Immunopathologic studies in myocardial biopsies of patients with Chagas' disease and idiopathic cardiomyopathy

Right ventricular endomyocardial biopsies were studied in 30 patients, 15 with myocardiopathy from chronic Chagas'disease and 15 with idiopathic congestive myocardiopathy; five other myocardial samples were taken at necropsies of patients with chronic Chagas' disease. The authors tried to establish by means of direct immunofluorescence techniques whether there were immunoglobulins G, A and M, fibrinogen and C3 complement deposition in the myocardium; only one of these 30 patients exhibited a positive reaction to IgG, it was a patient with idiopathic congestive myocardiopathy. All fragments from patients with Chagas' disease showed no response to any of the fluorescent conjugates. These findings do not support the idea that anti-myoeardial antibodies have pathogenic importance in the evolution of dilated or chagasic myocardiopathies.

Acute myocardial infarction in chronic Chagas' cardiomyopathy: report of two cases with no obstructive coronary artery lesions

This report describes two patients with chronic Chagas' Heart Disease who developed clinical and laboratorial signs of myocardial infarction. Both patients presented sudden oppressive chest pain, without precipitating factor. In the first case, the highest MB-CK value was 65 IU, 22 hours after the beginning of the pain. On the second case, it was 77 IU at 18 hours after the beginning of the pain. In both cases ECG changes suggesting non-transmural infarction were present. The 99mTc PYP myocardial scintigram of the first case was positive. Coronary angiograms performed on the 18th and 9th day, respectively, after the acute infarction did not display obstructive lesions. Possible mechanisms causing myocardial infarction with normal coronary arteries in Chagas' Disease may include: embolic event's, particularly when there is associated congestive heart failure; coronary thrombosis and coronary spasms.

Influence of computed tomography attenuation correction in myocardial perfusion imaging in obese population

Marked regional variations in myocardial activity that are not related to myocardial perfusion defects.Verify the influence of CT-AC inMPI results in patients with BMI between 30 and 35 and higher than 30 for male and female population.

Radiopharmaceuticals for myocardial perfusion imaging: SPECT & PET

Myocardial perfusion imaging (MPI) is used on a daily basis to access coronary blood flow in patients that are suspected or have known Coronary Artery Disease (CAD). A Single Photon Emission Computed Tomography (SPECT) or and Positron Emission Tomography (PET) scan are used to access regional blood flow quantification either at rest or stress, the imaging acquisition is connected to an Electrocardiogram (ECG) and it is able to determine and quantify other myocardial parameters like myocardial wall thickness and wall motion. PET is not used so broadly due to its high procedure cost, the proximity with cyclotron, where are produced the majority of radiopharmaceuticals used in PET, due to their shor thalf-life. This work is intended to carry out a review of the tests relating to radiopharmaceuticals that are used in clinical practice in SPECT or PET for assessment of myocardial perfusion, also focusing very promising radiopharmaceuticals that are under investigation or in clinical trials with great potential for conventional nuclear medicine or PET, proceeding to a comparative analysis of both techniques and respective radiopharmaceuticals used.

Chronic myocardial damage in experimental T. cruzi infection of a new world primate, Cebus sp. monkey

Eighteen Cebus apella monkeys, (juvenile and adult of both sexes) were inoculated five years ago, with three Trypanosoma cruzi strains (CA1, n = 10; Colombian, n=4 and Tulahuen, n=4), either by conjunctival or intraperitoneal route, once or repeatedly. Parasitological, hematological, serological, enzymatic, radiographic, electro and echocardiographic findings have been peviously published15 and they are similar to those observed in human pathology. The most frequent electrocardiographic alteration was right branch bundle block. Six animals, chosen at random, were sacrificed. Those sacrificed 20 to 25 months post-first inoculation showed focal accumuli of leukocytes with myocytolysis. Foci of diffuse interstitial fibrosis with mild infiltrate of leukocytes among fibers were observed in the animals sacrificed 36 to 47 months post-inoculation. No parasites were seen. The lesions were more prominent in the ventricular walls and the septum. The fact that the infiltrates were predominant in the animals sacrificed at a shorter time after first inoculation and that fibrosis was more severe in those sacrificed at a longer time suggests that there is a progression of the infiltrative lesions to fibrosis, with a leukocytic activity indicative of a chronic phase. These lesions are similar to those described in human chronic Chagas' disease. This would demonstrate that this model is useful in evaluating a progress in the knowledge of the pathogenesis which is still a controversial issue, immunology, immunogenesis and chemotherapeutic agents of the chronic and indeterminate phases of this disease.

Infectious agents in coronary atheromas: a possible role in the pathogenesis of plaque rupture and acute myocardial infarction

In this review we report our recent findings of histopathological features of plaque instability and the association with Mycoplasma pneumoniae (MP) and Chlamydia pneumoniae (CP) infection, studying thrombosed coronary artery segments (CAS) of patients who died due to acute myocardial infarction. Vulnerable plaques are known to be associated with fat atheromas and inflammation of the plaque. Here we demonstrated that vulnerability is also related with focal positive vessel remodeling that maintains relatively well preserved lumen even in the presence of large atheromatous plaques. This phenomena may explain why the cinecoronariography may not detect large and dangerous vulnerable plaques. Greater amount of these bacteria in vulnerable plaques is associated with adventitial inflammation and positive vessel remodeling: the mean numbers of lymphocytes were significantly higher in adventitia than in the plaque, good direct correlation was obtained between numbers of CD20 B cells and numbers of CP infected cells in adventitia, and between % area of MP-DNA in the plaque and cross sectional area of the vessel, suggesting a cause-effect relationship. Mycoplasma is a bacterium that needs cholesterol for proliferation and may increase virulence of other infectious agents. In conclusion, co-infection by Mycoplasma pneumoniae and Chlamydia pneumoniae may represent an important co-factor for plaque instability, leading to coronary plaque thrombosis and acute myocardial infarction, since larger amount of these bacteria strongly correlated with histological signs of more vulnerability of the plaque. The search of CMV and Helicobacter pilori in these tissues resulted negative.

The Prognostic Impact of Renal Failure in Patients with ST-Segment Elevation Acute Myocardial Infarction

INTRODUCTION: Renal insufficiency (RI) is associated with higher morbidity and mortality in patients (P) with coronary artery disease and in P submitted to angioplasty. In ST-segment elevation acute myocardial infarction (STEAMI), this impact has not been well demonstrated. AIM: To evaluate the impact of RI in P with STEAMI. METHODS: We evaluated 160 P admitted with STEAMI, mean age of 62+/-14 years, 76% male. We determined creatinine levels on admission. RI was defined as a level >1.5 mg/dl. Analysis of clinical, electrocardiographic and laboratory variables was performed, in relation to the endpoint defined as the occurrence of death at 30-day follow-up. RESULTS: There were 16 deaths (10%) at 30-day follow-up. P with RI (n=21) were older (68+/-11 vs 61+/-14 years, p<0.001), more often had diabetes (57 vs 24 %, p=0.004) and presented more often with Killip class > or =2 (57 vs 12%, p<0.001). The use of statins (62 vs 83%, p=0.05) and beta-blockers (24 vs 65%, p<0.001) was lower in P with RI. Mortality was higher in RI P (62 vs 2%, p<0.001). The univariate predictors of death were age > or =75 years, diabetes, Killip class > or =2 on admission, RI, non-use of statins and beta-blockers and use of diuretics. In multivariate analysis, independent predictors of death at 30 days were RI (HR 29.6, 95% CI 6.3-139.9, p<0.001) and non-use of beta-blockers (HR 0.13, 95% CI 0.02-1.01, p=0.01). CONCLUSION: In P admitted for STEAMI, the presence of RI was an independent predictor of death at 30 days whereas the usage of beta-blockers was protective.

Lesões Inalatórias no Doente Queimado

Inhalation injuries are currently the factor most responsible for mortality in thermally injured patients. Inhalation injuries may occur independently, but generally occur together with skin burn. Smoke inhalation affects all levels of the respiratory system and the extent of the inhalation injury depends on the duration, exposure, amount and toxicity of the fume temperature, concentration and solubility of toxic gases, the occurrence of the accident in a closed space and pre-existing diseases. Smoke inhalation also induces changes in the systemic organs with the need for more fluid for resuscitation. Systemic vasoconstriction, with an elevation in systemic vascular resistance, a fall in myocardial contractility and a great increase in lymphatic flow in soft tissue are the most important changes in systemic organs. On admission of a burn patient there is a high suspicion of inhalation injury when there are signs and symptoms such as hoarseness, strides, dyspnea, carbonaceous sputum, anxiety or disorientation, with or without face burns. The patient with these findings has partial airway obstruction and there is substantial risk complete airway obstruction occurring of secondary to the edema. Patients with suspected inhalation injury should be intubated so as to maintain airway patency and avoid a total obstruction. This group of patients frequently develop respiratory failure with the need for mechanical ventilatory support. Nosocomial infections, sepsis and multiple organ system failure may occur. Late complications of inhalation injury are tracheitis, tracheal stenosis or tracheomalacia and chronic airway disease, which is relatively rare. Early diagnosis of inhalation injury and treatment in a Burn Unit by a group of highly motivated clinicians and a good team of nurses is essential in order to decrease the morbidity and mortality related to inhalation injury.

Description of an injury in a human caused by a false tocandira (Dinoponera gigantea, Perty, 1833) with a revision on folkloric, pharmacological and clinical aspects of the giant ants of the genera Paraponera and Dinoponera (sub-family Ponerinae)

The authors observed an injury caused by the sting of a false tocandira ant in the hand of an amateur fisherman and they describe the clinical findings and the evolution of the envenoming, which presented an acute and violent pain, cold sweating, nausea, a vomiting episode, malaise, tachycardia and left axillary's lymphadenopathy. About three hours after the accident, still feeling intense pain in the place of the sting, he presented an episode of great amount of blood in the feces with no history of digestive, hematological or vascular problems. The intense pain decreased after eight hours, but the place stayed moderately painful for about 24 hours. In that moment, he presented small grade of local edema and erythema. The authors still present the folkloric, pharmacological and clinical aspects related to the tocandiras stings, a very interesting family of ants, which presents the largest and more venomous ants of the world.

Serial Changes in Oxidized Low-Density Lipoprotein Associated with Culprit Vessel in ST - Elevation Myocardial Infarction - a Promising Marker?

The aim of the present study was to investigate variations in oxidized LDL (oxLDL) at the onset of acute myocardial infarction (AMI) and over the recovery period, exploring their relationship with coronary disease severity. A follow-up of 50 AMI patients was evaluated against 25 healthy volunteers (reference group). The AMI patients were evaluated at three time points: at admission before the administration of IIb/IIIa inhibitors and angioplasty, and two and 40 days after intervention. Plasma oxLDL concentrations were measured by ELISA. oxLDL was found to be significantly higher in AMI patients in the acute phase relative to reference levels, decreasing progressively over the recovery period. The results also demonstrated that oxLDL levels were decreased in patients with the left circumflex artery (LCX) as culprit vessel compared to the left anterior descending coronary (LAD) or right coronary artery (RCA). The results highlight a significant increase in oxLDL concentration related to coronary artery disease severity, as conditions such as LCX lesions are usually associated with a favorable prognosis, contrasting with LAD-associated conditions that can compromise large areas of myocardium. The results thus suggest that oxLDL may constitute a promising marker in assessment of AMI evolution.

ACUTE KIDNEY INJURY CAUSED BY Crotalus AND Bothrops SNAKE VENOM: A REVIEW OF EPIDEMIOLOGY, CLINICAL MANIFESTATIONS AND TREATMENT

SUMMARY Ophidic accidents are an important public health problem due to their incidence, morbidity and mortality. An increasing number of cases have been registered in Brazil in the last few years. Several studies point to the importance of knowing the clinical complications and adequate approach in these accidents. However, knowledge about the risk factors is not enough and there are an increasing number of deaths due to these accidents in Brazil. In this context, acute kidney injury (AKI) appears as one of the main causes of death and consequences for these victims, which are mainly young males working in rural areas. Snakes of the Bothrops and Crotalus genera are the main responsible for renal involvement in ophidic accidents in South America. The present study is a literature review of AKI caused by Bothrops and Crotalus snake venom regarding diverse characteristics, emphasizing the most appropriate therapeutic approach for these cases. Recent studies have been carried out searching for complementary therapies for the treatment of ophidic accidents, including the use of lipoic acid, simvastatin and allopurinol. Some plants, such as Apocynaceae, Lamiaceae and Rubiaceae seem to have a beneficial role in the treatment of this type of envenomation. Future studies will certainly find new therapeutic measures for ophidic accidents.

Safety and Effectiveness of the Genous™ Endothelial Progenitor Cell-Capture Stent in the First Year Following ST-Elevation Acute Myocardial Infarction: A Single Center Experience and Review of the Literature

PURPOSE: The Genous™ stent (GS) is designed to accelerate endothelization, which is potentially useful in the pro-thrombotic environment of ST-elevation acute myocardial infarction (STEMI). We aimed to evaluate the safety and effectiveness of the GS in the first year following primary percutaneous coronary intervention (PCI) and to compare our results with the few previously published studies. METHODS AND MATERIALS: All patients admitted to a single center due to STEMI that underwent primary PCI using exclusively GS, between May 2006 and January 2012, were enrolled. The primary study endpoints were major adverse cardiac events (MACEs), defined as the composite of cardiac death, acute myocardial infarction and target vessel revascularization, at one and 12months. RESULTS: In the cohort of 109 patients (73.4% male, 59 ±12years), 24.8% were diabetic. PCI was performed in 116 lesions with angiographic success in 99.1%, using 148 GS with median diameter of 3.00mm (2.50-4.00) and median length of 15mm (9-33). Cumulative MACEs were 2.8% at one month and 6.4% at 12months. Three stent thromboses (2.8%), all subacute, and one stent restenosis (0.9%) occurred. These accounted for the four target vessel revascularizations (3.7%). At 12months, 33.9% of patients were not on dual antiplatelet therapy. CONCLUSIONS: GS was safe and effective in the first year following primary PCI in STEMI, with an apparently safer profile comparing with the previously published data. SUMMARY: We report the safety and effectiveness of the Genous™ stent (GS) in the first year following primary percutaneous coronary intervention in ST-elevation acute myocardial infarction. A comprehensive review of the few studies that have been published on this subject was included and some suggest a less safe profile of the GS. Our results and the critical review included may add information and reinforce the safety and effectiveness of the GS in ST-elevation in acute myocardial infarction.

Is It Possible to Simplify Risk Stratification Scores for Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Angioplasty?

INTRODUCTION: There are several risk scores for stratification of patients with ST-segment elevation myocardial infarction (STEMI), the most widely used of which are the TIMI and GRACE scores. However, these are complex and require several variables. The aim of this study was to obtain a reduced model with fewer variables and similar predictive and discriminative ability. METHODS: We studied 607 patients (age 62 years, SD=13; 76% male) who were admitted with STEMI and underwent successful primary angioplasty. Our endpoints were all-cause in-hospital and 30-day mortality. Considering all variables from the TIMI and GRACE risk scores, multivariate logistic regression models were fitted to the data to identify the variables that best predicted death. RESULTS: Compared to the TIMI score, the GRACE score had better predictive and discriminative performance for in-hospital mortality, with similar results for 30-day mortality. After data modeling, the variables with highest predictive ability were age, serum creatinine, heart failure and the occurrence of cardiac arrest. The new predictive model was compared with the GRACE risk score, after internal validation using 10-fold cross validation. A similar discriminative performance was obtained and some improvement was achieved in estimates of probabilities of death (increased for patients who died and decreased for those who did not). CONCLUSION: It is possible to simplify risk stratification scores for STEMI and primary angioplasty using only four variables (age, serum creatinine, heart failure and cardiac arrest). This simplified model maintained a good predictive and discriminative performance for short-term mortality.