Severe aortic stenosis with low transvalvular gradient and severe left ventricular dysfunction:result of aortic valve replacement in 52 patients.
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BACKGROUND: The outcome of aortic valve replacement in patients with severe aortic stenosis, low transvalvular gradient, and severe left ventricular dysfunction is not well known. METHODS AND RESULTS: Between 1985 and 1995, 52 patients with left ventricular ejection fraction (EF) < or =35% and aortic stenosis with transvalvular mean gradient <30 mm Hg underwent aortic valve replacement. The mean (+/-SD) preoperative characteristics included EF, 26+/-8%; aortic valve mean gradient, 23+/-4 mm Hg; aortic valve area, 0.7+/-0.2 cm(2); and cardiac output, 3.7+/-1.2 L/min. Simultaneous coronary artery bypass graft surgery was performed in 32 patients (62%). Perioperative (30-day) mortality was 21% (11 of 52 patients). Ten additional patients died during follow-up. Advanced age (P=0.048) and small aortic prosthesis size (P=0.03) were significant predictors of hospital mortality by univariate analysis. By multivariate analysis, the only predictor of surgical mortality was smaller prosthesis size. The only predictor of postoperative survival was improvement in postoperative functional class (P=0.04). Postoperative functional improvement occurred in most patients. Postoperative EF was assessed in 93% of survivors; 74% demonstrated improvement. Positive change in EF was related to smaller preoperative aortic valve area and female sex. CONCLUSIONS: Despite severe left ventricular dysfunction, low transvalvular mean gradient, and increased operative mortality, aortic valve replacement was associated with improved functional status. Postoperative survival was related to younger patient age and larger aortic prosthesis size, and medium-term survival was related to improved postoperative functional class. (+info)
Rate of change in aortic valve area during a cardiac cycle can predict the rate of hemodynamic progression of aortic stenosis.
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BACKGROUND: The ability to predict the rate of hemodynamic progression in an individual patient with valvular aortic stenosis has been elusive. The purpose of the present study was to evaluate whether the rate of change in aortic valve area (AVA) measured during the ejection phase of a cardiac cycle predicts the rate of hemodynamic progression in patients with asymptomatic aortic stenosis. METHODS AND RESULTS: In 84 adults with initially asymptomatic aortic stenosis and a baseline AVA of > or =0.9 cm(2), annual echocardiographic data were obtained prospectively (mean follow-up 2.8+/-1.3 years). With the initial echocardiogram, the ratio of AVA measured at mid-acceleration and mid-deceleration to the AVA at peak velocity was calculated. The primary outcome variable was the annual rate of change in AVA (rate of progression), with rate of progression classified as rapid (a reduction in AVA of > or =0.2 cm(2)/y) or slow (<0.2 cm(2)/y). Rapid progression was significantly associated with an AVA ratio of > or =1.25 (P=0.004, risk ratio 3.1, 95% CI 1.2 to 7.9). The sensitivity, specificity, and positive predictive value of AVA ratio of > or =1.25 for the prediction o rapid progression of valvar aortic stenosis was 64%, 72%, and 80% respectively. The decrease in ejection fraction measured from the initial to final echocardiogram was small but greater for patients with an AVA ratio of > or =1.25 (-4+/-7% versus +2+/-7%, P<0.001). CONCLUSIONS: A flow-dependent change in AVA can be measured during a routine transthoracic echocardiographic study. The rate of change in AVA is an additional measure of disease severity and may be used to predict an individual's risk for subsequent rapid disease progression. (+info)
Infective endocarditis complicated with progressive heart failure due to beta-lactamase-producing Cardiobacterium hominis.
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We describe a 66-year-old woman with infective endocarditis due to Cardiobacterium hominis whose condition, complicated by severe aortic regurgitation and congestive heart failure, necessitated aortic valve replacement despite treatment with ceftriaxone followed by ciprofloxacin. The blood isolate of C. hominis produced beta-lactamase and exhibited high-level resistance to penicillin (MIC, >==256 microgram/ml) and reduced susceptibility to vancomycin (MIC, 8 microgram/ml). (+info)
The effect of allogeneic or xenogeneic immune responses and preservation techniques on transplanted aortic valve grafts.
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We examined the effect of allogeneic and xenogeneic immune responses on the histopathological changes in aortic valve grafts and the influence of preservation techniques on these changes. Brown Norway rats and Syrian hamsters were used as allogeneic and concordant xenogeneic donors of aortic valve grafts, respectively. The allografts and xenografts were implanted heterotopically in the abdominal aorta of Lewis rat recipients immediately after harvest (homovital), after cryopreservation, or after preservation with antibiotics at 4 degrees C (fresh preservation). Allografts and xenografts were explanted at days 7, 28 or 56 and at days 3, 7 or 14, respectively, for the histopathological examination. The allografts underwent histological changes characteristic of graft arteriosclerosis. No significant effect of cryopreservation on these changes was observed. The fresh-preserved graft was, however, predisposed to focal destruction of the elastic fibers and to early disappearance of the leaflet. The lesions in xenografts were characterized by severe destruction of the elastic fibers. Compared to homovital xenografts, both cryopreserved and fresh-preserved xenografts showed more prominent disruption of the elastic fibers, well-developed valvular and vascular thrombi and earlier disappearance of the leaflet. In conclusion, it could be assumed that failure in retention of cellular and extracellular components during fresh preservation accelerates structural deterioration of allografts. As for xenografts, even the extracellular matrix may have potential xenogeneic immunogenicity. There is a possibility of these preservation techniques reducing xenogeneic immunogenicity of the endothelial cells, probably because of loss of these cells. However, it appears that, even in this setting, other cellular and extracellular components could trigger immune responses causing structural deterioration of xenografts. (+info)
Single-oral-dose azithromycin prophylaxis against experimental streptococcal or staphylococcal aortic valve endocarditis.
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Azithromycin and ampicillin protected 94 and 72% of animals challenged with Streptococcus oralis, respectively (P = 0.177), while azithromycin and vancomycin protected 59 and 94% of the methicillin-resistant Staphylococcus aureus (MRSA)-challenged animals, respectively (P = 0.018). Azithromycin is effective in preventing experimental streptococcal endocarditis, but against MRSA it is less effective than vancomycin. (+info)
Abnormal aortic valve development in mice lacking endothelial nitric oxide synthase.
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BACKGROUND: Endothelium-derived nitric oxide (NO) is produced by an oxidative reaction catalyzed by endothelial NO synthase (eNOS). NO plays a crucial role in controlling cell growth and apoptosis, as well as having well-characterized vasodilator and antithrombotic actions. More recently, endothelium-derived NO was shown to be involved in postdevelopmental vascular remodeling and angiogenesis, as well as in the formation of limb vasculature during embryogenesis. Therefore, we investigated the role of endothelium-derived NO during cardiovascular development using mice deficient in eNOS. METHODS AND RESULTS: We examined the hearts of 12 mature eNOS-deficient and 26 mature wild-type mice. Five of the mature eNOS-deficient mice had a bicuspid aortic valve; none of the 26 wild-type animals exhibited identifiable valvular or cardiac abnormalities. Immunohistochemical analysis revealed prominent eNOS expression localized to the endothelium lining the valve cusps of the aorta in mature wild-type mice; expression was localized to the myocardium and endothelial cell monolayer lining the valve leaflets in the developing embryo. CONCLUSIONS: These results show a strong association between eNOS deficiency and the presence of a bicuspid aortic valve; they provide the first molecular insight into one of the most common types of congenital cardiac abnormality. (+info)
A controlled surgical approach to annulo-aortic ectasia.
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Annulo-aortic ectasia has attracted much surgical attention in the last 20 years. Replacement of the aortic valve and ascending aorta from the valve ring to just proximal to the innominate artery eliminates most, if not all, the pathologically involved tissue. Composite valve-Dacron tube grafting, plus elective saphenous vein grafts from the coronary orifices to the Dacron tube or distal aortic wall, provide a safe systematic approach to this entity. A review of surgical techniques and a description of a successful case employing this method are presented. (+info)
Mitral and aortic valve endocarditis due to Staphylococcus lugdunensis.
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Staphylococcus lugdunensis is a recently described coagulase negative staphylococcal species involved in human infections. Endocarditis caused by Staphylococcus lugdunensis has been reported rarely: fewer than 50 cases have been described so far. The infection is frequently complicated by embolic events and carries a high mortality rate. We report a case of endocarditis due to Staphylococcus lugdunensis in which the native mitral and aortic valves were infected. The bacterium was isolated on cultures from the aortic and mitral vegetations. Appropriate medical and surgical treatment led to a good outcome of the infection. At 6-year follow-up, there was no evidence of recurrence, and the patient showed good functional recovery. He was in New York Heart Association functional class I. (+info)