Lipid-lowering therapy in calcific aortic stenosis

Effect of End-Stage Renal Disease on Rate of Progression of Aortic Stenosis

This study aimed to investigate the progression of mild-to-moderate aortic stenosis (AS) in patients with end-stage renal disease (ESRD) and determine its metabolic and hemodynamic contributors and clinical outcomes. A total of 74 patients with ESRD (50 men, age 72 ± 11 years) with mild-to-moderate AS were compared with 79 age- and gender-matched controls with normal kidney function. Clinical, laboratory, and echocardiographic features and clinical outcomes including aortic valve (AV) intervention, hospitalization due to heart failure, and cardiovascular death were analyzed. Patients with ESRD were divided into 2 subgroups according to their rate of AV area changes (group 1 [n = 28], rapid progression; and group 2 [n = 46], slow progression). Progression in the degree of AS was noted in 38% of patients with ESRD and 18% of controls (p <0.01) during comparable echocardiographic follow-up durations (29 ± 15 vs 27 ± 24 months, respectively, p = 0.57). In ESRD, patients in group 1 were older (p <0.01) with higher baseline log parathyroid hormone (p <0.01) and larger stroke volume (p = 0.03) than those in group 2. During clinical follow-up (48 ± 23 months), patients in group 1 showed poorer clinical outcomes than those in group 2 and controls (log-rank p <0.01). Age, left atrial volume index ≥42 ml/m(2), and annual increases of peak pressure gradient across the AV (mm Hg/year) demonstrated additive predictive values for prognosis. AS in ESRD progresses in an accelerated manner along with higher metabolic and hemodynamic loads on AV compared with those with normal kidney function. Accelerated progression of mild-to-moderate AS in ESRD results in poor prognosis.

Modification of the secretion pattern of proteases, inflammatory mediators, and extracellular matrix proteins by human aortic valve is key in severe aortic stenosis

One of the major challenges in cardiovascular medicine is to identify candidate biomarker proteins. Secretome analysis is particularly relevant in this search as it focuses on a subset of proteins released by a cell or tissue under certain conditions. The sample can be considered as a plasma subproteome and it provides a more direct approximation to the in vivo situation. Degenerative aortic stenosis is the most common worldwide cause of valve replacement. Using a proteomic analysis of the secretome from aortic stenosis valves we could identify candidate markers related to this pathology, which may facilitate early diagnosis and treatment. For this purpose, we have designed a method to validate the origin of secreted proteins, demonstrating their synthesis and release by the tissue and ruling out blood origin. The nLC-MS/MS analysis showed the labeling of 61 proteins, 82% of which incorporated the label in only one group. Western blot and selective reaction monitoring differential analysis, revealed a notable role of the extracellular matrix. Variation in particular proteins such as PEDF, cystatin and clusterin emphasizes the link between aortic stenosis and atherosclerosis. In particular, certain proteins variation in secretome levels correlates well, not only with label incorporation trend (only labeled in aortic stenosis group) but, more importantly, with alterations found in plasma from an independent cohort of samples, pointing to specific candidate markers to follow up in diagnosis, prognosis, and therapeutic intervention.

Proteomic profile of human aortic stenosis: insights into the degenerative process

Degenerative aortic stenosis is the most common worldwide cause of valve replacement. While it shares certain risk factors with coronary artery disease, it is not delayed or reversed by reducing exposure to risk factors (e.g., therapies that lower lipids). Therefore, it is necessary to better understand its pathophysiology for preventive measures to be taken. In this work, aortic valve samples were collected from 20 patients that underwent aortic valve replacement (55% males, mean age of 74 years) and 20 normal control valves were obtained from necropsies (40% males, mean age of 69 years). The proteome of the samples was analyzed by quantitative differential electrophoresis (2D-DIGE) and mass spectrometry, and 35 protein species were clearly increased in aortic valves, including apolipoprotein AI, alpha-1-antitrypsin, serum albumin, lumican, alfa-1-glycoprotein, vimentin, superoxide dismutase Cu-Zn, serum amyloid P-component, glutathione S-transferase-P, fatty acid-binding protein, transthyretin, and fibrinogen gamma. By contrast, 8 protein species were decreased (transgelin, haptoglobin, glutathione peroxidase 3, HSP27, and calreticulin). All of the proteins identified play a significant role in cardiovascular processes, such as fibrosis, homeostasis, and coagulation. The significant changes observed in the abundance of key cardiovascular proteins strongly suggest that they can be involved in the pathogenesis of degenerative aortic stenosis. Further studies are warranted to better understand this process before we can attempt to modulate it.

Inside human aortic stenosis: a proteomic analysis of plasma

Valvular aortic stenosis (AS) produces a slowly progressive obstruction in left ventricular outflow track. For this reason, aortic valve replacement is warranted when the valvular stenosis is hemodinamically significant, becoming the most common worldwide cause of aortic valve surgery. Recent epidemiologic studies have revealed an association between degenerative AS and cardiovascular risk factors for atherosclerosis, althought reducing the exposure to such factors and statin therapies both fail to delay or reverse the pathology. Hence, a deeper understanding of the pathophysiology of this disease is required to identify appropriate preventive measures. A proteomic analysis of plasma will permit to know and identify the changes in protein expression induced by AS in this tissue. Using two-dimensional difference gel electrophoresis (2D-DIGE) followed by mass spectrometry (MS), we compared the crude (not pre-fractioned) and pre-fractioned plasma from AS patients and control subjects. We sought to identify plasma proteins whose expression is modified in AS. In addition we investigated if crude plasma presented some alterations in the more abundant proteins since to date, has never been studied before. We also further investigated the link between this disease and atherosclerosis with a view to identifying new potential markers and therapeutic targets.

Review: Does lowering cholesterol have an impact on the progression of aortic stenosis?

Several studies suggest that atherosclerotic disease is not a focal disease restricted to culprit lesions in the intima of the arterial wall, but seems to act as a general disease affecting the entire cardiovascular system. Evolving research has lately focused on the atherosclerotic component in calcific aortic stenosis (AS) as it seems that the valve is affected in a pattern similar to that of the vasculature. The hope is therefore, that we someday in the management of patients with calcific AS can apply some of the same treatment strategies as in atherosclerotic vascular disease. This article reviews the pathophysiological mechanisms of calcific AS, reviews current clinical trials of statin use in aortic stenosis and reports on on-going trials, evaluating whether cholesterol lowering therapy can slow disease progression in different populations. Finally, we review if computerized tomography, biomarkers, and clinical characteristics such as left ventricular ejection fraction, can be useful in stratifying patients to potential benefit of statin therapy.