[Factors associated to high-flow nasal cannula treatment failure in pediatric patients with respiratory failure in two pediatric intensive care units at high altitude]. / Factores asociados al fracaso de la terapia con cánulas nasales de alto flujo en pacientes pediátricos con insuficiencia respiratoria en dos unidades de cuidados críticos pediátricos a gran altitud.

INTRODUCTION: Acute respiratory failure is the leading cause of hospitalization in pediatrics. High-flow nasal cannulas (HFNCs) offer a new alternative, but the evidence and indications are still debated. The performance of HFNCs at high altitude has not been described to date. OBJECTIVE: To describe the use of HFNCs in pediatric patients admitted with respiratory failure and explore the factors associated with treatment failure. METHODOLOGY: A prospective cohort study was carried out in patients between 1 month and 18 years of age managed with HFNCs. The demographic and treatment response data were recorded at baseline and after 1, 6 and 24hours. The number of failures was determined, as well as the length of stay, complications and mortality. Patients with treatment failure were compared with the rest. RESULTS: A total of 539 patients were enrolled. Infants (70.9%) of male sex (58.4%) and airway diseases such as asthma and bronchiolitis (61.2%) were more frequent. There were 53 failures (9.8%), with 21 occurring in the first 24hours. The median length of stay was 4 days (IQR 4); there were 5 deaths (0.9%) and 13 adverse events (epistaxis) (2.2%). Improvement was observed in vital signs and severity over time, with differences in the group that failed, but without interactions. The final logistic model established an independent relationship of failure between the hospital (OR 2.78, 95%CI 1.48-5.21) and the initial respiratory rate (OR 1.56, 95%CI 1.21-2.01). CONCLUSIONS: HFNCs afford good clinical response, with few complications and a low failure rate. The differences found between institutions suggest a subjective relationship in the decision of therapy failure.

[Difficulty of epidural puncture for obstetric analgesia: risk factors]. / Factores asociados a la dificultad de punción epidural en analgesia obstétrica.

INTRODUCTION: Predicting technical difficulties in performing an epidural block can affect the anesthesiologist's choice of technique or decisions about who should carry it out. Our aim was to determine patient characteristics associated with difficulty in performing an epidural block for obstetric analgesia. MATERIAL AND METHODS: We designed a prospective observational study in 540 pregnant women who requested epidural analgesia for obstetric labor. Patient characteristics (age, weight, height), anatomical features (body constitution, visible and/or palpable spinal apophyses, structural anomalies), technical features (number of attempts, repositioning of the needle), anesthesiologist's experience (resident or staff), block success, time taken to accomplish the procedure, and obstetrical variables (parity, gestational age, cervical dilatation). RESULTS: The factor that best correlates with puncture difficulty in the obstetric patient is the presence of visible or palpable spinal apophyses and palpation prior to carrying out the block. Factors like weight, body constitution, or anesthesiologist's experience seem to influence the rate of success or failure of the epidural block for obstetric analgesia, although to a lesser degree. CONCLUSIONS: The most important factor for predicting success of an epidural block for obstetric analgesia in our practice is the presence of palpable spinal apophyses.

Risk factors affecting survival in heart transplant patients.

BACKGROUND: Certain cardiovascular risk factors have been linked to morbidity and mortality in heart transplant (HT) patients. The sum of various risk factors may have a large cumulative negative effect, leading to a substantially worse prognosis and the need to consider whether HT is contraindicated. The objective of this study was to determine whether the risk factors usually available prior to HT result in an excess mortality in our setting that contraindicates transplantation. MATERIALS AND METHODS: Consecutive patients who underwent heart transplantation from November 1987 to January 2004 were included. Heart-lung transplants, retransplants, and pediatric transplants were excluded. Of the 384 patients, 89% were men. Mean age was 52 years (range, 12 to 67). Underlying disease included ischemic heart disease (52%), idiopathic dilated cardiomyopathy (36%), valvular disease (8%), and other (4%). Variables considered risk factors were obesity (BMI >25), dyslipidemia, hypertension, prior thoracic surgery, diabetes, and history of ischemic heart disease. Survival curves by number of risk factors using Kaplan-Meier and log-rank for comparison of curves. RESULTS: Overall patient survival at 1, 5, 10, and 13 years was 76%, 68%, 54%, and 47%, respectively. Survival at 10 years, if fewer than two risk factors were present, was 69%; 59% if two or three factors were present; and 37% if more than three associated risk factors were present (P = .04). CONCLUSIONS: The presence of certain risk factors in patients undergoing HT resulted in lower survival rates. The combination of various risk factors clearly worsened outcomes. However, we do not believe this should be an absolute contraindication for transplantation.

Predictive factors for development of diabetes mellitus post-heart transplant.

INTRODUCTION: It is known that there is a high incidence of diabetes mellitus (DM) among heart transplant (HT) patients, which may be up to 30% at 5 years. The presence of DM has been associated with increased morbidity (infections, renal dysfunction, or graft vascular disease), and its development has been related primarily to immunosuppressive therapy. The objective of this study was to determine, in our experience, the presence of predictive variables for the development of DM following HT. METHODS: We studied 315 consecutive non-DM patients (88.6% men, mean age 51.5 years) who underwent HT in our hospital from November 1987 to May 2003, analyzing all variables that could be related to the development of DM during follow-up. Student t-test and chi(2) test were used for univariate statistical analysis and logistic regression for multivariate analysis. RESULTS: Of the 315 patients, 64 developed DM (20.3%) during a mean follow-up of 3.3 years. The univariate analysis showed that patients developing DM are older (54.9 +/- 8.7 versus 50.7 +/- 11.8 years, P = .008), have a higher body mass index (BMI) (27.3 +/- 3.8 versus 25.7 +/- 3.7, P = .003), a higher prevalence of HT (37.5% versus 23.5%, P = .023), a lower frequency of urgent HT (9.4% versus 26.2%, P = .004), are more often treated with steroids (85.9% versus 70.1%, P = .011) and tacrolimus (12.5% versus 4.4%, P = .015), and have a higher frequency of rejection episodes (71.2% versus 44.6%, P = .001). Multivariate analysis identified the following as predictive factors for the development of DM: age (OR = 1.04, P = .013), urgent HT (OR = 0.36, P = .031), treatment with tacrolimus (OR = 3.89, P = .012), and number of rejections (OR = 2.34, P = .002). CONCLUSION: In our population, age, urgent HT (which had a protective effect), treatment with tacrolimus, and number of rejections were independent predictive variables for the development of DM during follow-up.

Age-associated changes in lymphoid and antigen-presenting cell functions in mice immunized with Trypanosoma cruzi antigens.

The purpose of these studies was to analyze the role of different immune cell populations in the immune response against Trypanosoma cruzi antigens in aged mice. Mice of different ages (3 and 12 months old) were immunized i.d. with S-105 plus Bordetella pertussis as adjuvant and we compared the activities of the lymph node cells taken from 3- and 12-month-old donor animals to transfer DTH or antibody production to 3-month-old recipients. This study revealed that adherent and non-adherent immune lymph node cells of aged donor animals did not transfer response against the foreign antigen (S-105) whereas 3-month-old non-adherent lymph node cells transferred a DTH response as well as helped the specific antibody production. When total lymph node cells from 3- and 12-month-old mice were mixed, we observed an inhibition of S-105 transferred response indicating a suppressive effect of aged cells on the 3-month-old mice cells. Furthermore, we analyzed the participation of antigen-presenting cells (APC) in the immune response changes related to the previously described aged mice. Peritoneal cavities cells (PC), pulsed in vivo with S-105, obtained from 3- and 12-month-old mice were transferred to normal recipients and a DTH response to S-105 was studied. We observed that the DTH response was lower in the recipients of aged PC with respect to recipients of young PC. The results suggest that APC from aged mice are involved in controlling the cellular immune response to S-105. Age-related changes in immune T cell and APC are discussed in the context of these observations.

Effect of aging on autoimmune response to rat male accessory glands: young, but not aged, antigen-presenting cells efficiently induce suppression in aged rats.

The present report analyzes the suppressor cell system of aged rats in an experimental model of autoimmunity to rat male accessory glands (RAG). A state of specific suppression to RAG was induced when young rats are pretreated with peritoneal cells (PC) obtained from syngeneic young rats i.p. injected 2 h previously with chromatographic fraction I (Sephadex G-100) (FI) of RAG (yFI-PC). Although the yFI-PC injection diminished the DTH in aged rats the autoimmune response remained positive. Peritoneal cells obtained from aged rats injected with FI of RAG (oFI-PC) did not suppress the DTH response in either aged or young rats. In both young and aged, pretreatment with yFI-PC stimulates spleen cells capable of inducing suppression (inductor-phase suppressor cells) when they are transferred to young recipients. However, the spleen inductor-phase suppressor cells of 12-month-old rats are unable to suppress the autoimmune response in their own aged environment. To obtain effective suppression in 12-month-old rats, the injection of yFI-PC was necessary prior to and subsequent to immunization. In this work we observe that 12-month-old rats could efficiently induce inducer phase and effector-phase suppressor cells when the adequate young antigen-presenting cells were present to stimulate them.

Age-related alterations in inflammatory response during experimental autoimmune prostatitis.

Experimental autoimmune prostatitis (EAP) is an experimental model of autoimmune disease, developed in Wistar rats against prostatic components. The 12-and 18-month-old rats with EAP show a higher cellular autoimmune response and lower humoral autoimmune response compared to 3-month-old rats. The analysis of NO(.) and O(2)(-) production by peritoneal exudate cells (PECs) resulted in a higher NO(.) and O(2)(-) production in EAP rats at all ages, compared to control animals. PECs from 12- and 18-month-old rats produced more NO(.) and less O(2)(-) than PECs from 3-month-old rats. However, lipopolysacharide (LPS) did not stimulate PECs from aged rats for NO(.) production as much as in 3-month-old rats and thus, turning out in a lower index of LPS-stimulation of PECs from aged rats, compared to 3-month-old rats. Furthermore, the mast cells number in prostates of EAP rats, especially the number of degranulated cells, was higher than in control animals, but no significant differences were found between 3- and 12-month-old control rats. In conclusion, these results show that aging affects differentially the inflammation mediators during EAP.

Aging: the cellular immune response against autologous and foreign antigens is affected before the humoral response.

In this study we examined the auto- and hetero-immune response in mice of different ages immunized with antigens of Trypanosoma cruzi (S-105). We observed that 20-day- and 12-month-old mice showed decreased response to foreign antigens and increased response to autoantigens, compared with 3-month-old immunized mice. The 6-month-old mice showed hetero- and auto-immune cellular responses similar to those of 12-month-old animals; however, the humoral response was similar to that of 3-month-old animals against either antigen, suggesting that the compartments of the immune response are altered at different moments in the same individual. Immune response against a foreign antigen is correlated with the presence of cellular infiltrate in skeletal and heart muscle whereas no modifications in the tissue are noticed in animals with an autoimmune response. Also, we observed from cell transfer experiments that lymph node cells are involved in the dysregulation that we noticed with aging.

Enhancement of natural antibodies in mice immunized with exoantigens of pI 4.5 from Trypanosoma cruzi.

This paper deals with the enhancement of natural antibodies in mice immunized with a previously purified exoantigen of Trypanosoma cruzi from infected mouse plasma by isoelectric focusing, called Ea 4.5. A simultaneous rinse of IgG antibodies recognizing acidic sciatic nerve antigen (SNA) and other conserved antigens such as myoglobin, actin, thyroglobulin, and tubulin was observed. The highest level of antibodies was revealed when myoglobin was used as antigen in the ELISA test. Good correlation was found between the level of antibodies reactive with SNA and with highly conserved antigens. Furthermore, absorption experiments showed that a fraction of antibodies binding SNA are polyreactive and also react with the highly conserved antigens. The histological studies of sciatic nerve, heart and skeletal muscle performed 1 month after the last immunization revealed no modifications with respect to the control animals. Based on these and a previous result [1], indicating that injection of Ea 4.5 induced in mice a partial protection against T. cruzi, the possibility exists that a percentage of antibodies induced by Ea 4.5 may correspond to the natural autoantibody type and take part in protective and/or pathogenic effects.

Changes in the development of experimental autoimmune prostatitis (EAP) by castration in aged rats.

During Experimental Autoimmune Prostatitis (EAP), 12-month-old rats show a higher cellular autoimmune response and lower humoral autoimmune response against prostatic components than 3-month-old rats subjected to the same antigen stimulus. We analyzed if thymus recovery by orchidectomy could affect the development of EAP in 12-month-old rats. Thirty days after gonadectomy, 12-month-old rats showed an increment in the thymic mass and in the thymocytes absolute number, with percentages of the four main cell subpopulations (defined by CD4-CD8 molecules expression) similar to the 3-month-old rats. The DTH response of castrated 12-month-old with EAP were diminished in comparison with sham-castrated 12-month-old rats with EAP, resembling the values observed in 3-month-old rats with EAP. The prostates of castrated 12-month-old rats with EAP did not show inflammatory mononuclear cell infiltration, as did control 3- and 12-month-old rats with EAP. Castration seems to modulate negatively EAP in 12-month-old rats, possibly through the regeneration of thymus after testosterone deprivation.

Diminished percentage of antigen bearing cells in the lymph nodes of immune aged rats.

We have demonstrated previously that during experimental autoimmune prostatitis (EAP), aged rats show a diminished humoral autoimmune response. In the present paper we have studied the transport of the autoantigen from the site of injection toward lymphatic organs in rats of different ages with or without EAP. We used as autoantigen prostatic components (rat accessory glands (RAG)) conjugated with fluorescein isothiocyanate (FITC). Studies of flow cytometry, fluorescent microscopy and confocal microscopy show no differences in the percentage of RAG-FITC positive cells or in the localization of the cells in the popliteal lymph nodes of not-immunized young and aged rats. On the other hand, in 18-month-old rats immunized with either RAG or Ovalbumin there were lower levels of specific IgG antibodies and fewer antigen containing cells in the draining lymph nodes than those of 3- or 12-month-old rats. In all groups fluorescent cells were MHC class II positive and some were IgM positive. Our results demonstrate that in immunized 18-month-old rats there is a diminished percentage of cells bearing the antigen in the draining lymph nodes after antigen injection in the skin, related to the levels of specific antibodies able to form antigen-antibody complexes in the periphery.

IgE dependent autoimmune response. Effect of Trypanosoma cruzi infection.

The autoimmune response to mouse accessory glands (MAG) was investigated in male BALB/c mice immunized with different doses of chemically modified mouse accessory glands (MMAG) and complete Freund's adjuvant (CFA). This autoimmune response was studied at several time intervals using the skin test with MAG. It was found that 5 mg of MMAG induced on the day 15 an autoimmune response detected by specific skin test at 20 min., 3 h and 24 h. The results of the immediate type hypersensitivity (ITH) were higher than those with the other skin tests. In order to study the type of immunoglobulin involved, the ITH was also analyzed by passive cutaneous anaphylaxis (PCA) at different time intervals with treated and untreated sera at 56 degrees C. The findings suggest the presence of reaginic antibodies, IgE being the major antibody as detected by enzime linked immunosorbent assay (ELISA). The MAG was subsequently fractionated using Sephandex G-100 and the fractions thus obtained (FI,FII and FIII) were used to challenge mice immunized with MMAG. It was found that FI was the only fraction which revealed an ITH similar to that revealed by MAG. The effect of infection with Trypanosoma cruzi on the autoimmune response to MAG was analyzed with different mouse groups intraperitoneally treated with 2 x 10(3) blood trypomastigotes/animal at several time intervals: namely, on days -5, 0, +5 and +10 with respect to the immunization with MMAG. The autoimmune response to MAG showed suppression when the animals received the parasites on the same day as the autoantigen.

Effects of fosinopril on the blood pressure and lipid profile of patients undergoing heart transplantation.

PURPOSE: The purpose of this study was to determine whether the angiotensin-converting enzyme inhibitor, fosinopril, has an antihypertensive effect in patients undergoing heart transplantation (HT), as well as any action on lipid levels (total cholesterol and its fractions, triglycerides and lipoprotein[a] [Lp(a)]). METHODS: The study included 15 male patients aged 54 +/- 10 years; nine had undergone transplantation as a result of ischemic heart disease and six as a result of idiopathic dilated cardiomyopathy. The average time from the heart transplantation was 12 +/- 4 months. Six transplantations were performed after antidiabetic treatment, and six were performed with patients receiving a hypolipidemic agent. The subjects of the study were patients with mild to moderate hypertension who were receiving antihypertensive treatment; the antihypertensive medications were withdrawn during 7 days. Periodic blood pressure and basal analytic determinations were then carried out after 4 and 12 weeks of treatment and 7 days after withdrawal of the antihypertensive medications. RESULTS: Significant differences (p < 0.05) were found in the systolic blood pressure (SBP) and diastolic blood pressure (DBP) compared with the basal values (SBP 160 +/- 11 mm Hg; DBP 98 +/- 8 mm Hg), after 4 weeks of treatment (SBP 138 +/- 10 mm Hg; DBP 83 +/- 7 mm Hg), and after 12 weeks of treatment (SBP 137 +/- 12 mm Hg; DBP 84 +/- 9 mm Hg); these differences persisted 7 days after the drug was withdrawn (SBP 150 +/- 12 mm Hg; DBP 95 +/- 10 mm Hg). The total cholesterol, low-density lipoprotein (LDL) cholesterol, and Lp(a) dropped compared with the basal levels (total cholesterol 184 +/- 19, LDL cholesterol 123 +/- 13, Lp(a) 29 +/- 12), after 4 weeks (total cholesterol 172 +/- 21, LDL cholesterol 116 +/- 8, Lp(a) 26 +/- 8) and after 12 weeks (total cholesterol 169 +/- 20, LDL cholesterol 115 +/- 6, Lp(a) 25 +/- 8) of treatment, returning to basal values on withdrawal of the drug. CONCLUSIONS: Fosinopril is a useful drug for the treatment of the mild to moderate arterial hypertension of heart transplant recipients, in addition to being capable of reducing the serum levels of total cholesterol, LDL cholesterol, and Lp(a). It should therefore be considered a first-line antihypertensive agent with beneficial effects on the lipid profile.

Is the prognosis poorer in heart transplanted patients who develop a right bundle branch block?

BACKGROUND: Currently studies conflict on the impact on mortality of right bundle branch block development after transplantation. Most studies conclude that right bundle branch block does not affect patient survival. However, no distinction is made between patients in whom right bundle branch block progresses and those in whom it remains unchanged during follow-up. The objective of this study is to assess clinical or survival differences between patients who develop right bundle branch block and those who do not, and also to analyze these differences depending on progression of this conduction abnormality. MATERIALS AND METHODS: Ninety-seven consecutive heart transplant recipients with more than 1 year's survival were analyzed. Twelve-lead standard ECGs were performed during the first week after transplantation, which allowed for classification of patients depending on the presence or absence of right bundle branch block. Subsequently, throughout the first year, 2 groups were identified, depending on increase of the conduction defect. The groups were compared and factors determining the presence of right bundle branch block and progression of the conduction defect were found. Survival curves for the conduction defect were also compared. RESULTS: Fifty percent of the patients developed right bundle branch block after transplantation; it was progressive in 10. Progressive right bundle branch block was related to greater renal dysfunction (odds ration [OR] = 10.8; confidence interval [CI] = 2-58; p = 0.006), a larger number of rejections (p = 0.01), and a greater death rate (OR = 12.8; CI = 2.5-64; p = 0.002). The presence of progressive right bundle branch block was an independent predictor of long-term mortality (OR = 27.9; CI = 4.2-186.3; p = 0.0006). CONCLUSIONS: The development of right bundle branch block after transplantation is related to intraoperative factors and to a greater number of rejections. The presence of this conduction disorder, particularly if it progresses during the first year, identifies a sub-group of patients with a poorer long-term prognosis.

Participation of different cellular types in the enhancement of autoimmune response of old animals to sex accessory glands in male rats: importance of macrophages.

In a previous work, we showed that the immunization of male rats, 3 and 12 months old, with saline extract of rat male accessory glands chemically modified (MRAG) and human serum albumin (HSA) induced a higher humoral and cellular autoimmune response in old animals than in young ones. We have also demonstrated that the facilitation of the autoimmune response is transferred by spleen total cells of 12-month-old animals. The immune response to HSA was not modified. In this work, the cellular type involved in such facilitation was analyzed. For this transference experiment, cells enriched in T and B lymphocytes and macrophages were used. The results showed that the macrophage is the main cellular type involved. However, the transference was only total with the three cellular types together. The study, performed with macrophages pulsed in vivo with MRAG-HSA and then transferred to normal recipients, indicated that although the macrophages from young and old animals were capable of presenting the antigens, the latter did this with significantly greater efficiency for the autoantigen.

Effect of aging on the autoimmune response to sex accessory glands in male rats.

The effect of aging on the immune response to autoantigen of rat male accessory glands (RAG) was studied in Wistar rats. Male and female rats, 3 and 12 months old, were immunized with chemically modified RAG and heterologous antigen (human serum albumin, HSA). The study of delayed type hypersensitivity (DTH) and antibodies against RAG revealed a higher response in 12-month-old animals than in 3-month-old animals (P less than 0.005), regardless of their sexes. No differences in DTH and humoral responses to HSA were observed. Experiments on the transfer of spleen cells showed an increase in response elicited by RAG immunization in young recipients of cells from normal or immunized old syngeneic donors. On the contrary, old recipients of spleen cells from normal or immunized young donors maintained their high response the same as non-transferred old rats. Therefore, both the lymphoid cells and the environment in which the response was elicited seem to be involved in the increase of the autoimmune response.

Relationship between fibrinogen protein and fibrinogen function in postmyocardial infarction patients.

The present study investigates the association between increases in the concentration and function of plasma fibrinogen in two groups of patients with chronic ischemic heart disease (11 with recurrent ischemic events and 19 free of these episodes) and in 34 healthy controls. The fibrinogen function index (fibrinogen function per unit of fibrinogen protein) (FgFI) was used as a measure of the fibrinogen clotting potential. The prothrombin fragment 1+2 (F1+2) and thrombin-antithrombin (TAT) were used as procoagulant markers. Plasma sialic acid (SA) was also evaluated as an inflammatory marker. No differences were found between FgFI (1.06+/-0.13 vs. 1.02+/-0.13), F1+2 (1.2+/-0.5 vs. 1.1+/-0.4 nmol/l) and TAT (2.5+/-1.3 vs. 2.5+/-0.7 microg/ml) in postinfarction patients without recurrent coronary ischemic events and the control group. However, postinfarction patients who suffered recurrent coronary ischemic events had significantly higher FgFI than patients without these symptoms (1.19+/-0.09 vs. 1.06+/-0.13), P<.01) and than the control group (1.19+/-0.09 vs. 1.02+/-0.13, P<.001). Moreover, the F1+2 (1.4+/-0.5 vs. 1.1+/-0.4 nmol/l, P<.05) and TAT (3.6+/-3.3 vs. 2.5+/-0.7 microg/ml, P<.05) were significantly higher in patients who suffered recurrent coronary ischemic events than in the control group. However, F1+2 and TAT were not different between patients with and without these symptoms. The fibrinogen protein (Fg-protein) concentration and high molecular weight fibrinogen (HMW-Fg) levels were significantly higher in both postinfarction patient groups than in the control group and in postinfarction patients with recurrent coronary ischemic events than in postinfarction patients without these symptoms. The plasma SA levels were significantly increased in postinfarction patients with and without recurrent coronary ischemia as compared with the control group. A positive correlation was found between fibrinogen and SA levels (r=.5, P<.01). In conclusion, our study indicates that the procoagulant factors, among which we include fibrinogen, F1+2 and TAT play a very active role in recurrent ischemic events in postmyocardial infarction patients. High plasma concentrations of both fibrinogen and SA suggests that fibrinogen becomes elevated as a consequence of inflammatory processes. The FgFI as an indicator of clotting potential of fibrinogen appears to be associated with ischemic events in chronic coronary artery disease.

Radioimmunometric assay of B-type natriuretic peptide (BNP) in heart transplantation: correlation between BNP determinations and biopsy grading of rejection.

The aim of this study was to determine whether elevated brain natriuretic peptide (BNP) levels after heart transplantation are correlated with the severity of rejection by using endomyocardial biopsy (EMB) and echocardiographic parameters indicative of ventricular function of the transplanted heart. This was an observational study of 80 orthotopic heart transplant recipients (11 women and 69 men; mean age 53+/-11 years). BNP determinations were performed within 48 h of endomyocardial biopsy. The echocardiographic study and BNP determination were also performed in a group of healthy volunteers. We found significantly higher BNP mean levels in heart transplant patients than in healthy volunteers (volunteers, 16.7+/-16.2 pg.ml-1; transplant, 213.4+/-268.6 pg.ml-1; P<0.001). Transplant recipients with rejection grades 2, 3 and 4 on EMB had significantly higher BNP levels than those with rejection grades 0 and 1 (higher rejection grade, 162.5+/-168.4 pg.ml-1; lower rejection grade, 292+/-361.8 pg.ml-1; P<0.01). BNP values of patients with good left ventricular function (LVF) were significantly lower than in patients with mildly and moderately impaired LVF and patients with severely impaired LVF (good function, 199.76+/-233.6 pg.ml-1; mildly/moderately impaired LVF, 937+/-644.5 pg.ml-1; severely impaired LVF, 1038+/-491.2 pg.ml-1; P<0.001). It is concluded that BNP plasma levels are elevated in heart transplant patients compared to the normal population. The distribution of BNP levels in heart transplanted patients show a wide range. BNP elevation is greater in patients with higher rejection grades on EMB and greater impairment of left ventricular function.

Antigens of the major histocompatibility system in ischemic heart disease and idiopathic dilated cardiomyopathy.

BACKGROUND: Although dilated cardiomyopathy (DCM) is a disease of unknown and probably multifactorial etiology, a change in immune mechanisms is presumably significant, with many abnormalities in humoral and cellular responses having been reported. The heart thus becomes the target organ for an initial episode of myocardial damage that triggers an autoimmune response. HYPOTHESIS: The purpose of this study was to analyze the frequency of different human leukocyte antigens in patients with a diagnosis of well-advanced DCM and ischemic heart failure, comparing them with a control group of presumably healthy subjects. METHODS: The group with dilated cardiomyopathy consisted of 50 patients (7 women and 43 men), aged from 14 to 64 years. The group with ischemic heart disease included 76 patients (4 women and 72 men), with ages ranging from 34 to 64. The control group, consisting of 1,337 presumably healthy subjects from the Spanish Mediterranean area, was recruited based on paternity studies. RESULTS: Compared with the control group, we found in DCM a greater incidence of B15 (20 vs. 6%) and DQ3 (83 vs. 50%) antigens. In ischemic heart disease we found a lower incidence of A1 (3 vs. 22%), B8 (5 vs. 12%), and DQ2 (16 vs. 50%) in comparison with the control group. CONCLUSIONS: In the Spanish Mediterranean area, the presence of antigens B-15 and DQ3 would be associated with advanced DCM. The absence of antigens A1, B8, and DQ2 would be associated with the occurrence of severe ischemic heart disease.

Utility of cardiac magnetic resonance imaging for the diagnosis of heart transplant rejection.

OBJECTIVES: To assess the value of the use of cardiac MRI to detect rejection (necrosis) and its ability to discriminate it from other pathologic alterations (edema and fibrosis). MATERIALS AND METHODS: A prospective and consecutive study was designed in which cardiac MRI was performed at the same time as the scheduled endomyocardial biopsy. The study period was from 31-10-01 to 01-05-02. Ten patients with claustrophobia were excluded. Sixty-four examinations were performed in the remaining 40 patients. MRI assessment was blinded to the biopsy result. The 17 biopsies performed were insufficient (too small sample). Rejection was defined as the presence of at least 1 focus of myocyte necrosis. Technique. A high-field (1.5 T) GE CV/i magnetic resonance imaging system was used to obtain pre- and postcontrast white and black blood anatomic sequences (breathhold fast spin-echo T1-weighted images), as well as myocardial cine, perfusion and viability sequences. Variables analyzed. Ejection fraction, ventricular volumes, pericardial effusion, hypertrophy, absolute and relative myocardial intensity and uptake. Statistics. Variables were normally distributed. Student's t test was used for quantitative variables and the chi2 test for proportions. RESULTS: Mean age, 51+/-13 years. Women 5, men 35. Time since HT, 13 to 3725 days. No significant differences were found between rejection and ventricular volumes or the presence of effusion and hypertrophy. Visual estimation of myocardial perfusion and viability sequences did not detect any significant changes. Uptake showed a clear trend to increase in patients with necrosis: 34+/-21 versus 23+/-17 for relative uptake, P<.05. There were also differences in uptake when fibrosis was present: 68+/-47 versus 102+/-48 in the group without fibrosis, P <.05; but not in the presence of edema: 93+/-55 versus 94 +/- 45 for absolute uptake. CONCLUSIONS: (1) Cardiac MRI is a promising technique for diagnosis of rejection. (2) Patients with myocyte necrosis show a clear trend toward increased myocardial uptake. (3) Interstitial fibrosis is associated with decreased levels of uptake.