42 research outputs found
923-3 Fluosol Reduces Myocardial Reperfusion Injury by Prolonged Suppression of Neutrophils by its Detergent Component (RheothRx) and not by Enhancing O2Delivery
Fluosol, a complex mixture of O2carrying perfluorocarbons (PFCs) emulsified by the detergent pluronic F-68 and a variety of lipids, significantly reduces myocardial reperfusion injury (RI) in animals and humans as shown in some initial clinical trials. Potential mechanisms for Fluosol include enhanced O2delivery to the reperfused tissue and modulation of various neutrophil (PMNs) functions. Recent studies in dogs and man demonstrate the same beneficial effect for treatment of Rl with the detergent component alone, RheothRx, which is currently undergoing clinical trials. We have shown that the effect of Fluosol on PMNs is related to this detergent. However, prolonged infusion (48 hrs) of detergent is required to reduce Rl to the same extent as Fluosol given over only 1 hr. Possible mechanisms for the beneficial effects of Fluosol (O2delivery vs effects on PMNs) were investigated in a model of regional ischemia utilizing rabbits undergoing 30mins of circumflex occlusion and 48 hrs of reperfusion. Infarct size (area of necrosis, AN) was determined histologically and expressed as percent of risk region (area at risk, AR). Animals received Fluosol (30cc/kg) with or without O2or saline over the first 60mins of reperfusion. AR was similar in all groups. (Mean±SEM of AN/AR (%), n=11 for all groups). The treatment with Fluosol with or without O2(44±3 and 40;±3, respectively) was significantly (p<0.05) reduced compared to control (63±4). Another group received F-I08, a larger size pluronic detergent found to be 2.5-fold more potent in suppressing PMN function in vitrocompared to F-68, during the first 3 hrs of reperfusion. This treatment did not alter the infarct size (63±5). RheothRx was found to form 4 nm micelles in solution whereas Fluosol formed particles approximately 100 times larger. Similar sized particles were formed by substituting the perfluorocarbons with mineral oil. The in vitroactivity of this pluronic/mineral oil micelle on PMN function was similar to Fluosol. Infusion of these larger oil micelles was tolerated by rabbits and used in further infarct studies.ConclusionsThese studies suggest that (1) reduction of RI by Fluosol is not due to enhanced O2delivery by the PFCs to reperfused myocardium and (2) since the Fluosol emulsion markedly reduces the clearance of the detergent F-68 (t½: Fluosol ≅ 8 hrs vs RheothRx ≅ 1.5 hrs). prolonged PMN suppression rather than potency of suppression is the mechanism whereby Fluosol ameliorates RI. Fluosol's clinical efficacy may be enhanced by prolonging its infusion to ensure an adequate blood level to suppress PMN function beyond the time of reperfusion injury. RheothRx's clinical usefulness may be facilitated by decreasing its renal clearance by delivering larger micelles of the detergent in order to produce prolonged PMN suppression with a shorter infusion time
Current worldwide nuclear cardiology practices and radiation exposure: results from the 65 country IAEA Nuclear Cardiology Protocols Cross-Sectional Study (INCAPS)
Aims To characterize patient radiation doses from nuclear myocardial perfusion imaging (MPI) and the use of radiation-optimizing ‘best practices' worldwide, and to evaluate the relationship between laboratory use of best practices and patient radiation dose. Methods and results We conducted an observational cross-sectional study of protocols used for all 7911 MPI studies performed in 308 nuclear cardiology laboratories in 65 countries for a single week in March-April 2013. Eight ‘best practices' relating to radiation exposure were identified a priori by an expert committee, and a radiation-related quality index (QI) devised indicating the number of best practices used by a laboratory. Patient radiation effective dose (ED) ranged between 0.8 and 35.6 mSv (median 10.0 mSv). Average laboratory ED ranged from 2.2 to 24.4 mSv (median 10.4 mSv); only 91 (30%) laboratories achieved the median ED ≤ 9 mSv recommended by guidelines. Laboratory QIs ranged from 2 to 8 (median 5). Both ED and QI differed significantly between laboratories, countries, and world regions. The lowest median ED (8.0 mSv), in Europe, coincided with high best-practice adherence (mean laboratory QI 6.2). The highest doses (median 12.1 mSv) and low QI (4.9) occurred in Latin America. In hierarchical regression modelling, patients undergoing MPI at laboratories following more ‘best practices' had lower EDs. Conclusion Marked worldwide variation exists in radiation safety practices pertaining to MPI, with targeted EDs currently achieved in a minority of laboratories. The significant relationship between best-practice implementation and lower doses indicates numerous opportunities to reduce radiation exposure from MPI globall
Associação de Nível de Renda e Doença Isquêmica do Coração: Papel Potencial da Caminhabilidade
Resumo Fundamento O nível socioeconômico tem sido associado à doença isquêmica do coração (DIC). Bairros de alta renda podem expor os indivíduos a um ambiente construído que promova caminhadas para atividades diárias (caminhabilidade). Faltam dados sobre a associação entre renda e DIC em países de renda média. Também é incerto se a caminhabilidade medeia essa associação. Objetivos Investigar se a renda está associada à DIC em um país de renda média e se a caminhabilidade dos bairros medeia a associação entre renda e DIC. Métodos O presente estudo transversal avaliou 44.589 pacientes encaminhados para imagem de perfusão miocárdica (SPECT-MPI). A renda e a caminhabilidade foram derivadas do setor censitário residencial dos participantes. A pontuação quantitativa da caminhabilidade combinou as seguintes 4 variáveis: conectividade viária, densidade residencial, densidade comercial e uso misto do solo. A DIC foi definida pela presença de perfusão miocárdica anormal durante um estudo SPECT-MPI. Utilizamos modelos ajustados com efeitos mistos para avaliar a associação entre nível de renda e DIC e realizamos uma análise de mediação para medir o percentual da associação entre renda e DIC mediada pela caminhabilidade. Consideramos valores de p abaixo de 0,01 como estatisticamente significativos. Resultados Dos 26.415 participantes, aqueles que residiam no setor censitário do tercil de menor renda eram mais fisicamente inativos (79,1% versus 75,8% versus 72,7%) quando comparados aos setores censitários do tercil de maior renda (p < 0,001). A renda foi associada à DIC (odds ratio: 0,91 [intervalo de confiança de 95%: 0,87 a 0,96] para cada aumento de 1000,00 dólares internacionais na renda), para homens e mulheres igualmente (p para interação = 0,47). Os setores censitários com maior renda estiveram associados a uma melhor caminhabilidade (p < 0,001); no entanto, a caminhabilidade não mediou a associação entre renda e DIC (porcentagem mediada = −0,3%). Conclusões A renda foi independentemente associada a maior prevalência de DIC em um país de renda média, independentemente de gênero. Embora a caminhabilidade tenha sido associada à renda do setor censitário, ela não mediou a associação entre renda e DIC
Current worldwide nuclear cardiology practices and radiation exposure : results from the 65 country IAEA Nuclear Cardiology Protocols Cross-Sectional Study (INCAPS)
To characterize patient radiation doses from nuclear myocardial perfusion imaging (MPI) and the use of radiation-optimizing 'best practices' worldwide, and to evaluate the relationship between laboratory use of best practices and patient radiation dose. We conducted an observational cross-sectional study of protocols used for all 7911 MPI studies performed in 308 nuclear cardiology laboratories in 65 countries for a single week in March-April 2013. Eight 'best practices' relating to radiation exposure were identified a priori by an expert committee, and a radiation-related quality index (QI) devised indicating the number of best practices used by a laboratory. Patient radiation effective dose (ED) ranged between 0.8 and 35.6 mSv (median 10.0 mSv). Average laboratory ED ranged from 2.2 to 24.4 mSv (median 10.4 mSv); only 91 (30%) laboratories achieved the median ED ≤ 9 mSv recommended by guidelines. Laboratory QIs ranged from 2 to 8 (median 5). Both ED and QI differed significantly between laboratories, countries, and world regions. The lowest median ED (8.0 mSv), in Europe, coincided with high best-practice adherence (mean laboratory QI 6.2). The highest doses (median 12.1 mSv) and low QI (4.9) occurred in Latin America. In hierarchical regression modelling, patients undergoing MPI at laboratories following more 'best practices' had lower EDs. Marked worldwide variation exists in radiation safety practices pertaining to MPI, with targeted EDs currently achieved in a minority of laboratories. The significant relationship between best-practice implementation and lower doses indicates numerous opportunities to reduce radiation exposure from MPI globally
Challenges and Opportunities in Nuclear Cardiology from Latin American and Asian Perspectives.
One of the most important missions of the AmericanSocietyofNuclearCardiology(ASNC)istoimprovethequality of clinical practice of nuclear cardiology around theworld. Cardiovascular disease (CVD) remains the leadingcauseofdeaththroughouttheworld,especiallyindevelopingnations where 80% of CVD deaths occur (1).With this in mind, ASNC conducted international sessionsaspartofthe21stAnnualScientificSessioninSeptember2016inBocaRaton,FL,andfocusedonthecurrentstatusofnuclearcardiologyintworegionswheremortalityremainshigh,LatinAmerica and Asia
Cardiac sympathetic nervous system imaging with 123I-meta-iodobenzylguanidine: Perspectives from Japan and Europe
Cardiac sympathetic nervous system dysfunction is closely associated with risk of serious cardiac events in patients with heart failure (HF), including HF progression, pump-failure death, and sudden cardiac death by lethal ventricular arrhythmia. For cardiac sympathetic nervous system imaging, 123I-meta-iodobenzylguanidine (123I-MIBG) was approved by the Japanese Ministry of Health, Labour and Welfare in 1992 and has therefore been widely used since in clinical settings. 123I-MIBG was also later approved by the Food and Drug Administration (FDA) in the United States of America (USA) and it was expected to achieve broad acceptance. In Europe, 123I-MIBG is currently used only for clinical research. This review article is based on a joint symposium of the Japanese Society of Nuclear Cardiology (JSNC) and the American Society of Nuclear Cardiology (ASNC), which was held in the annual meeting of JSNC in July 2016. JSNC members and a member of ASNC discussed the standardization of 123I-MIBG parameters, and clinical aspects of 123I-MIBG with a view to further promoting 123I-MIBG imaging in Asia, the USA, Europe, and the rest of the world
923-3 Fluosol Reduces Myocardial Reperfusion Injury by Prolonged Suppression of Neutrophils by its Detergent Component (RheothRx) and not by Enhancing O 2 Delivery
Value of gated-SPECT MPI for ischemia-guided PCI of non-culprit vessels in STEMI patients with multivessel disease after primary PCI
There remains a clinical question of which patients benefit from revascularization of non-culprit coronary artery stenosis in the setting of acute ST-segment elevation myocardial infraction (STEMI). This is a large population of patients with prior studies showing 40 to 70% of patients with STEMI having non-culprit stenosis. This article reviews the current state of the literature evaluating outcomes of those previously randomized to revascularization of non-culprit stenosis around the time of the STEMI. We propose a new study design to utilize gated-SPECT in the decision process by using an ischemic burden of > 5% as a cut-off for revascularization vs. complete revascularization without ischemia assessment