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Biomedical subjects

J Acar

Publications and source records attributed to J Acar.

At least 55 records · Page 3Linked to original sources
PubMed1995

Nosocomial acquisition of multiresistant Acinetobacter baumannii: risk factors and prognosis.

To identify risk factors for and prognostic indicators of the nosocomial acquisition of multiresistant Acinetobacter baumannii in an intensive care unit, we prospectively studied 40 patients: 13 who were infected with this organism and 27 who were colonized. Isolates were identified by pulsed-field gel electrophoresis; the infected/colonized patients were compared with 348 noninfected, noncolonized patients by logistic regression analysis and with matched historical controls in a cohort study. The severity of illness (evaluated by the APACHE II score; P < .05) and previous infection (P < .001) were retained as independent risk factors for acquiring A. baumannii. Logistic regression analysis selected a high APACHE II score (P < .01) and the acquisition of A. baumannii (P < .01) as factors independently associated with death. The acquisition of A. baumannii was associated not only with high mortality but also with a length of stay on the intensive care unit in excess of that due to the underlying disease alone; specifically, the attributable mortality was 25%, with a risk ratio for death of 2.0 (95% confidence interval, 1.11-3.62), and the duration of stay for infected/colonized patients was 10.3 days longer than that for controls (P < .001).

APACHE↗
PubMed1995

Native cardiac disease predisposing to infective endocarditis.

Although no epidemiological studies are available to evaluate the exact risk of infective endocarditis complicating native cardiac disease, analysis of data in the literature shows that cardiac disease can be classified into three groups of decreasing risk: (1) high risk disease includes cyanotic congenital heart lesions, previous bacterial endocarditis, aortic valve disease, mitral regurgitation and uncorrected left-to-right shunt, but not atrial septal defect; (2) cardiac conditions of moderate risk include mitral valve prolapse with valvar regurgitation or leaflet thickening, isolated mitral stenosis, tricuspid valve disease, pulmonary stenosis and hypertrophic cardiomyopathy; (3) conditions of low or no risk include isolated atrial septal defect, ischaemic heart disease and/or previous coronary artery bypass graft surgery, surgically corrected left-to-right shunt with no residual shunt, mitral valve prolapse with thin leaflets in the absence of regurgitation, and calcification of the mitral annulus.

Causality↗
PubMed1995

Surgical treatment of infective endocarditis.

Optimal timing of surgery in infective endocarditis (IE) depends mainly on the haemodynamic tolerance of the patient. Emergency surgery is required in cases of refractory heart failure due to valvular lesions, intracardiac fistulas and high grade cardiac conduction abnormalities caused by septal abscesses. Surgery must be considered in all patients who have undergone a transient episode of heart failure such as a pulmonary oedema and it must be early--within 2 or 3 weeks of starting antibiotic therapy in patients with aortic regurgitation. Bacteriological indications are less frequent: persistent sepsis beyond the first week in spite of medical therapy, mycotic IE or prosthetic valve endocarditis caused by Gram-negative or staphylococcal organisms. Some complications may swing the argument in favour of surgery: detection of root abscesses or mycotic aneurysms using transoesophageal echocardiography, and systemic embolisms with persistent, large and mobile vegetative lesions. Mortality rate depends on the haemodynamic status but also on the severity of anatomical lesions, on the type of endocarditis (native or prosthetic valve), on the type of surgery and on bacterial aetiologies. It varies between 5% and 30%. The late postoperative outcome is good. The actuarial survival rate at 8 years was 70% in our series of 31 patients with aortic regurgitation and early surgery. In mitral regurgitation, conservative surgery is possible in most cases. In our department, 48 patients with mitral bacterial lesions have been operated on with conservative surgery without operative mortality. IE was active in 14, recent in 12 and had occurred earlier in 22.(ABSTRACT TRUNCATED AT 250 WORDS)

Endocarditis, Bacterial↗
PubMed1995

Percutaneous mitral commissurotomy in the elderly.

Immediate and mid-term results of percutaneous mitral commissurotomy (PMC) were assessed in 75 patients aged > or = 70 years (mean 75 +/- 4 (70 to 86)). Co-morbidities were present in 30 patients (40%), and 58 patients had calcified valves (77%). Technical failure occurred in two patients. PMC was performed in 73 patients, using a single balloon in five, two balloons in 28, and the Inoue balloon in 42. After PMC, valve area increased from 1.0 +/- 0.2 to 1.6 +/- 0.3 cm2 as assessed by 2D echo (P<0.001). Three procedural deaths occurred (4%). Good initial results (valve area > or = 1.5 cm2 with mitral regurgitation < or = 214) were obtained in 48 patients (66%). In multivariate analysis, predictors of poor initial results were previous commissurotomy (P=0.01) and valve calcification (P=0.04). Mean follow-up was 24 +/- 18 months. The 4-year actuarial results were: survival in 59 +/- 18%; no need for operation in 59 +/- 18%; and persistent good functional results (NYHA class I or II) in 34 +/- 16%. The only predictor of mid-term good functional results was the quality of initial results (P<0.002). In conclusion, PMC in the elderly results in moderate but significant improvement in valve function at an acceptable risk; although subsequent functional deterioration is frequent. PMC is a useful although only palliative treatment in these patients.

Aged↗
PubMed1995

The effect of left ventricular systolic function on long term survival in mitral and aortic regurgitation.

To identify the predictive factors of left ventricular dysfunction (LVD) after surgery, we performed an uni- and multivariate analysis of the data concerning 286 patients operated for pure aortic regurgitation between 1980 and 1994 and 460 patients operated for pure non-ischemic mitral regurgitation over a period of 24 years. Among the aortic regurgitation patients, 28 developed left ventricular dysfunction not attributable to residual aortic valve dysfunction, another valvular lesion or hypertensive or ischemic heart disease. By univariate analysis identified predictive factors of LVD were duration of symptoms prior to surgery, duration of the history of diastolic murmur, NYHA class, cardiothoracic ratio, LV echographic diameters, fractional shortening of short axis, LV end-systolic volume and LV ejection fraction. Multivariate analysis identified three independent predictors: NYHA functional class, LV end-systolic diameter and LV ejection fraction. Of 428 operative survivors with non-ischemic mitral regurgitation 63 developed severe LVD. Univariate analysis identified functional class III or IV, duration of symptoms prior to surgery, atrial fibrillation, echo LV and LA diameters, angio LV volumes, LV ejection fraction, cardiac index and type of surgery as independent predictors of LVD. Multivariate analysis showed that type of surgery, LV ejection fraction, LV end-diastolic and end-systolic volume and echo LV end-systolic diameter were all independent predictors of LVD.

Adolescent↗
PubMed1995

Thrombolytic therapy: future issues.

A considerable amount of work has been devoted to thrombolytic therapy (about 3000 references from 1991 to 1995 in a Medline search). The most important and well established indication of thrombolytic treatment is acute myocardial infarction (MI). Megatrials have evidenced a significant 30 to 40% reduction in hospital mortality in the treated patients. However, lack of sufficient thrombolysis in approximately 25% of patients, reocclusion in 6 to 16% of patients and intracranial hemorrhage in about 0.5% of patients are the main concerns regarding thrombolysis. Three approaches should improve the results of thrombolytic therapy in acute MI: earlier medical treatment, use of more efficacious thrombolytic agents in combination with more active antithrombotic agents and reduction of severe bleeding with safer combination of drugs. An improved of laboratory monitoring may also reduce the incidence of severe hemorrhagic events. In acute pulmonary embolism (PE), a change of indication for treatment based on echocardiography and high probability ventilation-perfusion lung scan results (without requiring pulmonary angiography) could broaden the use of thrombolysis. However, thus far, there has not been a demonstration of a reduction in mortality in large controlled studies. Thrombolysis in acute ischemic stroke is an attractive treatment but thrombolytic treatment is still at an experimental stage. However, the successful use of rt-PA in acute MI has renewed the interest in thrombolysis for focal cerebro-vascular ischaemia. Large controlled studies with SK, rt-PA or UK locally or intravenously administered have been recently undertaken to evaluate the benefit/risk ratio of treatment which seems surprisingly variable in different subgroups of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Ischemia↗
PubMed1995

[Recommendations for prevention of thromboembolism in heart valve diseases. Working Group on Valvular Heart Disease, European Society of Cardiology].

Thromboembolic events are still a major cause of morbidity and mortality in patients with native valvular heart disease and in patients with prosthetic heart valves. Although the introduction of oral anticoagulation reduced this risk, thromboembolism and anticoagulation-related hemorrhages still represent significant problems in the management of these patients. In this article the guidelines developed by the Working Group on Valvular Heart Disease of the European Society of Cardiology for the management of antithrombotic therapy in heart valve disease are thoroughly discussed. The indication for and intensity of anticoagulation in various clinical situations, the concept of risk factor-adjusted intensity of anticoagulation, and the concept of control of oral anticoagulation with the International Normalized Ratio are presented.

Administration, Oral↗
PubMed1995

[Acute mitral valve insufficiency].

This type of disease has benefited considerably, over recent decades, from progress in ultrasound technique and new methods of medical and surgical treatment. The aetiologies of mitral incompetence can be classified into 4 categories according to their mechanism: 1. Mutilating valve lesions, usually secondary to bacterial endocarditis, but sometimes secondary to trauma (percutaneous valvuloplasty). 2. Rupture of chordae tendineae, either spontaneous or bacterial, in a context of pre-existing valvular heart disease, usually degenerative. 3. Papillary muscle lesions, usually corresponding to rupture of a papillary muscle or the head of a papillary muscle, associated with myocardial infarction. 4. Biological or mechanical valve prosthesis dysfunction. The consequences of acute mitral incompetence depend on its aetiology and the presence or absence of previous mitral valve disease. Three factors determine the clinical presentation and prognosis: the volume of regurgitation, left ventricular function and left atrial compliance. In pure forms, such as those occurring after rupture of chordae tendineae, the haemodynamic profile consists of a marked elevation of left ventricular filling pressures, left atrial mean and systolic pressures (large V wave), and a reduction of the cardiac output. The left ventricular end-diastolic volume is moderately increased, while the end-systolic volume is normal or decreased and the ejection fraction is increased. The clinical picture is that of acute left ventricular failure with a systolic murmur of mitral regurgitation and a pulmonary hypertension syndrome. The absence of left ventricular hypertrophy on the electrocardiogram and the absence of left-sided dilatation on radiological examination indicate the recent nature of the haemodynamic disturbances. The diagnosis of acute IM is confirmed by Doppler ultrasound, which defines the mechanism and sometimes eliminates the need for an invasive investigation. The clinical course depends on the aetiology, the volume of regurgitation, left ventricular function and the treatment implemented. First-line treatment must include vasodilators. Sodium nitroprussate infusion decreases the left ventricular end-diastolic volume and the volume of regurgitation and increases the cardiac output. It allows a rapid reduction of pulmonary artery and capillary hypertension. When this treatment is not sufficient, intra-aortic counterpulsation may be useful. Emergency surgery is sometimes necessary, but usually after improvement of the haemodynamic state by vasodilators. Depending on the aetiology, surgery may consist of valve replacement or surgical repair, which can give excellent results even in the presence of active bacterial endocarditis. In other cases, following control of the acute phase by medical treatment, mitral incompetence will become chronic.

Acute Disease↗
PubMed1994

Plasma atrial and brain natriuretic peptides in mitral stenosis treated by valvulotomy.

1. In order to appreciate the effect of changes in left atrial pressure on plasma brain natriuretic peptide, 20 patients with mitral stenosis treated by percutaneous valvulotomy were studied 10 min before and 15 min after the first balloon inflation. They were also studied 24 h before and 48 h after the valvulotomy. At these times the effect of postural changes on brain natriuretic peptide secretion was examined. A group of 10 control subjects was also studied under basal conditions. In each case, plasma atrial natriuretic peptide was measured in parallel with plasma brain natriuretic peptide. 2. Similarly to plasma atrial natriuretic peptide, plasma brain natriuretic peptide was elevated in patients with mitral stenosis (32 +/- 2.9 and 32 +/- 2.8 pg/ml in the upright and supine position respectively versus 13.5 +/- 0.5 and 13.8 +/- 1.8 pg/ml in controls; P < 0.01). Changing from standing to lying did not modify plasma brain natriuretic peptide, whereas it produced an increase in plasma atrial natriuretic peptide in controls (13.3 +/- 1.6 versus 24.8 +/- 5.2 pg/ml; P < 0.01) and in patients 48 h after valvulotomy (52.5 +/- 4.6 versus 66.9 +/- 6.6 pg/ml; P < 0.01). Plasma brain natriuretic peptide also fell at this time (18.8 +/- 1.1 and 19.1 +/- 1.1 pg/ml in the upright and supine position respectively; P < 0.01) similarly to plasma atrial natriuretic peptide and cyclic GMP (P < 0.01). The acute left atrial mean pressure variation was significantly correlated with the parallel change in plasma atrial natriuretic peptide (P < 0.001) but not in plasma brain natriuretic peptide.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Pregnancy and prosthetic heart valves: a French cooperative retrospective study of 155 cases.

A French cooperative retrospective study analysed 155 pregnancies in 103 women with prosthetic heart valves: 95 mechanical prosthesis (MP) and 60 bioprostheses (BP). Among them 13 MP and 10 BP were bivalvular and four were mixed implants. In all, 182 (108 MP and 74 BP) prostheses were exposed to the risk of pregnancy. Among the 108 MP-bearing patients, 16 thromboembolic accidents (TEA) were recorded: 10 thromboses in 13 mitral, two aortic and one pulmonary MP. TEA were four times more frequent under oral anticoagulant therapy. Among the 74 BP, seven suffered premature valve failure. Ninety-nine infants were born to 50 MP-bearing women (53%) and 48 BP-bearing patients (80%) (P < 0.001). Twenty miscarriages were reported; they occurred more often under anticoagulant treatment (17%) than without it (4%) P < 0.02). Coumarin-induced embryopathies were rare (only one definitively identified). Because pregnancy with an MP under anticoagulant therapy is dangerous for the mother and may effect the fetus, the therapeutic indications for women of child-bearing age must be taken into consideration. In a women already with an MP at the time of conception, the duration of heparin therapy should be limited to the following two periods: from the 6th to the 12th week (coumarin-induced embryopathies) and during the last 2 weeks of gestation (haemorrhages during delivery and the neonatal period).

Adult↗
PubMed1994

[Value of transesophageal echocardiography in the follow-up of successful percutaneous mitral valvotomy].

This study was undertaken to determine the value of transoesophageal echocardiography in the follow-up of patients with severe mitral stenosis having undergone successful percutaneous mitral commissurotomy as defined as a final valve surface area > 1.5 cm2 without > 2/4 mitral regurgitation (MR). Eighty one patients who had undergone successful procedures were studied by transthoracic (TTE) and transoesophageal echocardiography (TOE) before, immediately after (24 to 48 hours) and at medium term (8 +/- 4 months) after balloon commissurotomy. The three main parameters studied were the degree of MR, presence of inter-atrial shunt and spontaneous left atrial contrast. Immediately after commissurotomy the MR was graded 0/4 in 6 patients (7.5%), 1/4 in 48 patients (59%) and 2/4 in 27 patients (33.5%). The TOE showed small traumatic lesions (localised valve tears, rupture of an accessory chordae tendinae) in 9 cases (11%). At medium term follow-up, the MR was stable in 75 patients (93%), decreased by one grade in 3 patients (3.5%), without the occurrence of severe MR. Interatrial shunts were more frequently observed by TOE than by TTE or oximetry with a prevalence of 57%. They usually disappeared at medium term follow-up. There were 3 factors associated with its persistence: a shunt visible at TTE, immediately after commissurotomy, visualisation of an atrial septal defect and a shunt jet width > or = 5 mm at TOE immediately after commissurotomy. Spontaneous contrast was common before the procedure (65%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Early transesophageal echocardiography after mitral valve replacement. Significance of minor abnormal signals].

The aim of this study was to determine the frequency, significance and prognosis of small, abnormal, strand-like echos observed by early transoesophageal echocardiography after mitral mechanical valve replacement with hemi-disc prostheses. One hundred and twenty nine consecutive patients operated between October 1988 and June 1992 underwent transoesophageal echocardiography on average 15 +/- 7 days after surgery. A second transoesophageal echocardiography was performed in 52 patients on average 8 months after the first postoperative examination. The frequency of small strand-like echos and of non-obstructive thromboses of the valve at the initial transoesophageal examination was 43% and 8.5% respectively. A multivariate analysis showed that the only independent predictive factor for prosthetic valve strands was spontaneous intra-atrial contrast (p < 0.01). The presence of strands was significantly related to the prevalence of early thrombo-embolic events (confirmed non-obstructive valve thrombosis and systemic embolism). Strands were observed in 80% of cases with early thromboembolic complications compared with only 38% of cases with no early thromboembolic events (p < 0.04). Univariate analysis showed that the protamine/heparin ratio at the end of cardiopulmonary bypass and the percentage of ineffective postoperative heparinisation were higher in patients with these small, abnormal echos (p < 0.05 and p < 0.001, respectively). These appearances disappear at long-term transoesophageal echocardiographic control examinations in about half the cases. The authors conclude that the majority of these small, abnormal echos are thrombotic in nature and are associated with a higher thromboembolic risk, justifying effective anticoagulation in the first postoperative hours whenever possible, considering the risk of bleeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗