18F-fluorodeoxyglucose use after cardiac transplant: A comparative study of suppression of physiological myocardial uptake.

BACKGROUND: 18F-fluorodeoxyglucose (FDG) has been useful in the evaluation of myocardial inflammatory processes. However, it is challenging to identify them due to physiological 18F-FDG uptake. There are no publications demonstrating the application of FDG in post-transplant rejection in humans yet. The aim of this study is to determine the feasibility of suppression of myocardial FDG uptake in post-transplant patients, comparing three different protocols of preparation. METHODS: Ten patients after heart transplantation were imaged by FDG associated with three endomyocardial biopsies (EMB), scheduled in the first year after the procedure. Before each imaging, patients were randomized to one of three preparations: (1) hyperlipidic-hypoglycemic diet; (2) fasting longer than 12 hours; and (3) fasting associated with intravenous heparin. All patients would undergo the three methods. FDG images were analyzed using visual analysis scores and relative radiotracer cardiac uptake (RRCU). RESULTS: The suppression rate of radiotracer activity ranged from 55% to 62%. Visual analysis showed that preparation 3 presented less efficacy in the suppression compared to the others. However, RRCU did not show difference between the preparations. CONCLUSIONS: Suppression of physiological myocardial FDG uptake after cardiac transplantation is feasible. The usefulness of heparin in the suppression is unclear.

Budget impact of applying appropriateness criteria for myocardial perfusion scintigraphy: The perspective of a developing country.

Myocardial perfusion imaging is widely used for the risk stratification of coronary artery disease. In view of its cost, besides radiation issues, judicious evaluation of the appropriateness of its indications is essential to prevent an unnecessary economic burden on the health system. We evaluated, at a tertiary-care, public Brazilian hospital, the appropriateness of myocardial perfusion scintigraphy indications, and estimated the budget impact of applying appropriateness criteria. An observational, cross-sectional study of 190 patients with suspected or known coronary artery disease referred for myocardial perfusion imaging was conducted. The appropriateness of myocardial perfusion imaging indications was evaluated with the Appropriate Use Criteria for Cardiac Radionuclide Imaging published in 2009. Budget impact analysis was performed with a deterministic model. The prevalence of appropriate requests was 78%; of inappropriate indications, 12%; and of uncertain indications, 10%. Budget impact analysis showed that the use of appropriateness criteria, applied to the population referred to myocardial perfusion scintigraphy within 1 year, could generate savings of $ 64,252.04 dollars. The 12% inappropriate requests for myocardial perfusion scintigraphy at a tertiary-care hospital suggest that a reappraisal of MPI indications is needed. Budget impact analysis estimated resource savings of 18.6% with the establishment of appropriateness criteria for MPI.

A comparative study on the quality of in vivo labeled red blood cell radionuclide ventriculography images employing different freeze-dried reagents.

Radionuclide ventriculography or Multi Gated Acquisition (MUGA) employing [ 99m Tc]Technetium red blood cell (RBC) labeling is considered the gold standard for cardiotoxicity assessments in cancer patients undergoing chemotherapy. This in-vivo RBC labeling technique involves the reduction of [ 99m Tc]Technetium by the stannous chloride present in freeze-dried reagent kits, with the pyrophosphate kit (PYP) being the most employed for this purpose. The literature, however, describes diethylenetriaminepentaacetic acid (DTPA) as an alternative to PYP, although a lack of comparative data from MUGA images between both reagents is noted. A retrospective cross-sectional observational study was conducted at the Brazilian National Cancer Institute Nuclear Medicine Service concerning 80 randomized MUGA images, 20 obtained employing DTPA between 2020 and 2023 and 60 obtained employing PYP between 2017 and 2020, applying the mean count per pixel (ct/pixel) and heart background (C/F) ratios as quality image indicators. Although the heart ct/pixel ratio was statistically lower in the DTPA images compared with PYP ( P  = 0.02), the C/F ratio was statistically similar when comparing both radiopharmaceuticals ( P  = 0.697). A semi-quantitative analysis of MUGA images obtained with DTPA and PYP indicates similar image quality, supporting the use of DTPA as an alternative to PYP without compromising diagnostic interpretations.

Improvement of Laboratory Hepatic Parameters After Treatment With 177 Lu-DOTATATE : Cohort in an Oncology Reference Center.

PURPOSE: Well-differentiated neuroendocrine neoplasms (NETs) overexpress the somatostatin receptor, which is the target for the peptide receptor radionuclide therapy (PRRT). NETs have a slow growth rate and can metastasize to liver, bone, and lungs. In NETs patients, liver metastasis is an important prognostic marker because liver failure is one of the most common causes of death in this population. In this regard, we aimed to describe the changes in laboratorial parameters in patients submitted to PRRT with 177 Lu-DOTATATE, focusing on hepatic parameters. PATIENTS AND METHODS: One hundred ten patients treated with 1 to 4 cycles of 7.4 GBq (200 mCi) of 177 Lu-DOTATATE from January 2011 to December 2021 were analyzed in this retrospective observational single-center study. Patients were submitted to blood tests before and after each cycle of PRRT. Laboratory measurements were collected to assess liver function, cholestasis, kidney, and bone marrow function. RESULTS: In the general population (n = 110), ALP ( P = 0.013) and GGT ( P < 0.001) showed a statistically significant reduction. Patients with high liver disease volume showed a statistically significant reduction in ALT ( P = 0.016), whereas patients with low liver disease volume showed a statistically significant reduction in GGT ( P = 0.013). All parameters for bone marrow function showed a statistically significant decrease in all population subsets. CONCLUSIONS: Patients treated with 177 Lu-DOTATATE showed a significant improvement in liver function and cholestasis parameters, and a consistent decrease in bone marrow function, even in the presence of advanced liver disease.

Neutrophil to lymphocyte ratio as a prognosis biomarker of PRRT in NET patients.

PURPOSE: Peptide Receptor Radionuclide Therapy (PRRT) with 177Lu-DOTATATE is a palliative therapeutic option for advanced Neuroendocrine Tumors (NETs). Prognostic factors can predict long-term outcomes and determine response to therapy. Among those already explored, biomarkers from full blood count, including neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) has shown value for other solid tumors and for NETs patients submitted to other forms of therapy. However, its relation to PRRT response and patients' prognosis is still to be determined. METHODS: Medical records from 96 patients submitted to PRRT between 2010 and 2017 were reviewed, median NLR and PLR were calculated from baseline flood blood count and dichotomized as high or low. Progression-free survival (PFS) and Overall Survival (OS) were calculated. RESULTS: NLR and PLR median values were 1.8 and 123, respectively. Patients with low NLR had a significantly longer OS (estimated median of 77.5 months, 95% CI: 27.3-127.7) when compared to patients with high NLR (estimated median of 47.7 months, 95% CI: 34.7-60.8); p = 0.04. Patients with low NLR had a trend toward a longer median PFS when compared to patients with high NLR [estimated medians of 77 months (95% CI: 27.3-127.7), and 47.7 months, (95% CI: 34.7-60.7)], respectively, p = 0.08. CONCLUSION: Patients with advanced-stage NET with NLR higher than 1.8 have worse long term clinical outcomes after PPRT. Larger studies are needed to validate the optimal cutoff for this biomarker.

In vitro nematocidal activity of Punica granatum L. against gastrointestinal helminths in goats.

The objective of this study was to evaluate the in vitro ovicidal activity, phytochemistry, and toxicity of a saline extract obtained from peel of Punica granatum L fruits. The ovicidal activity was evaluated by the hatching inhibition of eggs recovered from fecal samples of naturally infected goats; the phytochemical analysis was carried out using the fruit peel; and the toxicity was tested on Artemia salina, using saline extract. The results showed that the ovicidal effect of the tested extract was 99% (25 mg mL-1), 99% (12.5 mg mL-1), 98% (6.25 mg mL-1), and 95% (3.12 mg mL-1), higher than that of the control drug, thiabendazole (83%). The phytochemical analysis showed presence of phenols, anthraquinones, and condensed and hydrolysable tannins in the fruit extract. The toxicity test of the extract of P. granatum showed an LC50 of 6.19 mg mL-1, which indicates a safe use for a concentration of 3.12 mg mL-1, since it was the tested concentration that was below the reliable LC50. The saline extract from peels of P. granatum has ovicidal activity, important secondary metabolites, and absence of toxicity at the lowest concentration tested. However, in vivo tests in experimental models are recommended before performing experiments in ruminants.

Assessment of intra-arterial injected autologous bone marrow mononuclear cell distribution by radioactive labeling in acute ischemic stroke.

OBJECTIVE: To evaluate the feasibility of monitoring the autologous mononuclear bone marrow (ABMMN) cells implanted into the brain after acute ischemic stroke by the technique of labeling with Tc-99m-HMPAO. CASE REPORT: A 37-year-old man presented with aphasia, right-side hypoesthesia, and right homonymous hemianopsia after an acute ischemic stroke of the left middle cerebral artery. He was included in an autologous bone marrow mononuclear cell-based therapy research protocol about the safety of intra-arterial autologous bone marrow mononuclear cell transplantation for acute ischemic stroke. Nine days after the stroke he received 3.0 x 10(7) ABMMN cells delivered into the left cerebral middle artery via a balloon catheter. Approximately 1% of these cells were labeled with 150 MBq (4 mCi) Tc-99m by incubation with hexamethylpropylene amine oxime (HMPAO). RESULTS: Brain perfusion images with Tc-99m ECD demonstrated hypoperfusion in the left temporal and parietal regions. The perfusion brain images were compared with tomographic views of the brain obtained 8 hours after ABMMN-labeled cell delivery, revealing intense accumulation of the ABMMN-labeled cells in the ipsilateral hemisphere. A whole-body scan was done and showed left brain, liver, and spleen uptake. CONCLUSIONS: Our results showed that Tc-99m HMPAO can be used to label ABMMN cells for in vivo cell visualization, and that brain SPECT imaging with labeled ABMMN cells is a feasible noninvasive method for studying the fate of transplanted cells in vivo. Additionally, our findings demonstrate the localization of these intra-arterially injected cells.

[Clinical impact of positron emission tomography by coincidence system with 18F-FDG on therapeutic decision-making of patients with ischemic cardiomyopathy after myocardial infarction]. / Impacto clínico da tomografia por emissão de pósitrons realizada pelo sistema de coincidência com FDG-18F, na conduta terapêutica de pacientes com cardiopatia isquêmica pós-infarto do miocárdio.

OBJECTIVE: To evaluate the influence of the myocardium viability study by coincidence imaging using 18F-FDG in the clinical decision-making of patients with ischemic cardiomyopathy and left ventricular dysfunction. METHODS: Thirty-one patients were submitted to myocardial viability study with 18F-FDG by coincidence imaging between September 2003 and November 2004. The physician answered a questionnaire about the choice of therapeutic procedure before and after PET. RESULTS: Twenty-seven patients (87%) had myocardial viability. Twenty-one (68%) physicians thought that PET changed the therapeutic procedure for their patients and 27 (87%) considered that PET added to the therapeutic decision. The current treatment decision (clinical or revascularization) correlated with myocardial viability (p=0.006). CONCLUSIONS: Coincidence imaging is a useful tool to help physicians in a difficult decision about the best treatment for patients with ischemic cardiomyopathy. Symptoms, electrocardiogram, ejection fraction and myocardial fibrosis area did not correlate with myocardium viability, so they should not be used to decide whether to perform a myocardial viability study or not.

Gastrointestinal bleeding diagnosed by red blood cell scintigraphy in a patient with aortic stenosis: a case of Heyde syndrome.

The authors report a case of small bowel bleeding diagnosed by Tc-99m-labeled red blood cell (RBC) scintigraphy during the postoperative period after aortic valve replacement. There is a relationship between aortic valve stenosis and gastrointestinal bleeding in elderly patients, called Heyde syndrome. The described patient had chronic anemia that worsened after surgery. RBC scintigraphy localized the source of bleeding from jejunal angiodysplasia confirmed by mesenteric angiography. This case illustrates the diagnostic information provided by RBC scintigraphy in this syndrome.

Nuclear medicine in the management of patients with heart failure: guidance from an expert panel of the International Atomic Energy Agency (IAEA).

Heart failure is increasing worldwide at epidemic proportions, resulting in considerable disability, mortality, and increase in healthcare costs. Gated myocardial perfusion single photon emission computed tomography or PET imaging is the most prominent imaging modality capable of providing information on global and regional ventricular function, the presence of intraventricular synchronism, myocardial perfusion, and viability on the same test. In addition, I-mIBG scintigraphy is the only imaging technique approved by various regulatory agencies able to provide information regarding the adrenergic function of the heart. Therefore, both myocardial perfusion and adrenergic imaging are useful tools in the workup and management of heart failure patients. This guide is intended to reinforce the information on the use of nuclear cardiology techniques for the assessment of heart failure and associated myocardial disease.

Comparação entre avaliação de isquemia miocárdica pela reserva de fluxo fracionada e cintilografia de perfusão miocárdica / Comparison between myocardial ischemia evaluation by fractional flow reserve and myocardial perfusion scintigraphy

Lesões coronárias moderadas podem ser, ou não, responsáveis pela isquemia miocárdica. A análise funcional das lesões pode ser realizada por métodos invasivos e não invasivos. Comparar a análise funcional das lesões coronarianas moderadas pela reserva de fluxo fracionado e pela cintilografia de perfusão miocárdica. Foram estudados prospectivamente 47 pacientes com doença arterial coronária estável com pelo menos uma lesão coronariana moderada obstrutiva. Eles foram submetidos à reserva de fluxo fracionado e à cintilografia de perfusão miocárdica com intervalo médio de 24,5 dias, entre janeiro de 2013 e dezembro de 2015. Não houve alteração no estado clínico e nem no procedimento de revascularização entre exames. As variáveis populacionais foram descritas como mediana e interquartil. A reserva de fluxo fracionado foi realizada em um de tronco de coronária esquerda; 37 artérias coronárias descendentes; 12 artérias circunflexas e quatro artérias coronárias direitas. Reserva de fluxo fracionado < 0,8 foi considerada positiva. A análise comparativa entre os resultados dos testes foi feita pelo teste de Fisher bicaudal, sendo considerado significativo valor de p < 0,05. A reserva de fluxo fracionado < 0,8 foi encontrada no tronco de coronária esquerda (100%); 13 na artéria coronária descendente (35,14%); seis na artéria circunflexa (50%) e duas na artéria coronária direita (50%). Dentre os pacientes com reserva de fluxo fracionado positiva, 83% tinham isquemia miocárdica demonstrada na cintilografia de perfusão miocárdica (p = 0,058). Analisando especificamente o território da artéria coronária descendente, 83% dos pacientes com reserva de fluxo fracionado negativa não tinham isquemia na cintilografia de perfusão miocárdica, mas 69% dos pacientes com reserva de fluxo fracionado positiva não tinham isquemia na cintilografia de perfusão miocárdica (p = 0,413). Pode ocorrer discordância entre os resultados de análise funcional de lesões coronárias moderadas por testes invasivos e não invasivos

Moderate coronary artery lesions can be, or not, responsible for myocardial ischemia. The functional analysis of these lesions can be performed by invasive and noninvasive methods.To compare the functional analysis of moderate coronary lesions by fractional flow reserve and myocardial perfusion scintigraphy. 47 patients with stable coronary artery disease and at least one moderate coronary artery obstruction were prospectively studied. They were submitted to fractional flow reserve and myocardial perfusion scintigraphy with a median interval of 24.5 days between January 2013 and December 2015. There was no change in clinical status or revascularization procedure between the exams. The population variables were described as medians and interquartile range. Fractional flow reserve was performed in one left main coronary artery; 37 left descending coronary arteries; 12 circumflex arteries and 4 right coronary arteries. Fractional flow reserve < 0.8 was considered positive. The comparative analysis between the results of the tests was performed by two-tailed Fisher's test and a p-value 0.05 was considered significant.Fractional flow reserve < 0.8 was found in the left main coronary artery (100%); 13 in the left descending coronary artery (35.14%); 6 in circumflex artery (50%) and 2 in the right coronary artery (50%). Among the patients with positive fractional flow reserve, 83% had myocardial ischemia demonstrated by the myocardial perfusion scintigraphy (p = 0.058).When analyzing specifically the left descending coronary artery, 83% of the patients with negative fractional flow reserve showed no ischemia at the myocardial perfusion scintigraphy, but 69% of the patients with positive fractional flow reserve showed no ischemia at the myocardial perfusion scintigraphy (p = 0.413). Disagreements can occur between the results of the functional analysis of moderate coronary lesions by invasive and noninvasive tests

Cardiac I123-MIBG correlates better than ejection fraction with symptoms severity in systolic heart failure.

BACKGROUND: The association of autonomic activation, left ventricular ejection fraction (LVEF) and heart failure functional class is poorly understood. OBJECTIVE: Our aim was to correlate symptom severity with cardiac sympathetic activity, through iodine-123-metaiodobenzylguanidine (123I-MIBG) scintigraphy and with LVEF in systolic heart failure (HF) patients without previous beta-blocker treatment. METHODS: Thirty-one patients with systolic HF, class I to IV of the New York Heart Association (NYHA), without previous beta-blocker treatment, were enrolled and submitted to 123I-MIBG scintigraphy and to radionuclide ventriculography for LVEF determination. The early and delayed heart/mediastinum (H/M) ratio and the washout rate (WR) were performed. RESULTS: According with symptom severity, patients were divided into group A, 13 patients in NYHA class I/II, and group B, 18 patients in NYHA class III/IV. Compared with group B patients, group A had a significantly higher LVEF (25% ± 12% in group B vs. 32% ± 7% in group A, p = 0.04). Group B early and delayed H/M ratios were lower than group A ratios (early H/M 1.49 ± 0.15 vs. 1.64 ± 0.14, p = 0.02; delayed H/M 1.39 ± 0.13 vs. 1.58 ± 0.16, p = 0.001, respectively). WR was significantly higher in group B (36% ± 17% vs. 30% ± 12%, p= 0.04). The variable that showed the best correlation with NYHA class was the delayed H/M ratio (r= -0.585; p=0.001), adjusted for age and sex. CONCLUSION: This study showed that cardiac 123I-MIBG correlates better than ejection fraction with symptom severity in systolic heart failure patients without previous beta-blocker treatment.

Prevalence of induced ischemia by mental distress.

BACKGROUND: The myocardial radionuclide imaging with mental distress seems to induce ischemia through a particular physiopathology when compared to radionuclide imaging with physical or pharmacological distress. OBJECTIVE: To assess the prevalence of induced myocardial ischemia by mental distress in patients with thoracic pain and radionuclide imaging with normal conventional distress, with 99mTc-Sestamibi. METHODS: Twenty-two patients were admitted with thoracic pain at emergency or were referred to the nuclear medicine service of our institution, where myocardial radionuclide imaging of distress or rest without ischemic alterations was carried out. The patients were, then, invited to go through an additional phase with mental distress induced by color conflict (Strop Color Test) with the objective of detecting myocardial ischemia. Two cardiologists and nuclear physicians performed the blind analysis of perfusional data and consequent quantification through Summed Difference Score (SDS), punctuating the segments that were altered after mental distress and comparing it to the rest period image. The presence of myocardial ischemia was considered if SDS > or = 3. RESULTS: The prevalence of mental distress-induced myocardial ischemia was 40% (9 positive patients). Among the 22 studied patients, there were no statistical differences with regard to the number of risk factors, mental distress-induced hemodynamic alterations, usage of medications, presented symptoms, presence or absence of coronary disease and variations of ejection fraction and final systolic volume of Gated SPECT. CONCLUSION: In a selected sample of patients with thoracic pain and normal myocardial radionuclide imaging, the research of myocardial ischemia induced by mental distress through radionuclide imaging may be positive in up to 40% of cases.

Use of resting myocardial scintigraphy during chest pain to exclude diagnosis of acute myocardial infarction.

BACKGROUND: Images of myocardial perfusion taken during an episode of chest pain have been used for patients in the emergency department. OBJECTIVE: To evaluate the operating characteristics of 99mTc-Tetrofosmin scintigraphy during an episode of chest pain to exclude the diagnosis of acute myocardial infarction. METHODS: One hundred and eight patients admitted with chest pain, or up to four hours after the end of symptoms and nondiagnostic electrocardiogram, underwent resting scintigraphy and measurement of troponin I concentrations. Patients with a history of myocardial infarction (MI) were not excluded (24 patients). Troponin I concentrations were determined at admission and 6 hours later. Nuclear physicians performed a blind analysis of the images, and myocardial infarction was confirmed whenever troponin I level increase was three times that of the control. RESULTS: Resting perfusion image was abnormal in all 6 patients with MI. Only 1 patient had a normal image and increased troponin levels. Fifty-five patients had positive images without MI, and 46 patients had normal images and troponin levels. The prevalence of the disease was 6.5%. The sensitivity and specificity of the resting images during an episode of chest pain to diagnose MI was 85.7% and 45.5%, respectively. The negative predictive value was 97.7%. CONCLUSION: Patients undergoing chest pain protocol with SPECT showed an excellent negative predictive value to exclude diagnosis of myocardial infarction. These results suggest that resting perfusion image is an important tool at the chest pain unit.

Oocyte development and ovarian maturation of the black triggerfish, Melichthys niger (Actinopterygii: Balistidae) in São Pedro e São Paulo Archipelago, Brazil

The oogenesis is a key stage in the reproductive development of an organism, which can be best understood from histological analysis of ovaries in different maturity stages. In order to provide information on the reproductive biology of the black triggerfish, M. niger, in particular on its oogenesis process, this study aimed at identifying and characterizing the oocyte development stages and its organization within the different stages of ovarian maturation based on specimens from São Pedro e São Paulo Archipelago. In this present report, a number of 294 ovaries were histologically analyzed. It was verified that they are composed of ovigerous lamellae containing oocytes at different development stages. Five different stages of oogenesis were identified: young cells, with an average size of 12.9 ìm; previtellogenic oocytes (perinucleolar), with an average size of 53.5 ìm; cortical-alveoli oocytes with an average size of 83.1 ìm; vitellogenic oocytes, with an average size of 160.4 ìm and mature oocytes, with an average size of 289.8 ìm. In addition to the germ cells, some somatic structures were also identified, such as: ovarian wall, follicular cells and blood vessels. Based on the type and number of oocytes observed, four stages of ovarian maturation were identified: early maturation, represented by only 2.2% of the sample; middle maturation, represented by 9.9%; mature, represented by 44.2% and resting, represented by 43.9%. The identification of five oocyte development stages in the ovarians from M. niger, suggested that the specie follows a pattern similar to that described for other marine fish.

A oogênese é um estágio chave no desenvolvimento reprodutivo de um organismo, o qual pode ser melhor compreendido a partir de análises histológicas dos ovários em diferentes estágios de maturidade. A fim de fornecer informações sobre a biologia reprodutiva do cangulo-preto, M. niger, em especial sobre o seu processo de oogênese, este estudo teve como objetivo identificar e caracterizar as fases do desenvolvimento ovocitário e sua organização dentro dos diferentes estágios de maturação ovariana, baseado em espécimes do Arquipélago de São Pedro e São Paulo. No presente estudo, um número de 294 ovários foram analisados histologicamente. Foi verificado que eles são constituídos por lamelas ovígeras contendo ovócitos em diferentes estágios de desenvolvimento. Foram identificados cinco diferentes estágios da oogênese: células jovens, com tamanho médio de 12,9 ìm; ovócitos pré-vitelogênicos (perinucleolares), com tamanho médio de 53,5 ìm; ovócitos alvéolo-corticais, com tamanho médio de 83,1 ìm; ovócitos vitelogênicos, com tamanho médio de 160,4 ìm e ovócitos maduros, com tamanho médio de 289,8 ìm. Além das células germinativas, algumas estruturas somáticas também foram identificadas, tais como: parede do ovário, células foliculares e vasos sanguíneos. Baseado no tipo e número de ovócitos observados, quatro estágios de maturação ovariana foram identificados: início de maturação, representado por apenas 2,2% da amostra; média maturação, representado por 9,9%; madura, representado por 44,2% e em repouso representado por 43,9%. A identificação de cinco estágios do desenvolvimento ovocitário nos ovários de M. niger, sugere que a espécie segue um padrão semelhante ao descrito para outros peixes marinhos.

O I123-MIBG cardíaco se correlaciona melhor do que a fração de ejeção com a gravidade dos sintomas na insuficiência cardíaca sistólica / Cardiac I123-MIBG correlates better than ejection fraction with symptoms severity in systolic heart failure

FUNDAMENTO: A associação da ativação autonômica, fração de ejeção do ventrículo esquerdo (FEVE) e classe funcional da insuficiência cardíaca é mal compreendida. Objetivo: Nosso objetivo foi correlacionar a gravidade dos sintomas com a atividade simpática cardíaca, através do uso de iodo-123-metaiodobenzilguanidina (123I-MIBG); e com FEVE em pacientes com insuficiência cardíaca (IC) sistólica sem tratamento prévio com betabloqueador. MÉTODOS: Trinta e um pacientes com IC sistólica, classe I a IV da New York Heart Association (NYHA), sem tratamento prévio com betabloqueador, foram inscritos e submetidos à cintilografia com 123I-MIBG e ventriculografia radioisotópica para determinação da FEVE. A relação precoce e tardia coração/mediastino (H/M) e a taxa de washout (WO) foram medidas. RESULTADOS: De acordo com a gravidade dos sintomas, os pacientes foram divididos em grupo A, com 13 pacientes em classe funcional NYHA I/II, e grupo B, com 18 pacientes em classe funcional NYHA III/ IV. Em comparação com os pacientes do grupo B, o grupo A apresentou uma FEVE significativamente maior (25% ± 12% para o grupo B vs. 32% ± 7% no grupo A, p = 0,04). As relações precoces e tardias H/M do Grupo B foram menores do que as do grupo A (H/M precoce 1,49 ± 0,15 vs. 1,64 ± 0,14, p = 0,02; H/M tardia 1,39 ± 0,13 vs. 1,58 ± 0,16, p = 0,001, respectivamente). A taxa de WO foi significativamente maior no grupo B (36% ± 17% vs. 30% ± 12%, p = 0,04). A variável que mostrou a melhor correlação com a NYHA foi a relação H/M tardia (r = -0,585, p = 0,001), ajustada para idade e sexo. CONCLUSÃO: Esse estudo mostrou que o 123I-MIBG cardíaco se correlaciona melhor do que a fração de ejeção com a gravidade dos sintomas em pacientes com insuficiência cardíaca sistólica sem tratamento prévio com beta-bloqueador.

BACKGROUND:The association of autonomic activation, left ventricular ejection fraction (LVEF) and heart failure functional class is poorly understood. OBJECTIVE: Our aim was to correlate symptom severity with cardiac sympathetic activity, through iodine-123-metaiodobenzylguanidine (123I-MIBG) scintigraphy and with LVEF in systolic heart failure (HF) patients without previous beta-blocker treatment. METHODS: Thirty-one patients with systolic HF, class I to IV of the New York Heart Association (NYHA), without previous beta-blocker treatment, were enrolled and submitted to 123I-MIBG scintigraphy and to radionuclide ventriculography for LVEF determination. The early and delayed heart/mediastinum (H/M) ratio and the washout rate (WR) were performed. RESULTS: According with symptom severity, patients were divided into group A, 13 patients in NYHA class I/II, and group B, 18 patients in NYHA class III/IV. Compared with group B patients, group A had a significantly higher LVEF (25% ± 12% in group B vs. 32% ± 7% in group A, p = 0.04). Group B early and delayed H/M ratios were lower than group A ratios (early H/M 1.49 ± 0.15 vs. 1.64 ± 0.14, p = 0.02; delayed H/M 1.39 ± 0.13 vs. 1.58 ± 0.16, p = 0.001, respectively). WR was significantly higher in group B (36% ± 17% vs. 30% ± 12%, p= 0.04). The variable that showed the best correlation with NYHA class was the delayed H/M ratio (r= -0.585; p=0.001), adjusted for age and sex. CONCLUSION: This study showed that cardiac 123I-MIBG correlates better than ejection fraction with symptom severity in systolic heart failure patients without previous beta-blocker treatment.

Value of combining activated brain FDG-PET and cardiac MIBG for the differential diagnosis of dementia: differentiation of dementia with Lewy bodies and Alzheimer disease when the diagnoses based on clinical and neuroimaging criteria are difficult.

Dementia with Lewy bodies (DLB) is the second most common cause of dementia. The diagnosis of DLB is particularly important because these patients show good response to cholinesterase inhibitors. Clinical and neuroimaging criteria for DLB have not been acceptable for predictive accuracy. We report a case of progressive dementia in which the differentiation of DLB and Alzheimer disease (AD) on the basis of clinical criteria alone was not possible. The patient was admitted to the hospital because he became worse after he had started treatment for severe AD. Both MRI and brain magnetic resonance spectroscopy were normal. The patient underwent myocardial scintigraphy with I-123 MIBG showing marked reduction in cardiac MIBG accumulation. The heart to mediastinum ratio of MIBG uptake was impaired in both early and delayed images. FDG-PET scan before and after activation with a visual attention task showed occipital cortex hypometabolism as compared with AD and a normal control. This case illustrates the value of combining activated brain FDG PET and cardiac MIBG. The association of these 2 techniques could be used as a potential diagnostic tool in a patient with dementia misdiagnosed as AD.

Medium term prognostic value of stress myocardial perfusion scintigraphy in a chest pain unit.

OBJECTIVE: To evaluate the prognostic value of stress myocardial perfusion scintigraphy (MPS) applied to patients with suspected acute coronary syndrome (ACS). METHODS: Retrospective study. Patients with suspected acute coronary syndrome (ACS) admitted into the chest pain unit (CPU) from December 2002 to April 2004, after exclusion of acute myocardial infarction (AMI) and high risk unstable angina they underwent stress MPS. RESULTS: Selected 301 patients, 65.3 +/- 12.5 years and 164 (54.5%) male gender. The test was performed 13 +/- 12 hours after admission. Myocardial ischemia (ISQ) was found in 142 patients (47.2%). Male gender (n=94, p=<0.0001), history of diabetes mellitus (n=31, p=0.033), past of AMI (n=52, p=<0.0001), past of surgical myocardial revascularization (n=46, p=<0.0001) and past of percutaneous revascularization (n=68, p=<0.0001) presented correlation with ISQ. The follow-up was 697.7 +/- 326.6 days. No MPS variable correlated with the occurrence of primary outcome. Abnormal scintigraphy (n=76, p < 0.0001), ISQ (n=73, p < 0.0001) and post-stress left ventricular ejection fraction below 45% (n=21, p=0.006) correlated with secondary outcome. The presence of ISQ was the major variable in the multivariate analysis for the prediction of secondary outcome (RR = 6.5; CI 95% = 0.009). CONCLUSION: Presence of ISQ was the major independent factor in prediction of adverse events for patients admitted into the CPU.