Effects of laser irradiation on cardiac valves: transcatheter in vivo vaporization of aortic valve.
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Animals↗
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Results for “CARDIAC VALVES”
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The homograft. A new dimension for cardiac valve replacement.
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Aortic Valve↗
[Early valve replacement of the infected cardiac valve. Analysis of 27 cases].
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Adolescent↗
Direct microscopic examination of imprints in patients undergoing cardiac valve replacement.
BACKGROUND: Bacteriological analysis of cardiac valves might be indicated in patients with suspected endocarditis. METHODS: We report here a prospective study on fifty-three consecutive patients whose native valves were sent to the bacteriological and pathological laboratories, to investigate the performance of direct microscopic examination of imprints and valve culture. RESULTS: On the basis of a histopathological gold standard to classify the inflammatory valve process, the sensitivity, the specificity, the positive and the negative predictive values of direct microscopic examination of imprints and valve culture were 21%, 100%, 100%, 60%, and 21%, 72%, 38%, 52% respectively. This weak threshold of the direct microscopic examination of imprints could be due to antimicrobial therapy prescribed before cardiac surgery and the fact that the patients came from a tertiary hospital receiving patients with a prolonged history of endocarditis. CONCLUSION: Clinical context and histopathology are indispensable when analyzing the imprints and valve culture.
Journal Article↗
Histologic changes in three explanted native cardiac valves following use of fenfluramines.
Use of fenfluramines, either alone or co-administered with phentermine ("fen-phen") as anorexic agents in obesity, has been associated with the development of clinically significant cardiac valve disease. We present the macroscopic and histologic findings in cardiac valves explanted from three patients who presented with valvular disease after fenfluramine or fenfluramine-phentermine use and underwent single valve replacement surgery. Paraffin sections were prepared with hematoxylin and eosin, trichrome, elastic-van Gieson, and Giemsa stains, as well as immunostains using antibody to CD3 and CD20. All three patients (two females, ages 37 and 43, and a 49-year-old male) developed progressively symptomatic mitral (2 patients) or aortic (1 patient) valvular insufficiency following dexfenfluramine (2 patients) or fenfluramine-phentermine (1 patient) use. Macroscopic changes included irregular leaflet thickening, accompanied by chordal fusion in the mitral valves, but without vegetations, commissural fusion, or evidence of annular dilation. Histologically, fibromyxoid plaques and nodules just below the valve surface, superficial to a generally intact elastic fiber layer, were associated with CD3-positive lymphocytes. Valves from all three patients had central myxoid degenerative changes, which were focal/mild in one mitral valve, diffuse/moderate in one mitral valve, and diffuse/marked in one aortic valve. Focal areas of superficial fibromyxoid change or intimal thickening may also be seen in cardiac valves from patients with drug-unrelated processes leading to symptomatic or asymptomatic valvulopathy. Therefore, when valve tissue is available for histopathologic examination, valvular disease can be attributed to use of fenfluramines only if the following criteria are satisfied: (i) the macroscopic and microscopic features are consistent with fenfluramine-related valvulopathy, (ii) clinical, echocardiographic, and intraoperative findings support the diagnosis, and (iii) the history of drug exposure predates the development or exacerbation of valvular dysfunction.
Adult↗
Autopsy-determined causes of death after cardiac valve replacement.
We reviewed records of 378 patients who died after cardiac valve replacement and underwent autopsy at The Methodist Hospital, Houston, from 1962 through 1979. Patients were divided according to postoperative interval at death: within 30 days (early) or 30 days to ten years (late). Early deaths (279 patients) were due almost exclusively to cardiovascular abnormalities or operative complications (94%). Only 6% of early deaths were caused by prosthesis-associated complications. In contrast, late deaths (99 patients) were valve related in 47% of cases, including complete thrombotic occlusion or systemic thromboembolism (21%), prosthetic valve endocarditis (14%), valve dehiscence (6%), anticoagulation-related hemorrhage (3%), and mechanical degeneration (2%). Nine percent of late deaths were unrelated to cardiovascular disease. Thus, while early deaths primarily reflected the severity of preexisting or associated cardiovascular disease, prosthesis-associated complications were an important cause of late death after cardiac valve replacement.
Anticoagulants↗
Effects of hypertonic saline-dextran solution in cardiac valve surgery with cardiopulmonary bypass.
BACKGROUND: Hypertonic saline-dextran (HSD) solution may be beneficial in patients undergoing coronary artery surgery with cardiopulmonary bypass. Valvular dysfunction is associated with high pulmonary wedge pressure, pulmonary hypertension, and ventricular dysfunction. Fluid overload or transient left ventricular failure may occur with HSD infusion in such patients. This study evaluates the cardiorespiratory effects and tolerance of HSD solution infusion in patients undergoing cardiac valve surgery. METHODS: This prospective, randomized, double-blind study compared clinical, laboratory, hemodynamic, and respiratory measurements, and fluid balance in 50 patients over a 48-hour period after cardiopulmonary bypass for cardiac valve surgery. Twenty-five patients received 4 mL/kg of HSD during 20 minutes before cardiopulmonary bypass (HSD group). The control group received the same volume of Ringer's solution (Ringer group). RESULTS: Hospital mortality was zero. The HSD patients had a near zero fluid balance (6.5 +/- 13.5 mL/Kg/48 hours), and the control patients had a positive balance (91.0 +/- 33.7 mL/Kg/48 hours). Hemoglobin was similar in both groups, but more blood transfusions were necessary in the Ringer group (1.21 +/- 1.28 vs 0.48 +/- 0.59 units per patients). The HSD solution induced a higher cardiac index and left ventricular systolic work index postoperatively, and a lower systemic vascular resistance index until 6, 24, and 48 hours. Right ventricular systolic work index increased and pulmonary vascular resistance index decreased after HSD infusion. A better Pao(2)/Fio(2) relation was observed at 1 and 6 hours postoperatively in the HSD group and was associated with a shorter extubation time (432.0 +/- 123.6 vs 520.8 +/- 130.2 minutes). Increased oxygen delivery index occurred in the HSD group. The HSD infusion was well tolerated as none of the patients experienced fluid overload or had left ventricular failure develop. No other complication attributable to the use of HSD solution was observed. CONCLUSIONS: The HSD solution infusion in patients during cardiac valve surgery with cardiopulmonary bypass was well tolerated. Hemodynamic and respiratory functions improved and fluid balance was near zero during the first 48 hours as compared with a large positive balance in the control group. We conclude that HSD infusion is advantageous for patients undergoing cardiac valve surgery.
Adult↗
Five-year clinical experience with the Omniscience cardiac valve.
Clinical data on the Omniscience cardiac valve prosthesis (sizes 19 to 31 mm) were obtained from 326 patients (155, aortic valve replacement [AVR]; 125, mitral valve replacement [MVR]; and 46, double-valve replacement) during a five-year period (650 patient-years) with 96% accountability. Mean age was 56 +/- 12 years, and 40% (130) of the patients were 61 years old or older. Thirty-one percent (101) had prior or concomitant coronary artery bypass grafting procedures, 9% (28) had a previous malfunctioning prosthesis, and 17% (57) had other cardiac surgical procedures. Eighty percent were in New York Heart Association (NYHA) Functional Class III or IV preoperatively. Early mortality was 10% (34). Five-year actuarial thrombus-free rate is 96% for patients who underwent AVR and 95% for patients having MVR. Postoperatively, 89% (172/193) were in NYHA Class I or II, and 84% (163/193) improved by at least one Functional Class. A significantly high proportion of the postoperative hematological values fall within normal ranges: red blood cell count, 94% (176/187); hematocrit, 88% (166/188); and hemoglobin, 93% (176/190). Ninety-eight percent (287/292) are free from clinical anemia. Four of the 5 patients with clinical anemia had a preoperative history of this condition. Levels of lactic dehydrogenase in 3 patients suggested the probable presence of clinically significant hemolysis, although all 3 have normal hematological values. Actuarial five-year survival for patients who underwent AVR or MVR are similar (82% and 80%, respectively), indicating satisfactory and comparable levels of safety and performance.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Hypothermic circulatory arrest for cardiac valve replacement reoperations.
Three patients had cardiac valve replacement using hypothermic circulatory arrest. The patients had multiple previous operations via median sternotomy, and 1 had functioning coronary bypass grafts. This technique provided simple and safe reentry to the heart without necessity of control of the aorta or venae cavae, adequate myocardial and cerebral protection from ischemia, and excellent operating conditions for the valve replacement.
Adult↗
Autologous tissue cardiac valve for aortic valve replacement: technical aspects and early results.
BACKGROUND: The known complications of heterograft bioprostheses and homograft valves have renewed the interest in the use of autologous material. A new technique to construct a tissue prosthesis for aortic valve replacement using the patient's pericardium harvested at the time of operation was developed. The glutaraldehyde-tanned pericardium is mounted on a stent requiring no suturing. Intraoperative testing assures adequate valve function. METHODS: The autologous tissue cardiac valve was implanted in 50 patients in the aortic position between March 1994 and May 1995. Echocardiograms were performed in all patients before hospital discharge, at 3 months (41 patients), and at the end of first postoperative year (12 patients). The mean age was 69.8 +/- 5 years (range, 58 to 82 years). Eighty-four percent of patients presented with aortic stenosis and 16% had a combined lesion. Additional cardiac procedures were performed in 21 patients. RESULTS: Aortic cross-clamp time was 72 +/- 19 minutes, and bypass time was 97 +/- 28 minutes. There were three in-hospital deaths, and 2 patients died within the first postoperative year. Predischarge echocardiography demonstrated excellent hemodynamics, with a mean gradient of 20 +/- 8 mm Hg and no or trivial aortic insufficiency in 45 patients. One patient had moderate aortic insufficiency. At first follow-up 36 patients (90%) were in New York Heart Association class I and 4 patients were in class II. Echocardiography showed no evidence of valve failure or degeneration (mean gradient, 17 +/- 5mm Hg; aortic insufficiency = grade 0 [trivial] in 35 patients, grade II in 3 patients, and grade III in 1 patient). Similarly, no degeneration or valve failure with increasing aortic insufficiency was seen in the patients studied at the end of the first postoperative year. CONCLUSIONS: These results demonstrate that an autologous tissue cardiac valve can be manufactured in the operating room without significant additional operating time. Intraoperative testing minimizes the risk of primary failure with aortic insufficiency. Short-term results are encouraging with good hemodynamic performance of the valve and no signs of degeneration. However, long-term durability needs to be demonstrated.
Aged↗
Comparison of the hemodynamic effects of amrinone in patients who required low-to-moderate-dose and high-dose catecholamines after cardiac valve replacement.
OBJECTIVES: To determine hemodynamic response to amrinone in patients after cardiac surgery, in relation to the postoperative cardiac function, which was indicated by the required doses of catecholamines. DESIGN: Prospective clinical study. SETTING: Surgical intensive care unit in a university hospital. PATIENTS: Fourteen patients who required a low-to-moderate dose of dopamine and dobutamine (group L) and 14 patients who required a high dose of dopamine and dobutamine (group H) after cardiac valve replacement. INTERVENTIONS: A loading dose of amrinone (0.75 mg/kg) was administered during a 15-min period and the continuous infusion was followed incrementally by doses of 5, 10, and 20 microg/kg/min every 60 mins on the first postoperative day. MEASUREMENTS AND MAIN RESULTS: Hemodynamic variables were determined by the radial and pulmonary artery catheters at a dose of 0, 5, 10, and 20 microg/kg/min. Two-way repeated-measures analysis of variance showed significant interaction in the two groups in cardiac index and mean systemic arterial pressure. Cardiac index increased in a dose-dependent manner in group L but was unchanged in group H. Systemic vascular resistance index decreased in a dose-dependent manner in both groups. The mean systemic arterial pressure decreased in group L at a dose of 5 microg/kg/min and returned to the baseline level at doses of 10 and 20 microg/kg/min. On the other hand, the mean systemic arterial pressure significantly decreased in group H at a dose of 20 microg/kg/min. CONCLUSIONS: The inotropic effects of amrinone after cardiac valve replacement may be associated with the postoperative myocardial reserve, which was indicated by the required doses of catecholamines, although a similar vasodilative effect was observed in both groups.
Adult↗
Bloodstream infections in patients with implanted prosthetic cardiac valves.
A bloodstream infection in a patient with a recently implanted prosthetic cardiac valve is an ominous sign. In the six studies reviewed, the overall mortality rate for patients with bloodstream infections with and without prosthetic valve endocarditis (PVE) were 48% and 51%, respectively. Patients with PVE usually die from a complication of endocarditis. The high mortality rate in patients without endocarditis can be attributed to a severely ill cohort of hospitalized patients, who have a prolonged postoperative course and require life support in intensive care units for multiple organ failure. Although gram-positive cocci (especially coagulase-negative staphylococci) are the most common organisms associated with PVE, any microorganism isolated from the bloodstream must be considered as a potential cause of endocarditis in patients with prosthetic cardiac valves. The conclusion of earlier studies, that PVE was unlikely if infection was due to a gram-negative aerobic bacillus or if a portal of entry could be established, has not been supported by recent studies. An aggressive search for evidence of endocarditis must be performed in all patients with implanted heart valves and bloodstream infections. Successful treatment for most cases of early-onset PVE is primarily surgical.
Bacteremia↗
Evaluation of operatively excised cardiac valves: etiologic determination of valvular heart disease.
Morphologic evaluation of operatively excised native cardiac valves can lead to an etiologic diagnosis in most instances using a simple 10-step approach. With few exceptions, histologic evaluation of excised cardiac valves provides little additional information beyond this proposed morphologic assessment.
Aortic Valve Insufficiency↗
[Percutaneous cardiac valve replacement: a review].
Surgery is no longer the only technique to replace a cardiac valve. New percutaneous procedures allow aortic or pulmonary valve implantation. Even if the feasibility of these procedures has been proved, cases reported are very rare and selected. This emergent technology is still at an early stage of development and new prospective studies will be necessary to evaluate these procedures correctly before concluding their clinical benefit. At this time surgery remains the gold standard in terms of cardiac valve replacement.
Cardiac Catheterization↗
Relationship between preoperative endotoxin immune status, gut perfusion, and outcome from cardiac valve replacement surgery.
STUDY OBJECTIVE: Endotoxin is a powerful trigger of systemic inflammation. Since cardiac surgery exposes patients to endotoxemia, this study was set up to define the relationship between preoperative endogenous endotoxin immune status, gut perfusion, and outcome following cardiac valve replacement surgery. DESIGN: Observational study. SETTING: University hospital. PATIENTS: Fifty-nine consecutive patients undergoing cardiac valve replacement. MEASUREMENTS AND MAIN RESULTS: Blood was assayed for IgG and IgM endotoxin core antibody (EndoCAb) levels preoperatively, immediately postoperatively, and at 4 h and 24 h postoperatively. Intraoperative gut mucosal perfusion was assessed using gastric tonometry. Complications were assessed for groups above and below the median EndoCAb value of a healthy population (100 median units micro/mL). Of the 59 patients, 12 developed at least one of a set of predefined complications. Of these 12, all had preoperative levels of IgM EndoCAb below 100 MU/mL (p<0.025). Eleven had IgG EndoCAb levels below 100 MU/mL (0.05<p<0.1). There was no relationship between the fall in gastric intramucosal pH and exposure to endotoxin as implied by the fall in unbound IgM EndoCAb levels, although the specificity of tonometry for predicting complications could be improved by considering the patient's preoperative EndoCAb status. CONCLUSIONS: Preoperative EndoCAb levels were related to poor outcome following cardiac surgery and may be used to improve the specificity of GI tonometry in predicting postoperative complications.
Adolescent↗
The porcine bioprosthesis. A review of 1,000 consecutive patients undergoing cardiac valve replacement.
Early and late experience with 1,000 patients undergoing porcine xenograft replacement of cardiac valves from 1974 through 1981 at Emory University Hospital is presented. Hemodynamic performance of the modified orifice Hancock and the Carpentier-Edwards valves has been quite satisfactory. There has been a low incidence of thromboembolism in the absence of routine anticoagulation. Less than 20 per cent of our patients are anticoagulated long-term, the primary indication being chronic artrial fibrillation. Endocarditis has developed in 0.7 per cent of patients, an incidence comparing most favorably with that of mechanical prostheses. Valve dysfunction secondary to primary tissue failure is a definite problem. The highest incidence of tissue failure occurred in young patients after six years of implantation. Detailed analysis of long-term patient survival showed a low incidence of valve related deaths. The porcine xenograft is a satisfactory prosthesis for cardiac valve replacement. Our data suggests its use should be limited to older patients or to patients in whom anticoagulation is contraindicated. It should be explained to all patients that long-term durability is unknown and that re-replacement of these bioprostheses within a decade is quite likely.
Adolescent↗
Mild renal failure is associated with adverse outcome after cardiac valve surgery.
The present study was performed to ascertain whether the presence of mild renal failure (defined as a serum creatinine concentration of 1. 5 to 3.0 mg/dL) is an independent risk factor for adverse outcome after cardiac valve surgery. An extensive set of preoperative and postoperative data was collected in 834 prospectively evaluated patients undergoing cardiac valve surgery at 14 Veterans Affairs Medical Centers. Univariate and multivariable analyses were performed to determine whether an independent association of mild renal dysfunction with adverse outcomes was present. Patients with mild renal failure had significantly greater 30-day mortality rates (P = 0.001; 16% versus 6%) and frequency of postoperative bleeding (P = 0.023; 16% versus 8%), respiratory complications (P = 0.02, 29% versus 16%), and cardiac complications (P = 0.002; 18% versus 7%) than patients with normal renal function (serum creatinine <1.5 mg/dL) when controlling for multiple other variables. The presence of a serum creatinine concentration of 1.5 to 3.0 mg/dL is significantly and independently associated with adverse outcomes after cardiac valve surgery.
Age Factors↗
Biochemical and cellular characterization of cardiac valve tissue after cryopreservation or antibiotic preservation.
It has been reported that aortic homografts that have been cryopreserved before transplantation remain viable longer as an allograft than tissue stored at 4 degrees C in an antibiotic solution. In the present study, we tested the hypothesis that storage of cardiac valve tissue by cryopreservation or by antibiotic preservation may alter the metabolic status of the tissue. Initially, we collected aortic valves composed of cardiac tissue, aortic root, and valvular tissue from cadaver donors. These specimens were divided into three equal portions, and one portion was analyzed before storage while the other two parts were stored for 3 weeks at either 4 degrees C in an antibiotic solution or at -196 degrees C in liquid nitrogen. All specimens were examined with regard to the following parameters: tissue structure, tissue viability, cell proliferative capacity, metabolic function, and identification of cell-specific antigens. We found no significant alterations in the structure of any of the three tissue components after antibiotic preservation or cryopreservation; however, cell viability and cell number were decreased in all three groups. All tissue samples grew in culture before storage. When we compared activities of the following organellar marker enzymes--lysosomal acid lipase, plasma membrane 5' nucleotidase, mitochondrial cytochrome oxidase, and microsomal neutral alpha-glucosidase--we observed no major differences between tissues stored by either technique. In addition, we observed no loss of enzymic activity as a result of storage. Finally, when cell lines isolated from each tissue specimen were incubated with monoclonal antibodies against cell-specific antigens in an immunoperoxidase assay, all the cell cultures proved to be endothelial cells. These results suggest that although cardiac valve tissue stored by cryopreservation or by antibiotic preservation retained its normal structure and metabolic capabilities, both storage techniques produced significant decreases in cell numbers and viability. However, only endothelial cells from tissue stored by cryopreservation retained the capacity to proliferate in vitro. These findings have important implications for the function of aortic homografts transplanted after storage.
5'-Nucleotidase↗