Determinants of Occurrence of Aortic Sclerosis in an Aging Population

The Associations of Aortic Valve Sclerosis, Aortic Annular Increased Reflectivity, and Mitral Annular Calcification with Subsequent Aortic Stenosis in Older Individuals: Findings from the Cardiovascular Health Study

BACKGROUND

Although aortic valve sclerosis (AVS) is well described as preceding aortic stenosis (AS), the associations of AS with antecedent mitral annular calcification (MAC) and aortic annular increased reflectivity (AAIR) have not been characterized. In a population-based prospective study, the authors evaluated whether MAC, AAIR, and AVS are associated with the risk for incident AS.

METHODS

Among participants of the Cardiovascular Health Study free of AS at the 1994-1995 visit, the presence of MAC, AAIR, AVS, and the combination of all three was evaluated in 3,041 participants. Cox proportional-hazards regression was used to assess the association between the presence of calcification and the incidence of moderate or severe AS in three nested models adjusting for factors associated with atherosclerosis and inflammation both relevant to the pathogenesis of AS.

RESULTS

Over a median follow-up period of 11.5 years (interquartile range, 6.7-17.0 years), 110 cases of incident moderate or severe AS were ascertained. Strong positive associations with incident moderate or severe AS were found for all calcification sites after adjustment for the main model covariates: AAIR (hazard ratio [HR], 2.90; 95% CI, 1.95-4.32; P < .0005), AVS (HR, 2.20; 95% CI, 1.44-3.37; P < .0005), MAC (HR, 1.67; 95% CI, 1.14-2.45; P = .008), and the combination of all three (HR, 2.50; 95% CI, 1.65-3.78; P < .0005). In a secondary analysis, the risk for AS increased with the number of sites at which calcification was present.

CONCLUSIONS

In a large cohort of community-dwelling elderly individuals, there were strong associations between each of AAIR, AVS, MAC, and the combination of the three and incident moderate or severe AS. The novel finding that AAIR had a particularly strong association with incident AS, even after adjusting for other calcification sites, suggests its value in identifying individuals at risk for AS and potential inclusion in routine assessment by transthoracic echocardiography.

Impairment of Anti-Aggregatory Responses to Nitric Oxide and Prostacyclin: Mechanisms and Clinical Implications in Cardiovascular Disease

The propensity towards platelet-rich thrombus formation increases substantially during normal ageing, and this trend is mediated by decreases in platelet responsiveness to the anti-aggregatory nitric oxide (NO) and prostacyclin (PGI₂) pathways. The impairment of soluble guanylate cyclase and adenylate cyclase-based signalling that is associated with oxidative stress represents the major mechanism of this loss of anti-aggregatory reactivity. Platelet desensitization to these autacoids represents an adverse prognostic marker in patients with ischemic heart disease and may contribute to increased thrombo-embolic risk in patients with heart failure. Patients with platelet resistance to PGI₂ also are unresponsive to ADP receptor antagonist therapy. Apart from ischemia, diabetes and aortic valve disease are also associated with impaired anti-aggregatory homeostasis. This review examines the association of impaired platelet cyclic nucleotide (i.e., cGMP and cAMP) signalling with the emerging evidence of thromboembolic risk in cardiovascular diseases, and discusses the potential therapeutic strategies targeting this abnormality.

Arterial biomarkers in the evaluation, management and prognosis of aortic stenosis

Degenerative aortic valve stenosis is the most common primary valve disease and a significant cause of cardiovascular morbidity and mortality. In an era when new techniques for the management of aortic stenosis are gaining ground, the understanding of this disease is more important than ever to optimize treatment. So far, the focus has been placed on the assessment of the valve itself. However, the role that the arterial system plays in the pathogenesis and natural history of the disease needs to be further elucidated. Arteriosclerosis, when it coexists with a stenotic valve, augments the load posed on the left ventricle contributing to greater impairment of cardiovascular function. Arterial stiffness, a well-established predictor for cardiovascular disease and all-cause mortality, could play a role in the prognosis and quality of life of this population. Several studies using a variety of indices to assess arterial stiffness have tried to address the potential utility of arterial function assessment in the case of aortic stenosis. Importantly, reliable data identify a prognostic role of arterial biomarkers in aortic stenosis and stress their possible use to optimize timing and method of treatment. This review aims at summarizing the existing knowledge on the interplay between the heart and the vessels in the presence of degenerative aortic stenosis, prior, upon and after interventional management. Further, it discusses the evidence supporting the potential clinical application of arterial biomarkers for the assessment of progression, severity, management and prognosis of aortic stenosis.

Stenosis coexists with compromised α1-adrenergic contractions in the ascending aorta of a mouse model of Williams-Beuren syndrome

Williams-Beuren syndrome (WBS) is a rare disorder caused by a heterozygous deletion of 26–28 contiguous genes that affects the brain and cardiovascular system. Here, we investigated whether WBS affects aortic structure and function in the complete deletion (CD) mouse model harbouring the most common deletion found in WBS patients. Thoracic aortas from 3–4 months-old male CD mice and wild-type littermates were mounted in wire myographs or were processed for histomorphometrical analysis. Nitric oxide synthase (NOS) isoforms and oxidative stress levels were assessed. Ascending aortas from young adult CD mice showed moderate (50%) luminal stenosis, whereas endothelial function and oxidative stress were comparable to wild-type. CD mice showed greater contractions to KCl. However, α1-adrenergic contractions to phenylephrine, but not with a thromboxane analogue, were compromised. Decreased phenylephrine responses were not affected by selective inducible NOS blockade with 1400 W, but were prevented by the non-selective NOS inhibitor L-NAME and the selective neuronal NOS inhibitor SMTC. Consistently, CD mice showed increased neuronal NOS expression in aortas. Overall, aortic stenosis in CD mice coexists with excessive nNOS-derived NO signaling that compromises ascending aorta α1-adrenergic contractions. We suggest that increased neuronal NOS signaling may act as a physiological ‘brake’ against the detrimental effects of stenosis.

New Developments in Platelet Cyclic Nucleotide Signalling: Therapeutic Implications

Altered platelet physiology may contribute to the emergence of thrombosis in patients with many forms of cardiovascular disease. Excess platelet activation may reflect increased stimulation of pro-aggregatory pathways. There is, however, increasing evidence that excessive platelet response, due to impaired efficacy of anti-aggregatory autacoids such as nitric oxide (NO) and prostacyclin (PGI₂), may be just as important. For example, diminished platelet response to NO has been documented in acute and chronic myocardial ischaemia, heart failure, aortic valve disease and in the presence of hyperglycaemia. This "NO resistance" has been shown to reflect both the scavenging of NO by reactive oxygen species and dysfunction of its intracellular "receptor", soluble guanylate cyclase. Importantly, these abnormalities of NO signalling are potentially reversible through judicious application of pharmacotherapy. The analogous condition of impaired PGI₂/adenylate cyclase (AC) signalling has received comparatively less attention to date. We have shown that platelet response to prostaglandin E₁ (PGE₁) is frequently impaired in patients with symptomatic myocardial ischaemia. Because the effects of ADP receptor antagonists such as clopidogrel and ticagrelor at the level of the P2Y₁₂ receptor are coupled with changes in activity of AC, impaired response to PGE₁ might imply both increased thrombotic risk and a reduced efficacy of anti-aggregatory drugs. Accordingly, patient response to treatment with clopidogrel is determined not only by variability of clopidogrel bio-activation, but also extensively by the integrity of platelet AC signalling. We here review these recent developments and their emerging therapeutic implications for thrombotic disorders.

Echocardiographic Approaches and Protocols for Comprehensive Phenotypic Characterization of Valvular Heart Disease in Mice

The aim of this manuscript and accompanying video is to provide an overview of the methods and approaches used for imaging heart valve function in rodents, with detailed descriptions of the appropriate methods for anesthesia, the echocardiographic windows used, the imaging planes and probe orientations for image acquisition, the methods for data analysis, and the limitations of emerging technologies for the evaluation of cardiac and valvular function. Importantly, we also highlight several future areas of research in cardiac and heart valve imaging that may be leveraged to gain insights into the pathogenesis of valve disease in preclinical animal models. We propose that using a systematic approach to evaluating cardiac and heart valve function in mice can result in more robust and reproducible data, as well as facilitate the discovery of previously underappreciated phenotypes in genetically-altered and/or physiologically-stressed mice.

Markers of subclinical atherosclerosis in patients with aortic valve sclerosis: A meta-analysis of literature studies

OBJECTIVE

Growing evidence suggested an association between aortic valve sclerosis (AVSc) and cardiovascular (CV) events. However, little is known about the association of AVSc with major markers of subclinical atherosclerosis. We performed a meta-analysis of literature studies to address this issue.

METHODS

Studies on the relationship between AVSc and common carotid artery intima-media thickness (IMT), prevalence of carotid plaques (CPs), flow-mediated dilation (FMD), aortic pulse wave velocity (PWV) and augmentation index (AIx) were systematically searched in electronic databases. Thirteen studies enrolling 1086 AVSc patients and 2124 controls were included.

RESULTS

Compared to controls, AVSc patients showed higher IMT (MD: 0.32mm; 95%CI: 0.07, 0.58; p=0.014), and higher prevalence of CPs (OR: 4.06; 95%CI: 2.38, 6.93; p<0.001). Moreover, lower FMD (MD: -4.48%; 95%CI: -7.23, -1.74; p=0.001) and higher PWV (MD: 0.96%; 95%CI: 0.11, 1.81; p=0.027) were found in AVSc subjects than in controls, with no differences in AIx (MD: 0.76%; 95%CI: -0.97, 2.49; p=0.389). In meta-regression analyses, body mass index and triglyceride levels have an impact on the difference in IMT between cases and controls, while male gender and smoking habit were associated with the difference in the prevalence of CPs between the two groups.

CONCLUSIONS

AVSc is significantly associated with altered markers of subclinical atherosclerosis, thus supporting the concept that AVSc and atherosclerosis share common etiopathological mechanism and/or risk factors.

Quantification of Aortic Valve Calcifications Detected During Lung Cancer-Screening CT Helps Stratify Subjects Necessitating Echocardiography for Aortic Stenosis Diagnosis

No study has been published on aortic valve calcification (AVC) extent at lung cancer screening low-dose CT (LDCT) and its relationship with aortic stenosis (AS). The purpose of this study was to estimate the cutoff value of AVC on LDCT for detecting AS in asymptomatic Asian subjects. Six thousand three hundred thirty-eight subjects (mean age, 55.9 years ± 8.6) self-referred to health-promotion center underwent LDCT, coronary calcium scoring CT (CSCT), and echocardiography. AVC was quantified using Agatston methods on CT. AVC extent on LDCT was compared with that on CSCT, and AVC threshold for diagnosing AS was calculated. Clinical factors associated with AS and AVC were sought.AVC was observed in 403 subjects (64.9 years ± 8.7) on LDCT (6.4%), and AVC score measured from LDCT showed strong positive correlation with that from CSCT (r = 0.83, P < 0.0001). Of 403 subjects, 40 (10%) were identified to have AS on echocardiography. Cutoff value of AVC score for detecting AS was 138.37 with sensitivity of 90.0% and specificity 83.2%. On multivariate analysis, age (odds ratio [OR] = 1.10, 95% CI: 1.09-1.12) and hypertension (OR = 1.39, 95% CI: 1.10-1.76) were associated with the presence of AVC, whereas AVC extent at LDCT (OR = 104.32, 95% CI: 16.16-673.70) was the only significant clinical factor associated with AS; AVC extent on LDCT (OR = 104.32, 95% CI: 16.16-673.70) was the significant clinical factor associated with AS.The AVC extent on LDCT is significantly related to the presence of AS, and we recommend echocardiography for screening AS based on quantified AVC values on LDCT.

Arterial wave reflection and aortic valve calcification in an elderly community-based cohort

BACKGROUND

Aortic valve calcification (AVC) without stenosis is common in the elderly, is associated with cardiovascular morbidity and mortality, and may progress to aortic valve stenosis. Arterial stiffness and pulse-wave reflection are important components of proximal aortic hemodynamics, but their relationship with AVC is not established.

METHODS

To investigate the relationship of arterial wave reflection and stiffness with AVC, pulse wave analysis and AVC evaluation by echocardiography were performed in 867 participants from the Cardiovascular Abnormalities and Brain Lesions study. Participants were divided into four categories on the basis of the severity and extent of AVC: (1) none or mild focal AVC, (2) mild diffuse AVC, (3) moderate to severe focal AVC, and (4) moderate to severe diffuse AVC. Central blood pressures and pulse pressure, total arterial compliance, augmentation index, and time to wave reflection were assessed using applanation tonometry.

RESULTS

Indicators of arterial stiffness and wave reflection were significantly associated with AVC severity, except for central systolic and diastolic pressures and time to reflection. After adjustment for pertinent covariates (age, sex, race/ethnicity, and estimated glomerular filtration rate), only augmentation pressure (P = .02) and augmentation index (P = .002) were associated with the severity of AVC. Multivariate logistic regression analysis revealed that augmentation pressure (odds ratio per mm Hg, 1.14; 95% confidence interval, 1.02-1.27; P = .02) and augmentation index (odds ratio per percentage point, 1.07; 95% confidence interval, 1.01-1.13; P = .02) were associated with an increased risk for moderate to severe diffuse AVC, even when central blood pressure value was included in the same model.

CONCLUSIONS

Arterial wave reflection is associated with AVC severity, independent of blood pressure values. Increased contribution of wave reflection to central blood pressure could be involved in the process leading to AVC.

Diagnosis and management of valvular aortic stenosis

Valvular aortic stenosis (AS) is a progressive disease that affects 2% of the population aged 65 years or older. The major cause of valvular AS in adults is calcification and fibrosis of a previously normal tricuspid valve or a congenital bicuspid valve, with rheumatic AS being rare in the United States. Once established, the rate of progression of valvular AS is quite variable and impossible to predict for any particular patient. Symptoms of AS are generally insidious at onset, though development of any of the three cardinal symptoms of angina, syncope, or heart failure portends a poor prognosis. Management of symptomatic AS remains primarily surgical, though transcatheter aortic valve replacement (TAVR) is becoming an accepted alternative to surgical aortic valve replacement (SAVR) for patients at high or prohibitive operative risk.

Aging of the nitric oxide system: are we as old as our NO?

Background

Impaired generation and signaling of nitric oxide (NO) contribute substantially to cardiovascular (CV) risk (CVR) associated with hypertension, hyperlipidemia, and diabetes mellitus. In our rapidly aging society, advanced age is, in itself, a consistent and independent CVR factor. Many processes involved in aging are modulated by NO. We therefore postulated that aging might be independently associated with impaired NO signaling.

Methods and Results

In a prospective cohort study of 204 subjects (mean age 63±6 at study entry), we evaluated the effects of 4 years of aging on parameters of NO generation and effect, including platelet aggregability and responsiveness to NO, and plasma concentrations of the NO synthase inhibitor, asymmetric dimethylarginine (ADMA). Clinical history, lipid profile, high‐sensitivity C‐reactive protein, routine biochemistry, and 25‐hydroxyvitamin D levels were obtained at study entry and after 4 years of follow‐up. Aging was associated with marked deterioration of responsiveness of platelets to NO (P<0.0001) and increases in plasma ADMA concentrations (P<0.0001). There was a significant correlation between changes in these parameters over time (r=0.2; P=0.013). On multivariable analyses, the independent correlates of deterioration of responsiveness of platelets to NO were female gender (β=0.17; P=0.034) and low vitamin D concentrations (β=0.16; P=0.04), whereas increases in ADMA were associated with presence of diabetes (β=0.16; P=0.03) and impaired renal function (β=0.2; P=0.004).

Conclusions

Aging is associated with marked impairment of determinants of NO generation and effect, to an extent which is commensurate with adverse impact on CV outcomes. This deterioration represents a potential target for therapeutic interventions.

The prevalence, incidence, progression, and risks of aortic valve sclerosis: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to comprehensively review the epidemiology of aortic sclerosis (ASc) and its association with cardiovascular events.

BACKGROUND

ASc, which is defined as thickening or calcification of the aortic valve without significant obstruction of blood flow, is a common finding on cardiac imaging.

METHODS

We searched MEDLINE and EMBASE from inception to April 2013 for studies describing the epidemiology of ASc and performed a meta-analysis of the risk of adverse events using a random effects model.

RESULTS

Twenty-two studies were identified from the systematic review. The prevalence of ASc increased in proportion to the average age of study participants, ranging from 9% in a study in which the mean age was 54 years to 42% in a study in which the mean age was 81 years. In total, 1.8% to 1.9% of participants with ASc had progression to clinical aortic stenosis per year. There was a 68% increased risk of coronary events in subjects with ASc (hazard ratio [HR]: 1.68; 95% confidence interval [CI]: 1.31 to 2.15), a 27% increased risk of stroke (HR: 1.27; 95% CI: 1.01 to 1.60), a 69% increased risk of cardiovascular mortality (HR: 1.69; 95% CI: 1.32 to 2.15), and a 36% increased risk of all-cause mortality (HR: 1.36; 95% CI: 1.17 to 1.59).

CONCLUSIONS

ASc is a common finding that is more prevalent with older age. Despite low rates of progression to ASc, there is an independent increase in morbidity and mortality associated with the condition.

The living aortic valve: From molecules to function

The aortic valve lies in a unique hemodynamic environment, one characterized by a range of stresses (shear stress, bending forces, loading forces and strain) that vary in intensity and direction throughout the cardiac cycle. Yet, despite its changing environment, the aortic valve opens and closes over 100,000 times a day and, in the majority of human beings, will function normally over a lifespan of 70–90 years. Until relatively recently heart valves were considered passive structures that play no active role in the functioning of a valve, or in the maintenance of its integrity and durability. However, through clinical experience and basic research the aortic valve can now be characterized as a living, dynamic organ with the capacity to adapt to its complex mechanical and biomechanical environment through active and passive communication between its constituent parts. The clinical relevance of a living valve substitute in patients requiring aortic valve replacement has been confirmed. This highlights the importance of using tissue engineering to develop heart valve substitutes containing living cells which have the ability to assume the complex functioning of the native valve.

Link between aortic valve sclerosis and myocardial no-reflow in ST-segment elevation myocardial infarction

OBJECTIVE

The"no-reflow" phenomenon is associated with a worse prognosis at follow-up for patients with acute ST-segment elevation myocardial infarction (STEMI). Predicting and preventing no-reflow is therefore a crucial step in improving the prognosis of STEMI patients. The purpose of this study was to investigate the association between aortic valve sclerosis (AVS) and myocardial no-reflow in patients with STEMI.

PATIENTS AND METHODS

Patients with a first-time diagnosis of STEMI were enrolled consecutively. No-reflow was defined as a final TIMI 3 flow with a myocardial blush of grade < 2, temporary epicardial coronary no-reflow, and distal coronary occlusion. AVS was defined by echocardiography as thickening and calcification of the normal trileaflet aortic valve without obstruction to the left ventricular outflow.

RESULTS

No-reflow developed in 41 patients. In univariate analysis, age, male gender, smoking, culprit lesion Syntax score (SX score), and hypertension were significantly associated with no-reflow. Multivariate binary logistic regression analyses demonstrated age [95 % confidence interval (CI), 1.024-1.096; p=0.001), AVS (95 % CI, 1.002-1.100; p=0.039], culprit lesion SX score (95 % CI, 1.08-1.021 p=0.008), and symptom-to-balloon time (95 % CI, 1.020-1.097; p=0.002) as independent determinants of myocardial no-reflow.

CONCLUSION

AVS was significantly and independently associated with myocardial no-reflow in STEMI patients.

Mitral and aortic valve sclerosis/calcification and carotid atherosclerosis: results from 1065 patients

This study assesses whether aortic valve sclerosis (AVS) and mitral annulus calcification (MAC) are associated with carotid artery atherosclerosis, independently of traditional cardiovascular risk factors. A total of 1065 patients underwent both echocardiography and carotid artery ultrasound scanning. AVS and MAC were defined as focal areas of increased echogenicity and thickening of the aortic leaflets or mitral valve annulus. Carotid artery atherosclerosis was defined as presence/absence of any atherosclerotic plaque or presence/absence of plaque >50 %. Of 1065 patients (65 ± 9 years; 38 % female) who comprised the study population, 642 (60 %) had at least one atherosclerotic plaque. AVS, but not mitral valve sclerosis; was associated with the presence of carotid atherosclerosis (odds ratio (OR) 1.9, 95 % confidence interval (CI) 1.2-3.9; P = 0.005) and the degree of carotid atherosclerosis (OR 2.1, 95 % CI 1.2-3.9; P = 0.01) in a multivariate model including age, gender, previous ischemic heart disease, hypertension, dyslipidemia, smoking, diabetes, family cardiovascular history, left ventricular size, mass, and ejection fraction, and left atrial size. AVS is a significant predictor of carotid atherosclerosis, independently of other cardiovascular clinical and echocardiographic risk factors.

Pooled estimates of immediate and late outcome of mitral valve surgery in octogenarians: a meta-analysis and meta-regression

OBJECTIVE

The authors evaluated the outcome of patients≥80 years undergoing mitral valve (MV) surgery.

DESIGN

Systematic review of the literature and meta-analysis.

SETTING

None.

PARTICIPANTS

None.

INTERVENTIONS

None.

MAIN RESULTS

Twenty-four studies reporting on 5,572 patients ≥80 years of age who underwent MV surgery were included in this analysis. Pooled proportion of operative mortality was 15.0% (95% confidence interval [CI] 11.9-18.1), stroke was 3.9% (95% CI 2.6-5.2), and dialysis was 2.7% (95% CI 0.5-4.9). Early date of study (p = 0.014), increased age (p = 0.006), MV replacement (p = 0.008), procedure other than isolated MV surgery (p = 0.010), MV surgery associated with coronary artery surgery (p = 0.029), aortic cross-clamping time (p<0.001), and cardiopulmonary bypass time (p<0.001) were associated significantly with increased operative mortality. MV repair had lower operative mortality compared with MV replacement (7.3% v 14.2%, relative risk 0.573, 95% CI 0.342-0.962). Random-effects metaregression showed that prolonged aortic cross-clamping time (p = 0.005) was the only determinant of increased operative mortality, even when adjusted (p<0.001) for date of study (p = 0.004). Operative mortality was significantly higher in studies reporting a mean cross-clamp time >90 minutes (17.0% v 7.4%, p<0.001). Survival rates at 1, 3, and 5 years were 76.1%, 67.7%, and 56.5%, respectively.

CONCLUSIONS

MV surgery in patients ≥80 years of age is associated with operative mortality, which has decreased significantly during recent years. Prolonged aortic cross-clamp time is a major determinant of operative mortality. MV repair may achieve better results than MV replacement in the very elderly. Five-year survival of these patients is good and justifies surgical treatment of MV diseases in octogenarians.

HEART AND AGE (PART II): CLINICAL MANIFESTATIONS OF AGEING

Ageing is an inevitable process which affects quality of life and reduces life expectancy. Age-related cardiac changes reduce compensatory reserves of the heart and accelerate the disease development. Such changes in cardiac structure and function, observed in the absence of cardiovascular disease (CVD), are considered age-related. However, taking into account the high prevalence of CVD in the elderly, it is problematic to define the genuine cardiac ageing. This review discusses a range of subclinical cardiac conditions which are common in older people. 

Outcome of patients aged ≥80 years undergoing combined aortic valve replacement and coronary artery bypass grafting: a systematic review and meta-analysis of 40 studies

AIM

This study was planned to evaluate the outcome of patients aged ≥80 years undergoing combined conventional aortic valve replacement (AVR) and coronary artery bypass grafting (CABG).

METHODS

This is a systematic review of the literature and meta-analysis of data on patients aged ≥80 years who underwent combined AVR and CABG.

RESULTS

The literature search yielded 40 observational studies reporting on 8,975 patients aged ≥80 years. Pooled proportion of immediate postoperative mortality was 9.7% (95% CI 8.4-11.1, 40 studies, 8,975 patients). Immediate mortality was 8.2% (95% CI 6.5-10.0) in 15 studies with a mid-date from 2000 to 2007 and 10.8% (95% CI 9.1-12.7) in 25 studies with a mid-date from 1982 to 1999 (P = .043). Postoperative stroke rate was 3.7% (95% CI 2.8-4.8, 12 studies, 2,770 patients), and postoperative implantation of pacemaker was 4.3% (95% CI 2.6-6.5, 5 studies, 535 patients). The mean length of stay in intensive care unit was 5.3 days (95% CI 3.3-7.3, 5 studies, 490 patients), and the mean length of in-hospital stay was 16.9 days (95% CI 12.4-21.4, 5 studies, 424 patients). One-, 3-, 5- and 10-year pooled survival rates after combined AVR and CABG were 83.2%, 72.9%, 60.8%, and 25.7%, respectively.

CONCLUSIONS

Conventional AVR and CABG in patients aged ≥80 years are associated with significant operative mortality and morbidity as well as prolonged in-hospital treatment. However, conventional surgery is associated with remarkably good late survival. This suggests that any alternative treatment modality must prove itself of being enough durable also in the very elderly.

Prevalence of calcific aortic valve disease in the elderly and associated risk factors: a population-based study in a Mediterranean area

AIMS

To determine the prevalence of aortic valve sclerosis (ASC) and stenosis (AS) in the elderly in a Mediterranean area and to identify associated clinical factors.

METHODS AND RESULTS

Population cross-sectional study in a random sample of 1068 people ≥65 years in a Mediterranean area. ASC was categorized as absent, mild-to-moderate, or moderate-to-severe depending on the severity of thickening and calcification. The relation between the severity of ASC and potential risk factors was assessed by multinomial logistic regression analysis. Some degree of thickening and/or calcification was present in 45.4%, of the sample, 73.5% in >85 years. AS prevalence was 3% for the total cohort and 7.4% in >85 years. Adjusting for gender it was found that age, smoking habit, hypertension, waist circumference, and ankle-brachial index <0.9 were associated with degrees of ASC. Except for waist circumference, there was a gradient between the magnitude of association and the severity of ASC. The OR for age was 1.56 (95% CI 1.39-1.76) for mild-to-moderate ASC and 2.03 (95% CI 1.72-2.4) for moderate-to-severe ASC, and for smoking habit 1.59 (95% CI 1.08-2.34) for mild-to-moderate ASC and 2.13 (95% CI 1.19-3.78) for moderate-to-severe ASC. Diabetes and renal impairment were associated with advanced but not with early stages of ASC.

CONCLUSIONS

The prevalence of ASC and AS in people ≥65 years is similar to that reported in other regions. The gradient in the association of cardiovascular risk factors with the severity of ASC suggests that they may be causally implied in the pathogenesis of the disease.

Predictors of echocardiographic progression in patients with mild aortic stenosis

Background and Objectives

The factors related to the progression of mild aortic stenosis (AS) remain unknown. We wanted to evaluate the long-term outcomes and predictors of echocardiographic progression in patients with mild AS.

Subjects and Methods

We prospectively included 103 consecutive asymptomatic patients (62.1±11.9 years, 31 males) with mild AS. Mild AS was defined as aortic valve (AV) thickening accompanied by a peak aortic jet velocity (AV Vmax) ≥2.0 and <3.0 m/sec, and rapid progression of AS was defined as an average annual increase in the AV Vmax ≥0.2 m/sec, and cardiac events were defined as cardiac death or AV replacement.

Results

During a median echocardiographic follow-up time of 6.0 years, the average change in the AV Vmax was 0.08±0.10 m/sec per year. The rate of progression was significantly associated with age, moderate-to-severe AV calcification and the baseline AV Vmax, but not with the serum cholesterol level. The baseline AV Vmax (2.6±0.3 m/sec vs. 2.2±0.3 m/sec, respectively, p<0.001) and the incidence of moderate-to-severe AV calcification (92.9% vs. 36.5%, respectively, p<0.001) were significantly higher in the rapid progression group than in the slow progression group. The 7-year cardiac event-free survival rate was lower in the rapid progression group than in the slow pro-gression group (87.5±8.3% vs. 100%, respectively).

Conclusion

The progression of AS was slower than expected and it was related to age, the baseline AV Vmax and AV calcification. Because of the marked individual variability in progression, the patients showing rapid progression of AS need closer follow-up.

Ramipril retards development of aortic valve stenosis in a rabbit model: mechanistic considerations

BACKGROUND AND PURPOSE

Aortic valve stenosis (AVS) is associated with significant cardiovascular morbidity and mortality. To date, no therapeutic modality has been shown to be effective in retarding AVS progression. We evaluated the effect of angiotensin-converting enzyme inhibition with ramipril on disease progression in a recently developed rabbit model of AVS.

EXPERIMENTAL APPROACH

The effects of 8 weeks of treatment with either vitamin D₂ at 25,000 IU for 4 days a week alone or in combination with ramipril (0.5 mg·kg⁻¹) on aortic valve structure and function were examined in New Zealand white rabbits. Echocardiographic aortic valve backscatter (AV(BS)) and aortic valve:outflow tract flow velocity ratio were utilized to quantify changes in valve structure and function.

KEY RESULTS

Treatment with ramipril significantly reduced AV(BS) and improved aortic valve :outflow tract flow velocity ratio. The intravalvular content of the pro-oxidant thioredoxin-interacting protein was decreased significantly with ramipril treatment. Endothelial function, as measured by asymmetric dimethylarginine concentrations and vascular responses to ACh, was improved significantly with ramipril treatment.

CONCLUSIONS AND IMPLICATIONS

Ramipril retards the development of AVS, reduces valvular thioredoxin-interacting protein accumulation and limits endothelial dysfunction in this animal model. These findings provide important insights into the mechanisms of AVS development and an impetus for future human studies of AVS retardation using an angiotensin-converting enzyme inhibitor.

Aortic valve sclerosis and clinical outcomes: moving toward a definition

The presence of aortic valve sclerosis has been suggested as a marker of increased cardiovascular risk, including increased mortality. However, it remains unclear whether aortic valve sclerosis is independently associated with risk or merely a marker of coexistent cardiovascular risk factors. Aortic valve sclerosis is usually diagnosed on transthoracic echocardiography, the most widely used imaging modality in observational and natural history studies of aortic valve disease. Defining aortic valve sclerosis has remained challenging due to the variable and qualitative nature of its description by ultrasound techniques. Importantly, artifacts common to ultrasound imaging and awareness of demographic and clinical history information may bias the diagnosis of aortic valve sclerosis. Because clinicians may alter treatment recommendations or follow-up based on echocardiographic reporting of aortic valve sclerosis, highlighting pitfalls of the subjective nature by which aortic valve sclerosis is identified and establishing diagnostic criteria are necessary. This review describes the diagnostic criteria for aortic valve sclerosis used in outcome studies, summarizes the epidemiological findings reporting the relationship between aortic valve sclerosis and clinical outcome, and proposes a definition of aortic valve sclerosis based on the literature.

Aortic valve disease: preventable or inevitable?

Calcific aortic valve stenosis is the most frequent valve disease and the most common cause of aortic valve replacement in the western world, concomitant with aging of the general population and habitual consumption of a high-calorie diet. For years it was considered to be a passive wear and tear process but now it is recognized as an active process similar to atherosclerosis with involvement of several mediators, such as adhesion molecules, TGFs, cathepsin enzymes and bone regulatory proteins. As conviction grew that aortic stenosis has a genesis similar to atherosclerosis, the hypothesis that statins might be able to alter the progression of the disease also grew. Various retrospective studies confirmed the benefits of statin use at an earlier stage of the disease, but some disappointing results were demonstrated by randomized clinical trials.

Does vitamin D modulate asymmetric dimethylarginine and C-reactive protein concentrations?

BACKGROUND

Vitamin D deficiency is associated with significant increases in the incidence of cardiovascular risk factors and mortality. However, the mechanisms underlying this association remain unclear. The current study evaluated the possible relationships among vitamin D status, endothelial dysfunction, and inflammation.

METHODS

Plasma concentrations of 25-hydroxyvitamin D(3) were determined by radioimmunoassay in a normal population cohort (n=253) aged 51 to 77 years (mean 63.4+/-6 years). Asymmetric dimethylarginine, a marker/mediator of endothelial dysfunction, was assayed by high-performance liquid chromatography. High-sensitivity C-reactive protein levels were used as a marker of inflammatory activation.

RESULTS

On univariate analyses, low 25-hydroxyvitamin D(3) levels were inversely correlated with asymmetric dimethylarginine concentrations, high-sensitivity C-reactive protein levels, and body mass index. Seasonal fluctuations in 25-hydroxyvitamin D(3) levels were associated with reciprocal asymmetric dimethylarginine concentration fluctuations. Hypertension and treatment with an angiotensin-converting enzyme inhibitor/angiotensin receptor blocker also were associated with low 25-hydroxyvitamin D(3) levels. On multiple linear analysis, both asymmetric dimethylarginine (beta=-0.19, P=.003) and high-sensitivity C-reactive protein (beta=-0.14, P=.03) concentrations were inversely correlated with plasma 25-hydroxyvitamin D(3) concentrations; other significant correlates were male gender (beta=0.19, P=.003), calcium levels (beta=0.14, P=.03), and use of angiotensin-converting enzyme inhibitor (beta=-0.17, P=.007).

CONCLUSION

Low 25-hydroxyvitamin D(3) levels are associated with markers of endothelial dysfunction and inflammatory activation, representing potential mechanisms for incremental coronary risk.

Lack of association between aortic sclerosis and left ventricular hypertrophy in elderly subjects

BACKGROUND

The presence of aortic sclerosis has been associated with increased LV mass, particularly in hypertensive subjects. However, aortic sclerosis has also been associated with endothelial dysfunction, which may provide stimuli for development of left ventricular hypertrophy independent of afterload. Thus, we have sought to determine whether aortic sclerosis is a determinant of increased left ventricular mass in a non-hypertensive cohort of aging subjects.

METHODS

79 subjects, mean age 68 ± 6 years, without existing cardiovascular disease or previous antihypertensive therapy were studied. LV volumes were calculated from the short axis stack of cardiac MRI and LV mass was indexed to height(2.7). The presence of aortic sclerosis was assessed with echocardiography using backscatter from the aortic valve (AV(BS)) and visual scoring. Plasma asymmetric dimethylarginine levels and vascular responses to salbutamol were used to assess endothelial function. ANCOVA was used to test the relationship between LV mass index and afterload. Univariate and multivariate analyses were performed to find determinants of increased LV mass.

RESULTS

15 (19%) of subjects had aortic sclerosis on the basis of AV(BS); none had aortic valve areas <1.5 cm(2). There was no significant difference in LV mass between subjects with and without aortic sclerosis. While LV mass was directly related to systolic blood pressure, this relationship was independent of the presence/absence of aortic sclerosis. On multivariate analysis, significant correlates of increased LV mass were male gender, systolic blood pressure and increased BMI, but not presence of aortic sclerosis.

CONCLUSIONS

In this aging normotensive population free of established cardiovascular disease, aortic sclerosis is not associated with left ventricular hypertrophy.