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BACKGROUND: The progress of electronic health technologies and biobanks holds enormous promise for efficient research. Evidence shows that studies based on sharing and secondary use of data/samples have the potential to significantly advance medical knowledge. However, sharing of such resources for international collaboration is hampered by the lack of clarity about ethical and legal requirements for transfer of data and samples across international borders. MAIN TEXT: Here, the International Clinical Trial Center Network (ICN) reports the legal and ethical requirements governing data and sample exchange (DSE) across four continents. The most recurring requirement is ethical approval, whereas only in specific conditions approval of national health authorities is required. Informed consent is not required in all sharing situations. However, waiver of informed consent is only allowed in certain countries/regions and under certain circumstances. The current legal and ethical landscape appears to be very complex and under constant evolution. Regulations differ between countries/regions and are often incomplete, leading to uncertainty. CONCLUSION: With this work, ICN illuminates the unmet need for a single international collaborative framework to facilitate DSE. Harmonising requirements for global DSE will reduce inefficiency and waste in research. There are many challenges to realising this ambitious vision, including inconsistent terminology and definitions, and heterogeneous and dynamic legal constraints. Here, we identify areas of agreement and significant difference as a necessary first step towards facilitating international collaboration. We propose the establishment of a working group to continue the comparison across jurisdictions, create a standardised glossary and define a set of basic principles and fundamental requirements for DSE.
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Registros Eletrônicos de Saúde/ética , Registros Eletrônicos de Saúde/legislação & jurisprudência , Disseminação de Informação/ética , Disseminação de Informação/legislação & jurisprudência , Cooperação Internacional/legislação & jurisprudência , Bancos de Tecidos/ética , Bancos de Tecidos/legislação & jurisprudência , Saúde Global , Humanos , Internacionalidade , Propriedade/ética , Propriedade/legislação & jurisprudênciaRESUMO
BACKGROUND: Limited data exist on human zinc absorption from wheat biofortified via foliar (FBW) or root (hydroponically fortified wheat, HBW) zinc application. Stable isotope labels added at point of consumption (extrinsic labeling) might not reflect absorption from native zinc obtained by intrinsic labeling. OBJECTIVES: We measured fractional and total zinc absorption (FAZ, TAZ) in FBW and HBW wheat, compared with control wheat (CW) and fortified wheat (FW). The effect of labeling method was assessed in HBW (study 1), and the effect of milling extraction rate (EXR, 80% and 100%) in FBW (studies 2 and 3). METHODS: Generally healthy adults (n = 71, age: 18-45 y, body mass index: 18.5-25 kg/m2) were allocated to 1 of the studies, in which they served as their own controls. In study 1, men and women consumed wheat porridges colabeled intrinsically and extrinsically with 67Zn and 70Zn. In studies 2 and 3, women consumed wheat flatbreads (chapatis) labeled extrinsically. Zinc absorption was measured with the oral to intravenous tracer ratio method with a 4-wk wash-out period between meals. Data were analyzed with linear mixed models. RESULTS: In study 1 there were no differences in zinc absorption from extrinsic versus intrinsic labels in either FW or HBW. Similarly, FAZ and TAZ from FW and HBW did not differ. TAZ was 70-76% higher in FW and HBW compared with CW (P < 0.01). In studies 2 and 3, TAZ from FW and FBW did not differ but was 20-48% higher compared with CW (P < 0.001). Extraction rate had no effect on TAZ. CONCLUSIONS: Colabeling demonstrates that extrinsic zinc isotopic labels can be used to accurately quantify zinc absorption from wheat in humans. Biofortification through foliar zinc application, root zinc application, or fortification provides higher TAZ compared with unfortified wheat. In biofortified wheat, extraction rate (100-80%) has a limited impact on total zinc absorption. These studies were registered on clinicaltrials.gov (NCT01775319).
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Biofortificação , Grão Comestível/química , Alimentos Fortificados , Absorção Intestinal , Triticum/química , Zinco/farmacocinética , Adolescente , Adulto , Disponibilidade Biológica , Pão , Feminino , Farinha , Humanos , Hidroponia , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Zinco/sangue , Isótopos de Zinco/análiseRESUMO
BACKGROUND: Non-alcoholic steatohepatitis (NASH) is defined by liver inflammation and consecutive fibrotic damage caused by a deposition of fat in the liver. No licensed medical treatments exist and lifestyle modification is difficult to incorporate into everyday life. We investigated the efficacy and safety of a 48-week treatment with vitamin D3 in NASH patients. METHODS: Histologically determined NASH patients with elevated alanine aminotransferase (ALT) and decreased 25-OH vitamin D level at baseline received vitamin D3 or placebo orally over a 48-week period. The primary endpoint of this study was the change in ALT from baseline to the end-of-treatment. Steatohepatitis was categorized according to the Steatosis, Activity and Fibrosis Score and disease activity was assessed using the NAFLD activity score. RESULTS: Serum 25-OH vitamin D levels significantly increased only in the vitamin D3 group over the 48-week treatment phase indicating compliance. In contrast to placebo, patients in the vitamin D group had markedly decreased ALT levels after the end-of-treatment phase. A significant decrease during treatment with vitamin D was also observed for cytokeratin-18 fragments compared with placebo. The study was not powered to detect changes in histological score, hence only descriptive results for histopathological characteristics are available. CONCLUSIONS: Treatment with 2100 IE vitamin D q.d. over 48 weeks was well tolerated and led to a significant improvement of serum ALT levels in patients with hypovitaminosis D and histology-proven NASH as the primary endpoint together with a trend toward reduction of hepatic steatosis, which was not significant due to a small number of available biopsy specimens.
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Alanina Transaminase/sangue , Calcifediol/administração & dosagem , Hepatopatia Gordurosa não Alcoólica/sangue , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Adulto , Método Duplo-Cego , Feminino , Humanos , Fígado/patologia , Masculino , Pessoa de Meia-Idade , Hepatopatia Gordurosa não Alcoólica/patologia , Projetos Piloto , Índice de Gravidade de Doença , Suíça , Resultado do Tratamento , Deficiência de Vitamina D/sangue , Adulto JovemRESUMO
Background: Rice can be fortified with the use of hot or cold extrusion or coating, but the nutritional qualities of the resulting rice grains have never been directly compared.Objective: Using fortified rice produced by coating or hot or cold extrusion, we compared 1) iron and zinc absorption with the use of stable isotopes, 2) iron and zinc retention during cooking, and 3) starch microstructure.Methods: We conducted 2 studies in young women: in study 1 [n = 19; mean ± SD age: 26.2 ± 3.4 y; body mass index (BMI; in kg/m2): 21.3 ± 1.6], we compared the fractional iron absorption (FAFe) from rice meals containing isotopically labeled ferric prophosphate (57FePP), zinc oxide (ZnO), citric acid, and micronutrients fortified through hot extrusion (HER1) with rice meals fortified through cold extrusion containing 57FePP, ZnO, citric acid, and micronutrients (CER); in study 2 (n = 22; age: 24 ± 4 y; BMI: 21.2 ± 1.3), we compared FAFe and fractional zinc absorption (FAZn) from rice meals fortified through hot extrusion (HER2) compared with rice meals fortified through coating containing 57FePP, ZnO, a citric acid and trisodium cirate mixture (CA/TSC), and micronutrients (COR) relative to rice meals extrinsically fortified with ferrous sulfate (reference). Rice types HER1 and CER contained citric acid, whereas types HER2 and COR contained CA/TSC. We assessed retention during standardized cooking experiments and characterized the rice starch microstructure.Results: FAFe (95% CI) was greater from CER [2.2% (1.4%, 3.4%)] than from HER1 [1.2% (0.7%, 2.0%)] (P = 0.036). There was no difference in FAFe between HER2 [5.1% (3.7%, 7.1%)] and COR [4.0% (2.9%, 5.4%)] (P = 0.14), but FAFe from COR was lower than that from the reference meal [6.6% (4.9%, 9.0%)] (P = 0.003), and the geometric mean FAZn (95% CI) did not differ between HER2 [9.5% (7.9%, 11.6%)] and COR [9.6% (8.7%, 10.7%)] (P = 0.92). Cooking in a rice-to-water ratio of 1:2 resulted in iron and zinc retentions >80%, and cooking in excess water did not affect iron retention from hot-extruded rice but caused iron losses of 25% from CER and COR. Distinct variations in starch microstructure were found in CER and HER1.Conclusions: Iron absorption was 64% higher from CER than from hot-extruded rice, with no difference between COR compared with hot-extruded rice. Lower extrusion temperatures may generate a more readily digestible starch structure, allowing for greater iron release in vivo but lower mineral retention during cooking. This trial was registered at clinicaltrials.gov as NCT02176759.
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Manipulação de Alimentos/métodos , Ferro/farmacocinética , Minerais/química , Oryza/química , Amido/química , Adulto , Disponibilidade Biológica , Culinária , Estudos Cross-Over , Feminino , Alimentos Fortificados , Humanos , Suíça , Adulto JovemRESUMO
BACKGROUND: Biofortification of staple food crops is a promising strategy to combat zinc deficiency, and it is of particular interest for rice and crops that are not consumed as flours and therefore not suitable for postharvest fortification. Because zinc absorption is decreased by phytic acid (PA) and perhaps other dietary components, it is important to measure the absorption of zinc from a biofortified crop before determining its efficacy. OBJECTIVE: In this study, we compared the zinc absorption from zinc-biofortified rice (hydroponically enriched with (70)Zn) with that from a control rice of the same variety fortified with (70)ZnSO4 at point of use to reach the same total zinc content of 1.1 mg/meal. Both rice meals had a PA:Zn molar ratio of 12. METHODS: Fractional absorption of zinc (FAZ) was measured with the use of the double-isotope tracer ratio method in 16 apparently healthy adults [18-45 y old; BMI (in kg/m(2)) 19-25] who consumed 2 single meals at 4-wk intervals in random order in a crossover design. RESULTS: The FAZ from the biofortified rice (mean ± SD: 25.1 ± 8.7%) did not differ significantly from that of the point-of-use fortified rice (mean ± SD: 20.8 ± 7.1%) (P = 0.08). CONCLUSIONS: These results suggest that the native zinc accumulated in the biofortified rice was readily released from the rice matrix and that its absorption by adults was influenced by PA and other food components in a similar way to the inorganic zinc compound added to the rice at point of use. Moreover, rice biofortification is likely to be as good as postharvest zinc fortification as an intervention strategy to combat zinc deficiency. This trial was registered at clinicaltrials.gov as NCT01633450.
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Alimentos Fortificados , Sulfato de Zinco/farmacocinética , Zinco/farmacocinética , Adolescente , Adulto , Disponibilidade Biológica , Índice de Massa Corporal , Grão Comestível/química , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Oryza/química , Ácido Fítico , Adulto Jovem , Zinco/administração & dosagem , Zinco/deficiência , Sulfato de Zinco/administração & dosagemRESUMO
The water-soluble zinc salts gluconate, sulfate, and acetate are commonly used as supplements in tablet or syrup form to prevent zinc deficiency and to treat diarrhea in children in combination with oral rehydration. Zinc citrate is an alternative compound with high zinc content, slightly soluble in water, which has better sensory properties in syrups but no absorption data in humans. We used the double-isotope tracer method with (67)Zn and (70)Zn to measure zinc absorption from zinc citrate given as supplements containing 10 mg of zinc to 15 healthy adults without food and compared absorption with that from zinc gluconate and zinc oxide (insoluble in water) using a randomized, double-masked, 3-way crossover design. Median (IQR) fractional absorption of zinc from zinc citrate was 61.3% (56.6-71.0) and was not different from that from zinc gluconate with 60.9% (50.6-71.7). Absorption from zinc oxide at 49.9% (40.9-57.7) was significantly lower than from both other supplements (P < 0.01). Three participants had little or no absorption from zinc oxide. We conclude that zinc citrate, given as a supplement without food, is as well absorbed by healthy adults as zinc gluconate and may thus be a useful alternative for preventing zinc deficiency and treating diarrhea. The more insoluble zinc oxide is less well absorbed when given as a supplement without food and may be minimally absorbed by some individuals. This trial was registered at clinicaltrials.gov as NCT01576627.
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Citratos/farmacocinética , Suplementos Nutricionais , Gluconatos/farmacocinética , Óxido de Zinco/farmacocinética , Zinco/administração & dosagem , Adolescente , Adulto , Disponibilidade Biológica , Estudos Cross-Over , Deficiências Nutricionais/prevenção & controle , Diarreia/tratamento farmacológico , Método Duplo-Cego , Feminino , Humanos , Absorção Intestinal , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Zinco/deficiência , Zinco/metabolismo , Zinco/uso terapêutico , Isótopos de Zinco/metabolismoRESUMO
Herpes labialis affects one third of the population. We evaluated the topical application of an antiviral compound, hydroxypropyl-ß-cyclodextrin (2-HPßCD), in reducing herpes labialis relapses. In this double-blind, randomized, placebo-controlled trial, 40 patients were randomized to a polyethylene glycol (PEG) formulation containing 20% 2-HPßCD or to a vehicle control arm. The gel was applied to the lips twice daily for 6 months. The primary objective was reducing herpes relapses. Surprisingly, the drug group had significantly more relapses than the vehicle group (p = 0.003). While the median numbers of relapses in the preceding year were 12 in the vehicle group and 10 in the drug group, both groups experienced very few relapses during the 6-month treatment period, with a median of 0 in the vehicle group and a median of 2 in the drug group. The impressive reduction of relapses in both groups may be due to a placebo effect or due to the topical treatment with PEG.
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Antivirais/uso terapêutico , Herpes Labial/prevenção & controle , beta-Ciclodextrinas/uso terapêutico , 2-Hidroxipropil-beta-Ciclodextrina , Aciclovir/uso terapêutico , Administração Tópica , Adulto , Antivirais/administração & dosagem , Método Duplo-Cego , Feminino , Géis/uso terapêutico , Humanos , Pessoa de Meia-Idade , Veículos Farmacêuticos/uso terapêutico , Polietilenoglicóis/uso terapêutico , Prevenção Secundária , Adulto Jovem , beta-Ciclodextrinas/administração & dosagemRESUMO
BACKGROUND: Epicutaneous allergen administration using a patch may be an alternative to subcutaneous or sublingual immunotherapy. OBJECTIVE: To optimize treatment dose and to demonstrate the efficacy and safety of epicutaneous immunotherapy. METHODS: This monocentric, placebo-controlled, double-blind trial included 132 patients with grass pollen-induced rhinoconjunctivitis. In February 2008, patients were randomly allocated to receive placebo or 3 different doses of allergen. Before and during the pollen season 2008, patients received 6 weekly patches. Efficacy was assessed 4 to 5 months later (n = 110) and during the pollen season of the treatment-free follow-up year in 2009 (n = 93). The primary outcome was patient-reported changes in hay fever symptoms assessed by a visual analog scale. Secondary outcome measures were weekly visual analog scale symptom scores during pollen season, use of rescue medication, changes in conjunctival and skin reactivity, as well as safety. RESULTS: Hay fever symptoms during the pollen season were reduced by more than 30% in 2008 and by 24% in 2009 in the high-dose group as compared with that in the placebo group, and the alleviation of symptoms in the follow-up year was dependent on the treatment dose. Higher allergen doses were associated with drug-related adverse events (AEs), predominantly manifested by pruritus, erythema, wheal, or eczema. Eleven systemic AEs of grades 1 to 2 required treatment and led to study exclusion. The dropout rate due to AEs was 8.3%. No drug-related serious AE was recorded. CONCLUSION: Epicutaneous immunotherapy is safe and efficacious in a dose-dependent manner after 6 patches only.
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Alérgenos/imunologia , Conjuntivite Alérgica/terapia , Dessensibilização Imunológica , Poaceae/imunologia , Pólen/imunologia , Administração Cutânea , Adulto , Conjuntivite Alérgica/imunologia , Dessensibilização Imunológica/efeitos adversos , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
OBJECTIVE: Clinical research has faced new challenges during the COVID-19 pandemic, leading to excessive operational demands affecting all stakeholders. We evaluated the impact of COVID-19 on clinical research strategies and compared different adaptations by regulatory bodies and academic research institutions in a global context, exploring what can be learned for possible future pandemics. METHODS: We conducted a cross-sectional online survey and identified and assessed different COVID-19-specific adaptation strategies used by academic research institutions and regulatory bodies. RESULTS: All 19 participating academic research institutions developed and followed similar strategies, including preventive measures, manpower recruitment, and prioritisation of COVID-19 projects. In contrast, measures for centralised management or coordination of COVID-19 projects, project preselection, and funding were handled differently amongst institutions. Regulatory bodies responded similarly to the pandemic by implementing fast-track authorisation procedures for COVID-19 projects and developing guidance documents. Quality and consistency of the information and advice provided was rated differently amongst institutions. CONCLUSION: Both academic research institutions and regulatory bodies worldwide were able to cope with challenges during the COVID-19 pandemic by developing similar strategies. We identified some unique approaches to ensure fast and efficient responses to a pandemic. Ethical concerns should be addressed in any new decision-making process.
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COVID-19 , Adaptação Psicológica , COVID-19/epidemiologia , Estudos Transversais , Humanos , Pandemias/prevenção & controle , Inquéritos e QuestionáriosRESUMO
BACKGROUND: Clinical trials remain key to the development of evidence-based medical practice. However, they are becoming increasingly complex, mainly in a multinational setting. To address these challenges, the European Union (EU) adopted the Clinical Trial Regulation EU No. 536/2014 (CTR). Once in force, the CTR will lead to more consistent rules and simplification of procedures for conducting clinical trials throughout the EU. Existing harmonization initiatives and "research infrastructures" for clinical trials may facilitate this process. This publication offers a snapshot of the current level of harmonization activities in academic clinical research in Europe. METHODS: A survey was performed among the member and observer countries of the European Clinical Research Infrastructure Network (ECRIN), using a standardized questionnaire. Three rounds of data collection were performed to maximize completeness and comparability of the received answers. The survey aimed to describe the harmonization of academic clinical research processes at national level, to facilitate the exchange of expertise and experience among countries, and to identify new fields of action. RESULTS: Most scientific partners already have in place various working groups and harmonization activities at national level. Furthermore, they are involved in and open to sharing their know-how and documents. Since harmonization was mainly a bottom-up approach up until now, the extent and topics dealt with are diverse and there is only little cross-networking and cross-country exchange so far. CONCLUSIONS: Currently, the ECRIN member countries offer a very solid base and collaborative spirit for further aligning processes and exchanging best practices for clinical research in Europe. They can support a smooth implementation of the EU CTR and may act as single contact with consolidated expertise in a country.
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Desbridamento , Dessensibilização Imunológica/métodos , Rinite Alérgica Sazonal/terapia , Pele/metabolismo , Fita Cirúrgica/efeitos adversos , Administração Cutânea , Adolescente , Adulto , Alérgenos/imunologia , Humanos , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/terapia , Hipersensibilidade Imediata/imunologia , Hipersensibilidade Imediata/terapia , Pessoa de Meia-Idade , Pólen/imunologia , Estudos Retrospectivos , Rinite Alérgica Sazonal/imunologia , Pele/imunologia , Suíça , Adulto JovemRESUMO
In Switzerland, Pharmaceutical Medicine has existed as one of 46 physician specialties accredited by the Federal Office of Public Health for more than 20 years. As a medical-scientific discipline, our goal is to enable best possible therapeutic coverage for the benefit of patients and society through a medical need-based development and optimal use of medicinal products. The role of the specialist in Pharmaceutical Medicine is to closely collaborate with various stakeholders of the healthcare system in the context of the discovery, research, development and approval of new medicinal products, as well as safe and effective use of new and established medicinal products in daily clinical practice. The post-graduate training consists of 2 years of patient-related clinical work, followed by 3 years of vocational training at certified training centers in Pharmaceutical Medicine. This also includes completion of an academic post-graduate diploma in Pharmaceutical Medicine (30 ECTS) according to the IFAPP/PharmaTrain syllabus and a 1 day board exam. As part of an ongoing revision of the training curriculum, we are developing a Swiss Catalog of Core Competencies in Pharmaceutical Medicine (SC3-PM), based on the IFAPP competency framework for drug development specialists in industry. In this article we discuss how we adapt the scope of the IFAPP competency framework to better reflect such roles in academic institutions or regulatory bodies in Switzerland.
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BACKGROUND: Zinc deficiency and contaminated water are major contributors to diarrhea in developing countries. Food fortification with zinc has not shown clear benefits, possibly because of low zinc absorption from inhibitory food matrices. We used a novel point-of-use water ultrafiltration device configured with glass zinc plates to produce zinc-fortified, potable water. OBJECTIVE: The objective was to determine zinc bioavailability from filtered water and the efficacy of zinc-fortified water in improving zinc status. DESIGN: In a crossover balanced study, we measured fractional zinc absorption (FAZ) from the zinc-fortified water in 18 healthy Swiss adults using zinc stable isotopes and compared it with zinc-fortified maize porridge. We conducted a 20-wk double-blind randomized controlled trial (RCT) in 277 Beninese school children from rural settings who were randomly assigned to receive a daily portion of zinc-fortified filtered water delivering 2.8 mg Zn (Zn+filter), nonfortified filtered water (Filter), or nonfortified nonfiltered water (Pump) from the local improved supply, acting as the control group. The main outcome was plasma zinc concentration (PZn), and the 3 groups were compared by using mixed-effects models. Secondary outcomes were prevalence of zinc deficiency, diarrhea prevalence, and growth. RESULTS: Geometric mean (-SD, +SD) FAZ was 7-fold higher from fortified water (65.9%; 42.2, 102.4) than from fortified maize (9.1%; 6.0, 13.7; P < 0.001). In the RCT, a significant time-by-treatment effect on PZn (P = 0.026) and on zinc deficiency (P = 0.032) was found; PZn in the Zn+filter group was significantly higher than in the Filter (P = 0.006) and Pump (P = 0.025) groups. We detected no effect on diarrhea or growth, but our study did not have the duration and power to detect such effects. CONCLUSIONS: Consumption of filtered water fortified with a low dose of highly bioavailable zinc is an effective intervention in children from rural African settings. Large community-based trials are needed to assess the effectiveness of zinc-fortified filtered water on diarrhea and growth. These trials were registered at clinicaltrials.gov as NCT01636583 and NCT01790321.
Assuntos
Fenômenos Fisiológicos da Nutrição Infantil , Água Potável/administração & dosagem , Alimentos Fortificados , Absorção Intestinal , Saúde da População Rural , Zinco/metabolismo , Adulto , Benin/epidemiologia , Criança , Estudos Cross-Over , Deficiências Nutricionais/dietoterapia , Deficiências Nutricionais/epidemiologia , Deficiências Nutricionais/metabolismo , Deficiências Nutricionais/fisiopatologia , Diarreia/etiologia , Diarreia/fisiopatologia , Diarreia/prevenção & controle , Método Duplo-Cego , Humanos , Estudos Longitudinais , Plasma/química , Prevalência , Método Simples-Cego , Suíça , Ultrafiltração , Urina/química , Zinco/administração & dosagem , Zinco/deficiência , Zinco/uso terapêutico , Isótopos de ZincoRESUMO
OBJECTIVES: The goal of this study was to assess the predictive value of myocardial perfusion imaging with (13)N-ammonia positron emission tomography (PET) and coronary flow reserve (CFR) on long-term prognosis in patients with suspected myocardial ischemia. BACKGROUND: No prognostic data exist on the predictive value of CFR and (13)N-ammonia PET. METHODS: Perfusion and CFR were assessed in 256 patients using (13)N-ammonia PET, and follow-up was obtained in 245 (96%) patients. Sixteen early revascularized patients were excluded and 229 were assigned to normal versus abnormal perfusion or normal versus abnormal CFR (<2.0). Major adverse cardiac events (MACE) (cardiac death, nonfatal myocardial infarction, late revascularization, or hospitalization for cardiac reasons) were assessed using the Kaplan-Meier method. Cox proportional hazard regression was used to identify independent predictors for cardiac events. RESULTS: During follow-up (5.4 +/- 2.2 years), 78 patients had at least 1 cardiac event, including 29 cardiac deaths. Abnormal perfusion (n = 126) was associated with a higher incidence of MACE (p < 0.001) and cardiac death (p < 0.05). In patients with normal perfusion, abnormal CFR was independently associated with a higher annual event rate over 3 years compared with normal CFR for MACE (1.4% vs. 6.3%; p < 0.05) and cardiac death (0.5% vs. 3.1%; p < 0.05). In abnormal perfusion, CFR remained predictive throughout the 10-year follow-up (p < 0.001). CONCLUSIONS: Perfusion findings in (13)N-ammonia PET and CFR are strong outcome predictors. CFR allows further risk stratification, suggesting a "warranty" period of 3 years if normal CFR is associated with normal perfusion. Conversely, in patients with abnormal perfusion, an impaired CFR has added value for predicting adverse outcomes.
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Amônia , Circulação Coronária/fisiologia , Isquemia Miocárdica/diagnóstico por imagem , Miocárdio/metabolismo , Tomografia por Emissão de Pósitrons/métodos , Amônia/farmacocinética , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Incidência , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/epidemiologia , Isquemia Miocárdica/fisiopatologia , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Radioisótopos , Estudos Retrospectivos , Taxa de Sobrevida , Suíça/epidemiologia , Fatores de TempoRESUMO
We evaluated the determinants of vessel contrast in prospectively ECG-triggered CT coronary angiography (CTCA). Seventy patients underwent low-dose CTCA using body mass index (BMI)-adapted tube parameters and a fixed contrast material bolus. Contrast to noise ratio (CNR) was calculated from contrast (between coronaries and perivascular tissue) and image noise (standard deviation of aortic attenuation). Cardiac output (CO) was calculated from gated (99m)Tc-tetrofosmin-SPECT. Mean radiation dose was 2.13 +/- 0.69 mSv. Image noise was not affected by BMI (r = 0.1, P = 0.36), while CNR was inversely related to body surface area (BSA) (r = -0.5, P < 0.001) and CO (r = -0.45, P < 0.001). After successfully overcoming the impact of BMI on image noise by adapting tube parameters, CNR mainly depends on coronary vessel contrast. The latter reflects the dilution of the contrast material by blood volume and CO, which are both correlated to BSA. Therefore, BSA adapted contrast administration may help to compensate for this effect.