Non-rigid motion-compensated 3D whole-heart T2 mapping in a hybrid 3T PET-MR system.

PURPOSE: Simultaneous PET-MRI improves inflammatory cardiac disease diagnosis. However, challenges persist in respiratory motion and mis-registration between free-breathing 3D PET and 2D breath-held MR images. We propose a free-breathing non-rigid motion-compensated 3D T2 -mapping sequence enabling whole-heart myocardial tissue characterization in a hybrid 3T PET-MR system and provides non-rigid respiratory motion fields to correct also simultaneously acquired PET data. METHODS: Free-breathing 3D whole-heart T2 -mapping was implemented on a hybrid 3T PET-MRI system. Three datasets were acquired with different T2 -preparation modules (0, 28, 55 ms) using 3-fold undersampled variable-density Cartesian trajectory. Respiratory motion was estimated via virtual 3D image navigators, enabling multi-contrast non-rigid motion-corrected MR reconstruction. T2 -maps were computed using dictionary-matching. Approach was tested in phantom, 8 healthy subjects, 14 MR only and 2 PET-MR patients with suspected cardiac disease and compared with spin echo reference (phantom) and clinical 2D T2 -mapping (in-vivo). RESULTS: Phantom results show a high correlation (R2 = 0.996) between proposed approach and gold standard 2D T2 mapping. In-vivo 3D T2 -mapping average values in healthy subjects (39.0 ± 1.4 ms) and patients (healthy tissue) (39.1 ± 1.4 ms) agree with conventional 2D T2 -mapping (healthy = 38.6 ± 1.2 ms, patients = 40.3 ± 1.7 ms). Bland-Altman analysis reveals bias of 1.8 ms and 95% limits of agreement (LOA) of -2.4-6 ms for healthy subjects, and bias of 1.3 ms and 95% LOA of -1.9 to 4.6 ms for patients. CONCLUSION: Validated efficient 3D whole-heart T2 -mapping at hybrid 3T PET-MRI provides myocardial inflammation characterization and non-rigid respiratory motion fields for simultaneous PET data correction. Comparable T2 values were achieved with both 3D and 2D methods. Improved image quality was observed in the PET images after MR-based motion correction.

Multi-center study of inter-rater reproducibility, image quality, and diagnostic accuracy of CZT versus conventional SPECT myocardial perfusion imaging.

BACKGROUND: Cadmium-zinc-telluride (CZT)-based detectors exhibit higher diagnostic sensitivity in myocardial perfusion imaging (MPI) than conventional Anger-MPI for detection of coronary artery disease (CAD); however, reduced specificity and diagnostic accuracy of CZT-MPI were observed. This study aims to compare these different camera systems and to examine the degree of inter-rater reproducibility among readers with varying experience in MPI. METHODS: 83 patients who underwent double stress/rest examinations using both a CZT and conventional SPECT cameras within one visit were included. Anonymized and randomized MPI-images were distributed to 15 international readers using a standardized questionnaire. Subsequent coronary angiography findings of ten patients served as a reference for analysis of sensitivity and specificity. RESULTS: Image quality was significantly better in CZT-MPI with significantly lower breast attenuation (P < 0.05). CZT-MPI exhibited higher sensitivity than Anger-MPI (87.5% vs. 62.5%) and significantly reduced specificity (40% vs. 100%). Readers experienced with both camera systems had the highest inter-rater agreement indicating higher reproducibility (CZT 0.54 vs. conv. 0.49, P < 0.05). CONCLUSIONS: Higher diagnostic sensitivity of CZT-MPI offers advantages in detection of CAD yet potentially of at the cost of reduced specificity, therefore it requires special training and a differentiated evaluation approach, especially for non-experienced readers with such camera systems.

Relación entre ingesta dietética y estado nutricional del hierro en mujeres chilenas en edad fértil de una comunidad universitaria

RESUMEN Propósito: Relacionar la ingesta dietaria de hierro con el estado nutricional de éste en una muestra de mujeres en edad fértil de Santiago de Chile. Método: A 51 mujeres entre 18 - 35 años se aplicó una Encuesta de Tendencia de Consumo para estimar el aporte de hierro dietario, junto con la medición de los biomarcadores bioquímicos a modo de determinar el estado de los depósitos de hierro. Mediante prueba estadística de Mann-Whitney se analizaron diferencias significativas entre los grupos según estado nutricional del hierro y sus parámetros sanguíneos. Resultados: Treinta y siete de las participantes (72,5%) no cumple con la ingesta recomendada de hierro diario. Dos de las mujeres presentaron anemia, 2 deficiencia de hierro sin anemia y 12 tenía los depósitos de hierro depletados. Tres de las mujeres que presentaron depósitos deficientes tuvieron una ingesta de hierro adecuada, mientras que el 71% de las mujeres con depósitos normales presentaron una ingesta de hierro insuficiente. Conclusiones: Hay un bajo cumplimiento de los requerimientos diarios de hierro y no se observan mejores valores hematológicos a mayor ingesta de hierro, a pesar de presentar un alto porcentaje con depósitos normales de hierro. Se requiere mayor análisis de la alimentación de este grupo de la población para identificar el tipo de hierro que se está aportando principalmente y si hay otros factores dietarios y no dietarios afectando los depósitos de hierro.

ABSTRACT Objectives: To relate dietary intake of iron with iron status in a sample of women of childbearing age from Santiago de Chile. Methods: A Food Frequency Survey was applied to 51 women between 18 - 35 years of age to estimate intake of dietary iron, together with the measurement of biochemical biomarkers to determine iron stores. Using the Mann-Whitney statistical test, significant differences were analyzed between the groups according to nutritional status of iron and its blood parameters. Results: Thirty seven of the participants (72.5%) do not meet the recommended daily iron intake. Two had anemia, 2 had iron deficiency without anemia, and twelve had depleted iron stores. Three women with deficient iron stores had an adequate iron intake, while 71% of women with normal iron stores showed an insufficient iron intake. Conclusions: We observed a low compliance with the daily iron requirements and no better hematological values were associated with higher iron intake, despite a high percentage of women with normal iron stores. To identify the type of iron mainly contributed by the diet and if there are other dietary and non-dietary factors affecting iron stores, further analysis of this population group is required.

Initial investigation of free-breathing 3D whole-heart stress myocardial perfusion MRI.

Objective: Myocardial first-pass perfusion imaging with MRI is well-established clinically. However, it is potentially weakened by limited myocardial coverage compared to nuclear medicine. Clinical evaluations of whole-heart MRI perfusion by 3D methods, while promising, have to date had the limit of breathhold requirements at stress. This work aims to develop a new free-breathing 3D myocardial perfusion method, and to test its performance in a small patient population. Methods: This work required tolerance to respiratory motion for stress investigations, and therefore employed a "stack-of-stars" hybrid Cartesian-radial MRI acquisition method. The MRI sequence was highly optimised for rapid acquisition and combined with a compressed sensing reconstruction. Stress and rest datasets were acquired in four healthy volunteers, and in six patients with coronary artery disease (CAD), which were compared against clinical reference information. Results: This free-breathing method produced datasets that appeared consistent with clinical reference data in detecting moderate-to-strong induced perfusion abnormalities. However, the majority of the mild defects identified clinically were not detected by the method, potentially due to the presence of transient myocardial artefacts present in the images. Discussion: The feasibility of detecting CAD using this 3D first-pass perfusion sequence during free-breathing is demonstrated. Good agreement on typical moderate-to-strong CAD cases is promising, however, questions still remain on the sensitivity of the technique to milder cases.

Phase analysis, a novel SPECT technique for left ventricular dyssynchrony: Are degrees and milliseconds interchangeable?

BACKGROUND: Phase analysis of gated single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy provides a measure of left ventricular dyssynchrony and may have applications for identifying patients suitable for cardiac resynchronisation therapy. Phase analysis is typically described in degrees of cardiac cycle, less intuitive to cardiologists familiar with ECGs. We assessed the relationship between time and degrees, to determine whether they are interchangeable. METHODS AND RESULTS: 399 patients underwent normal stress-only SPECT myocardial perfusion imaging using Technetium-99m-tetrofosmin. Data analysis used QGS software (Cedars Sinai) calculating bandwidth and standard deviation. Heart rate, age, gender, stress modality, and ejection fraction were analyzed for their relation to phase variables. 13 patients were excluded for conduction abnormalities including right and left bundle branch block and ventricular pacing. Heart rate was strongly correlated to bandwidth and standard deviation measured in time, but unrelated when measured in degrees. Although bandwidth measured by time and degrees were strongly correlated with each other this relationship was not perfect (correlation coefficient 0.87, P < .001). The addition of heart rate to the model explained most of the residual variation between the two. The results for standard deviation were similar. CONCLUSION: In patients with normal myocardial perfusion and QRS duration bandwidth measured by degrees is not directly interchangeable with time in milliseconds. However most of the variation is explainable by heart rate, which predominantly affects measures of time rather than degrees. We would propose that although the values are less intuitive to cardiologists, normal ranges for phase measured in degrees are potentially more robust.

Regadenoson myocardial perfusion scintigraphy for the evaluation of coronary artery disease in patients with lung disease: A series of five cases.

Coronary artery disease (CAD) is a leading cause of death and morbidity globally. Myocardial perfusion scintigraphy (MPS) is commonly used for the diagnosis of CAD, necessitating hyperaemia achieved either by physical exertion or by pharmacological stress, most commonly through use of a coronary arteriolar dilator. This is challenging in patients with respiratory conditions because exercise may be submaximal and adenosine is contraindicated because of the risk of bronchoconstriction. Regadenoson is the only selective adenosine A2A receptor agonist approved as a vasodilator in MPS. The risk of bronchospasm with regadenoson has been investigated in large, randomised trials; however, patients with the most severe respiratory conditions were not included. In this case series, we present the use of regadenoson MPS in five patients with moderate-to-severe lung conditions, including patients requiring lung volume reduction surgery and lung transplant. In all cases, regadenoson MPS provided valuable information for risk assessment and treatment optimisation. Although dyspnoea occurred in all patients, regadenoson was well tolerated without serious adverse events or bronchospasm; in no case was intervention required to treat dyspnoea.

Simultaneous 13N-Ammonia and gadolinium first-pass myocardial perfusion with quantitative hybrid PET-MR imaging: a phantom and clinical feasibility study.

BACKGROUND: Positron emission tomography (PET) is the non-invasive reference standard for myocardial blood flow (MBF) quantification. Hybrid PET-MR allows simultaneous PET and cardiac magnetic resonance (CMR) acquisition under identical experimental and physiological conditions. This study aimed to determine feasibility of simultaneous 13N-Ammonia PET and dynamic contrast-enhanced CMR MBF quantification in phantoms and healthy volunteers. METHODS: Images were acquired using a 3T hybrid PET-MR scanner. Phantom study: MBF was simulated at different physiological perfusion rates and a protocol for simultaneous PET-MR perfusion imaging was developed. Volunteer study: five healthy volunteers underwent adenosine stress. 13N-Ammonia and gadolinium were administered simultaneously. PET list mode data was reconstructed using ordered subset expectation maximisation. CMR MBF was quantified using Fermi function-constrained deconvolution of arterial input function and myocardial signal. PET MBF was obtained using a one-tissue compartment model and image-derived input function. RESULTS: Phantom study: PET and CMR MBF measurements demonstrated high repeatability with intraclass coefficients 0.98 and 0.99, respectively. There was high correlation between PET and CMR MBF (r = 0.98, p < 0.001) and good agreement (bias - 0.85 mL/g/min; 95% limits of agreement 0.29 to - 1.98). Volunteer study: Mean global stress MBF for CMR and PET were 2.58 ± 0.11 and 2.60 ± 0.47 mL/g/min respectively. On a per territory basis, there was moderate correlation (r = 0.63, p = 0.03) and agreement (bias - 0.34 mL/g/min; 95% limits of agreement 0.49 to - 1.18). CONCLUSION: Simultaneous MBF quantification using hybrid PET-MR imaging is feasible with high test repeatability and good to moderate agreement between PET and CMR. Future studies in coronary artery disease patients may allow cross-validation of techniques.

Guidelines in review: Comparison of ESC and AHA guidance for the diagnosis and management of infective endocarditis in adults.

Over recent years, new evidence has led a rethinking of the available guidance on the diagnosis and management of infective endocarditis (IE). This review compares the most recently available guidance provided by the American Heart Association (AHA) IE Writing Committee, and the Task Force for the management of IE of the European Society of Cardiology (ESC). This represents the sixth of a new series of comparative guidelines review published in the Journal.

Salutogénesis de la alimentación en chile: actores involucrados y brechas detectadas / Nutritional Salutogenesis in Chile: key stakeholders and detected gaps

OBJETIVOS: Conocer los principales actores involucrados y las brechas detectadas en el proceso de aprendizaje alimentario de una población adulta urbana en Santiago de Chile. MATERIALES Y MÉTODOS: De una muestra de 100 beneficiarios de un CESFAM, se incluyó a quienes tuvieran un alto Índice de Alimentación Saludable (IAS). Se realizaron entrevistas semiestructuradas, las cuales fueron grabadas en audio, transcritas de manera textual y analizadas mediante la Teoría Fundamentada. RESULTADOS: Se entrevistó a 16 personas con IAS alto, en su mayoría mujeres. Los principales actores del proceso de aprendizaje alimentario resultan ser los padres, las experiencias adquiridas en el trabajo y la consulta con el profesional nutricionista. Se detectó una brecha de educación alimentaria entre la población general y el equipo de nutricionistas en contextos de atención primaria de salud. CONCLUSIONES: Los padres, los contextos laborales y la consulta con el nutricionista son las principales influencias en el proceso de aprendizaje alimentario. También fueron identificados tres grupos poblacionales (adolescentes femeninas, madres y niños), como poblaciones carentes de intervención nutricional de carácter educativo-preventivo por nutricionistas en el contexto de la atención primaria de salud en Chile, situación que podría perpetuar y mantener los malos hábitos de alimentación de la población general.

OBJECTIVES: To identify key stakeholders involved in the nutritional educational processes and detect gaps in this process in an urban adult population in Santiago, Chile. MATERIALS AND METHODS: From a sample of 100 individuals registered at a primary health care facility, those with a high Healthy Eating Index (HEI) were included in the study. Semi-structured interviews were conducted, which were recorded in audio, transcribed verbatim, and analyzed according to Grounded Theory. RESULTS: A total of 16 people with HEI were interviewed, who were mainly women. The main actors involved in the nutritional educational process turned out to be the individuals' parents, workplace experiences, and clinical consultations with professional nutritionists. A nutritional education gap was detected between the general population and teams of nutritionists in primary health care contexts. CONCLUSIONS: Parents, the workplace, and consultations with nutritionists are the main influences in the nutritional learning process. Three population groups (female adolescents, mothers, and children) were also identified as lacking educational and preventive interventions by nutritionists in the primary health care context in Chile; this situation could perpetuate and maintain unhealthy eating habits among the general population.

Hybrid positron emission tomography-magnetic resonance of the heart: current state of the art and future applications.

Hybrid positron emission tomography-magnetic resonance (PET-MR) imaging is a novel imaging modality with emerging applications for cardiovascular disease. PET-MR aims to combine the high-spatial resolution morphological and functional assessment afforded by magnetic resonance imaging (MRI) with the ability of positron emission tomography (PET) for quantification of metabolism, perfusion, and inflammation. The fusion of these two modalities into a single imaging platform not only represents an opportunity to acquire complementary information from a single scan, but also allows motion correction for PET with reduction in ionising radiation. This article presents a brief overview of PET-MR technology followed by a review of the published literature on the clinical cardio-vascular applications of PET and MRI performed separately and with hybrid PET-MR.

Guidelines in review: Comparison of ESC and ACC/AHA guidelines for the diagnosis and management of patients with stable coronary artery disease.

In 2012, the American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) Task Force on Practice Guidelines jointly with the American College of Physicians, American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons produced a set of recommendations intended to assist physicians in the diagnosis and management of patients with stable ischemic heart disease. Two years later, a focused update on the 2012 guidelines was published. A year before this update, The Task Force on the management of stable coronary artery disease (CAD) of the European Society of Cardiology (ESC) issued a guideline on the management of stable CAD. This document brings together European and American recommendations that include the use of stress testing and non-invasive imaging for the diagnosis and management of patients with known or suspected stable CAD.

Guidelines in review: Comparison of the 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes and the 2015 ESC guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation.

In this Guidelines in Review, we review side-by-side the recommendations provided by the 2014 AHA/ACC Guideline for the management of patients with non-ST-elevation acute coronary syndromes and the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation. We review the recommendations for imaging in the evaluation of patients with possible ACS followed by the diagnostic evaluation of patients with proven NSTE-ACS, based on their risk for adverse clinical events.

CXCR2 Inhibition - a novel approach to treating CoronAry heart DiseAse (CICADA): study protocol for a randomised controlled trial.

BACKGROUND: There is emerging evidence of the central role of neutrophils in both atherosclerotic plaque formation and rupture. Patients with lower neutrophil counts following acute coronary syndromes tend to have a greater coronary flow reserve, which is a strong predictor of long-term cardiovascular health. But so far, no data are available regarding the impact of neutrophil inhibition on cardiovascular clinical or surrogate endpoints. Therefore, the aim of this study is to investigate the effects of AZD5069, a cysteine-X-cysteine chemokine receptor 2 (CXCR2) inhibitor, on coronary flow reserve and coronary structure and function in patients with coronary artery disease. METHODS/DESIGN: Ninety subjects with coronary artery disease undergoing percutaneous coronary intervention will be included in this investigator-driven, randomised, placebo-controlled, double-blind, phase IIa, single-centre study. Participants will be randomised to receive either AZD5069 (40 mg) administered orally twice daily or placebo for 24 weeks. Change in coronary flow reserve as determined by 13N-ammonia positron emission tomography-computed tomography will be the primary outcome. Change in the inflammatory component of coronary plaque structure and the backward expansion wave, an invasive coronary physiological measure of diastolic function, will be assessed as secondary outcomes. DISCUSSION: Cardiovascular surrogate parameters, such as coronary flow reserve, may provide insights into the potential mechanisms of the cardiovascular effects of CXCR2 inhibitors. Currently, ongoing trials do not specifically focus on neutrophil function as a target of intervention, and we therefore believe that our study will contribute to a better understanding of the role of neutrophil-mediated inflammation in coronary artery disease. TRIAL REGISTRATION: EudraCT, 2016-000775-24 . Registered on 22 July 2016. International Standard Randomised Controlled Trial Number, ISRCTN48328178 . Registered on 25 February 2016.

Comparison of ESC and ACC/AHA guidelines for myocardial revascularization.

In 2014, the Task Force on Myocardial Revascularization of the European Society of Cardiology and the European Association for Cardio-Thoracic Surgery with the special contribution of the European Association of Percutaneous Cardiovascular Interventions published a comprehensive set of recommendations on myocardial revascularization in patients presenting with acute or chronic coronary artery disease. In the United States, pertinent guidance on this topic has been published by the American College of Cardiology, American Heart Association and other relevant societies in multiple guideline documents that have been published in recent years. This document brings together European and American recommendations on myocardial revascularization with a focus on the role of cardiac imaging.