A case-control investigation of the relation between hyperlipidaemia and calcific aortic valve stenosis

Lipoprotein(a) Gene Polymorphism Increases a Risk Factor for Aortic Valve Calcification

Calcific aortic valve disease (CAVD) is a multifactorial condition. Both environmental and genetic factors play an important role in its etiology. CAVD exhibits a broad spectrum, varying from mild valve thickening to severe valve calcification and stenosis. Progression of the disease consists of chronic inflammation, lipoprotein deposition, and active leaflet calcification. It is a process similar to coronary artery disease. In this study, we investigated Lp(a) levels and gene polymorphisms associated with calcific aortic stenosis from blood samples after echocardiography in the evaluation of 75 patients diagnosed with CAVD and 77 controls. Blood tests were run in our laboratory to rule out certain risk factors before echocardiography examination. A significant association among smoking, elevated LDL level and creatinine, low albumin levels, Lp(a) level, rs10455872, and rs3798220 polymorphisms may be considered genetic risk factors for the development of calcific aortic stenosis.

Lipoprotein(a) and the Apolipoprotein B/A1 Ratio Independently Associate With Surgery for Aortic Stenosis Only in Patients With Concomitant Coronary Artery Disease

Background

Aortic stenosis (AS) has different clinical phenotypes, including AS with or without concomitant coronary artery disease (CAD). It is unknown whether these phenotypes share the same risk factors. In particular, lipoprotein(a) [Lp(a)] and apolipoproteins (Apo) are associated with AS, but it is unknown whether these associations differ among phenotypes. In this prospective analysis we examined the impact of Lp(a) and Apo in subgroups of patients with AS.

Methods and Results

We identified 336 patients (mean age at survey 56.7 years, 48% female) who underwent surgery for AS after a median 10.9 years (interquartile range 9.3 years), participants in 1 of 3 large population surveys. For each patient, 2 matched referents were allocated. Lp(a) and Apo were analyzed in the baseline samples. Uni‐ and multivariable logistic regression analyses were used to estimate risks related to a 1 (ln) standard deviation increase in Lp(a) and the ratio of Apo B to Apo A1 (Apo B/A1 ratio). High levels of Lp(a) predicted surgery for AS in 203 patients with concomitant CAD (odds ratio [95% confidence intervals]) (1.29 [1.07‐1.55]), but not in 132 patients without CAD (1.04 [0.83‐1.29]) in the fully adjusted model. Similarly, a high Apo B/A1 ratio predicted surgery in patients with concomitant CAD (1.43 [1.16‐1.76]) but not in those without CAD (0.87 [0.69‐1.10]).

Conclusions

High levels of Lp(a) and a high Apo B/A1 ratio were associated with surgery for AS in patients with concomitant CAD but not in those with isolated AS. This finding may lead to a new avenue of research for targeted risk factor interventions in this population.

Anti-inflammatory Effects of Statins in Patients with Aortic Stenosis

Background: Aortic stenosis is an inflammatory process, as evidenced by increased tissue expression and serum levels of various endothelial cellular adhesion molecules. Aortic stenosis and atherosclerosis have many risk factors in common, including hypercholesterolemia. In atherosclerosis, statins lower cholesterol and display some anti-inflammatory activity. We hypothesized that statins might also have anti-inflammatory effects in patients with aortic stenosis.

Methods: This observational cross-sectional study measured levels of cellular adhesion molecules in 129 patients (88 male, mean age 68) with aortic stenosis (mean echo gradient 49 mm Hg, range 22 to 112) and compared levels in patients already on statin therapy for primary or secondary prevention of coronary artery disease, to those not on treatment. Concomitant conditions included hypertension (47%), diabetes (10%), and ischemic heart disease (54%). A comparison group consisted of 45 patients with stable ischemic heart disease.

Results: Patients on statins (35) were more likely to have hypertension (62% vs 42%, P = .05), but no significant differences existed in sex, age, concomitant ischemic heart disease, or diabetes. Statin-treated patients had a 20% lower vascular cellular adhesion molecule level than those without (484 ± 143 ng/L vs 604 ± 245 ng/L, P = .006). The reduction in cellular adhesion molecule levels was consistent in patients with aortic stenosis alone, aortic stenosis and ischemic heart disease, or ischemic heart disease alone. There were no differences in the levels of the other adhesion molecules between the three groups, or related to statin therapy.

Conclusion: Statin therapy is associated with reduced serum levels of vascular cellular adhesion molecules in patients with aortic stenosis. Vascular cellular adhesion molecule levels are similar in patients who have aortic stenosis, ischemic heart disease, or both. A prospective study is required to confirm this finding and to determine whether this suppression of endothelial inflammation translates into a slowing of the progression of aortic stenosis.

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).

Progression of aortic stenosis in elderly patients over long-term follow up

BACKGROUND

The natural history of aortic stenosis (AS) in elderly patients remains poorly defined. In an elderly cohort over long-term follow-up, we assessed: 1) rates and predictors of hemodynamic progression and 2) composite aortic valve replacement (AVR) or death endpoint.

METHODS

Consecutive Department of Veterans' Affairs patients with AS (>60 years) were prospectively enrolled between 1988 and 1994 (n=239) and followed until 2008. Patients with ≥ 2 trans-thoracic echocardiograms >6 months apart were included in the progression analysis (n=147). Baseline demographics, comorbidities and echocardiography parameters were recorded. Follow-up was censored at AVR/death.

RESULTS

The age of patients was 73 ± 6 years; 82% were male. Baseline AS severity was mild (67%), moderate (23%) and severe (10%). Follow-up was 6.5 ± 4 years (range: 1-17 years). Annualized mean aortic valve gradient progression rates were: mild AS 4 ± 4 mmHg/year; moderate AS 6 ± 5 mmHg/year and severe AS 10 ± 8 mmHg/year (p<0.001). Five-year event-free survival was 66 ± 5%, 23 ± 7% and 20 ± 10% for mild, moderate and severe AS respectively. Progression to severe AS occurred in 35% and 74% of patients with mild and moderate AS respectively. Independent predictors of rapid progression were: baseline AS severity (per grade) (OR 2.6, p=0.001), aortic valve calcification (per grade) (OR 2.1, p=0.01), severe renal impairment (OR 4.0, p=0.04) and anemia (OR 2.3, p=0.05).

CONCLUSIONS

In elderly patients, hemodynamic progression of AS is predicted by AS severity, renal function, aortic valve calcification and history of anemia. These factors identify patients at high risk of rapid hemodynamic progression, for whom more frequent clinical and echocardiographic surveillance is advisable.

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.

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.

Aortic valve disease and treatment: the need for naturally engineered solutions

The aortic valve regulates unidirectional flow of oxygenated blood to the myocardium and arterial system. The natural anatomical geometry and microstructural complexity ensures biomechanically and hemodynamically efficient function. The compliant cusps are populated with unique cell phenotypes that continually remodel tissue for long-term durability within an extremely demanding mechanical environment. Alteration from normal valve homeostasis arises from genetic and microenvironmental (mechanical) sources, which lead to congenital and/or premature structural degeneration. Aortic valve stenosis pathobiology shares some features of atherosclerosis, but its final calcification endpoint is distinct. Despite its broad and significant clinical significance, very little is known about the mechanisms of normal valve mechanobiology and mechanisms of disease. This is reflected in the paucity of predictive diagnostic tools, early stage interventional strategies, and stagnation in regenerative medicine innovation. Tissue engineering has unique potential for aortic valve disease therapy, but overcoming current design pitfalls will require even more multidisciplinary effort. This review summarizes the latest advancements in aortic valve research and highlights important future directions.

Administration of angiotensin-converting enzyme inhibitors is associated with slow progression of mild aortic stenosis in Japanese patients

It is almost unknown which demographic factors or medications affect the progression of aortic stenosis (AS) in Japanese patients with mild AS. We identified a total of 194 patients with native tricuspid valvular AS, defined as a continuous-wave Doppler determined peak aortic valve jet velocity of ≥ 2.0 m/s, in whom echo Doppler studies were repeated at an interim of at least 6 months. Annualized change in peak jet velocity was calculated, and effects of age, sex, diabetes mellitus, blood pressure, serum low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels, and use of statins and antihypertensive agents on the progression of AS were retrospectively evaluated. Peak aortic valve jet velocity was 2.36 ± 0.79 m/s (mean ± SD) and annualized increase in peak aortic valve jet velocity was 0.17 ± 0.32 m/s/year for all the studied patients. The increase in peak aortic valve jet velocity was lower in patients taking angiotensin-converting enzyme inhibitors (ACE-Is) than in those not taking ACE-Is (0.04 ± 0.22 vs. 0.20 ± 0.32 m/s/year, P < 0.05). Such protective associations were not observed for other first-line antihypertensive agents and statins. Multiple linear regression analysis revealed that ACE-I treatment, decrease in left ventricular ejection fraction, and higher peak aortic valve jet velocity at the first echocardiogram were associated with slower progression of AS. Administration of ACE-Is was associated with the slow progression of mild AS in Japanese patients. Prospective study to assess this hypothesis is needed.

Insights into the use of biomarkers in calcific aortic valve disease

Calcific aortic valve disease (CAVD) is the most common acquired valvular disorder in developed countries. CAVD ranges from mild thickening of the valve, known as aortic valve sclerosis (AVSc), to severe impairment of the valve motion, which is termed aortic valve stenosis (AVS). The prevalence of CAVD is nearing epidemic status: its preceding stage, in which there is aortic sclerosis without obstruction of the left ventricular outflow, is present in almost 30% of adults aged over 65 years. As there is no existing medical therapy to treat or slow the progression of CAVD, surgery for advanced disease represents the only available treatment. Aortic valve replacement is the second most frequently performed cardiac surgical procedure after coronary artery bypass grafting, and consequently CAVD represents a major societal and economic burden. The pathophysiological development of CAVD is incompletely defined. At the present time, the major methods for its diagnosis are clinical examination, echocardiography, and cardiac catheterization. Yet, due to the multiple biological pathways leading to CAVD, there are many potential biomarkers that might be suitable for deriving clinically useful information regarding the presence, severity, progression, and prognosis of CAVD. Although at the present time the available data do not permit recommendations for clinicians, they do support a paradigm of screening patients based on multiple biomarkers to provide the information necessary to optimize future therapeutic interventions. This review summarizes the results of several studies investigating the value of potential biomarkers that have been used to predict the severity, progression, and prognosis of CAVD.

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.

Association between calcific aortic stenosis and hypercholesterolemia: is there a need for a randomized controlled trial of cholesterol-lowering therapy?

BACKGROUND

Calcific aortic stenosis may have common etiological factors with atherosclerosis.

HYPOTHESIS

In this retrospective, case-control study, we aimed to determine whether there is an association between hypercholesterolemia and calcific aortic valve stenosis.

METHODS

Consecutive patients undergoing single aortic or mitral valve replacement in a regional cardiothoracic surgical center were reviewed and preoperative patient characteristics were recorded: demographics, comorbidity (including coronary artery disease and associated risk factors), serum total cholesterol, lipid-lowering therapy, and serum creatinine.

RESULTS

Serum total cholesterol concentrations were significantly higher in patients with calcific aortic stenosis than in controls (6.2+/-1.1 vs. 5.3+/-1.1 mmol/l; p < 0.001). The significant difference in serum cholesterol concentrations remained following correction for gender and body mass index (p = 0.02) and when patients with coronary artery disease were excluded (6.3+/-1.1 vs. 5.3+/-1.4 mmol/l; p<0.001). Subgroup analysis demonstrated that the association between elevated serum cholesterol concentrations and calcific aortic stenosis was particularly strong in patients with tricuspid aortic valves (6.4+/-1.2 vs. 5.3+/-1.1 mmol/l; p < 0.001) compared with those with bicuspid valves (5.9+/-1.1 vs. 5.3+/-1.1 mmol/l; p = 0.06).

CONCLUSIONS

We conclude that hypercholesterolemia is associated with calcific aortic stenosis and may be implicated in its pathogenesis and progression. We believe that there is now a need for a randomized, controlled trial of cholesterol-lowering therapy in patients with calcific aortic stenosis.

Medical therapy for rheumatic heart disease: is it time to be proactive rather than reactive?

Rheumatic Heart Disease (RHD) is well known to be an active inflammatory process which develops progressive calcification and leaflet thickening over time. The potential for statin therapy in slowing the progression of valvular heart disease is still controversial. Retrospective studies have shown that medical therapy is beneficial for patients with calcific aortic stenosis and recently for rheumatic valve disease. However, the prospective randomized clinical trials have been negative to date. This article discusses the epidemiologic risk factors, basic science, retrospective and prospective studies in valvular heart disease and a future clinical trial to target RHD with statin therapy to slow the progression of this disease. Recent epidemiological studies have revealed the risk factors associated with valvular disease include male gender, smoking, hypertension and elevated serum cholesterol and are similar to the risk factors for vascular atherosclerosis. An increasing number of models of experimental hypercholesterolemia demonstrate features of atherosclerosis in the aortic valve (AV), which are similar to the early stages of vascular atherosclerotic lesions. Calcification, the end stage process of the disease, must be understood as a prognostic indicator in the modification of this cellular process before it is too late. This is important in calcific aortic stenosis as well as in rheumatic valve disease. There are a growing number of studies that describe similar pathophysiologic molecular markers in the development of rheumatic valve disease as in calcific aortic stenosis. 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 of RHD affecting the valves. This review will summarize the potential for statin therapy for this patient population.

C-Reactive protein predicts severity, progression, and prognosis of asymptomatic aortic valve stenosis

BACKGROUND

C-Reactive protein (CRP) has been shown to play a pivotal role in the pathogenesis of atherosclerosis progression. The aim of this study was to assess whether CRP predicts severity, progression, and prognosis of aortic valve stenosis (AS).

METHODS

One hundred and thirty-five patients with asymptomatic AS were studied. Patients were diagnosed as mild (n = 18, aortic valve area [AVA] > or =1.5 cm(2)), moderate (n = 57, AVA 1.0-1.49 cm(2)), or severe AS (n = 60, AVA <1.0 cm(2)) by Doppler echocardiography. Patients with serial (baseline and at 1 year) echocardiographic examination (n = 47) were grouped as either slow (n = 22, DeltaAVA <-0.15 cm(2)/y) or rapid progression group (n = 25, DeltaAVA > or =-0.15 cm(2)/y). In addition, long-term prognosis was compared between patients with low CRP (n = 68, CRP <0.15 mg/dL) and those with high CRP (n = 67, CRP > or =0.15 mg/dL).

RESULTS

Baseline CRP was significantly higher in patients with severe AS than in those with mild or moderate AS (mild AS 0.17 +/- 0.43, moderate AS 0.22 +/- 0.28, severe AS 0.53 +/- 0.66 mg/dL, P = .001). By multivariate logistic regression analysis, CRP was an independent predictor of severe AS (odds ratio 3.51, P = .015). Similarly, CRP was significantly higher in the rapid progression group than in the slow progression group (0.56 +/- 0.76 vs 0.19 +/- 0.25 mg/dL, P = .004). Furthermore, long-term survival was significantly lower in the high CRP group than in the low CRP group (log rank: P < .001).

CONCLUSION

C-Reactive protein predicts severity, progression, and prognosis in patients with asymptomatic AS.

Risk factors for progression of calcific aortic stenosis and potential therapeutic targets

Current thought regarding the progression of calcific aortic stenosis (AS) is presented. After summarizing contemporary ideas about AS pathogenesis, the present article examines the factors that may affect disease progression. Data indicate that this process may be accelerated by aortic valve structure, degree of valvular calcification, chronic renal insufficiency and cardiovascular risk factors such as diabetes and dyslipidemia. Finally, the present review discusses potential therapeutic targets to slow AS progression.

Relationship between angiotensin-converting enzyme gene polymorphism and severity of aortic valve calcification

OBJECTIVE

To investigate the role of angiotensin-converting enzyme (ACE) gene polymorphism in patients with degenerative aortic valve calcification (AVC).

PATIENTS AND METHODS

Our study consisted of 305 Turkish patients of European descent (139 male, 166 female; mean plus or minus age, 68 plus or minus 9 years) referred to our echocardiography laboratory for aortic valve evaluation between June 2, 2003, and April 29, 2005. The severity of AVC was graded from 1 to 6 by echocardiography. We used polymerase chain reaction to determine ACE gene polymorphism.

RESULTS

The ACE insertion/deletion genotype distributions for the study population were in Hardy-Weinberg equilibrium (chi square equals 3.5, P equals .18). The study population was divided into 3 groups based on the severity of AVC: those with grade 1 calcification were in group 1, those with grades 2 to 4 in group 2, and those with grades 5 to 6 in group 3. Group 1 patients were significantly younger, less likely to have hypertension and diabetes, and had higher high-density lipoprotein cholesterol levels. The genotype frequencies were significantly different among groups, with the insertion/insertion genotype being less prevalent in group 3 patients. In multivariate analysis, independent predictors of severe AVC were hypertension (odds ratio [OR], 5.6; 95% confidence interval [CI], 2.8 to 11.0; P less than .001), low high-density lipoprotein cholesterol (OR, 2.7; 95 percent CI, 1.5 to 4.9; P equals .001), and the deletion/deletion and insertion/deletion vs insertion/insertion genotype (OR, 3.2; 95 percent CI, 1.5 to 7.2; P equals .004).

CONCLUSION

These results suggest that ACE gene polymorphism may be associated with severe AVC.

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.

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.

Familial Aggregation of Calcific Aortic Valve Stenosis in the Western Part of France

BACKGROUND

Calcific aortic valve stenosis (CAVS) is the most common valvular defect in developed countries. Unlike mitral valve prolapse, there is no demonstration that a familial factor could play a role in the occurrence of this disease. The aim of this study was to demonstrate a familial aggregation for CAVS.

METHODS AND RESULTS

We used the files of 2527 consecutive patients operated on for CAVS in our institution between 1992 and 2002 to map the distribution of operated CAVS in the western part of France. In a second step, we investigated clinically and genealogically the clusters with the highest rates of operated CAVS to detect familial forms of the disease. The geographic distribution of CAVS is highly heterogeneous, with an average frequency of operated CAVS of 1.13 per 1000 inhabitants but up to 9.38 per 1000 in specific parishes. A screening of the population from the parishes with the highest rate of operated CAVS allowed us to identify 5 families with > or =3 sibs affected by CAVS. A large genealogical analysis performed in one of these families allowed us to link 48 patients who derived from 34 nuclear families. Genealogical information could be traced to a common ancestor within 13 generations.

CONCLUSIONS

Identification of clusters and large families affected by a classic form of CAVS demonstrates a familial aggregation for this disease.

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.

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.

Aortic stenosis: is it simply a degenerative process or an active atherosclerotic process?

Aortic stenosis remains the most common cause of cardiac valve replacement in developed countries. The prevalence of this condition increases with age, and many of the risk factors for coronary artery disease also appear related to the development and progression of aortic stenosis. Recent studies also suggest a relationship between calcium and lipid accumulation in both coronary artery disease and aortic stenosis. Most important, there is growing evidence that aggressive treatment of coronary artery disease risk factors, particularly hyperlipidemia, may influence the progression of aortic stenosis. In this article the current literature is reviewed as it relates to vascular biology, pathogenesis of aortic valve disease, and current and newly emerging management approaches in the care of the patient with aortic stenosis.

Lipid profile of patients with aortic stenosis might be predictive of rate of progression

BACKGROUND

Aortic stenosis is one of the most commonly encountered valvular pathology requiring surgery in developed countries. There are similarities between risk factors for coronary atherosclerosis and the development of aortic stenosis. We designed a retrospective study, evaluated the lipid profile and previous echocardiographic recordings of patients with aortic stenosis, and searched the association of rate of progression and lipid profile.

METHODS AND RESULTS

The annual rates of progression in the peak and mean aortic gradients were 8.5 +/- 3.2 and 6.7 +/- 2.2 mm Hg/year, respectively. We classified the annual rate of progression of peak aortic gradient into 2 groups, group 1 with <10 mm Hg ("slow progressors") and group 2 with > or =10 mm Hg annual rate of progression ("fast progressors"). The annual rate of progression in group 1 was significantly higher than that in group 2, both in peak and mean aortic gradients (12 +/- 2 mm Hg and 6.4 +/- 1.6 mm Hg; 9 +/- 1.3 mm Hg and 5.2 +/- 1.1 mmHg; P <.001 for both). There was a highly significant difference between group 1 and group 2 for total cholesterol/high-density lipoprotein (HDL) cholesterol level ratio (7.1 +/- 1.4 vs 5.2 +/- 1.3, P <.001). There was a significant correlation between annual rate of progression in peak gradient and total cholesterol/HDL cholesterol level ratio (r = 0.399, P =.009). Smoking (P =.024, Beta = 0.26), presence of coronary heart disease (P =.011, Beta = 0.31), and total cholesterol/HDL cholesterol level ratio (P =.004, Beta = 1.98) were independently predictive of fast progression of the peak aortic gradient in the regression analysis.

CONCLUSION

In a small group of patients from Turkey with aortic stenosis, there seems to be an association between the rate of progression and total cholesterol/HDL cholesterol level ratio, with fast progression occurring in the group with higher ratios.

Aortic valve calcification on computed tomography predicts the severity of aortic stenosis

AIM

Incidental aortic valve calcification is often detected during computed tomography. The aim was to compare the severity of valvular stenosis and calcification in patients with aortic stenosis.

MATERIALS AND METHODS

One hundred and fifty-seven patients aged 68+/-11 years (range: 34-85) with aortic valve stenosis underwent multislice helical computed tomography and Doppler echocardiography performed by independent, blinded observers. The aortic valve calcium score was determined using automated computer software calibrated with a phantom.

RESULTS

Doppler echocardiography demonstrated a post-valve velocity of 3.45+/-0.66 m/s and a peak gradient of 49+/-11 mmHg. Computed tomography showed excellent reproducibility and the median aortic valve calcium score was 5858 AU (interquartile range, 1555-14,596). The computed tomography aortic valve calcium score positively correlated with the Doppler post-valve velocity and peak gradient (r=0.54, p<0.0001 for both) of the aortic valve. All patients with severe aortic stenosis had a calcium score of >3700 AU.

CONCLUSION

Calcification of the aortic valve is closely associated with the severity of aortic stenosis, and heavy calcification suggests the presence of severe aortic stenosis that requires urgent cardiological assessment. Patients with lesser degrees of aortic valve calcification should be screened for aortic stenosis and monitored for disease progression.

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.

Hypercholesterolemic valvulopathy: an aspect of malignant atherosclerosis

Hypercholesterolemia affects not only the coronary artery, but also the aortic root, particularly the aortic valve. Aortic stenosis is critical in the prognosis for most patients with homozygous familial hypercholesterolemia (FH) and some heterozygous FH patients who result in aortic valve replacement (AVR). Histopathological examination of their valves shows lipid deposition, inflammatory cell infiltration and calcification in the aortic cusps. These pathological findings are common in non-FH patients with AVR. In homozygous FH patients, the aortic valves are injured by extreme hypercholesterolemia in a relatively short period of time, whereas in heterozygous FH patients with additional risk factors, the damage to the valves occurs over an intermediate time period. In the non-FH population with several risk factors, an underlying raised serum cholesterol level results in gradual impairment over a number of years. Aortic valvular dysfunction caused by hypercholesterolemia, which we termed hypercholesterolemic valvulopathy is recognized to be a life-threatening complication as the primary clinical characteristic of malignant atherosclerosis.

Aortic valvular disease in active patients: overcoming diagnostic and management challenges

Valvular heart disease in physically active patients can present a diagnostic challenge, because adaptations to exercise may mimic abnormalities. Electrocardiograms may be used to follow asymptomatic or mildly symptomatic athletes but are not very useful for those with valve disorders. Moderate-to-severe aortic insufficiency requires careful follow-up and periodic echocardiograms to monitor changes. Athletes with mild aortic stenosis can participate in all sports if they are asymptomatic and have a normal exercise response. Those with moderate disease should be restricted to sports with low static and dynamic requirements. Symptoms of severe aortic stenosis include exercise-induced syncope, angina, heart attack, and, rarely, sudden death; these athletes should not compete and should have aortic valve replacement.

Association of cholesterol levels, hydroxymethylglutaryl coenzyme-A reductase inhibitor treatment, and progression of aortic stenosis in the community

OBJECTIVES

This study was designed to analyze the association among cholesterol levels, lipid-lowering treatment, and progression of aortic stenosis (AS) in the community.

BACKGROUND

Aortic stenosis is a progressive disease for which there is no known medical treatment to prevent or slow progression. Despite plausible pathologic mechanisms linking hypercholesterolemia to AS progression, clinical studies have been inconsistent and affected by referral bias, and the role of lipid-lowering therapy is uncertain.

METHODS

We determined the association between blood cholesterol levels and progression of native AS (assessed by Doppler echocardiography at baseline and at least six months later; mean interval, 3.7 +/- 2.3 years) in a community-based study of 156 patients (age 77 +/- 12 years; 90 men). Thirty-eight patients received statin treatment during follow-up.

RESULTS

In untreated subjects, mean gradient increased from 22 +/- 12 mm Hg to 39 +/- 19 mm Hg, and aortic valve area (AVA) decreased from 1.20 +/- 0.35 cm(2) to 0.91 +/- 0.33 cm(2) (both p < 0.001). The annualized change in AVA was -0.09 +/- 0.17 cm(2)/year (-7% +/- 13%/year). Neither total cholesterol (r = -0.01, p = 0.92) nor low-density lipoprotein cholesterol (r = 0.01; p = 0.88) showed a significant correlation to AS progression. Nevertheless, progression of AS was slower in patients receiving statins compared with untreated patients (decrease in AVA -3 +/- 10% vs. -7 +/- 13% per year, respectively; p = 0.04), even when adjusted for age, gender, cholesterol, and baseline valve area (p = 0.04). The association of statin treatment with slower progression was confirmed when analysis was restricted to patients coming for a systematic follow-up (p=0.02). The odds ratio of AS progression with statin treatment was 0.46 (95% confidence interval, 0.21 to 0.96).

CONCLUSIONS

In the community, progression of AS shows no trend of association with cholesterol levels. Statin treatment, however, is associated with slower progression, suggesting that the effects of statin treatment on progression of AS should be pursued with appropriate clinical trials.

Detection of calcium deposits on heart valve leaflets by vibro-acoustography: an in vitro study

The presence of calcium deposits on heart valve leaflets constitutes a clinically significant diagnostic indication. A novel method for imaging and detecting calcium deposits on tissue heart valves is presented. The method, called vibro-acoustography, uses the radiation force of ultrasound to vibrate the tissue at low (kHz) frequency and records the resulting acoustic response to produce images that are related to the hardness of the tissue. The method is tested on excised human heart valve tissues. Resulting images clearly show calcium deposits with high contrast and are in agreement with the corresponding radiographs of the specimens.

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

BACKGROUND

Recent studies have supported the hypothesis that calcific aortic stenosis is the product of an active inflammatory process, with similarities to atherosclerosis. We sought to determine whether therapy with hydroxymethylglutaryl coenzyme A reductase inhibitors (statins) might slow the progression of aortic stenosis.

METHODS AND RESULTS

A retrospective study of 174 patients (mean age 68+/-12 years) with mild to moderate calcific aortic stenosis was conducted. Patients required normal left ventricular function, </=2+ aortic regurgitation, and >/=2 echocardiograms performed at least 12 months apart. Fifty-seven patients (33%) received treatment with a statin; the remaining 117 (67%) did not. The statin group was older and had a higher prevalence of hypertension, diabetes mellitus, and coronary disease. During a mean follow-up of 21 months, patients treated with statin had a smaller increase in peak and mean gradient and a smaller decrease in aortic valve area. When annualized, the decrease in aortic valve area for the nonstatin group was 0.11+/-0.18 cm(2) compared with 0.06+/-0.16 cm(2) for those treated with a statin (P=0.03). In multivariate analysis, statin usage was a significant independent predictor of a smaller decrease in valve area (P=0.01) and a lesser increase in peak gradient (P=0.02).

CONCLUSIONS

Statin-treated patients, despite a higher risk profile for progression, had reduced aortic stenosis progression compared with those not treated with a statin. These data provide justification for a prospective randomized trial to substantiate whether statin therapy slows the progression of aortic stenosis.

Predictors of cerebrovascular events and death among patients with valvular heart disease: A population-based study

BACKGROUND AND PURPOSE

There is little population-based information on cerebrovascular events and survival among valvular heart disease patients. We used the Kaplan-Meier product-limit method and the Cox proportional hazards model to determine rates and predictors of cerebrovascular events and death among valve disease patients.

METHODS

This population-based historical cohort study in Olmsted County, Minnesota, reviewed residents with a first echocardiographic diagnosis of mitral stenosis (n=19), mitral regurgitation (n=528), aortic stenosis (n=140), and aortic regurgitation (n=106) between 1985 and 1992.

RESULTS

During 2694 person-years of follow-up, 98 patients developed cerebrovascular events and 356 died. Compared with expected numbers, these observations are significantly elevated, with standardized morbidity ratio of 3.2 (95% CI, 2.6 to 3.8) and 2. 5 (95% CI, 2.2 to 2.7), respectively. Independent predictors of cerebrovascular events were age, atrial fibrillation, and severe aortic stenosis. The risk ratio of severe aortic stenosis was 3.5 (95% CI, 1.4 to 8.6), with atrial fibrillation conferring greater risk at younger age. Predictors of death were age, sex, cerebrovascular events, ischemic heart disease, and congestive heart failure, the greatest risk being among those with both congestive heart failure and cerebrovascular events (risk ratio=8.8; 95% CI, 5. 8 to 13.4). Valve disease type and severity were not independent determinants of death.

CONCLUSIONS

The risk of cerebrovascular events and death among patients with valve disease remains high. Age, atrial fibrillation, and severe aortic stenosis are independent predictors of cerebrovascular events, and age, sex, cerebrovascular events, congestive heart failure, and ischemic heart disease are independent predictors of death in these patients.

Extent and severity of atherosclerotic involvement of the aortic valve and root in familial hypercholesterolaemia

OBJECTIVE

To compare the frequency of valvar and supravalvar aortic stenosis in homozygous and heterozygous familial hypercholesterolaemia (FH).

DESIGN

Analysis of life time cholesterol exposure and prevalence of aortic atherosclerosis in 84 consecutive cases attending a lipid clinic.

SETTING

A tertiary referral centre in London.

PATIENTS

Outpatients with FH (six homozygous, 78 heterozygous).

INTERVENTIONS

Maintenance of lipid lowering treatment.

MAIN OUTCOME MEASURES

Calculated cholesterol x years score (CYS) and echocardiographic measurement of aortic root diameter, aortic valve thickness, and transaortic gradient.

RESULTS

Four homozygotes with a mean (SD) CYS of 387 (124) mmol/1 x years had severe aortic stenosis (treatment started after seven years of age), whereas the other two had echocardiographic evidence of supravalvar thickening but no aortic valve stenosis (treatment started before three years of age). On multivariate analysis, mean transaortic gradient correlated significantly with CYS (mean = 523 (175) mmol/1 x years) in heterozygotes (p = 0.0001), but only two had severe aortic valve and root involvement.

CONCLUSIONS

In patients with familial hypercholesterolaemia, aortic stenosis is common in homozygotes, and aortic root involvement is always present despite the lower CYS than in heterozygotes. It appears to be determined by short term exposure to high cholesterol concentrations in early life. Conversely, aortic root and valve involvement are rare in heterozygotes and occur only with severe, prolonged hypercholesterolaemia, possibly accelerating age related degenerative effects.