Aortic sclerosis--a marker of coronary atherosclerosis

Aort Kapak Sklerozunun Öngörülmesinde Yeni Hematolojik İnflamatuar Parametrelerin Önemi

Aim: Inflammatory process plays a critical role in the progression of aortic valve sclerosis (AVS). This study aims to evaluate the haematological and biochemical inflammatory markers in AVS patients.Methods: A retrospective observational study was included consecutive 557 patients who underwent an echocardiogram between June 2021 and September 2021. The study population was divided into two groups according to the presence of AVS. The groups were compared in terms of C-reactive protein (CRP), Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and monocyte-HDL cholesterol ratio (MHR).Results: The mean age was 63 ± 10 years. C-reactive protein (CRP), NLR, PLR and MHR were significantly higher in patients with AVS. The best cut-off values of the NLR were 1.4 (a sensitivity of 84%, a specificity of 74%), PLR was 116 (a sensitivity of 75%, a specificity of 54%), and MHR was 9.5 (a sensitivity of 78%, a specificity of 75%). CRP (OR: 1.246, 95% CI: 1.117 – 1.389; p < 0.001), NLR (OR: 2.10, 95% CI: 1.456 – 3.032; p < 0.001), and MHR (OR: 1.227, 95% CI: 1.125 – 1.339; p < 0.001) were independent predictors of the AVS when NLR and MHR analysed as a continuous variable. Using a cut off level of NLR > 1.4 (OR: 4.825, 95% CI: 2.430 – 9.583; p < 0.001) and MHR > 9.5 (OR: 13.937, 95% CI: 7.464 – 26.023; p < 0.001) were independent predictors of the AVS.Conclusion: Increased CRP levels, NLR and MHR were found to be independent predictors for AVS. Hematological inflammatory biomarkers are cost effective and helpful approach for prediction of AVS presence.

Proteomics Analysis Reveals Diverse Molecular Characteristics between Endocardial and Aortic-Valvular Endothelium

The variations in the protein profile of aortic-valvular (AVE) and endocardial endothelial (EE) cells are currently unknown. The current study's objective is to identify differentially expressed proteins and associated pathways in both the endothelial cells. We used endothelial cells isolated from the porcine (Sus scrofa) aortic valve and endocardium for the profiling of proteins. Label-free proteomics was performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Our proteomics analysis revealed that 29 proteins were highly expressed, and 25 proteins were less expressed in the valve than the endocardial endothelium. The cell surface markers, such as CD63, ICAM1, PECAM1, PROCR, and TFRC, were highly expressed in EE. In contrast, CD44 was highly expressed in AVE. The pathway analysis showed that metabolic process-related proteins and extracellular matrix-related proteins were enriched in valves. Differential enrichment of signaling pathways was observed in the endocardium. The hemostasis function-related proteins were increased in both endothelial cells. The proteins and pathways enriched in aortic-valvular and endocardial endothelial cells revealed the distinct phenotype of these two closely related cells.

Risk factors associated with valvular calcification in patients with chronic kidney disease. Analysis of NEFRONA study

INTRODUCTION

Patients with chronic kidney disease (CKD) are at high risk of cardiovascular morbidity and mortality. Subclinical cardiac structural alterations have prognostic value in these patients. The aim was to analyse the prevalence of valvular calcification, the evolution and the relationship with different risk factors.

MATERIAL AND METHODS

Part of the sample of the NEFRONA study was randomly selected. Aortic and mitral valve calcification were analysed in echocardiograms performed at the baseline visit and at 24 months.

RESULTS

We included 397 patients, the estimated basal glomerular filtrate (eGFR) was 33 ml/min with significant decrease to 30.9 ml/min. There was an increase in the area of carotid and femoral plaque, as well as an increase in patients with aortic and mitral calcification at 24 months. A positive association of mitral calcification at 24 months with age, ankle-brachial index (ABI) and calcium-phosphorus product (CaxP) at baseline visit was observed, without association with eGFR. Aortic calcification at 24 months was positively associated with age, phosphorous and total carotid plaque area at baseline, with no relationship to eGFR.

CONCLUSIONS

A significant prevalence of valvular calcification was observed in patients with CKD without known cardiovascular disease.Two-year progression was observed independently of the eGFR. Patients with higher risk of mitral valve calcification were those with older age, higher ABI and CaxP product. Patients with a higher risk of aortic calcification were those with older age, higher phosphorous levels and larger area of carotid plaque. Identifying these higher risk patients would help to avoid future cardiovascular events intensifying follow-ups.

[Risk factors associated with valvular calcification in patients with chronic kidney disease. Analysis of NEFRONA Study]

INTRODUCTION

Patients with chronic kidney disease (CKD) are at high risk of cardiovascular morbidity and mortality. Subclinical cardiac structural alterations have prognostic value in these patients. The aim was to analyse the prevalence of valvular calcification, the evolution and the relationship with different risk factors.

MATERIAL AND METHODS

Part of the sample of the NEFRONA study was randomly selected. Aortic and mitral valve calcification were analysed in echocardiograms performed at the baseline visit and at 24 months.

RESULTS

We included 397 patients, the estimated basal glomerular filtrate (eGFR) was 33ml/min with significant decrease to 30.9ml/min. There was an increase in the area of carotid and femoral plaque, as well as an increase in patients with aortic and mitral calcification at 24 months. A positive association of mitral calcification at 24 months with age, ankle-brachial index (ABI) and calcium-phosphorus product (CaxP) at baseline visit was observed, without association with eGFR. Aortic calcification at 24 months was positively associated with age, phosphorous and total carotid plaque area at baseline, with no relationship to eGFR.

CONCLUSIONS

A significant prevalence of valvular calcification was observed in patients with CKD without known cardiovascular disease.Two-year progression was observed independently of the eGFR. Patients with higher risk of mitral valve calcification were those with older age, higher ABI and CaxP product. Patients with a higher risk of aortic calcification were those with older age, higher phosphorous levels and larger area of carotid plaque. Identifying these higher risk patients would help to avoid future cardiovascular events intensifying follow-ups.

Clinical characteristics, microbiology, and outcomes of infective endocarditis in Qatar

Background: Infective endocarditis (IE) is a serious and potentially life-threatening disease. The epidemiology, treatment options, and outcomes have changed considerably over the last two decades. The aim of the study was to describe the epidemiology, clinical characteristics, and outcomes of patients with IE in Qatar.

Methods: Patients were identified from Hamad Medical Corporation hospitals’ electronic records, the national referral center for the State of Qatar. We included those aged ≥ 18 years with Duke Criteria-based diagnosis of IE during the period from January 2015 to September 2017. Demographic and clinical data were retrieved. Descriptive statistics were performed, and logistic regression analysis was used to describe the relationship between patient characteristics and all-cause in-hospital mortality. All potentially relevant variables were included in the univariate analysis, while those with p < 0.1 in the univariate logistic regression model were included in the multivariate analysis. For the final model, we calculated odds ratios (OR) adjusted for each of the variables included, along with their 95% confidence intervals (95% CI). Data were analyzed using STATA software version 15 (StataCorp, College Station, Texas, USA). The study was approved by the Institutional Research Board with a waiver for informed consent.

Results: Fifty-seven cases were included, of which 70% were males. The mean age was 51 years ( ± 16.8 years). Eleven (19%) were associated with prosthetic valves, and 6 (11%) with implantable cardiac devices. Fever (84%), dyspnea (46%), and heart failure (37%) were the most common presentations. Only 58% of patients had known preexisting valvular heart disease or an intracardiac device. Skin infections (10 patients, 18%) were the most prevalent portals of infection, followed by venous catheters, recent valve surgery, and implantable cardiac devices. Staphylococci were implicated in 19 (34%) and Streptococcaceae in 9 (16%) patients, whereas 21 (37%) patients were culture negative. Left-side IE (49 patients, 86%) was predominant. Acute kidney injury (AKI) (17 patients, 30%) and heart failure (11 patients, 19%) were common complications. The majority of patients received targeted antimicrobial therapy with at least two active agents. Only 9 (16%) patients underwent surgical intervention. Fourteen (25%) patients died of any cause before hospital discharge. Logistic regression analysis identified septic shock [OR 57.8, 95% CI 2.6–1360.2; p < 0.01] and AKI OR 33.9, 95% CI 2.9–398.1; p < 0.01) as the only risk factors independently associated with in-hospital mortality.

Conclusion: Staphylococci are the most common microbiological cause of IE in Qatar. Surgical intervention is uncommon, and mortality is relatively high. Our findings suggest that efforts should be directed toward improving IE prevention strategies in high-risk patients, encouraging early microbiological investigations and improving medical and surgical management.

Periaortic adipose tissue volume is associated with sclerotic changes in the adjacent aortic valve

Aortic sclerosis is associated with increased cardiovascular mortality and morbidity. Numerous studies have shown that visceral adiposity is associated with development of atherosclerosis, especially in the adjacent vascular wall. Considering the similar pathophysiology of aortic sclerosis and atherosclerosis, it can be hypothesized that visceral adipose tissue adjacent to aortic valve may be associated with aortic sclerosis. In this study, we investigated the relationship between periaortic adipose tissue volume and sclerotic changes in the adjacent aortic valve. In this retrospective study, 80 patients with a concurrent MSCT and echocardiography in the last 6 months were enrolled. Echocardiographic examinations were retrospectively evaluated regarding the presence of aortic sclerosis. Periaortic adipose tissue volume was calculated on a computer assisted work station (Leonardo Workstation, Siemens, Erlangen, Germany) by an experienced radiologist. Patient group (61.63 ± 8.55 years and 50% male) and the control group (61.45 ± 5.68 years, 50% male) each consisted 40 participants. Patient group had significantly higher BUN (42.50 (15.00-211.00) vs. 34.00 (12.00-107.00) mg/dL, p = 0.003), uric acid (5.40 (3.40-14.70) vs. 4.30 (2.30-6.70) ng/mL, p = 0.005) and LDL-C levels (121.50 (60.00-215.00) vs. 86.50 (49.00-209.00) mg/dL, p = 0.001) when compared to control group. Patient group had also significantly higher periaortic adipose tissue volume (32.45 (11.70-51.23) vs. 16.00 (6.29-32.96) ml, p < 0.001). Multivariate regression analysis revealed that periaortic adipose tissue volume was independently associated with the presence of aortic sclerosis (OR 0.241, 95% CI 0.143-0.946, p = 0.001). In this study, we demonstrated for the first time that periaortic adipose tissue volume was independently associated with the presence of sclerotic changes in the adjacent aortic valve.

Factors Associated with Discharge to a Skilled Nursing Facility after Transcatheter Aortic Valve Replacement Surgery

An assumption regarding transcatheter aortic valve replacement (TAVR), a minimally invasive procedure for treating aortic stenosis, is that patients remain at, or near baseline and soon return to their presurgical home to resume activities of daily living. However, this does not consistently occur. The purpose of this study was to identify preoperative factors that optimally predict discharge to a skilled nursing facility (SNF) after TAVR. Delineation of these conditions is an important step in developing a risk stratification model to assist in making informed decisions. Data was extracted from the American College of Cardiology (ACC) transcatheter valve therapy (TVT) registry and the Society of Thoracic Surgeons (STS) database on 285 patients discharged from 2012⁻2017 at a tertiary referral heart institute located in the southeastern region of the United States. An analysis of assessment, clinical and demographic variables was used to estimate relative risk (RR) of discharge to a SNF. The majority of participants were female (55%) and white (84%), with a median age of 82 years (interquartile range = 9). Approximately 27% (n = 77) were discharged to a SNF. Age > 75 years (RR = 2.3, p = 0.0026), female (RR = 1.6, p = 0.019), 5-meter walk test (5MWT) >7 s (RR = 2.0, p = 0.0002) and not using home oxygen (RR = 2.9, p = 0.0084) were identified as independent predictive factors for discharge to a SNF. We report a parsimonious risk-stratification model that estimates the probability of being discharged to a SNF following TAVR. Our findings will facilitate making informed treatment decisions regarding this older patient population.

The relationship between endothelial function and aortic valve calcification: Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Aortic valve calcification (AVC) may be associated with atherogenic processes arising from endothelial dysfunction (ED). Limited data is available about the relationship between ED, defined by flow mediated dilation (FMD%) and biomarkers, and the prevalence and progression of AVC in a multiethnic population.

METHODS

A sample of 3475 individuals from the Multi-Ethnic Study of Atherosclerosis (MESA), with both initial and repeat CT scans at a mean of 2.65 ± 0.84 years and FMD% and serologic markers of ED [ C-reactive protein (CRP), Von Willebrand factor (vWF), Plasminogen Activator Inhibitor (PAI), fibrinogen, Interleukin 6 (IL6), E-selectin and ICAM-1 (Intercellular Adhesion Molecule 1)], were analyzed. Multivariate modeling evaluated the association between ED and the prevalent AVC and AVC progression.

RESULTS

The median levels of FMD% was lower and vWF%, fibrinogen, IL6 and ICAM-1 were significantly higher in the AVC prevalence group versus no AVC prevalence (all p < 0.001). In the fully adjusted model for established risk factors, decreasing FMD% or increasing biomarkers was not independently associated with AVC prevalence [OR FMD% 1.028 (0.786, 1.346), CRP 0.981 (0.825, 1.168), vWF 1.132 (0.559, 2.292), PAI 1.124 (0.960, 1.316), fibrinogen 1.116 (0.424, 2.940), IL6 1.065 (0.779, 1.456), E-selectin 0.876 (0.479, 1.602) and ICAM-1 1.766 (0.834, 3.743)]. In the AVC progression group, FMD%, vWF%, fibrinogen and IL6 were significantly different (p < 0.05). After adjusting for cardiac risk factors, AVC progression was not independently associated with decreasing FMD% or increasing biomarkers [OR FMD% 1.105 (0.835, 1.463), CRP 1.014 (0.849, 1.210), vWF% 1.132 (0.559, 2.292), PAI 1.124 (0.960, 1.316), fibrinogen 0.909 (0.338, 2.443), IL6 1.061 (0.772, 1.459), E-selectin 0.794 (0.426, 1.480) and ICAM-1 0.998 (0.476, 2.092)].

CONCLUSIONS

Endothelial dysfunction by FMD% and biomarkers is not significantly associated with the prevalence or progression of aortic valve calcification after adjustment for cardiac risk factors.

Ideal Cardiovascular Health and the Prevalence and Severity of Aortic Stenosis in Elderly Patients

Background

The relationship between ideal cardiovascular health reflected in the cardiovascular health score (CVHS) and valvular heart disease is not known. The purpose of this study was to determine the association of CVHS attainment through midlife to late life with aortic stenosis prevalence and severity in late life.

Methods and Results

The following 6 ideal cardiovascular health metrics were assessed in ARIC (Atherosclerosis Risk in Communities) Study participants at 5 examination visits between 1987 and 2013 (visits 1–4 in 1987–1998 and visit 5 in 2011–2013): smoking, body mass index, total cholesterol, blood pressure, physical activity, and blood glucose. Percentage attained CVHS was calculated in 6034 participants as the sum of CVHS at each visit/the maximum possible score. Aortic stenosis was assessed by echocardiography at visit 5 on the basis of the peak aortic valve velocity. Aortic stenosis was categorized sclerosis, mild stenosis, and moderate‐to‐severe stenosis. Mean age was 76±5 years, 42% were men, and 22% were black. Mean percentage attained CVHS was 63±14%, and the prevalence of aortic stenosis stages were 15.9% for sclerosis, 4.3% for mild stenosis, and 0.7% for moderate‐to‐severe stenosis. Worse percentage attained CVHS was associated with higher prevalence of aortic sclerosis (P<0.001 for trend), mild stenosis (P<0.001), and moderate‐to‐severe stenosis (P=0.002), adjusting for age, sex, and race.

Conclusions

Greater attainment of ideal cardiovascular health in midlife to late life is associated with a lower prevalence of aortic sclerosis and stenosis in late life in a large cohort of older adults.

Association of Aortic Valve Sclerosis with Previous Coronary Artery Disease and Risk Factors

Background

Aortic valve sclerosis (AVS) is characterized by increased thickness, calcification and stiffness of the aortic leaflets without fusion of the commissures. Several studies show an association between AVS and presence of coronary artery disease.

Objective

The aim of this study is to investigate the association between presence of AVS with occurrence of previous coronary artery disease and classical risk factors.

Methods

The sample was composed of 2,493 individuals who underwent transthoracic echocardiography between August 2011 and December 2012. The mean age of the cohort was 67.5 ± 15.9 years, and 50.7% were female.

Results

The most frequent clinical indication for Doppler echocardiography was the presence of stroke (28.8%), and the most common risk factor was hypertension (60.8%). The most prevalent pathological findings on Doppler echocardiography were mitral valve sclerosis (37.1%) and AVS (36.7%). There was a statistically significant association between AVS with hypertension (p < 0.001), myocardial infarction (p = 0.007), diabetes (p = 0.006) and compromised left ventricular systolic function (p < 0.001). Conclusion: Patients with AVS have higher prevalences of hypertension, stroke, hypercholesterolemia, myocardial infarction, diabetes and compromised left ventricular systolic function when compared with patients without AVS. We conclude that there is an association between presence of AVS with previous coronary artery disease and classical risk factors.

Comparison of transesophageal echocardiographic analysis and circulating biomarker expression profile in calcific aortic valve disease

BACKGROUND AND AIM OF THE STUDY

Aortic valve sclerosis (AVSc), the early asymptomatic stage of calcific aortic valve disease (CAVD), is characterized by a progressive thickening of the aortic cusps without obstruction of the left ventricular outflow. In spite of its high prevalence, there are no molecular markers to characterize the early stages of CAVD before it progresses to a severe, symptomatic stage of aortic valve stenosis (AVS). The study aim was to identify any correlation between circulating biomarkers and transesophageal echocardiography (TEE) evaluation.

METHODS

A total of 330 patients with various degrees of CAVD was enrolled into the study. Blood was collected from each patient prior to surgery, and analyzed using ELISA kits following the manufacturers' instructions.

RESULTS

Significantly higher plasma osteopontin (OPN) levels were observed in AVSc patients (72.7 +/- 1.8 ng/ml; p < 0.001) and AVS patients (64.3 +/- 5.1 ng/ml; p < 0.001) when compared to controls (30.3 +/- 1.8 ng/ml). Parathyroid hormone (PTH) levels in AVSc and AVS patients (164.1 +/- 16.5 and 134.3 +/- 14.6 pg/ml; p < 0.001 and p = 0.04, respectively) were also significantly higher than in controls (61.8 +/- 4.92 pg/ml). Upon further analysis, plasma levels of OPN (p < 0.001) and PTH (p < 0.001) were found to be significantly higher in asymptomatic AVSc patients, even before calcium deposition was detected on TEE evaluation. Fetuin-A levels were lower at all stages of CAVD when compared to controls (p < 0.001 and p < or = 0.05, respectively), but were comparable among the patient groups. NT-proBNP levels were significantly higher in AVS patients than in controls (p < or = 0.01).

CONCLUSION

Serum levels of OPN, PTH, and fetuin-A showed a significant association with different stages of CAVD, with variations in their levels occurring before calcium nodules are visualized during TEE evaluation. The study results may help not only to provide a better understanding of the progression of CAVD but also to develop new tools that can be used to stage these patients.

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.

Aortic atheroma and adverse cerebral outcome: risk, diagnosis, and management options

Aortic atheromatous disease is a common finding in the patient presenting for cardiac surgery. Adverse neurologic outcome has been closely linked to the extent of aortic atherosclerosis. In order to optimize perioperative outcomes, the location and severity of disease needs accurate characterization using multimodal techniques. Although various preoperative radiographic techniques have variably identified patients with significant atheroma, intraoperative echocardiographic imaging has proven most useful in localizing and characterizing the degree of aortic atheroma. Epiaortic assessment of the ascending aorta has been utilized in guiding surgical modifications and interventions aimed at reducing the risk of neurologic injury. Although no particular technique has been definitely studied, avoidance of the identifiable atheromatous aortic region has been a main feature of the various modifications employed to optimize neurologic outcome after cardiac surgery.

Atherosclerotic inflammation triggers osteogenic bone transformation in calcified and stenotic human aortic valves: still a matter of debate

Sclerotic calcification of the aortic valve is a common disease in advanced age. However, pathophysiologic processes leading to valve calcifications are poorly understood. Transformation of atherosclerotic triggers to osteogenic differentiation is controversially discussed and is thought as a trigger of bone transformation in end stage disease. This study focuses on the transcriptional gene-profiling of severe calcified stenotic human aortic valves to clarify the molecular basis of the pathophysiological process. We collected severely calcified and stenotic human aortic valves (CSAV) with (CSAV+, n=10) and without (CSAV-, n=10) at least 4 weeks of statin pre-treatment prior to valve replacement and investigated transcriptional steady-state gene-profiling by using micro array technique and GAPDH-adjusted PCR for confirmation. Results were compared with findings in non-sclerotic aortic valves: C (n=6). Various parameters of inflammation were significantly up regulated as compared to C: eotaxin3, monokine induced by gamma-interferon, vascular adhesion protein-1 (VAP-1), peroxisome proliferative activated receptor-alpha or transforming growth factor beta 1 (TGF beta 1). Except for TGF beta 1 and VAP-1, statin pre-treatment neutralized altered gene expression. Genes of osteogenic bone transformation (tenascin C, bone sialoprotein, Cbfa1, Osteocalcin, Beta-catenin, Sox- and Cyclin-genes) were found unaltered in their expression in both, CSAV- or CSAV+ in comparison to C. This study shows continuing atherosclerotic inflammation on CSAV. Additionally, no evidence of initiated osteoblastic differentiation process was found. Pre-treatment of patients with statins partially neutralized the gene pattern of inflammation on the aortic valves. This suggests that there are potent benefits of statins on early development of inflammation on calcified aortic valves.

Left ventricular systolic and diastolic function in asymptomatic patients with moderate aortic stenosis

Tissue Doppler imaging (TDI) has improved the ability to detect subclinical changes in left ventricular (LV) function. The aim of this study was to investigate if asymptomatic patients with moderate aortic stenosis (AS) had impaired LV systolic and diastolic function. Fifty patients (mean age 65 +/- 12 years) recruited into the multicenter Simvastatin + Ezetimibe in Aortic Stenosis (SEAS) study with aortic peak velocities of 2.5 and 4.0 m/s were compared with 26 healthy subjects (mean age 64 +/- 12 years) (p = NS). Peak systolic tissue velocities and strain were measured at 8 LV locations and averaged. Early diastolic tissue velocity from the septal mitral annulus (E'sep) was measured as an index of LV relaxation. The ratio of early diastolic transmitral pulsed Doppler (E) to E'sep (E/E'sep) was calculated as an index of LV filling pressure. Peak systolic tissue velocity (4.1 +/- 1.0 vs 4.8 +/- 1.1 cm/s, p <0.01) and strain (-16.6 +/- 2.7% vs -17.9 +/- 2.0%, p <0.05) were decreased in patients with AS compared with controls. E'sep was decreased (4.9 +/- 1.0 vs 5.8 +/- 1.3 cm/s, p <0.01) and E/E'sep was increased (17.4 +/- 9.7 vs 11.7 +/- 3.8, p <0.01) in the AS group compared with the control group. In conclusion, asymptomatic patients with moderate AS have impaired LV systolic function as measured by reduced peak systolic tissue velocity and strain. Augmented LV filling pressure measured by E/E'sep and impaired LV relaxation measured by reduced E'sep also indicate diastolic dysfunction in these patients.

Tissue-engineered heart valve prostheses: ‘state of the heart’

In this article, we will review the current state of the art in heart valve tissue engineering. We provide an overview of mechanical and biological replacement options, outlining advantages and limitations of each option. Tissue engineering, as a field, is introduced, and specific aspects of valve tissue engineering are discussed (e.g., biomaterials, cells and bioreactors). Technological hurdles, which need to be overcome for advancement of the field, are also discussed.

Valvular endothelial cells and the mechanoregulation of valvular pathology

Endothelial cells are critical mediators of haemodynamic forces and as such are important foci for initiation of vascular pathology. Valvular leaflets are also lined with endothelial cells, though a similar role in mechanosensing has not been demonstrated. Recent evidence has shown that valvular endothelial cells respond morphologically to shear stress, and several studies have implicated valvular endothelial dysfunction in the pathogenesis of disease. This review seeks to combine what is known about vascular and valvular haemodynamics, endothelial response to mechanical stimuli and the pathogenesis of valvular diseases to form a hypothesis as to how mechanical stimuli can initiate valvular endothelial dysfunction and disease progression. From this analysis, it appears that inflow surface-related bacterial/thrombotic vegetative endocarditis is a high shear-driven endothelial denudation phenomenon, while the outflow surface with its related calcific/atherosclerotic degeneration is a low/oscillatory shear-driven endothelial activation phenomenon. Further understanding of these mechanisms may help lead to earlier diagnostic tools and therapeutic strategies.

Impaired tissue responsiveness to organic nitrates and nitric oxide: a new therapeutic frontier?

Nitric oxide (NO) is a physiologically important modulator of both vasomotor tone and platelet aggregability. These effects of NO are predominantly mediated by cyclic guanosine-3,'5'-monophosphate (cGMP) via activation of soluble guanylate cyclase. However, in patients with ischemic heart disease, platelets and coronary/peripheral arteries are hyporesponsive to the antiaggregatory and vasodilator effects of NO donors. NO resistance is also associated with a number of coronary risk factors and presents in different disease states. It correlates with conventional measures of "endothelial dysfunction," and represents a multifaceted disorder, in which smooth muscle and platelet NO resistance are equally important, as sites of abnormal NO-driven physiology. NO resistance results largely from a combination of "scavenging" of NO by superoxide anion radical (O(2)(-)) and of (reversible) inactivation of soluble guanylate cyclase. It constitutes an impaired physiological response to endogenous NO (endothelium-derived relaxing factor, EDRF) and, as such, may contribute to the increased risk of ischemic events. Impairment in responsiveness to NO in ischemic patients implies a potential problem that those patients, in greatest need of nitrate therapy, may be least likely to respond. The prognostic impact of NO resistance at vascular and platelet levels has been demonstrated in patients with ischemic heart disease, and it has been shown that a number of agents (angiotensin-converting enzyme [ACE] inhibitors, perhexiline, insulin, and possibly statins) ameliorate this anomaly. The current review examines different aspects of the "NO resistance" phenomenon and discusses some related methodological issues.

Aortic valve sclerosis: is it a cardiovascular risk factor or a cardiac disease marker?

BACKGROUND

Aortic valve sclerosis, without stenosis, has been associated with an increased cardiovascular mortality and morbidity due to myocardial infarction. However, it is unclear whether it is a cardiovascular risk factor or a cardiac disease marker. The goal of our study is to evaluate the difference in the prevalence of cardiovascular disease and risk factors among patients with or without aortic sclerosis.

METHODS

This observational study compared a group of 142 consecutive subjects with aortic valve sclerosis, assigned as group S, with a group of 101 subjects without aortic sclerosis, assigned as group C. Patients with bicuspid aortic valves and those with antegrade Doppler velocity across aortic valve leaflets exceeding 2.0 m/sec were excluded.

RESULTS

Mean ages of groups S and C were 71 +/- 8, and 68.8 +/- 6 years, respectively (P value = not significant). The prevalence of smoking, diabetes, hypercholesterolemia, hypertension, pulse pressure, left ventricular diastolic dysfunction, atrial fibrillation, and stroke was not significantly different between the two groups. However, there was a significantly higher prevalence of left ventricular hypertrophy (P = 0.05), ventricular arrhythmias (P = 0.02), myocardial infarction (P = 0.04), and systolic heart failure (P = 0.04) in aortic sclerosis group.

CONCLUSIONS

Aortic sclerosis is associated with a higher prevalence of left ventricular hypertrophy, ventricular arrhythmias, myocardial infarction, and systolic heart failure, while the prevalence of cardiovascular risk factors is not different between aortic sclerosis patients and controls. Hence, aortic sclerosis represents a cardiac disease marker useful for early identification of high-risk patients beyond cardiovascular risk factors rate.

Quantitative assessment of the atherosclerotic burden of the aorta by combined FDG-PET and CT image analysis: a new concept

INTRODUCTION

Our objective was to develop a technique for quantifying the extent of atherosclerosis in the aorta by combining standard uptake values (SUVs) in the aortic wall with volumetric data provided by computed tomography (CT).

METHODS

Eighteen patients who had both 18-fluorodeoxyglucose (FDG)-positron emission tomography (PET) and contrast-enhanced CT of the chest and abdomen were selected. All had homogeneous diffuse FDG wall uptake in four segments of the aorta. We divided the patients into three groups according to their age and measured FDG uptake in all four segments of the aorta by calculating the mean SUV for each segment. On each axial CT image, region-of-interest tracings along the inner and outer wall contours of the aorta were generated. The inner surface area was subtracted from the outer surface area. The net area values for each segment were subsequently multiplied by slice thickness to calculate arterial wall volume. By multiplying SUV with wall volume, we were able to calculate the atherosclerotic burden (AB) for each segment of the aorta. We compared the aortic wall volumes, SUVs and AB values in each arterial segment for each age group.

RESULTS

In each aortic wall segment, AB values, SUVs and wall volumes increased with age (P<.05).

CONCLUSION

AB can be used as an indicator of the extent of the atherosclerotic process in the aorta through the use of both metabolic and morphologic data provided by FDG-PET and CT, respectively. This may allow for the optimal screening, diagnosis and management of patients with this common and potentially lethal disorder.

Lethal and severe coronary arteritis in DBA/2 mice induced by fungal pathogen, CAWS, Candida albicans water-soluble fraction

CAWS is a microbial pathogen-associated molecular patterns (PAMPs) produced by Candida albicans. CAWS is a mannoprotein-beta-glucan complex and secreted into the culture supernatant. CAWS has various biological effects, causing acute shock and disrupting vascular permeability. Intraperitoneal administration of CAWS induces coronary arteritis in various strains of inbred mice. The CAWS-induced coronary arteritis is strain-dependent and most severe in DBA/2 mice with a significant number of these animals expiring with cardiomegaly during the observation period. In vivo and in vitro, splenocytes of DBA/2 mice produced various cytokines, such as IL-6, TNF-alpha, and IFN-gamma in response to CAWS. GM-CSF was also produced in response to CAWS. The production of cytokines was significantly enhanced in the presence of recombinant GM-CSF. In contrast, anti-GM-CSF significantly reduced the production of TNF-alpha and IFN-gamma. Augmented production of cytokines in response to CAWS would be a key to the severity of coronary arteritis.

Relationship between aortic valve sclerosis and the extent of coronary artery disease in patients undergoing diagnostic coronary angiography

BACKGROUND

Aortic valve sclerosis (AVS) is considered to be a manifestation of coronary atherosclerosis. Recent studies demonstrated an association between AVS and significant coronary artery disease (CAD).

AIM

We sought to determine the association between AVS and the extent of coronary atherosclerosis by means of the Gensini score system, which was calculated to yield a measure of the extent and severity of coronary atherosclerosis in patients referred for coronary angiography.

METHODS

A total of 160 consecutive patients referred for coronary angiography were subjected to echocardiography for screening of AVS and coronary risk assessment. Absence (group 1, n = 110) and presence of AVS (Group 2, n = 50) was established. The cardiac risk factors considered in this study were age, gender, family history of CAD, diabetes mellitus, hypertension, hypercholesterolemia and history of smoking. The body mass index was also measured. Atherosclerotic plaque burden was determined using the Gensini score. Significant CAD was defined as >50% reduction in the internal diameter of at least one coronary artery. Multivessel coronary disease was based on the presence of 2- or 3-vessel disease.

RESULTS

The AVS patients had a higher rate of 3-vessel disease (AVS group vs. non AVS: 40 vs. 13.6%; p < 0.001). No significant correlations were found between AVS and 1- and 2-vessel disease. Individuals with AVS were found to have a higher Gensini score (40.7 +/- 38.05 vs. 18 +/- 16.4; p < 0.001). Multivariate analysis identified age (p < 0.001), male sex (p = 0.01), triglycerides (p = 0.02), LDL cholesterol (p = 0.001) and Gensini score (p = 0.003) as independent predictors of AVS.

CONCLUSION

AVS is strongly interrelated with the coronary angiographic Gensini score. Echocardiographic detection of AVS in patients undergoing coronary angiography can provide a new surrogate marker of the extent of coronary atherosclerosis.

A legacy for the children - attitudes of older adults in the United Kingdom to genetic testing

AIM

The aim of this study was to assess understanding of genetics and attitudes towards genetic testing for clinical and research purposes in a group of older adults in the UK.

BACKGROUND

Increasingly, genomics will have an impact on the diagnosis, prevention and treatment of common diseases and the prescription of drugs. The chance of being affected by a medical condition increases with age and therefore the use of genetic testing as part of general health-care practice has an impact on the older population.

METHODS

Older adults were recruited to two focus groups (n=7 and n=10 respectively). Focus group discussions were guided by a series of questions and were audiotaped. The transcribed data were coded for significant statements, which were organized under thematic headings.

RESULTS

The mean age of participants was 76 years. The main themes to emerge were: understanding, approach to genetic testing and conditions for testing. In this cohort, the older adults were largely unsure about the underlying scientific basis of genetics but were keen to learn more. While enhanced medical knowledge could enable preventive measures to be taken and so reduce suffering, it was acknowledged that for some people knowing the future could potentially cause anxiety and harm. Participants were wary about research being used to benefit private companies and voiced ethical concerns about potential coercion to be tested and the misuse of science. However, all participants had an altruistic approach that influenced their willingness to be tested to benefit others in their family or the wider community. Conditions for testing included provision of information about the purpose of testing and feedback on the results.

CONCLUSIONS

Older adults are positive about the opportunities presented by genetic testing for clinical reasons and research, but need accurate information about the reasons for and implications of such testing.

RELEVANCE TO CLINICAL PRACTICE

The results of this study confirm the need for nurses to be proactive in developing the genetic competencies required to detect potential familial disease, make appropriate referrals to genetic services and ensure informed consent is obtained for genetic testing.

Bilateral ostial coronary stenosis and rheumatic aortic valve stenosis

A 49-year-old patient presented with angina pectoris and clinical findings of aortic valve stenosis and regurgitation. Rheumatic aortic valve stenosis and regurgitation was diagnosed on echocardiography. Coronary angiography findings showed severe calcification in the aorta root with right coronary ostial occlusion, and were suggestive of left main ostial stenosis and proximal main stem stenosis, which was confirmed on CT angiography. Curvilinear calcification of the aorta was present on CT angiography. The findings suggested syphilitic aortitis. Syphilis serology was positive (RPR titre 1/16). The angina was caused by severe coronary ostial disease likely due to syphilitic aortitis and exacerbated by the rheumatic aortic valve stenosis and regurgitation.