Antihypertensive therapy in patients with moderate to severe aortic stenosis.

ABSTRACT: Patients with aortic stenosis are at risk for developing hypertension. The selection of antihypertensives is a topic of debate due to a lack of consensus regarding their safety. This article provides an overview of antihypertensives used in patients with aortic stenosis, focusing on renin-angiotensin system inhibitors, beta-blockers, diuretics, and vasodilators.

Cholesterol (Blood lipid) lowering potential of Rosuvastatin chitosan nanoparticles for atherosclerosis: Preclinical study in rabbit model.

Atherosclerosis is the condition of narrowing of arteries due to plaque buildup on the artery walls. Aortic valve calcification (AVC) is one of the reasons of atherosclerosis which leads to narrowing at the opening of the aortic valve which is commonly referred as Aortic valve stenosis (AS). The Rosuvastatin-chitosan (ROS-chitosan) nanoparticles were prepared using ionotropic gelation method. Nanoparticulate formulation was optimized by 3 factor, 2 level full factorial design to find the effect of independent variables on particle size and percentage encapsulation efficiency. Particle size, encapsulation efficiency, scanning electron microscopy, in vitro drug release of nanoparticles was determined. The adult male rabbit of 4-5 months old were chosen for the study. Hypercholesterolemia was induced in experimental animals by administering diet with Cholesterol and Cholic acid (1.25 % and 0.5% respectively.) Blood lipid profile, interleukin 6 levels and histopathological study was performed. Rosuvastatin was found to be significantly effective in lowering the blood lipid levels. It helps to attenuate atherosclerosis as well as calcification of various valve tissues in experimental animals.

Role of Interleukin 17A in Aortic Valve Inflammation in Apolipoprotein E-deficient Mice.

Interleukin 17A (IL17A) is reported to be involved in many inflammatory processes, but its role in aortic valve diseases remains unknown. We examined the role of IL17A based on an ApoE-/- mouse model with strategies as fed with high-fat diet or treated with IL17A monoclonal antibody (mAb). 12 weeks of high-fat diet feeding can elevate cytokines secretion, inflammatory cells infiltration and myofibroblastic transition of valvular interstitial cells (VICs) in aortic valve. Moreover, diet-induction accelerated interleukin 17 receptor A (IL17RA) activation in VICs. In an IL17A inhibition model, the treatment group was intra-peritoneally injected with anti-IL17A mAb while controls received irrelevant antibody. Functional blockade of IL17A markedly reduced cellular infiltration and transition in aortic valve. To investigate potential mechanisms, NF-κB was co-stained in IL17RA+ VICs and IL17RA+ macrophages, and further confirmed by Western blotting in VICs. High-fat diet could activate NF-κB nuclear translocation in IL17RA+ VICs and IL17RA+ macrophages and this process was depressed after IL17A mAb-treatment. In conclusion, high-fat diet can lead to IL17A upregulation, VICs myofibroblastic transition and inflammatory cells infiltration in the aortic value of ApoE-/- mice. Blocking IL17A with IL17A mAb can alleviate aortic valve inflammatory states.

Inhibition of acetylation of histones 3 and 4 attenuates aortic valve calcification.

Aortic valve calcification develops in patients with chronic kidney disease who have calcium and phosphate metabolic disorders and poor prognoses. There is no effective treatment except valve replacement. However, metabolic disorders put patients at high risk for surgery. Increased acetylation of histones 3 and 4 is present in interstitial cells from human calcific aortic valves, but whether it is involved in aortic valve calcification has not been studied. In this study, we found that treating cultured porcine aortic valve interstitial cells with a high-calcium/high-phosphate medium induced calcium deposition, apoptosis, and expression of osteogenic marker genes, producing a phenotype resembling valve calcification in vivo. These phenotypic changes were attenuated by the histone acetyltransferase inhibitor C646. C646 treatment increased the levels of class I histone deacetylase members and decreased the acetylation of histones 3 and 4 induced by the high-calcium/high-phosphate treatment. Conversely, the histone deacetylase inhibitor suberoylanilide hydroxamic acid promoted valve interstitial cell calcification. In a mouse model of aortic valve calcification induced by adenine and vitamin D treatment, the levels of acetylated histones 3 and 4 were increased in the calcified aortic valves. Treatment of the models with C646 attenuated aortic valve calcification by restoring the levels of acetylated histones 3 and 4. These observations suggest that increased acetylation of histones 3 and 4 is part of the pathogenesis of aortic valve calcification associated with calcium and phosphate metabolic disorders. Targeting acetylated histones 3 and 4 may be a potential therapy for inoperable aortic valve calcification in chronic kidney disease patients.

Warfarin calcifies human aortic valve interstitial cells at high-phosphate conditions via pregnane X receptor.

Warfarin, a vitamin K antagonist, is the most common anticoagulant used to prevent thromboembolisms associated with atrial fibrillation or following valvular surgery. Although several studies have revealed that long-term warfarin use accelerates aortic valve calcification and the development of aortic stenosis (AS), the detailed mechanism for this phenomenon remains unclear. Therefore, our aim was twofold: to establish the conditions for warfarin-induced calcification of human aortic valve interstitial cells (HAVICs) using high-inorganic phosphate (Pi) conditions and to investigate the underlying mechanism. We prepared and cultured HAVICs from aortic valves affected by calcific aortic valve stenosis (AS group) and aortic valves affected by aortic regurgitation but without any signs of calcification (non-AS group). Under Pi concentrations of 3.2 mM, warfarin significantly increased the calcification and alkaline phosphatase (ALP) activity of AS but not non-AS group HAVICs. Furthermore, gene expression of bone morphogenetic protein 2 (BMP2), a calcigenic marker, was significantly increased following 7 days of warfarin treatment. Warfarin-induced calcification of AS group HAVICs at 3.2 mM Pi was significantly inhibited by dorsomorphin, a Smad inhibitor, and the pregnane X receptor (PXR) inhibitors, ketoconazole and coumestrol, but was unaffected by SN-50, an NF-κB inhibitor. Warfarin was also able to increase BMP2 gene expression at a physiological Pi concentration (1.0 mM). Furthermore, excess BMP2 (30 ng/mL) facilitated warfarin-induced ALP upregulation and HAVIC calcification, an effect which was significantly reduced in the presence of coumestrol. Together, our results suggest that warfarin accelerates calcification of HAVICs from AS patients via the PXR-BMP2-ALP pathway.

Warfarin, but not rivaroxaban, promotes the calcification of the aortic valve in ApoE-/- mice.

INTRODUCTION: Vitamin K antagonists, such as warfarin, are known to promote arterial calcification through blockade of gamma-carboxylation of Matrix-Gla-Protein. It is currently unknown whether other oral anticoagulants such as direct inhibitors of Factor Xa can have protective effects on the progression of aortic valve calcification. AIMS: To compare the effect of warfarin and rivaroxaban on the progression of aortic valve calcification in atherosclerotic mice. RESULTS: 42 ApoE-/- mice fed with Western-type Diet (WTD) were randomized to treatment with warfarin (n = 14), rivaroxaban (n = 14) or control (n = 14) for 8 weeks. Histological analyses were performed to quantify the calcification of aortic valve leaflets and the development of atherosclerosis. The analyses showed a significant increase in valve calcification in mice treated with warfarin as compared to WTD alone (P = .025) or rivaroxaban (P = .005), whereas no significant differences were found between rivaroxaban and WTD (P = .35). Quantification of atherosclerosis and intimal calcification was performed on the innominate artery of the mice and no differences were found between the 3 treatments as far as atherogenesis and calcium deposition is concerned. In vitro experiments performed using bovine interstitial valve cells (VIC) showed that treatment with rivaroxaban did not prevent the osteogenic conversion of the cells but reduce the over-expression of COX-2 induced by inflammatory mediators. CONCLUSION: We showed that warfarin, but not rivaroxaban, could induce calcific valve degeneration in a mouse model of atherosclerosis. Both the treatments did not significantly affect the progression of atherosclerosis. Overall, these data suggest a safer profile of rivaroxaban on the risk of cardiovascular disease progression.

Effects of early aldosterone antagonism on cardiac remodeling in rats with aortic stenosis-induced pressure overload.

UNLABELLED: Aldosterone plays a pivotal role in the pathophysiology of systolic heart failure. However, whether early aldosterone antagonism improves cardiac remodeling during persistent pressure overload is unsettled. We evaluated the effects of aldosterone antagonist spironolactone on cardiac remodeling in rats with ascending aortic stenosis (AS). METHODS: Three days after inducing AS, weaning rats were randomized to receive spironolactone (AS-SPR, 20mg/kg/day) or no drug (AS) for 18weeks, and compared with sham-operated rats. Myocardial function was studied in isolated left ventricular (LV) papillary muscles. STATISTICAL ANALYSES: ANOVA or Kruskal-Wallis tests. RESULTS: Echocardiogram showed that LV diastolic (Sham 8.73±0.57; AS 8.30±1.10; AS-SPR 9.19±1.15mm) and systolic (Sham 4.57±0.67; AS 3.61±1.49; AS-SPR 4.62±1.48mm) diameters, left atrial diameter (Sham 5.80±0.44; AS 7.15±1.22; AS-SPR 8.02±1.17mm), and LV mass were higher in AS-SPR than AS. Posterior wall shortening velocity (Sham 38.5±3.8; AS 35.6±5.6; AS-SPR 31.1±3.8mm/s) was lower in AS-SPR than Sham and AS; E/A ratio was higher in AS-SPR than Sham. Developed tension was lower in AS and AS-SPR than Sham. Time to peak tension was higher in AS-SPR than Sham and AS after post-rest contraction. Right ventricle weight was higher in AS-SPR than AS, suggesting more severe heart failure in AS-SPR than AS. Interstitial collagen fractional area and myocardial hydroxyproline concentration were higher in AS than Sham. Metalloproteinase-2 and -9 activity, evaluated by zymography, did not differ between groups. CONCLUSION: Early spironolactone administration causes further hypertrophy in cardiac chambers, and left ventricular dilation and dysfunction in rats with AS-induced chronic pressure overload.

Drug-induced aortic valve stenosis: An under recognized entity.

BACKGROUND: We have been intrigued by the observation that aortic stenosis (AS) may be associated with characteristic features of mitral drug-induced valvular heart disease (DI-VHD) in patients exposed to valvulopathic drugs, thus suggesting that beyond restrictive heart valve regurgitation, valvulopathic drugs may be involved in the pathogenesis of AS. METHODS: Herein are reported echocardiographic features, and pathological findings encountered in a series of patients suffering from both AS (mean gradient >15mmHg) and mitral DI-VHD after valvulopathic drugs exposure. History of rheumatic fever, chest radiation therapy, systemic disease or bicuspid aortic valve disease were exclusion criteria. RESULTS: Twenty-five (19 females, mean age 62years) patients having both AS and typical features of mitral DI-VHD were identified. Mean transaortic pressure gradient was 32+/-13mmHg. Aortic regurgitation was ≥ mild in 24 (96%) but trivial in one. Known history of aortic valve regurgitation following drug initiation prior the development of AS was previously diagnosed in 17 patients (68%). Six patients underwent aortic valve replacement and 3 both aortic and mitral valve replacement. In the 9 patients with pathology analysis, aortic valvular endocardium was markedly thickened by dense non-inflammatory fibrosis, a characteristic feature of DI-VHD. CONCLUSION: The association between AS and typical mitral DI-VHD after valvulopathic drug exposure may not be fortuitous. Aortic regurgitation was usually associated to AS and preceded AS in most cases but may be lacking. Pathology demonstrated the potential role of valvulopathic drugs in the development of AS.

HDL mimetic peptide CER-522 treatment regresses left ventricular diastolic dysfunction in cholesterol-fed rabbits.

OBJECTIVES: High-density lipoprotein (HDL) infusions induce rapid improvement of experimental atherosclerosis in rabbits but their effect on ventricular function remains unknown. We aimed to evaluate the effects of the HDL mimetic peptide CER-522 on left ventricular diastolic dysfunction (LVDD). METHODS: Rabbits were fed with a cholesterol- and vitamin D2-enriched diet until mild aortic valve stenosis and hypercholesterolemia-induced LV hypertrophy and LVDD developed. Animals then received saline or 10 or 30mg/kg CER-522 infusions 6 times over 2weeks. We performed serial echocardiograms and LV histology to evaluate the effects of CER-522 therapy on LVDD. RESULTS: LVDD was reduced by CER-522 as shown by multiple parameters including early filling mitral deceleration time, deceleration rate, Em/Am ratio, E/Em ratio, pulmonary venous velocities, and LVDD score. These findings were associated with reduced macrophages (RAM-11 positive cells) in the pericoronary area and LV, and decreased levels of apoptotic cardiomyocytes in CER-522-treated rabbits. CER-522 treatment also resulted in decreased atheromatous plaques and internal elastic lamina area in coronary arteries. CONCLUSIONS: CER-522 improves LVDD in rabbits, with reductions of LV macrophage accumulation, cardiomyocyte apoptosis, coronary atherosclerosis and remodelling.

Generation of Simulated Calcific Lesions in Valve Leaflets for Flow Studies.

BACKGROUND AND AIM OF THE STUDY: Calcific aortic valve disease (CAVD) is the most common valvular disorder. While fluid stresses are presumed to play a role in disease progression, the valvular hemodynamic changes experienced over the course of CAVD remain largely unknown. The study aim was to develop a laboratory protocol for the fabrication of tissue valve models mimicking mild and moderate calcific stenosis, for future use in flow studies. METHODS: Different hydroxyapatite (HA)-agarose mixtures were injected into porcine valve leaflets. Micro-computed tomography (micro-CT) was used to quantify HA deposition volume, area fraction and regional distribution, while von Kossa staining was performed to assess tissue mineralization. Particle image velocimetry measurements were carried out in intact and injected valves subjected to in vivo-like hemodynamics to characterize the degree of valvular stenosis in terms of geometric orifice area (GOA) and peak systolic velocity. RESULTS: The 5% HA-1% agarose solution (solution 1) and the 5% HA-0.5% agarose solution (solution 2) maximized the HA deposition volume. Leaflet injections with solution 1 resulted in a significant 1.9-fold increase in HA area fraction relative to solution 2 injections. While solution 1 injections generated multiple sites of high HA concentration, solution 2 injections produced smaller, discrete spots. Injections of both solution 1 and solution 2 into whole valves generated significant 47% and 32% reductions, respectively, in GOA and 1.8-fold and 1.5-fold increases, respectively, in peak systolic velocity, relative to untreated valves. CONCLUSION: Tissue valve models were generated that recapitulated the structure and hemodynamics of mild and moderate valvular calcification. Those models may be used for future investigations of the native valvular hemodynamic alterations that occur during CAVD.

P2Y2 receptor represses IL-6 expression by valve interstitial cells through Akt: implication for calcific aortic valve disease.

Calcific aortic valve disease (CAVD) is a disorder characterized by an abnormal mineralization, which may have intricate links with inflammation. Interleukin-6 (IL-6) and its cognate cytokines are widely expressed and exert pleiotropic effects on different tissues. In this study, we examined the expression of the IL-6 family of cytokines in human CAVD by using a transcriptomic approach and we performed in-depth functional assays with valve interstitial cells (VICs) to unravel the process regulating IL-6 expression and its role during the mineralization of the aortic valve. We documented by both microarray and q-PCR analyses an elevated expression of IL-6 in human CAVD, which was correlated with the remodeling process. IL-6 was highly expressed by VICs. We found that following treatment with a phosphate-containing medium the level of IL-6 expressed by VICs increased by several-fold. Phosphate-induced expression of IL-6 relied on reduced PI3K/Akt signaling downstream of the P2Y2 receptor (P2Y2R). In this regard, we found by using transfection experiments that Akt-1 is a negative regulator of the NF-κB pathway. In addition, by using a siRNA targeting IL-6 we found that phosphate-induced mineralization was largely dependent on IL-6 expression. A transfection of Akt-1 rescued the hypermineralizing phenotype of P2Y2R(-/-) mouse VICS (MVICs). Hence, we documented a novel mechanism whereby P2Y2R and Akt modulate the NF-κB pathway and its downstream target IL-6, which is a strong promoter of the mineralization of VICs.

CD34-negative mesenchymal stem-like cells may act as the cellular origin of human aortic valve calcification.

Although various osteogenic inducers contribute to the calcification of human aortic valve interstitial cells, the cellular origin of calcification remains unclear. We immunohistochemically investigated the cellular origin of valve calcification using enzymatically isolated cells from both calcified and non-calcified human aortic valve specimens. CD73-, 90-, and 105-positive and CD45-negative mesenchymal stem-like cells (MSLCs) were isolated from both types of valve specimens using fluorescence-activated cell sorting. MSLCs were further sorted into CD34-negative and -positive cells. Compared with CD34-positive cells, CD34-negative MSLCs were significantly more sensitive to high inorganic phosphate (3.2 mM), calcifying easily in response. Furthermore, immunohistochemical staining showed that significantly higher numbers (~7-9-fold) of CD34-negative compared with CD34-positive MSLCs were localized in calcified aortic valve specimens obtained from calcified aortic stenosis patients. These results suggest that CD34-negative MSLCs are responsible for calcification of the aortic valve.

Associations between aspirin and other non-steroidal anti-inflammatory drugs and aortic valve or coronary artery calcification: the Multi-Ethnic Study of Atherosclerosis and the Heinz Nixdorf Recall Study.

BACKGROUND: The association between non-steroidal anti-inflammatory drugs (NSAIDs) and the incidence of valvular and arterial calcification is not well established despite known associations between these drugs and cardiovascular events. OBJECTIVE: To compare the association between the baseline use of aspirin with other NSAID class medications with the incidence and prevalence of aortic valve calcification (AVC) and coronary artery calcification (CAC). METHODS: The relationship of NSAID use to AVC and CAC detected by computed tomography was assessed in 6814 participants within the Multi-Ethnic Study of Atherosclerosis (MESA) using regression modeling. Results were adjusted for age, sex, ethnicity, study site, anti-hypertensive medication use, education, income, health insurance status, diabetes, smoking, exercise, body mass index, blood pressure, serum lipids, inflammatory markers, fasting glucose, statin medication use, and a simple diet score. Medication use was assessed by medication inventory at baseline which includes the use of non-prescription NSAIDs. MESA collects information on both incident and prevalent calcification. The 4814 participants of the Heinz Nixdorf Recall (HNR) Study, a German prospective cohort study with similar measures of calcification, were included in this analysis to enable replication. RESULTS: Mean age of the MESA participants was 62 years (51% female). After adjustment for possible confounding factors, a possible association between aspirin use and incident AVC (Relative Risk(RR): 1.60; 95%Confidence Interval (CI): 1.19-2.15) did not replicate in the HNR cohort (RR: 1.06; 95%CI: 0.87-1.28). There was no significant association between aspirin use and incident CAC in the MESA cohort (RR 1.08; 95%CI: 0.91-1.29) or in the HNR cohort (RR 1.24; 95%CI: 0.87-1.77). Non-aspirin NSAID use was not associated with either AVC or CAC in either cohort. There were no associations between regular cardiac dose aspirin and incident calcification in either cohort. CONCLUSION: Baseline NSAID use, as assessed by medication inventory, appears to have no protective effect regarding the onset of calcification in either coronary arteries or aortic valves.

Early bioprosthetic valve calcification with alfacalcidol supplementation.

We report a case of early bioprosthetic valve calcification in a 76 year-old woman who had received supplementation with alfacalcidol, an analogue of vitamin D, for 3 years after her initial valve replacement. She underwent aortic valve replacement at the age of 71 and subsequently complained of shortness of breath. Ultrasonic cardiography revealed severe aortic stenosis and we performed a second aortic valve replacement with a bioprosthesis. Histopathologic and x-ray examination showed calcification on the explanted valve. She had not presented with any known risk for early bioprosthetic calcification, suggesting that vitamin D supplementation may accelerate calcification of bioprosthetic valves.

Complications of Bioglue postsurgery for aortic dissections and aortic valve replacement.

AIMS: Bioglue is an adhesive used during cardiovascular surgery to improve hemostasis perioperatively and to strengthen and reinforce vascular anastomoses. It has also been used to 'seal' the false lumen in patients presenting with acute aortic dissections. Herein, we examine the complications of Bioglue, which may lead to redo sternotomy in selected patients. METHODS: A review of pathology records at our institution from 2002 to 2010 found 4 cases of excised aortic tissue and/or aortic valves with previous Bioglue use at initial operation. Excised tissues and valves were examined, looking for the presence of Bioglue, inflammatory cells (acute, chronic, macrophage and giant cells) and micro-organisms. Patient demographics were also reviewed and recorded. RESULTS: We identified four cases of Bioglue use found at redo surgery, after the formation of pseudoaneurysm (n=3) and aortic stenosis (n=1). Mean interval to redo surgery was 2.28 + 0.32 years (range 2-2.6 years). Pseudoaneurysm formation was thought to be caused by an inflammatory reaction to the Bioglue itself in two cases, while one case found no such reaction. One patient with previous aortic valve replacement had large annular abscesses filled with necrotic debris surrounding the prosthesis and pannus found on the sewing cuff, comprised of Bioglue itself. CONCLUSIONS: The mechanisms leading to these complications include mechanical strain, inflammation and tissue necrosis. The judicious use of Bioglue when clinically indicated, and close follow-up of these patients with serial imaging, remain an integral part of avoiding future complications.

Inhibition of ectonucleotidase with ARL67156 prevents the development of calcific aortic valve disease in warfarin-treated rats.

Calcific aortic valve disease is the most common heart valve disorder. So far, there is no medical treatment for calcific aortic valve disease. The expression of ectonucleotidases, which metabolize nucleotides into phosphate products, may influence the calcification of the aortic valve. In this study, we investigated if the administration of an ectonucleotidase inhibitor, ARL67156 (6-N,N-Diethyl-D-ß,γ-dibromomethyleneATP trisodium salt), may prevent the calcification of the aortic valve in the warfarin-induced mineralization rat model. Male Wistar rats were treated with warfarin or warfarin+ARL67156 for 28 days. All rats had comprehensive Doppler-echocardiographic studies at 28 day. A gene profiling of ectonucleotidases expressed in aortas of rats was documented by quantitative real-time PCR. The amount of calcium was determined by quantitative method and von Kossa staining. Ex vivo cultures of rat aortas were also used to further assess the effect of ARL67156 on the calcifying process and Akt signaling. Mineralization of the aorta/aortic valve was documented in warfarin-treated rats and was accompanied by the development of aortic stenosis. These changes were paralleled by an increased of ectonucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1). Administration of the ectonucleotidase inhibitor, ARL67156 prevented the development of aortic stenosis by lowering the level of apoptosis and mineralization of the aortic valve/aorta. In addition, ARL67156 normalized the level of pAkt, an important kinase involved in the survival pathway. Inhibition of ectonucleotidase activity prevented the development of calcific aortic valve disease in a rat model. On that account, ectonucleotidase may represent a novel target in the treatment of calcific aortic valve disease.

Vitamin D(2) supplementation induces the development of aortic stenosis in rabbits: interactions with endothelial function and thioredoxin-interacting protein.

Understanding of the pathophysiology of aortic valve stenosis (AVS) and finding potentially effective treatments are impeded by the lack of suitable AVS animal models. A previous study demonstrated the development of AVS in rabbits with vitamin D(2) and cholesterol supplementation without any hemodynamic changes in the cholesterol supplemented group alone. The current study aimed to determine whether AVS develops in an animal model with vitamin D(2) supplementation alone, and to explore pathophysiological mechanisms underlying this process. The effects of 8 weeks' treatment with vitamin D(2) alone (n=8) at 25,000 IU/4 days weekly on aortic valve structure and function were examined in male New Zealand white rabbits. Echocardiographic aortic valve backscatter (AV(BS)), transvalvular velocity, and transvalvular pressure gradient were utilized to quantitate changes in valve structure and function. Valvular histology/immunochemistry and function were examined after 8 weeks. Changes in valves were compared with those in endothelial function and in valvular measurement of thioredoxin-interacting protein (TXNIP), a marker/mediator of reactive oxygen species-induced oxidative stress. Vitamin D(2) treated rabbits developed AVS with increased AV(BS) (17.6+/-1.4 dB vs 6.7+/-0.8 dB, P<0.0001), increased transvalvular velocity and transvalvular pressure gradient (both P<0.01 via 2-way ANOVA) compared to the control group. There was associated valve calcification, lipid deposition and macrophage infiltration. Endothelial function was markedly impaired, and intravalvular TXNIP concentration increased. In this model, vitamin D(2) induces the development of AVS with histological features similar to those of early AVS in humans and associated endothelial dysfunction/redox stress. AVS development may result from the loss of nitric oxide suppression of TXNIP expression.

Warfarin and aortic valve calcification in hemodialysis patients.

BACKGROUND: This retrospective cohort study was designed to determine the association between long-term exposure to warfarin and severity of aortic valve (AV) calcification in hemodialysis (HD) patients. METHODS: One hundred and eight HD patients underwent a study-specific echocardiogram. A grading scheme was used to classify AV calcification as none, mild, moderate and severe. Demographic, biochemical and medication data were abstracted by chart review. RESULTS: One hundred and eight subjects were enrolled. A minority had no calcification (n=17, 15.7%), the majority had mild calcification (n=62, 57.4%), and fewer had calcification rated as moderate (n=16, 14.8%) or severe (n=13, 12%). Dialysis vintage was associated with severity of AV calcification (p=0.04). The 18 subjects with long-term warfarin exposure (36.7 +/- 19.7 months) were more likely to have severe AV calcification (p=0.04). The odds ratio of falling into a higher category of AV calcification following 18 months of warfarin was 3.77 (95% confidence ratio, 0.97-14.70; p=0.055). There was an association between lifetime months of warfarin exposure and severity of AV calcification (p=0.004) that was independent of dialysis vintage, calcium and calcitriol intake. CONCLUSIONS: The data suggest that warfarin may be associated with severity of AV calcification in HD patients and support the need for prospective studies.