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At least 253 records · Page 14Linked to original sources
PubMed1994

Pregnancy outcome in women with cardiac valve prosthesis.

Twenty-one pregnancies in 16 women who conceived after cardiac valve replacement were reviewed. Oral anticoagulants were discontinued before conception or as soon as possible for subcutaneous heparin treatment (8000-14,000 IU every 8-12 h) and resumed in the second trimester until the last period of pregnancy when oral anticoagulants were replaced again by heparin. No therapeutic abortion was performed. The spontaneous abortion rate was found to be 14.3% (3/21). Preterm delivery (< or = 37 weeks) and low birth weight babies (< 2500 g) were 29.4% (5/17) and 35.3% (6/17), respectively, significantly more frequent than those of the control group (P < 0.02 and P < 0.0005). No significant statistical difference was found when the rate of spontaneous abortion [14.3% (3/21)] and the rate of fetal growth retardation [11.8% (2/17)] were compared with the control group. The majority of thromboembolic events (6/7) occurred during heparin regimen in three mothers; one of them subsequently died. No coumarin embryopathy was observed and the physical and mental development in the 16 surviving children was good. This study confirms: (1) the increased rate of preterm delivery and infants weighing < 2500 g; (2) the increased risk of maternal thrombosis related to heparin use; and (3) the good follow-up in the surviving children.

Abortion, Spontaneous↗
PubMed1998

Calcification of porcine and human cardiac valves: testing of various inhibitors for antimineralization.

Despite distinct advantages over mechanical cardiac valve prostheses, the use of bioprosthetic valves remains limited, due to poor long-term durability, primarily as a result of tissue calcification. A novel in vitro, anticalcification process based on treatment of porcine and human heart valves with metallocene dichlorides, as well as with amino acids (phenylalanine, aspartic acid, glutamic acid), has been developed. This anticalcification process reduced mineralization of porcine and human valves up to 32% and 28%, respectively.

Journal Article↗
PubMed2000

Preservation of collagen-induced whole blood platelet aggregation by tranexamic acid therapy in primary cardiac valve surgery.

Haemostatic disorder is one of the most common complications following cardiac surgery with cardiopulmonary bypass (CPB). Tranexamic acid reduces blood loss and allogeneic blood transfusion requirement in cardiac surgery. It had been thought that tranexamic acid inhibited fibrinolysis alone following CPB. In the present study, the haemostatic effects of tranexamic acid (20 mg/kg body weight bolus after induction of anaesthesia followed by continuous infusion at 2 mg/kg/h), including fibrinolysis and platelet function, were investigated in 22 patients (tranexamic acid group n = 12; control group n = 10) undergoing primary cardiac valve surgery. Fibrinolysis following CPB was reduced significantly in the tranexamic acid group. Following protamine administration, the reduction of collagen-induced whole blood platelet aggregation was mitigated significantly in the tranexamic acid group compared with the control group (36% reduction in the tranexamic acid group vs 58% in the control group; p = 0.011), although platelet counts did not differ between the two groups. In conclusion, tranexamic acid not only inhibits fibrinolysis directly, but also may preserve platelet function following CPB.

Adult↗
PubMed1975

Homologous dura mater cardiac valves. Study of 533 surgical cases.

A group of 533 patients had cardiac valves replaced with homologous dura mater valves. The dura mater was preserved in a solution of 98 per cent glycerol and antibiotics for a period of 12 days before used. The leaflets were mounted in a stainless steel ring covered by Dacron velour. Two hundred forty-five patients had mitral valve replacement; 205 patients, aortic valve replacement; 17 patients, tricuspid valve replacement; and 2 patients, pulmonary valve replacement. Sixty-four patients were subjected to multivalvular replacements. The patients were followed for a period of 1 to 40 months after surgery with satisfactory clinical and hemodynamic results. Because 2 patients developed endocarditis produced by fungii, fungicidal drugs were added to the preservative solution. No bacterial endocarditis has been observed. No pressure gradient through the valve has been noted at rest. Anticoagulant drugs have not been used in the postoperative period.

Adolescent↗
PubMed1979

Cardiac valve replacement in children: comparison of tissue with mechanical prostheses.

Replacement of cardiac valves in children has been associated with high rates of mortality and morbidity in the past. We have compared 24 children from 2 to 18 years of age who have received mechanical valves with 24 children who have received porcine valves. The groups were similar except that (1) there were more mitral operations in the mechanical valve group and more aortic operations in the porcine valve group; (2) more porcine than mechanical valves were implanted in recent years; and (3) the porcine valve group comprised more young patients under 8 years and required more complex operations. Early and late mortality rates were higher in the mechanical than in the porcine valve group. Major late complications were seen in 50 percent of the mechanical valve group and 13 percent of the porcine group. Implantation of an adult-sized aortic valve was made possible in all patients by the use of aortic augmentation annuloplasty. Higher operative mortality rates in the mechanical valve group may have been related more to technique of myocardial preservation during operation than to type of valve. Although differing rates of late morbidity and mortality may also have been related to myocardial preservation and other technical factors, the type of valve used seemed to be an important determinant of the better results in the porcine group. Despite unknown durability of the porcine valve, our data suggest that the safest prosthetic valve to use in children at this time is the glutaraldehyde-fixed porcine prosthesis.

Adolescent↗
PubMedDate not supplied

Seventy-six month experience with the Omniscience cardiac valve.

Between August 1978 and September 1984, 440 patients were implanted with the Omniscience cardiac valve at three North American medical centers (210 aortic, AVR; 165 mitral, MVR; and 65 double valve replacements). Total follow-up was 1056 patient years; survivors were followed up to 76 months (mean 32), with 99% accountability. One hundred and eighty-six (42%) also underwent prior or concomitant major cardiac surgical procedures. Mean age was 56 +/- 12 years. Preoperatively, 3% were in New York Heart Association (NYHA) Class I, 18% II, 54% III, 26% IV. The 5 1/2 year actuarial survival rate for death from valve-related causes (thromboembolism, valve thrombosis, perivalvular leak) was 97% overall. The 5 1/2 year actuarial survival rate from all death causes was 78%. The complication rates, expressed as %/patient-year (endocarditis 0.7; anticoagulant-related hemorrhage 1.0; perivalvular leak 1.5; pannus/tissue overgrowth 0.6; and transient ischemic episode 1.2) demonstrate that advanced age at implant and additional major cardiac surgical procedures do not affect occurrence. Actuarial freedom from thrombotic complications (thromboembolism with residual deficit and valve thrombosis) at 5 1/2 years was 95% overall. Postoperatively, of 348 patients with known NYHA, 65% were in NYHA I, 28% II, 5% III, and 2% IV.

Adolescent↗
PubMed1981

Successful pregnancy 10 years after triple cardiac valve replacement.

A case is described of a term pregnancy in a woman 10 years after she underwent replacement of tricuspid, mitral, and aortic valves for rheumatic heart disease. Improved functional cardiac status after valve replacement made full-term pregnancy feasible. Careful prenatal management is essential in reducing fetal and maternal risks. Women with prosthetic cardiac valves and who have achieved good functional cardiac status can tolerate pregnancy and delivery.

Adult↗
PubMed1992

Cardiac valve reconstruction and replacement: a brief review.

Surgical methods for improving the function of diseased cardiac valves are valve reconstruction (valvuloplasty) and valve replacement with mechanical prostheses, biologic prostheses, or homograft (donor) valves. Reconstruction is used primarily for incompetent mitral and tricuspid valves and addresses each part of the valve apparatus individually. Annuloplasty rings are often used to restore the size and shape of the valve orifice. Long-term anticoagulation therapy is not necessary. The designs of mechanical prostheses have evolved since the early caged-ball prostheses. Current models are noted for their durability. Patients who undergo implantation of these prostheses must also undergo long-term anticoagulation therapy. Biologic prostheses made from porcine valves or bovine pericardium are not as durable as their mechanical counterparts, but they do not require long-term anticoagulation therapy. Homografts are used in relatively few centers. They have good hemodynamics and do not necessitate long-term anticoagulation therapy. Radiologists should be familiar with the radiographic appearance of the various valve prostheses and annuloplasty rings and with the advantages and disadvantages of their use in cardiac valvular surgery.

Bioprosthesis↗
PubMed1991

Pregnancy and its complications after cardiac valve replacement.

The outcome of 64 pregnancies in 40 women who conceived after cardiac valve replacement were reviewed. Fetal wastage was 53.2% (25/47) in coumarin administered pregnancies, 36.4% (4/11) using heparin and 16.7% (1/6) without anticoagulants. Two fetal malformations were noted in coumarin administered pregnancies. There were two maternal deaths. Maternal morbidity due to antenatal bleeding, atrial fibrillation, thromboembolic episodes and cardiac failure were found to be 20.0% (8/40), 17.5% (7/40), 10.0% (4/40) and 10.0% (4/40), respectively.

Abnormalities, Drug-Induced↗
PubMed1977

LOW PROFILE BIOPROSTHESIS FOR CARDIAC VALVE REPLACEMENT: EARLY CLINICAL RESULTS.

Between May 1976 and April 1977, 100 patients underwent cardiac valve replacement with a unique low profile glutaraldehyde-treated porcine aortic xenograft. These patients were classified in four groups: Group I, 43 patients who underwent isolated mitral valve replacement (MVR); Group II, 27 patients who had isolated aortic valve replacement (AVR); Group III, 10 patients who had MVR and AVR; and Group IV, 20 patients who had MVR or AVR associated with other cardiac procedures. The operative mortality for Group I was 2.3% (1 of 43) and 15% (3 of 20) in Group IV. The total operative mortality was 4% (4 of 100) and the late mortality was 1.02% (1 of 96 survivors), who died apparently secondary to a cardiac arrhythmia. During a follow-up period extending for 16 months, thromboembolic complications occurred early in the postoperative period in 3% (3 of 100), one patient with neurological residual, and two patients with transient symptoms only. The embolic complications occurred only in Group I. Considering all patients in whom the mitral valves were replaced, the incidence of emboli was 4.9% (3 of 61). The 96 patients did not receive anticoagulant therapy. Reoperation was necessary in one patient because of periprosthetic leak. The incidence of endocarditis was 1.02% (1 of 96 survivors). We recommend anticoagulant therapy for eight to twelve weeks postoperatively in MVR patients after bioprosthetic insertion.

Journal Article↗
PubMed1988

Bjork-Shiley cardiac valves long term results: Winnipeg experience.

Between April 1970 and December 1984, 1183 Bjork-Shiley cardiac valve prostheses were implanted in 915 patients (470 males, 445 females). Four types of valves were used; Delrin disc prostheses in 75 patients, pyrolytic carbon spherical disc valves in 645 patients, the 60 degrees convexo-concave disc model in 197 patients and the 70 degrees model in seven patients. Isolated mitral valve replacement was performed in 278 patients, isolated aortic valve replacement in 363 and double valve replacement in 153. Concomitant surgery was performed in 121 patients, including a modified Bentall procedure in 15. Perioperative mortality was 6.4% (nine patients undergoing isolated aortic valve replacement; 16 in mitral valve group, 18 with double valve replacement and 16 undergoing concomitant surgery). The cumulative follow-up was 4592 patient-years, to a maximum of 15 years. There were 130 late deaths, 60% due to cardiac events. Actuarial survival for the mitral valve group was as follows: four of six patients with Delrin disc valves were alive at 13.4 years; in the pyrolytic group, survival was 82% at 10 years; in the 60 degrees convexo-concave group survival was 87.5% at seven years. In the aortic valve replacement group, 83% of patients with pyrolytic valves were alive at 10 years and 85.7% of the 60 degree convexo-concave group were alive at seven years. For patients undergoing double valve replacement, 72% were still alive after seven years. Thromboembolic events averaged 1.4 per 100 patient-years. There were seven complete valve thromboses in the mitral position requiring reoperation; six of these patients were long term survivors.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1985

Anticoagulation therapy in children with mechanical prosthetic cardiac valves.

From 1980 through 1984, 28 children younger than 19 years (mean 7.9) underwent cardiac valve replacement with 30 mechanical prostheses. Patients were followed for a total of 471 months (mean 15.7) and received either warfarin (mean 0.16 mg/kg/day) or acetylsalicylic acid and dipyridamole (mean 6.1 and 1.9 mg/kg/day, respectively) as thromboembolism prophylaxis. The frequency and incidence of thromboembolism and hemorrhage were compared. Warfarin-treated patients were at increased risk of hemorrhage (5 of 20 [25%], or 22 per 100 patient-years, vs 0 of 10 [0%], or 0 per 100 patient-years, p less than 0.05). Three of the 5 hemorrhagic episodes were mild, and in no case was hemorrhage life-threatening. Patients who did not receive warfarin had a greater risk of thromboembolism (2 of 10 [20%], or 12 per 100 patient-years, vs 0 of 20 [0%], or 0 per 100 patient-years, p less than 0.05). Both episodes of thromboembolism were life-threatening and necessitated emergency valve replacement. Although warfarin is associated with greater risk of hemorrhage than is acetylsalicylic acid and dipyridamole, warfarin is better than antiplatelet drugs in thromboembolism prophylaxis and is indicated for anticoagulation therapy in children with mechanical cardiac prostheses.

Aspirin↗
PubMed1975

Current status of the Beall, Bjork-Shiley, Braunwald-Cutter, Lillehei-Kaster and Smeloff-Cutter cardiac valve prostheses.

The Starr-Edwards ball valve prosthesis is generally the standard by which other cardiac valve substitutes are compared. This report reviews information pertaining to several prostheses--the Beall mitral valve and the Bjork-Shiley, Braunwald-Cutter, Lillehei-Kaster and Smeloff-Cutter aortic and mitral valves--considered by some to have specific advantages over the Starr-Edwards valves. Hospital and late mortality rates after valve replacement are comparable for the four aortic valve prostheses reviewed and depend more on patient selection than on the specific prosthesis utilized. Extensive clinical experience with the Bjork-Shiley aortic valve indicates that this prosthesis offers hemodynamic advantages over ball valve prostheses, especially in patients with a small aortic root. Clinical experience with the Lillehei-Kaster pivoting disc prosthesis has been less extensive, but this model provides theoretical hemodynamic advantages similar to those of the Bjork-Shiley aortic valve prosthesis. Problems associated with cloth wear and the unexpectedly slow rate, in man, of tissue ingrowth into the fabric of the Braunwald-Cutter aortic valve prosthesis have been discouraging, although this prosthesis has been associated with a very low thromboembolic rate in patients receiving anticoagulant therapy. The Smeloff-Cutter aortic prosthesis is hemodynamically similar to the Starr-Edwards prosthesis and has been proved to be a reliable and durable aortic valve substitute over the past several years. Mortality after mitral valve replacement is also largely influenced by factors other than prosthetic valve design. On the basis of postoperative data, the five mitral valve prostheses reviewed do not appear to have substantial hemodynamic differences. For patients with a small left ventricular cavity the low profile prostheses, such as the Beall, Bjork-Shiley and Lillehei-Kaster, may be advantageous. Most available evidence indicates that patients receiving aortic or mitral valve prostheses should be given anticoagulant therapy postoperatively.

Anticoagulants↗
PubMed1994

Spontaneously appearing microbubbles associated with prosthetic cardiac valves detected by transesophageal echocardiography.

During transesophageal echocardiographic studies in patients with prosthetic cardiac valves, we have noticed the presence of bright, highly mobile echoes (termed microbubbles because of their similarity to saline contrast bubbles) that move rapidly away from the valve. These echoes are distinct from spontaneous echo contrast. The purpose of this study was to determine the frequency with which microbubbles are detected in association with prosthetic valves. No microbubbles were detected in association with bioprosthetic valves. Thus analysis was limited to 198 studies performed in 138 patients with left-sided mechanical valves. Microbubbles were detected in 69 (35%) studies. No differences were found between studies with and without microbubbles with regard to patient characteristics or the indication for the study. Among the 173 individual valves studied, microbubbles were more frequently detected in association with mitral valves (34 of 82, 41%) versus aortic valves (14 of 91, 15%; p 0.0001). Microbubbles were more frequently detected with disc-type mitral valves (30 of 42, 17%) in comparison to Starr-Edwards mitral valves (4 of 39, 10%; p 0.0001). Microbubbles were more often detected with abnormal valves (28 of 76, 37%) than normal valves (20 of 97, 21%), p 0.02. We conclude that bright, highly mobile echoes (microbubbles) distinct from spontaneous echo contrast are frequently detected during transesophageal echocardiography in association with mechanical prosthetic valves. Although the cause and clinical significance of these microbubbles are unknown, it is important to distinguish these echoes from valvular masses such as thrombus or vegetations.

Aortic Valve↗
PubMed1979

Cardiac valve replacement. Problems solved and unsolved.

In this review the present state of cardiac valve replacement is summarized on the basis of the literature and personal experience in approximately 1500 cases, using various prosthetic models. Durability, hemodynamic performance at rest and during exercise, and thromboembolic risk are considered in particular and our choice of the various valve models is discussed on these grounds. The long-term durability has been significantly improved and has possibly been solved in the more advanced mechanical valves, while this question is still open in the present biological prostheses. Hemodynamic performance is considered less than optimal in all conventional mechanical prostheses and in the xenografts. Pressure gradients are abnormal in all mechanical as well as in stented biological prostheses, the latter being less likely to solve the problem of a narrow aortic root. The significantly lower incidence of thromboembolism and total valve thrombosis and the absence of anticoagulation accidents in patients with bioprostheses has tipped the balance for the present in favor of the latter, particularly in mitral valve replacement and certainly in all those patients in whom anticoagulation in impossible, unlikely, or undesirable.

Aortic Valve↗
PubMed1988

Transesophageal two-dimensional echocardiography and color Doppler flow velocity mapping in the evaluation of cardiac valve prostheses.

To determine the value of transesophageal ultrasound in the assessment of cardiac valve prostheses, 14 patients with clinically suspected mitral prosthesis malfunction were studied by transthoracic and transesophageal two-dimensional imaging as well as by color Doppler flow velocity mapping (color Doppler). Patients underwent left ventricular angiography (n = 13), surgery (n = 11), or both angiography and surgery (n = 10). Nine patients had only mitral valve replacement, four patients had both mitral and aortic valve replacement, and one patient had mitral, aortic, and tricuspid valve replacement. There were 16 biological and four mechanical prostheses. The degree of mitral regurgitation was graded by both transthoracic and transesophageal color Doppler according to the area of the regurgitant jet visualized and was compared with a three-point classification of mitral regurgitation by left ventricular angiography judged by observers blinded to the echocardiographic results. All transesophageal studies were performed without complication and were well tolerated. The pathological morphology of the mitral prosthesis was additionally or more clearly visualized by transesophageal two-dimensional imaging and subsequently proven at surgery in three patients with flail leaflets and one patient with a vegetation compared with images obtained by the transthoracic approach. Valvular regurgitation was graded by the transthoracic approach as absent in four patients, mild in two patients, moderate in five patients, and severe in only three patients. The transesophageal assessment showed absence of mitral regurgitation in two patients, moderate regurgitation in two patients, and severe regurgitation in 10 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗