itself, as well as a dilation of the ascending aorta. Although the bicuspid aortic valve may remain without clinical consequences for a lifetime, it may be responsible for severe complications such as aortic stenosis, aortic insufficiency, endocarditis and aortic dilation/dissection, sometimes requiring surgery. Moreover, the bicuspid aortic valve may be associated with other cardiovascular anomalies, mainly aortic coarctation. At present there are no prospective studies dealing with effect of physical training and competitive sports on the natural course of the bicuspid aortic valve. However, in order to take any decision about sports eligibility, sports physicians should perform an initial accurate staging of the bicuspid aortic valve, taking into account haemodynamic factors, aortic complications and associated significant cardiovascular anomalies. A strict follow-up, with serial cardiological controls, is mandatory as well as antibiotic prophylaxis for endocarditis, particularly in subjects engaged in contact sports.

Management of the Valve and Ascending Aorta in Adults with Bicuspid Aortic Valve Disease

Bicuspid aortic valve (BAV) disease is the most common congenital cardiac malformation, being present in 1% to 2% of the population. It is heritable and is three to four times more likely to occur in men. The pathogenesis of BAV disease is unknown. Bicuspid valves progress to aortic stenosis or insufficiency in the majority of patients. BAV disease is associated with several anomalies of the aorta including coarctation, aneurysm formation, and dissection. Several lines of evidence suggest that aortic complications are caused by the same underlying factor that causes BAV disease, rather than being a consequence of turbulent blood flow through a stenotic valve. Several different surgical options exist for patients with BAV disease depending on the age of presentation and the size and appearance of the aorta. We herein describe our surgical management of the aortic valve and ascending aorta in patients with BAV disease.

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.

Is aortic stenosis a preventable disease?

Aortic stenosis (AS) is the most common valvular disease requiring valve replacement. Its prevalence increases with age. When the severity of AS is only mild to moderate, it is well tolerated. When it becomes severe, AS confers significant morbidity and mortality. Adverse events can be avoided if it is possible to prevent or retard the progression from mild or moderate AS to severe AS. Progression of AS parallels the progression of sclerotic changes involving the aortic valve, which share histological and immunochemical similarities with the process of atherosclerosis. Far from being just a degenerative process, the development of AS is a complex and highly regulated process with a number of modifiable factors. One of the key factors appears to be lipoproteins, which are intimately involved in several pathways crucial to the development of AS. The importance of lipoproteins is further supported by epidemiological and clinical studies showing a strong association between lipoproteins and AS. The time has come to initiate prospective studies to assess the effect of cholesterol lowering on the progression of AS.