Trypanosoma cruzi discrete typing units in Chagas disease patients from endemic and non-endemic regions of Argentina.

Genetic diversity of Trypanosoma cruzi may play a role in pathogenesis of Chagas disease forms. Natural populations are classified into 6 Discrete Typing Units (DTUs) Tc I-VI with taxonomical status. This study aimed to identify T. cruzi DTUs in bloodstream and tissue samples of Argentinean patients with Chagas disease. PCR-based strategies allowed DTU identification in 256 clinical samples from 239 Argentinean patients. Tc V prevailed in blood from both asymptomatic and symptomatic cases and Tc I was more frequent in bloodstream, cardiac tissues and chagoma samples from immunosuppressed patients. Tc II and VI were identified in a minority of cases, while Tc III and Tc IV were not detected in the studied population. Interestingly, Tc I and Tc II/VI sequences were amplified from the same skin biopsy slice from a kidney transplant patient suffering Chagas disease reactivation. Further data also revealed the occurrence of mixed DTU populations in the human chronic infection. In conclusion, our findings provide evidence of the complexity of the dynamics of T. cruzi diversity in the natural history of human Chagas disease and allege the pathogenic role of DTUs I, II, V and VI in the studied population.

Effect of preservation solution on graft viability in single-lung transplantation from heart-beating donors in pigs.

BACKGROUND: Low-potassium-dextran preservation solution Perfadex (PER) may provide better outcome of transplanted lungs than high-potassium Euro-Collins (EC) solution. However, there are no comparative studies of the recipient inflammatory response to the graft. PURPOSE: The purpose of this study was to compare EC versus PER as preservation solutions with respect to the functional performance and inflammatory response in single-lung transplantation from heart-beating donors in pigs. MATERIALS AND METHODS: The donor left lung flushed with the corresponding cold preservation solution was stored at 3 degrees C for 3 hours. We assessed hemodynamic values and pulmonary function in the recipient over a 2-hour reperfusion period calculated as percent of basal values, and expressed as mean of the reperfusion period. Interleukin-8 (IL-8) concentration in the donor was estimated in bronchoalveolar lavage fluid 2 hours after recipient reperfusion. Biopsies of the donor right lung and the transplanted lung were obtained to measure myeloperoxidase (MPO) activity. IL-8 and MPO values were expressed as percent of the donor value. We evaluated the wet/dry pulmonary weight ratio (W/D), polymorphonuclear neutrophil count (PMN), and a score of histological damage in the transplanted graft. RESULTS: Pulmonary function evaluated by % static: 66.6 +/- 6.8 (EC), 82.3 +/- 10.2 (PER), and dynamic: 74.0 +/- 7.3 (EC), 89.3 +/- 7.7 (PER) compliances, as well as % IL-8: 562.5 +/- 168.6 (EC), 232.3 +/- 148.7 (PER), % MPO: 485.9 +/- 194.9 (EC), 140.8 +/- 21.1 (PER), W/D: 9.9 +/- 3.1 (EC), 6.8 +/- 1.4 (PER), PMN 13.5 +/- 6.8 (EC), 5.5 +/- 3.3 (PER) and the histological damage score: 3.0 +/- 1.5 (EC), 0.7 +/- 0.4 (PER) showed significant differences between the EC and the PER (P < .01). CONCLUSIONS: PER affords good lung preservation with early graft function and modest evidences of inflammation, lung injury, and edema compared with the EC perfused lung.

Anti-skeletal muscle glycolipid antibodies in human heart transplantation as predictors of acute rejection: comparison with other risk factors.

In forty-five patients who underwent orthotopic heart transplantation, the titer of anti-human skeletal muscle glycolipid antibodies (AGA) present in the sera at the moment of transplantation was correlated with the number of histologically diagnosed cellular grade 3A and humoral acute rejection episodes during the first 120 days after transplantation. Determination of a cutoff value of 0.800 for the AGA level was determined by a receiver operating characteristic curve. Thirteen of 19 patients (68.4%) with an AGA titer above 0.800 developed 24 severe rejection episodes, and of the 26 patients with an AGA titer below 0.800, only 4 (15.3%) presented 6 severe rejection episodes during that time. This was especially evident for the humoral rejection episodes, which were diagnosed in only 1 of the 26 patients with AGA below 0.800 and in 7 of the 19 with AGA above 0.800. Comparison by univariate analysis of other well-known risk factors for a greater number of rejection episodes during the early posttransplant period with the AGA level at the moment of transplantation revealed that the latter distinguished a greater number of patients at risk than the other factors, such as a female donor, the lymphocyte direct cross-match, or the status of the patients at transplantation; the odds ratios were 6.33 for the AGA level, 3.17 for the direct cross-match, and 2.76 for the status at transplantation. By multiple logistic regression analysis, the only relevant risk factors in our group of patients were the AGA level (P=0.0009) and the status at transplantation (P=0.0285). These results indicate that determination of the AGA level at the moment of transplantation could represent a useful method for distinguishing which patients are at risk for a greater number of rejection episodes during the early posttransplant period, with a greater sensitivity than other risk factors.

Anti-skeletal muscle glycolipid antibodies in human heart transplantation as markers of acute rejection. Correlation with endomyocardial biopsy.

In seventeen patients the result of the histological study of 153 endomyocardial biopsies (EMB) was compared with the ELISA titer of anti-human skeletal muscle glycolipid antibodies (AGA) present in serum samples collected simultaneously with the EMB procedure during the first four months following cardiac transplantation. The glycolipids were extracted from the quadriceps femoralis of blood group O patients. In the serum samples corresponding to the histological rejection grades with myocyte necrosis (greater than or equal to 2, International Society for Heart and Lung Transplantation grading) the AGA titer was significantly higher (P<0.005) than in the less severe rejection grades. The follow-up in each patient showed that the AGA titer raised in the serum samples collected immediately after, before, or coincidentally with a histological diagnosis of rejection grade 2 or 3A. In only one rejection grade 3A case was a false-negative result observed. Determination of the cut-off of the AGA level versus rejection grades 2 and 3A was determined by a relative-operating characteristic curve. An optical density (OD) of 0.040 showed maximum efficiency with sensitivity 53% and specificity 79%. Four patients who had AGA with an OD above 0.040 at the time of transplant had a significantly higher number of rejection grade 2 and 3A episodes than eleven patients with low pre-transplant AGA titers (P<0.05). These results indicate that search of anti-skeletal muscle glycolipid antibodies may represent a useful noninvasive method for monitoring heart rejection, and suggest that its investigation prior transplant may be a predictor of the number of grades 2 and 3A rejection episodes.

Ultrastructural and morphometric study of the human heart muscle cell in acute coronary insufficiency.

In 13 patients with acute coronary insufficiency (intermediate syndrome, postinfarction angina, and progressive angina), samples of the ischemic area of the myocardium were studied with the electron microscope and by morphometric methods in order to describe quantitatively the mitochondrial population. Three indices were measured: the fractional volume of the mitochondrial compartment of the cytoplasm, the number of mitochondria per unit volume of heart tissue, and the average individual mitochondrial volume. As a control, the same study was performed on samples obtained from patients with chronic coronary insufficiency and mitral stenosis. In all the ischemic hearts the most conspicuous ultrastructural modification of the muscle cells consisted in an irregular distribution of the mitochondriranules. Generally, odd shaped mitochondria were found. The modifications were not diffuse, and almost normal heart muscle cells were seen alongside deeply altered ones. In addition a definite decrease in the fractional volume of the mitochondrial compartment was found, which was apparently due to a decrease in the number of mitochondria per unit volume of cytoplasm. The average individual mitochondrial volume was similar in acute coronary insufficiency and in the control cases. On the basis of this evidence it is postulated that in sublethal ischemia definite ultrastructural modifications of the heart muscle cells are associated with a decrease in the number of mitochondria per unit volume of cytoplasm.

Right submammarian thoracotomy in female patients with atrial septal defects and anomalous pulmonary venous connections. Comparison between the transpectoral and subpectoral approaches.

A right submammarian incision with anterior thoracotomy was performed in 89 female patients to repair simple and complex forms of atrial septal defects. Patients' ages ranged from 8 to 38 years (mean 21.5 years). Seventy-seven had secundum-type atrial septal defects, one had the primum type, and 11 had an associated partial anomalous pulmonary venous connection. The patients were divided into two groups: 57 patients in group A, in whom, after a breast flap was elevated, a transpectoral approach was used to enter the chest; 32 patients in group B, in whom the pectoral muscle was not divided and a subpectoral approach was used. Aortic cannulation was accomplished without difficulty in all 89 patients. There were no early or late deaths in either group. Follow-up ranged from 24 to 108 months (mean 63.7 months) and included 86 patients, who were free of symptoms. In group A, however, among 54 patients examined, the volume of the right breast and pectoral muscle was smaller than the left in four patients (7.4%), and 21 (38.8%) had persistent right periareolar numbness. In 32 patients evaluated in group B, no difference was noted in the size of the breasts, and persistent numbness was present in four patients (12.5%). In summary, atrial septal defects or anomalous pulmonary venous connections can be safely repaired through a right submammarian thoracotomy in female patients. The subpectoral approach offers better results because breast asymmetry and paresthesias are significantly less prevalent (p less than 0.01).

A rare case of coronary artery obstruction.

A case of severe extrinsic compression of the left anterior descending coronary artery by an aneurysm of the left ventricular outflow tract is reported.

Loud systolic and diastolic murmurs originating on a right atrial metastatic tumor.

A 36-year-old asymptomatic man, who two months before had a normal clinical examination, developed two loud, grade 5/6 harsh systolic and diastolic murmurs, audible over the entire precordium. Two-dimensional echocardiography revealed a huge tumoral mass, attached to the right atrium near the tricuspid valve, pedicellated and of great mobility, reaching the right ventricular outflow tract during diastole, and coming back to the atrium in systole. Right-sided angiography confirmed the diagnosis, and after ablation of the tumor, the auscultation was normal again. Two loud murmurs constitute a quite uncommon manifestation of an intracavitary mass, and this unusual finding has not previously reported in the medical literature available to the authors.

Risk of recoarctation in neonates and infants after repair with patch aortoplasty, subclavian flap, and the combined resection-flap procedure.

Between September 1980 and August 1988, 47 patients younger than 12 months (27 neonates and 20 infants) underwent repair of aortic coarctation. Three surgical techniques were used: patch aortoplasty (group A: 5 neonates and 3 infants, mean age 4.5 months), subclavian flap (group B: 11 neonates and 8 infants, mean age 3.1 months), and the combined resection-flap procedure (group C: 11 neonates and 9 infants, mean age 2.7 months). There were 8 early deaths (3 in group A, 3 in group B, and 2 in group C) and 2 late deaths (both in group B), all of which occurred in patients with complex coexisting anomalies. Follow-up included 37 patients (5 in group A, 14 in group B, and 18 in group C) and ranged from 28 to 108 months (mean 68.0, 60.8, and 51.7 months, respectively). Residual arm-leg pressure gradients greater than 10 mm Hg were detected in 4 of 5 patients in group A, 11 of 14 patients in group B, and 1 of 18 patients in group C (p less than 0.005). There were no reoperations in any infant operated on after 1 month of age in any group (0% risk). However, 4 patients who underwent repair during their neonatal period, with recurrent gradients greater than 20 mm Hg, have required reoperation: in group A, 1 of 5 patients (20% risk) (1 of 2 neonates or 50% risk); in group B, 3 of 14 patients (21% risk) (3 of 9 neonates or 33% risk); and none in group C (0% risk in infants and neonates) (p less than 0.001). In summary, residual gradients and risk of recoarctation are significantly higher when a patch or a subclavian flap had been used for repair. The combined resection-flap procedure (an end-to-end anastomosis enlarged with a subclavian flap) is more effective in avoiding gradients and preventing recoarctation, especially in neonates.

Aspirin and prophylaxis of thromboembolic complications in patients with substitute heart valves.

Anticoagulation therapy with acenocoumarin or with anticoagulants plus aspirin was given to 65 and 57 patients, respectively, with cardiac valve replacement. The follow-up was 1,462 months (22.5 months per patient) for the first group and 1,411 months (24.7 months per patient) for the second group. The frequency of embolic accidents was significantly lower in the group taking aspirin: Thirteen thromboembolic accidents were detected in patients receiving the anticoagulant and 3 in the group receiving the anticoagulant plus aspirin. These figures represent a 20.3 per cent incidence (one each 9.3 years of treatment) for the anticoagulant group and a 5.2 per cent incidence (one accident each 39.1 years of treatment) for the other group. The statistical significance between groups is p less than 0.005. There was no difference in the hemorrhagic risk between the two groups. We conclude that the use of an anticoagulant plus aspirin is a good and safe therapy for the prevention of thromboembolism in these patients.

Surgical treatment of acute type A dissecting aneurysm, with preservation of the native aortic valve and use of biologic glue. Follow-up to 6 years.

We present an analysis of 59 patients operated on between 1983 and 1987 for acute type A dissecting aneurysm with aortic valve insufficiency. The ascending aorta was replaced with a Dacron tube, the layers of the dissection were unified with gelatin-resorcine-formaldehyde glue, and the natural aortic valve was preserved. Follow-up every 6 months was subject to actuarial analysis. The hospital mortality rate was 22%. The survivors were studied for 35.9 +/- 18.6 months (mean +/- standard deviation). Eight patients died (six of cardiovascular causes, one of cancer of the colon, and one of an unknown cause). Seventeen (36.9%) had aortic insufficiency, eight mild and nine moderate to severe. Four patients with severe insufficiency had reoperation with valve replacement. Excluding patients who have died or undergone reoperation, 29 of the remainder (90.6%) are free of symptoms. The follow-up survival rate is 61% +/- 6.93% (standard error) including hospital mortality. It is 55.4% +/- 7% (standard error) excluding reoperation and 44.2% +/- 7.1% (standard error) additionally excluding modest or severe aortic insufficiency. The use of gelatin-resorcine-formal glue allowed preservation of the native aortic valve, obviating the need for anticoagulants, and no embolic or hemorrhagic episodes were registered.

Experimental acute right ventricular failure and right ventricular assist in the dog.

We describe a technique for the production of acute progressive right ventricular failure in experimental animals that mimics the hemodynamic characteristics of right ventricular failure found in some patients being weaned from extracorporeal circulation after surgical repair of left ventricular abnormalities. The technique combines three alterations of right ventricular state: excision of the tricuspid valve, ventriculotomy, and ligation of the right coronary artery. Seven control dogs died within 3 hours after this intervention. Death was due to low cardiac output as a result of low left atrial and pulmonary arterial pressures. Right atrial pressure was high. Use of a right ventricular assist device in an additional seven dogs to pump blood from the right atrium to the pulmonary artery confirmed good preservation of left ventricular function by reestablishing adequate left ventricular filling pressure. All seven dogs survived for more than 3 hours. The validity of the technique in restricting failure principally to the right ventricle was thus demonstrated.

Comparison of two levels of anticoagulant therapy in patients with substitute heart valves.

After cardiac valve replacement patients were blindly randomized into two groups, both receiving aspirin (330 mg) and dipyridamole (75 mg) twice daily and the oral anticoagulant acenocoumarol (Sintrom). An international normalized ratio of 2.0 to 2.99 was assigned to group A and 3.0 to 4.5 to group B; both groups were subsequently analyzed for thromboembolic and hemorrhagic complications. Final evaluation included 51 and 48 patients, respectively. The follow-up was 626 months for group A (12.3 months/patient) and 486 months for group B (10.1 months/patient). The frequency of thromboembolism was equal in both groups: one transient ischemic attack in group A (a rate of 1.92/100 patient-years) and two transient ischemic attacks in group B (a rate of 4.94/100 patient-years). There was, however, a statistical difference in bleeding complications between the two groups (p less than 0.02). Two patients bled in group A, a rate of 3.9% (3.8/100 patient-years), which represents an incidence of one episode each 25.6 years of treatment; 10 patients bled in group B, a rate of 20.8% (24.7/100 patient-years) representing an incidence of one episode each 4 years of treatment. We conclude that an international normalized ratio of 2 to 3 is safer than a ratio of 3 to 4.5 and confers good protection from thromboembolism when oral anticoagulant therapy is used conjointly with platelet function-inhibiting drugs in patients with mechanical substitute heart valves.

Animal model of acute pulmonary thromboembolism treated by local recirculation of streptokinase through the lung.

Massive acute pulmonary thromboembolism has a high mortality within the first few hours. Surgical intervention can remove only larger thrombi. Systemic fibrinolytic administration requires many hours for adequate treatment. We describe an anesthetized dog model of acute, massive, disseminated pulmonary thromboembolism achieved by injection of 1.7 ml/kg of 1-hour-old thrombi directly into the pulmonary artery. The emboli were lysed with 50,000 IU streptokinase recirculated for 20 minutes through the isolated pulmonary vascular bed by use of a roller pump while the systemic bed was supported by conventional cardiopulmonary bypass. On reestablishing natural circulation all hemodynamic parameters returned to preembolism values. Success of lysis was histologically confirmed. Perfusion of the pulmonary vascular bed without inclusion of streptokinase in the perfusate worsened the hemodynamic state of the animals compared with an untreated nonperfused control group.

Early diagnosis of recurrence of Trypanosoma cruzi infection by polymerase chain reaction after heart transplantation of a chronic Chagas' heart disease patient.

Heart transplantation is contraindicated as an effective treatment for end-stage Chagas' heart disease because of post-operative recurrence of Trypanosoma cruzi infection and reactivation of disease after immunosupression. In a follow-up study of a heart transplanted patient with Chagas' disease, we prospectively evaluated the usefulness of the polymerase chain reaction (PCR) for early diagnosis of reactivation. We monitored post-operative recurrence of Trypanosoma cruzi infection with microscopic observation of the parasite in peripheral blood (Strout's method), endomyocardial biopsies (EMBs), skin lesions, and 2 PCR assays, based on the amplification of specific T cruzi kinetoplastid and nuclear DNA sequences. During follow-up, parasite DNA was amplified in blood samples and EMB sections 41 days before we observed patent parasitemia and cutaneous manifestations of reactivation, proving that PCR is much more sensitive than direct microscopic observation for early diagnosis of disease reactivation in heart-transplanted Chagas' disease patients.

Identification of programmed cell death (apoptosis) in situ by means of specific labeling of nuclear DNA fragments in heart biopsy samples during acute rejection episodes.

BACKGROUND AND METHODS: In sixty-three endomyocardial biopsy samples collected from six heart transplant recipients for the diagnosis of acute rejection episodes, the presence of apoptosis in individual cells was investigated in tissue sections by in situ labeling of nuclear DNA breaks by nick end labeling with biotinylated poly deoxyuridin triphosphate introduced by terminal deoxynucleotidyl transferase and alkaline phosphatase-conjugated streptavidin. In the samples collected at the moment of transplantation, no apoptotic cells were observed. Apoptotic nuclei were found in the myocytes and capillary endothelial and connective tissue cells of endomyocardial biopsy samples obtained from day 7 to day 146 after transplantation with a different prevalence according to the rejection grade (International Society for Heart and Lung Transplantation classification). RESULTS: In all the rejection grade 3A (eight of eight), in half of the rejection grade 2 (four of eight), and in some rejection grade 1B (three of eight) cases, apoptotic myocytes were found within or in the neighborhood of the inflammatory areas. In the rejection grades 0 and 1A and in the "Quilty" effect zones, no apoptotic myocytes could be observed. Apoptotic endothelial and interstitial cells were observed in all the rejection grades but with a higher prevalence in rejection grades 2 and 3A. CONCLUSIONS: During rejection episodes, apoptosis of myocytes is one of the mechanisms of immune-mediated death, and its investigation in tissue sections may represent a valuable tool for the diagnosis of myocyte damage.

Laparoscopic cholecystectomy in heart transplant recipients.

To our knowledge these are the first three cases of laparoscopic cholecystectomy in heart transplant recipients. In one case the procedure was performed in the early posttransplant period. All three patients had uneventful postoperative outcomes and early hospital discharge. Laparoscopic cholecystectomy may be a safe alternative for elective cholecystectomy in heart transplant recipients.

Cardiac myocyte nuclear size and ploidy status decrease after mechanical support.

Two patients with end-stage dilated cardiomyopathy of ischemic and idiopathic origin were treated with a left ventricular assist device (LVAD) as a bridge for heart transplantation. Myocardial tissue was collected during LVAD insertion and from the left ventricular apex of the explanted hearts. The myocyte diameter, nuclear area and DNA content of myocyte nuclei were measured by static cytomorphometry in tissue sections and in isolated myocytes with a digital analysis system. The presence of apoptotic nuclei was investigated by the TdT mediated X-dUTP nick end labeling technique (TUNEL). The prolonged use of a LVAD was associated with a reduction in myocyte diameter, indicating that the LVAD may induce a reversion of myocyte hypertrophy, a process described as "reverse remodeling." In addition, unloading of the heart induced a reduction in the size and DNA content of myocyte nuclei. These results suggest that the cardiomyocyte nuclei are in a dynamic state and, as it occurs with cell hypertrophy, nuclear hypertrophy and polyploidization may be a reversible phenomenon.

Right atrial approach for surgical correction of tetralogy of Fallot.

Total correction of tetralogy of Fallot was performed without a ventriculotomy in 39 patients aged 8 months to 39 years (mean age, 9.1 years) between May 1984 and July 1988. A transatrial approach was used to resect the obstructed infundibulum and to close the ventricular septal defect. In 14 patients, the pulmonary annulus was not enlarged (group 1). Twenty-five patients required a transannular patch (group 2), placed by extending the pulmonary artery incision 1 cm into the right ventricular infundibulum. Eleven patients had repair of pulmonary artery branch stenosis, and associated intracardiac anomalies were simultaneously corrected in 10 patients. After repair, the right ventricular to left ventricular systolic pressure ratios ranged from 0.36 to 0.59 (mean ratio, 0.45) in group 1 and 0.33 to 0.70 (mean ratio, 0.51) in group 2. There were no hospital or late deaths in group 1. Two patients in group 2 with a small left ventricle died shortly after operation. The 37 survivors were followed for 2 to 51 months. Postoperative catheterization in 7 patients detected no residual ventricular septal defects, mild pulmonary regurgitation in 2 patients (group 2), and right ventricular to left ventricular pressure ratios ranging from 0.25 to 0.42 (mean ratio, 0.34). Only 1 patient with a previous total repair by ventriculotomy is symptomatic and requires antiarrhythmic agents and diuretics. The other 36 patients are asymptomatic. In conclusion, tetralogy of Fallot can be safely repaired at any age without a ventriculotomy. The results indicate a minimal incidence of postoperative arrhythmias and pulmonary regurgitation, as well as improved right ventricular function.

Valve operations through a minimally invasive approach.

BACKGROUND: We analyzed in-hospital results of 87 patients undergoing minimally invasive valvular operations (right parasternal incision through third and fourth cartilages). METHODS: Age was 21 to 84 years (mean, 56.2 +/- 16); 45 patients (51.7%) were female. Five (5.7%) had a previous valvular operation and 8 (9.2%) had severe left ventricular dysfunction. Valve diseases were as follows: aortic in 35 patients (40.2%), mitral in 44 (50.5%), double in 5 (5.7%), tricuspid regurgitation in 2 (2.2%), and mitral periprosthetic leak in 1 (1.1%). RESULTS: Nineteen mitral repairs (21.9%), 22 replacements (25.3%), 1 leak closure (1.1%), 1 tricuspid repair (1.1%), and 1 replacement (1.1%) were performed. Thirty-one patients (35.7%) underwent aortic replacement, 2 (2.3%) aortic decalcification, 1 (1.1%) subaortic membrane resection, 4 (4.6%) a double-valve procedure, and 5 (5.7%) a single-valve operation combined with myocardial revascularization. In-hospital mortality was 5.7% (5 patients). Univariate analysis was significant for previous operation, New York Heart Association class IV and severe ventricular dysfunction. Multivariate analysis was significant for previous operation and severe ventricular dysfunction. Atrial fibrillation (12.6%) was the most frequent complication. Postoperative stay was 6.5 +/- 6 days. CONCLUSIONS: The minimally invasive approach is a useful technique in valvular surgery. Patients with a previous valvular operation, severe ventricular dysfunction, and New York Heart Association class IV dyspnea have higher in-hospital mortality.