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Biomedical subjects

V Bors

Publications and source records attributed to V Bors.

At least 19 recordsLinked to original sources

Posttransplantation cytotoxic immunoglobulin G is associated with a high rate of acute allograft dysfunctions in heart transplant recipients.

BACKGROUND: The significance of anti-human leukocyte antigen immunoglobin G (IgG) detected in the posttransplantation course of heart graft recipients remains unclear. METHOD: Sera from 121 cardiac allograft recipients transplanted between January 1992 and December 1994 were screened for the presence of lymphocytotoxic antibodies in the first year after transplantation. Dithiothreitol was used to differentiate IgG from immunoglobulin M. RESULTS: Nineteen patients (15%) had cytotoxic IgG develop, mainly during the first month after transplantation. The percentage of women was higher in this group (42% vs 15.7%; P <.05). Donor to recipient mismatches for sex, blood typing, cytomegalovirus serology, and human leukocyte antigen typing were comparable between IgG producers and nonproducers. The frequency of acute allograft dysfunction during the first year after transplantation was significantly higher among patients producing IgG (42% vs 5.9; P <.001). Most of these acute allograft dysfunctions were independent of cellular rejection lesions but were associated with a thickening of the posterior wall and the interventricular septum during the acute episode. Finally, all the patients but one recovered. Recurrences were not uncommon and, at 1 year after transplantation, the dose of cyclosporine used in patients producing IgG was significantly greater, as was the left ventricular thickness. CONCLUSION: Posttransplantation cytotoxic IgG is not uncommon and appears to be associated with a high rate of acute allograft dysfunction. Development of these antibodies can be caused by a previous undetected immunization, as suggested by the higher percentage of women in the producer group. Correlation with histologic lesions of humoral rejection are discussed.

Adolescent↗

Pacemaker infective endocarditis.

We identified 33 patients with definite pacemaker endocarditis--that is, with direct evidence of infective endocarditis, based on surgery or autopsy histologic findings of or bacteriologic findings (Gram stain or culture) of valvular vegetation or electrode-tip wire vegetation. Most of the patients (75%) were > or = 60 years of age (mean 66 +/- 3; range 21 to 86). Pouch hematoma or inflammation was common (58%), but other predisposing factors for endocarditis were rare. At the time that pacemaker endocarditis was found, the mean number of leads was 2.4 +/- 1.1 (range 1 to 7). The interval from the last procedure to diagnosis of endocarditis was 20 +/- 4 months (range 1 to 72). Endocarditis appeared after pacemaker implantation, early (< 3 months) in 10 patients and late (> or = 3 months) in 23 patients. Fever was the most common symptom, being isolated in 36%, associated with a poor general condition in 24%, and associated with septic shock in 9%. Transthoracic echocardiography showed vegetations in only 2 of 9 patients. Transesophageal echocardiography demonstrated the presence of lead vegetations (n = 20) or tricuspid vegetations (n = 3) in 23 of 24 patients (96%; p <0.0001 compared with transthoracic echocardiography). Pulmonary scintigraphy showed a typical pulmonary embolization in 7 of 17 patients (41%). Pathogens were mainly isolated from blood (82%) and lead (91%) cultures. The major pathogens causing pacemaker endocarditis were Staphylococcus epidermidis (n = 17) and S. aureus (n = 7). S. epidermidis was found more often in early than in late endocarditis (90% vs 50%; p = 0.05). All patients were treated with prolonged antibiotic regimens before and after electrode removal. Electrode removal was achieved by surgery (n = 29) or traction (n = 4). Associated procedures were performed in 9 patients. After the intensive care period, only 17 patients needed a new permanent pacemaker. Overall mortality was 24% after a mean follow-up period of 22 +/- 4 months (range 1 to 88). Eight patients who were significantly older (74 +/- 3 vs 63 +/- 3 years; p = 0.05) died < or = 2 months after electrode removal, whereas 25 were alive and asymptomatic.

Adult↗

La Pitié heart transplantation: 30-year single center clinical experience.

At La Pitié Hospital, 1,184 patients underwent cardiac transplantation for end-stage cardiac disease (1,122 orthotopic and 62 heterotopic) between April 1968-November 1998. Since April 1986, 140 patients have been supported using several different mechanical assist devices as a bridge to transplantation. Twenty-four retransplantations (2.2%) were performed for primary graft failure in 4 (17%), refractory acute rejection in 7(29%), coronary graft disease in 11 (46%) and others in 2 (8%) patients. In a case-control study, retransplanted patients were matched with first transplant patients and survival rates at one and 5 years were 59.4% and 38.8% compared with survival rates for retransplanted patients of 45.4% and 31.2%, respectively. Seventy-four patients survived more than 10 years (61 males, 13 females). Mortality did not increase after 10 years. Unfortunately many suffered complications: 77% had hypertension, hypercholesterolemia (22%), hyperuricemia (41%), osteoporosis (11%), osteonecrosis (5%) and diabetes (7%). Renal function remains one of the main problems; 16% had a creatinine > 180 mumol/L and patients are on chronic dialysis.

Actuarial Analysis↗

[The cardiowest total artificial heart: experience of 29 cases].

The authors studied the outcome of multi-organ failure in 29 patients with terminal cardiac failure and maintained with a Cardiotest total artificial heart whilst waiting for cardiac transplantation. Pre-implantation organ dysfunction was defined by the following criteria; assisted respiration of over 3 days, total billirubin and creatinine levels of over 2 mg/dL, a platelet count of less than 80,000/mL or a prothrombin ratio of less than 50% and central nervous system disturbances. Fourteen patients died during the period of circulatory assistance and 71% of deaths were due to multi-organ failure. Pre-implantation plasma total bilirubin levels were significantly higher in patients who died of multi-organ failure (p = 0.04). Eighty per cent of patients who died of multi-organ failure had at least 3 criteria of organ dysfunction before implantation of the artificial heart compared with only 37% in the other patients (p = 0.04). Finally, systemic vascular resistances before implantation were significantly lower in patients who died of multi-organ failure. The results of this study suggest that multi-organ failures does not develop during the period of circulatory assistance but represents an aggravation of a preexisting morbid condition. This observation should lead to a limitation of the indications of total circulatory assistance in some cases and, above all, to earlier intervention before multi-organ failure becomes irreversible.

Adult↗

Cardiac calcium release channel (ryanodine receptor) in control and cardiomyopathic human hearts: mRNA and protein contents are differentially regulated.

Abnormal intracellular calcium handling in cardiomyopathic human hearts has been associated with an impaired function of the sarcoplasmic reticulum, but previous reports on the gene expression of the ryanodine receptors (Ry2) are contradictory. We measured the mRNA levels, the protein levels and the number of high affinity [3H]ryanodine binding sites in the left ventricle of non-failing (n = 9) and failing human hearts [idiopathic dilated (IDCM n = 16), ischemic (ICM n = 7) or mixed (MCM n = 8) cardiomyopathies]. Ry2 mRNA levels were significantly reduced in IDCM (-30%) and unchanged in MCM and ICM and Ry2 protein levels were similar. In contrast, we observed a two-fold increase in the number of high affinity Ry2 (B(max) = 0.43 +/- 0.11 v 0.22 +/- 0.13 pmol/mg protein, respectively; P<0.01) and an unchanged K(d). Furthermore, levels of myosin heavy chain mRNA and protein per g of tissue were similar in failing and non-failing hearts, suggesting that the observed differences in Ry2 are not caused by the increase in fibrosis in failing heart. Therefore, the dissociation between the two-fold increase in the number of high affinity ryanodine receptors observed in all failing hearts and the slightly decreased mRNA level or unchanged protein level suggests that the ryanodine binding properties are affected in failing myocardium and that such modifications rather than a change in gene expression alter the channel activity and could contribute to abnormalities in intracellular Ca2+ handling.

Adult↗

Active native valve endocarditis: determinants of operative death and late mortality.

BACKGROUND: In this report, we reviewed 247 patients who underwent operation by our team for active native valve endocarditis between January 1979 and December 1993. METHODS: There were 201 male and 46 female patients (mean age, 45.4 +/- 6 years). The aortic valve was involved in 163 cases, the mitral valve in 36 cases, both mitral and aortic valves in 44 cases, and the tricuspid valve alone in 4 cases. The most common microorganisms were streptococci. Univariate Pearson (chi2 test) and multivariate (stepwise logistic regression [BMDPLR]) analyses were used to identify significant predictors of operative mortality, reoperation, and recurrent endocarditis. Cox proportional hazards regression model was used to study late survival. RESULTS: Operative mortality was 7.6% (n = 19). Increased age, cardiogenic shock at the time of operation, insidious illness, and greater thoracic ratio (>0.5) were the predominant risk factors; the length of antibiotic therapy appeared to have no influence. Two hundred thirteen patients were followed up. Median follow-up time was 6 years (range, 2 to 19 years). Overall survival rate (operative mortality excluded) was 71.3% +/- 3.8% at 9 years. Increased age, preoperative neurologic complications, cardiogenic shock at the time of operation, shorter duration of the illness, insidious illness before the operation, and mitral valve endocarditis were the predominant risk factors for late mortality. The probability of freedom from reoperation (operative mortality included) was 73.3% +/- 4.2% at 8 years; risk factors were younger age and aortic valve endocarditis. The rate of prosthetic valve endocarditis was 7%. No significant risk factor was found. CONCLUSIONS: Increased age, insidious illness, and hemodynamic failure are the main risk factors for operative mortality. Long-term survival is good except for patients with preoperative neurologic complications and mitral valve endocarditis.

Adult↗

[Video-assisted coronary artery bypass].

The benefits of the internal mammary artery (IMA), as a graft, particularly for the left anterior descending (LAD) coronary artery disease, have been demonstrated. Coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) is now an accepted technique of myocardial revascularization. Thoracoscopy and a minimal thoracotomy have been applied to cardiac surgery, however its use has not been well defined; in our approach, we harvested the left IMA thoracoscopically. Following this the left IMA-LAD coronary artery anastomosis was fashioned, by means of a left small anterior thoracotomy on the beating heart without CPB. A double lumen endotracheal tube was used so the lung could be collapsed. Three left lateral chest ports of 1 cm were made, and the thoracoscope was placed through the initial port, permitting inspection of the thorax. The other ports were used for IMA dissection, using endoscopic instruments (electrocautery, grasping, forceps,...), the side branches were controlled by either cautery or endoscopic clips. When it was possible, the anterior port was extended doing a small left anterior thoracotomy, the pericardium was exposed, the IMA was divided and exteriorized through the thoracotomy. After coronary artery control, the bypass graft was carried out on the beating heart without CPB, in 26 patients. From september 1995 to july 1996, we have operated on 30 patients using this technique. We believe that with increasing operator experience, this minimally invasive approach will have a major impact on the management of the coronary artery disease patients, with a faster recovery, shorter hospitalization, and certainly less cost.

Adult↗

Position-related factors in mitral and tricuspid bioprostheses degenerative changes.

We report clinicopathological findings in 15 patients in whom the same bioprosthesis (BP) had been implanted simultaneously in both mitral and tricuspid positions. The aim of the study was to investigate whether position-related factors played an important role in BP degeneration. There were 14 women and 1 man with a mean age of 34 +/- 11 years. The indications for the initial operation were rheumatic in 14 cases and endocarditis in one patient. The mean interval before reoperation was 7.5 +/- 3.3 years. Predominant cause of reoperation was: structural deterioration of both mitral and tricuspid BPs (6), mitral regurgitation (5), tricuspid BP dysfunction (1), para-aortic leak (1), mitro-aortic thrombi (1). Calcific deposits were the principal cause of early deterioration of mitral BPs and the major cause of late tricuspid BPs dysfunction. This lesion was predominantly related to local factors. Cuspal tears were the principal cause of late (> 9 yrs) mitral BP failure and most probably related to mechanical stress. Extensive fibrosis affected only tricuspid bioprostheses. In 7 patients more extensive degenerative changes occurred in bioprostheses in the mitral rather than the tricuspid position (Group I). However, in the remaining eight the magnitude of the changes was very similar in the two positions (Group II). The interval before reoperation was significantly longer in patients of Group II (9.8 yrs, range 5-13) than patients in Group I (4.9 yrs, range 3-6), (p < 0.01). We concluded that position-related factors exert a major role in bioprosthetic failure. These factors are more deleterious in the mitral position than in the tricuspid position.

Adolescent↗

Heart transplant for the failing ischaemic ventricle.

Clinical application of heart transplantation goes beyond 28 years experience. Ischaemic heart diseases remain, with idiopathic cardiomyopathies, the main indications for cardiac transplant. A combination of haemodynamic, contractile and viability measurements may be useful to choose between transplant and coronary revascularization for the failing ischaemic ventricle. Advances in the detection of early rejection, improved organ preservation procedures, and the introduction of new immunosuppressive therapy protocols have produced dramatic results in heart transplantation. Late graft atherosclerosis remains a serious threat despite retransplantation and, in some cases, mechanical circulatory support.

Contraindications↗

[Reoperation for aortic valve replacement after myocardial revascularization].

A series of 13 patients (11 male, 2 female, average age 61 +/- 6 years) with previous aortocoronary bypass surgery and reoperated for aortic valve replacement (AVR) were analysed retrospectively. At coronary bypass, 8 patients (Group I) has insignificant aortic stenosis (AS) (mean transvalvular pressure gradient < 40 mmHg and/or aortic valve surface > 1 cm2). The other 5 had no aortic valvular lesion (Group II). The average time interval between the two operations was 7 +/- 3.3 years (Group I: 6.7 +/- 3.5 years; Group II: 7.4 +/- 3.2 years). In Group I, 2 patients required early AVR (2 years) whereas the time of reoperation varied from 6 to 12 years in the other 6 patients. No operative complications related to the sternotomy or dissection of adhesions were observed. In 3 cases, it was necessary to free the implanted grafts on the right coronary artery to gain access to the initial part of the aorta. A transverse low aortotomy allowed AVR in good conditions in all cases. One patient in Group II died on the 5th postoperative day of a low output syndrome complicated by pneumonia. After an average follow-up of 3 +/- 2 years, 9 patients are still alive. Three patients in Group I died, two of cardiac failure and one of unknown causes. The authors conclude that "prophylactic" AVR in cases of insignificant AS in patients referred for coronary bypass surgery is not justified. Regular echocardiographic follow-up should lead to AVR at the most appropriate moment, sometimes after an interval of several years, with a low operative risk.

Aged↗

[Long term results of the surgical treatment of obstructive hypertrophic cardiomyopathies].

Between January 1973 and December 1993, 66 patients underwent surgery in our department for hypertrophic obstructive cardiomyopathy; mean basal outflow gradient was 48.4 +/- 36 mmHg, 20 patients had mitral valve lesions. Thirty six patients underwent myotomy-myomectomy alone, 13 mitral valve replacement alone, and 17 both myotomy-myomectomy and mitral valve replacement. The 30-day mortality rate was 7.5% for all patients; predominant risk factors were gender (female), greater cardiothoracic ratio, preoperative episodes of atrial fibrillation and lack of syncope. Overall survival rate (operative mortality included) was 65.3 +/- 8.6% at 13 years. Predominant risk factors for late mortality were the same than above, plus mitral valve replacement; so mitral valve repair, whenever feasible should be undertaken. Forty nine patients are still followed up: 46 are asymptomatic; Doppler mean basal outflow gradient was reduced to 10 +/- 1.4 mmHg. In conclusion, surgery relieves symptoms and outflow obstruction, and allows mitral valve reconstruction.

Actuarial Analysis↗

[Cardiac transplantation. Lack of donor organs. Current status].

The lack of donor organs in France has led to a decrease in the number of cardiac transplantations (636 in 1990. 429 in 1994), despite the fact that the number of indications remains high. The reasons for this inadequation are multiple, but family refusal remains the major cause (65% of cases of non-donation). Efforts should continue to try and reverse this attitude to make this unequaled treatment available. The difficulties should in no case influence the indications of transplantations.

Attitude to Death↗

Dynamic cardiomyoplasty: effect of discontinuing latissimus dorsi muscle stimulation on left ventricular systolic and diastolic performance and exercise capacity.

OBJECTIVES: This study sought to assess the short-term effect of discontinuing latissimus dorsi muscle stimulation on left ventricular systolic and diastolic performance and exercise tolerance in patients with improved functional status by cardiomyoplasty, in whom latissimus dorsi muscle was fully conditioned. BACKGROUND: Cardiomyoplasty has consistently improved the functional status of patients, but the short-term effect of latissimus dorsi muscle contraction has not been assessed in these patients. METHODS: Right-heart catheterization, Doppler-echocardiography and maximal exercise testing with expired gas analysis were performed in 10 patients with congestive heart failure who had undergone cardiomyoplasty at least 6 months earlier. Data were obtained when the latissimus dorsi muscle was stimulated every other systole and after stimulation was discontinued for 1 h. The power of this study to detect a 10% difference was > 80%. RESULTS: After cardiomyoplasty, left ventricular ejection fraction increased from 0.22 +/- 0.08 (mean +/- SD) to 0.27 +/- 0.07 after 6 months (p < 0.02 vs. before cardiomyoplasty) and to 0.24 +/- 0.09 after 1 year; functional class went from 3.0 +/- 0.0 to 2.0 +/- 0.5 after 6 months and to 2.0 +/- 0.7 after 1 year (both p < 0.001 vs. before cardiomyoplasty). After discontinuation of latissimus dorsi muscle stimulation, cardiac index did not change (2.28 +/- 0.45 vs. 2.30 +/- 0.46 liters/min per m2). Mean systemic arterial and pulmonary capillary wedge pressures were also similar (85.2 +/- 6.0 vs. 88.4 +/- 5.6 mm Hg and 14.9 +/- 7.1 vs. 13.6 +/- 6.8 mm Hg, respectively). Doppler E/A ratio decreased from 1.04 +/- 0.33 to 0.83 +/- 0.25 (p < 0.02), suggesting that left ventricular diastolic function may have been improved by latissimus dorsi muscle stimulation. Peak oxygen consumption was unaltered (1,633 +/- 530 vs. 1,596 +/- 396 ml/min). CONCLUSIONS: Alterations in left ventricular diastolic rather than systolic function may be responsible for the long-term clinical benefits of cardiomyoplasty.

Adult↗

Extra-annular procedures in the surgical management of prosthetic valve endocarditis.

Severe acute endocarditis can be associated with major destruction of the annulus. Meticulous surgical debridement of friable necrotic material is always necessary and major damage to the annulus of the valve may impair secure seating of the prosthesis. Extra-annular implantation of a prosthesis may be a life-saving procedure when annular implantation is impossible. Between 1978 and 1989, 36 patients underwent extra-annular complex procedures for annular abscesses. The infection involved the aortic prosthesis and the annulus in 22 patients, and the mitral prosthesis and the annulus in 14 patients. In cases of aortic root abscess, a subcoronary valved graft (11 patients), a supracoronary valved conduit (ten patients) or a left ventricle-abdominal aorta valved conduit (one patient) were implanted. In cases of mitral valve endocarditis with extensive annular abscess, intra-atrial insertion of a mitral prosthesis was performed. In such cases, repair of the aortic root with a valved conduit or intra-atrial implantation of a mitral valvular prosthesis can be life saving and can be expected to give excellent long-term results.

Abscess↗

Clinical experience with a total artificial heart as a bridge for transplantation: the pitie experience.

Since April 1986, 82 patients have received a pneumatic total artificial heart, 62 a JARVIK-7, and 20 a Cardiowest. The duration of support ranged from less than 1 day to 603 days (mean duration: 27 +/- 82). The indications were for acute shock (38 cases) or for chronic deterioration on the transplant waiting list (44 cases). The etiology was mainly due to idiopathic and ischemic cardiomyopathy. With the help of our scoring system, we divided our patients in three groups: Chronic Implantation, represented by two females staying on device for 6 and 19 months, respectively; a High-Risk group of 29 patients characterized by high-risk indications; graft failure, rejection, postcardiotomy patient, postpartum cardiomyopathy, and valvular and congenital reoperation. In addition, the dilated and ischemic cardiomyopathy patients with a score over 6 were included in this group; and an Elective Indication group (51 patients) represented all of the dilated and ischemic cardiomyopathy patients with a score under 6. Due to the shortage of donors, our criteria for transplantation are very strict. Transplants should be made only in cases of hemodynamic stability, on an extubated patient with normal renal and liver functions, without coagulation problems or infection. With such criteria, in the high-risk group, only four patients could be transplanted and of these two are still alive. In contrast, in the elective group, 31 were transplanted (61%), and 71% of these patients were discharged. The rate is improved in the most recent cases, with 90% of the Cardiowest patients being survivors.

Acute Disease↗