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Biomedical subjects

J Acar

Publications and source records attributed to J Acar.

At least 163 records · Page 9Linked to original sources
PubMed1985

[Long-term outcome of mechanical prostheses].

The insertion of mechanical valve prostheses has transformed the particularly severe natural history of certain valve diseases. The inherent complications of the valve decrease the quality of these results. Thromboembolic and haemorrhagic complications remain the major drawbacks of mechanical prostheses. These risks are reasonable for the aortic orifice, especially with well adapted anticoagulant treatment, but many authors prefer bioprostheses for the mitral orifice.

Heart Valve Prosthesis↗
PubMed1985

Enzyme-linked immunosorbent assay using three different antigen preparations for detection of antibodies to Chlamydia trachomatis.

The ability of an enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Chlamydia trachomatis was evaluated in 100 sera using three different antigen preparations as substrates (sonicated organisms, Triton X solubilized antigen and SDS solubilized antigen). The results were compared to those obtained by a standard microimmunofluorescence assay. The results obtained by the three ELISA techniques and the microimmunofluorescence method were in relatively good agreement (76%); some discrepant results were observed in sera with a low antibody titer. There was good agreement of results obtained by the three ELISA techniques (84%). The microimmunofluorescence method showed the greatest sensitivity. Assuming the microimmunofluorescence method accurately demonstrates antibodies, the ELISA using Triton X solubilized antigen showed the highest degree of specificity (97%), and the ELISA with sonicated organisms the greatest sensitivity (82%) and accuracy (86%).

Antibodies, Bacterial↗
PubMed1985

Long-term clinical and hemodynamic results of molsidomine treatment in patients with refractory heart failure.

In this report we describe the clinical and hemodynamic response of refractory cardiac failure to molsidomine. In the first part of the study the hemodynamic effects of a single oral dose of 2 or 4 mg of molsidomine were compared with placebo control in 23 patients. In the second phase the dose 8 to 24 mg/24 hours was used in nine patients with functional class III or IV symptoms over an average period of 28 months (range 7 to 42 months); a hemodynamic control study was performed. These data demonstrate that molsidomine has a hemodynamic effect on pulmonary artery pressure for 5 to 6 hours, that the peak effect is reached between 1 and 1 1/2 hours after oral intake, and that the clinical and hemodynamic benefits of molsidomine may be maintained in the long term in patients with particularly severe cardiac failure. The conditions of seven patients were clinically improved with treatment; significant reductions in mean right atrial, pulmonary artery, and pulmonary capillary pressures were observed.

Adult↗
PubMed1985

[Positive inotropic agents. Generalities and classification].

The aim of inotropic therapy is to increase the force of myocardial fibre shortening by improving the availability of calcium to the contractile proteins. Digitalis remains the most widely used drug, but its positive inotropic effects are weak and the therapeutic index is low. Dobutamine is the most useful catecholamine because the most cardioselective and it induces the least increase in myocardial oxygen consumption. There are three groups of new inotropic agents: sympathomimetics: pirbuterol and prenalterol are effective in the short term but tolerance is usually observed within a few weeks. Salbutamol and terbutaline have only been assessed in acute studies, phosphodiesterase inhibitors (MDL 17043, MDL 19025) are powerful inotropic agents in the short and medium term. ARL 115 has mainly been studied by parenteral administration, Amrinone has a largely unknown mode of action, but is a very effective positive inotropic drug; its side-effects limit it as age. However, its derivative, milrinone, seems to be more inotropic and less toxic. The new inotropic drugs currently under assessment are active in the short term but their long-term efficacy and side-effects are still little known. The ideal inotropic agent remains to be discovered.

Adrenergic beta-Agonists↗
PubMed1985

[Hemodynamic evaluation of Ionescu-Shiley pericardial bioprostheses].

36 patients with a total of 39 pericardial Ionescu-Shiley bioprostheses (20 aortic, 13 mitral and 3 double valve replacements) were studied. The population consisted if 12 women and 24 men with an average age of 33 +/- 11 years. The control was performed on average 7 +/- 4 months after surgery. At the time of investigation all patients were in functional classes I or II of the NYHA. The average cardio-thoracic ratio was 0.51 +/- 0.05. The catheter data showed a mean pulmonary capillary pressure of 10 +/- 2.7 mmHg, a mean cardiac index of 3.2 +/- 0.9 l/min/m2, a mean end diastolic volume of 132 +/- 33 ml/m2 and a mean ejection fraction of 0.53 +/- 0.12. Haemodynamic data was obtained under basal conditions and during intravenous infusion of isoproterenol. The average transvalvular pressure gradient was measured by transseptal catheterisation. The cardiac output was measured by dye dilution and the functional surface area calculated using the Gorlin formula (k = 44.5 for the aortic valve and k = 31 for the mitral valve). Perivalvular leaks were excluded by selective left ventriculography or aortography. The average transvalvular pressure gradients for the aortic valve prostheses (no 19 = 1, no 21 = 4, no 23 = 3, no 25 = 7, no 27 = 8) were 17 +/- 7 mmHg for no 19 and 21, 12 +/- 5 mmHg for no 23 and 25, and 9.7 +/- 2.7 mmHg for no 27.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

[Results and indications of coronarography in mitral valvulopathies].

Selective coronary angiography was carried out in 110 patients (68 women, 42 men; average age 57 +/- 8 years) with significant, isolated, non-ischaemic mitral valve disease. The indication for coronary angiography was angina or myocardial infarction in 42 cases and the investigation was carried out routinely in the other 68 cases. Coronary stenosis greater than 50 p. 100 was demonstrated in 25 cases (22.7 p. 100), 18 single vessel, 5 double or triple vessel disease and 2 cases of stenosis of the left main stem. The incidence of coronary artery disease was higher in patients with cardiovascular risk factors (0 factors: 13 p. 100; 1 factor: 22 p. 100, 2 or 3 factors: 45 p. 100; p less than 0.01). The coronary patients had higher mean pulmonary artery pressures (33 +/- 16 mmHg vs 25 +/- 8 mmHg, p 0.001), higher left ventricular end diastolic pressures (12.5 +/- 7 mmHg vs 9 +/- 5 mmHg, p less than 0.01) and greater left ventricular end diastolic volumes (83 + 40 ml/m2 vd 59 +/- 29 ml/m2, p less than 0.01). There was no difference in segmental wall motion between coronary and non coronary patients. 89 patients were referred for surgery, 17 of whom had coronary artery disease. 5 patients underwent coronary bypass surgery. The incidence of peroperative cardiac complications (low output, ventricular arrhythmias, myocardial infarction) was higher in the coronary patients (53 p. 100 vs 18 p. 100, p less than 0.01). The 6 year survival rate was 75 +/- 8 p. 100.(ABSTRACT TRUNCATED AT 250 WORDS)

Constriction, Pathologic↗
PubMed1985

[Recurrent systemic arterial embolism in patients with valve prostheses].

The first 400 cases of 1,436 patients undergoing cardiac valve replacement were analysed to determine the clinical features of recurrent systemic embolism. The average follow-up period was 87 months. Three groups of patients were compared: A: 289 cases without embolic complications (72.5 p. 100) B: 78 cases with a single systemic thrombo-embolic event. (TEE) (19,5 p. 100) C: 33 cases with recurrent TEE (8.25 p. 100). The incidence of recurrence is high (30 p. 100 of cases, 8,1 p. 100 per patient year, compared to 3.8 p. 100 for the first TEE). The site of recurrent embolism was the same in 45 p. 100 of cases. The consequences were serious, 30 to 40 p. 100 of events being associated with death or invalidating sequellae. Four factors predisposed to TEE: mitral valve prosthesis, atrial fibrillation, left atrial dilatation and poor anticoagulant control. Fifty-four months after the first TEE, 60 p. 100 with inadequate anticoagulation had a recurrence compared to 20 p. 100 of patients with satisfactory control. Twenty-six patients (Groups B and C) had operative or autopsy examination of the prosthesis: thrombosis was found in 12 out of 18 cases in Group B, and in 7 out of 8 cases in Group C. Reoperation may be necessary to change the valve (27 out of 1,436 patients). Strict adherence to anticoagulant therapy remains the best prophylaxis against TEE and their recurrence.

Adolescent↗
PubMed1985

[Thromboembolic complications in patients with prostheses].

By their frequency and their gravity thrombo-embolic accidents (TEA) represent the principal complication provoked by prosthetic valves. They rarely manifest themselves by an occlusive thrombosis of the valve but more usually by systemic embolisms, particularly neurological, which entail sequelae or death in more than a third of the patients. These embolisms are recurrent in one case in three. Several factors which favour TEAs are the mitral position of the valve, its mechanical nature, embolisms being rarer and less severe and occlusive thromboses exceptional with bioprostheses, and the imperfect quality of anticoagulant treatment. This last factor introduces an additional risk at least as serious as the TE risk (1 to 6 percent of patients/year with severe haemorrhage). The prevention of TEAs depends on the type of treatment with antivitamins K (AVK) and possibly on the combination of AVK--anti-aggregating agents. The best means of prevention lies in the rational choice of the prosthesis in each individual case. It is beyond question that the frequency of TEAs with mechanical valves in the mitral position and the requirement for anti-coagulant treatment entailing its own risks encourage extension of the indications for biological valves.

Anticoagulants↗
PubMed1984

Aorto-right ventricular shunt and associated aortic valve injury resulting from a penetrating wound of the heart.

A case of a traumatic aorto-right ventricular fistula associated with an aortic valve injury and subsequent successful treatment is reported. A possible delay in diagnosis necessitates follow-up of patients after penetrating thoracic wounds. Early surgical treatment is mandatory because of the risks of both heart failure and endocarditis and because of the low operative morbidity. An aortic approach appears to be preferable because it permits repair of both the fistula and the valvular injury. Reconstruction of valvular injuries is preferable since long-term competence without prosthetic replacement can be achieved.

Adult↗
PubMed1984

Plasma beta-thromboglobulin in patients with valvular heart disease with or without valve replacement: relationship with thromboembolic accidents.

Plasma beta-thromboglobulin (BTG) was measured in 132 patients with valvular heart disease: 43 were studied before, 89 after surgery (78 mechanical valves and 11 bioprostheses). In this group of 89 selected patients, a history of thromboembolism was present in 53 (5 of them had bioprosthesis). Some abnormalities have been observed in patients with valvular heart disease as compared with controls: decreased platelet count and retention on glass column, and increased BTG. There is no statistically significant difference in BTG level between patients with (m +/- SD: 62.4 +/- 42.0 ng ml-1), or without (59.5 +/- 41.0 ng ml-1) a prosthesis; in the small series of 11 patients with a bioprosthesis, BTG was slightly lower than in other patients (44.5 +/- 14.1 ng ml-1), but still higher than in controls (26.8 +/- 13.3 ng ml-1). In the patients with a history of thromboembolism, BTG was significantly higher (66.7 +/- 47.9 ng ml-1 than in patients without this complication (49.9 +/- 21.0 ng ml-1). Thus, BTG evaluation may have some value in valvular heart disease but, at present, it should be confined to systematic research including prospective studies.

Adult↗
PubMed1984

Recurrent systemic embolic events with valve prosthesis.

Among 1436 patients who underwent valve replacement, the 400 first cases were studied to assess the features of recurrent systemic embolic event. The mean follow-up was 87 months. Three groups of patients were compared: groups A-289 patients without any thromboembolic event (72.25%); group B-78 patients with only one embolic event (19.5%); group C-33 patients with several embolic events (8.25%). The frequency of recurrence was high: one patient out of three (linearized mean 8.9% in group C considering only one recurrence, vs 3.8% in group B). The recurrence have the same location in 45% of patients. The consequences of these embolisms are serious; each event has a 30 to 40% risk of death or major disability. Four variables seem statistically to promote the occurrence of embolic events: mitral prostheses, pre-operative fibrillation, left atrial enlargement, poor anticoagulant therapy. 54 months after the first embolic event, 60% of the patients with poor anticoagulant therapy experience a recurrent thromboembolism vs 20% with adequate therapy. Twenty-six patients of groups B and C had a pathological study of prostheses. Thrombosis of the prostheses was found in 12 out of 18 patients in group B and in 7 out of 8 patients; in group C. Strict observance of anticoagulant therapy is the better way to prevent thromboembolism and especially recurrences. A reoperation is sometimes necessary. Valve re-replacement was performed in 27 cases out of 1436 patients.

Actuarial Analysis↗
PubMed1984

Thromboembolic and haemorrhagic risk in mechanical and biological aortic prostheses.

Thromboembolism, valve thrombosis and haemorrhagic events have been compared in 356 Starr-Edwards (SE) 1260, 113 Björk-Shiley (BS), and 178 aortic bioprostheses operated upon between 1968 and 1982, and reviewed by the same group with less than 2% of patients lost of follow-up. Expressed in actuarial rate at 7 years the percentage of patients free of thromboembolism event is 87% for SE, 86% for BS, 94% for bioprostheses; the linearized rate is 2.9%/patient/year for SE, 2.2 for BS, 1.9 for bioprostheses (NS). Valve thrombosis was not observed in bioprostheses; 97.9% of patients with mechanical valves were free of valve thrombosis at 6.5 years. Haemorrhagic risk was lower with bioprostheses than with mechanical valves 0.2% patient/year vs 2.33 (P less than 0.005). The most important factor influencing thromboembolic and haemorrhagic risks is the quality of anticoagulant therapy. Other contributing factors are the date of the operation and associated mitral disease.

Actuarial Analysis↗
PubMed1984

Role of antidiuretic hormone in impaired water excretion of patients with congestive heart failure.

Plasma antidiuretic hormone (ADH), PRA, plasma osmolality, and the parameters of renal water excretion were measured after overnight dehydration and for 5 h after an oral load in 14 patients with congestive heart failure (CHF) treated with diuretics (group 1), 8 hypertensive patients without CHF also treated with diuretics (group 2), and 11 patients with coronary artery disease but without CHF who were not treated with diuretics (group 3). Under basal conditions, mean plasma osmolality was lower in group 1 than in group 3, but was not different in groups 1 and 2. Mean plasma ADH was higher in group 1 than in group 2 or 3. In response to the water load, plasma osmolality and plasma ADH levels decreased in the 3 groups. ADH levels remained significantly greater in group 1 than in groups 2 and 3 from 2-4 h after the water load despite more marked hypoosmolality in group 1 compared with that in either of the 2 control groups. Plasma ADH was significantly correlated with plasma osmolality only in the 2 control groups. Mean PRA was greater in patients with CHF and patients without CHF treated with diuretics than in untreated patients. Cumulative water excretion was lower in patients with CHF than in patients in the 2 control groups from 2-5 h after the water load. At 5 h, the mean percentage excretion of the ingested loads was 56.8%, 90.7%, and 91.2% in the patients of groups 1, 2, and 3 respectively. Free water clearance was lower and minimal urinary osmolality was greater in the patients with CHF than in those in the 2 control groups. Two patients with CHF, who excreted more than 75% of the water load, also had low plasma basal ADH levels. These data show that patients with CHF have an inappropriate response of plasma ADH to a marked fall in plasma osmolality. This disorder is not due to the diuretic therapy, since hypertensive patients treated with diuretics behaved similarly to untreated patients without CHF. The reasons for this inappropriate response of plasma ADH during a water load in patients with CHF are probably multifactorial.

Adult↗
PubMed1984

[Long-term clinical and hemodynamic results of the treatment of refractory cardiac failure with molsidomine].

Molsidomine, one of the sydnonimine group of drugs; the object of this study was to evaluate its efforts in refractory cardiac failure. In the first part of the study, the haemodynamic effects of a single oral dose of 2 or 4 mg of molsidomine were compared with placebo controls in 23 patients. This showed molsidomine to be an active venous vasodilator reducing pulmonary artery and right atrial pressures without changing cardiac index or systemic pressures. The peak effect was observed after 1 to 1,5 hours. In the second phase, molsidomine was used in 9 patients aged 32 to 71 years (mean 47 +/- 12 years) over an average period of 19 months (3,5 to 42 months). The maintenance dose varied from 8 to 24 mg/24 hours. These patients had refractory cardiac failure secondary to primary cardiomyopathy with dilatation (6 cases) or ischemic heart disease (3 cases). The 9 patients were in functional classes IV (5 cases) or III (4 cases). Four patients were theoretically good indications for transplantation. Haemodynamic control was performed 1,8 +/- 5 months after a washout period of 8 hours, and after initial right heart catheterisation, the measurements were repeated 1 hour after oral administration of a 4 mg dose of molsidomine. Two patients did not respond initially to molsidomine; one died, the other remained in functional Class III. Another patient who responded initially was improved for over two years but died in cardiac failure after 42 months' treatment. The other six patients have been significantly improved and were in functional Class II at their last control.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗