Coronary artery calcium score: has anything changed?

Calcium deposition along the coronary artery walls is a surrogate biomarker for atherosclerosis, and its presence in the coronary arteries could reflect the severity of coronary artery disease (CAD). High coronary artery calcium score (CACS) correlates with advanced disease and a higher likelihood of coronary stenoses. Many studies have supported the role of CACS as a screening tool for CAD. Historically, CACS was introduced with electron beam computed tomography (EBCT), but in the last 30 years, many changes have occurred in CT, where the development of multidetector spiral technology has made reliable the noninvasive study of the heart and coronary arteries. Correlation studies with intravascular ultrasound (IVUS) and histology have demonstrated the capability of multidetector CT (MDCT) to provide information useful for characterising atherosclerotic plaque in a noninvasive manner. This has shifted the interest from heavily calcified deposits to plaque with a low-density core and small, superficial calcified nodules, features more frequently present in atherosclerotic plaque prone to rupture and responsible for acute coronary events (culprit lesions). The purpose of this review article is to summarise the recent evolution and revolution in the field of CT, strengthen the importance of a coronary CT study not limited to CACS evaluation and CAD grading but also used to obtain information about plaque composition, and to improve stratification of the patient at risk for acute coronary events

Unidade de contexto e observação social sistemática em saúde: conceitos e métodos Context unit and systematic social observation: a review of concepts and methods

Assumimos que "onde você mora é importante para sua saúde, para além de quem você é". Entendemos que o impacto do local de moradia ou unidade de contexto (UC) na saúde das populações se deve à heterogeneidade dos atributos do entorno físico e social da UC, para além das características individuais ou agregadas daqueles ali aninhados. Estes atributos, embora dependentes dos indivíduos, são tipicamente externos a eles e potencialmente modificáveis. As UC são compreendidas como unidades ecológicas inseridas em conjuntos sucessivamente mais amplos e interdependentes. Quando relevante para a hipótese do estudo, unidades geográficas administrativas podem ser utilizadas como aproximações da UC. Outra alternativa é a que utiliza a percepção de seus moradores, a "vizinhança percebida". O ressurgimento do interesse com relação à determinação dos efeitos da UC sobre a saúde correlaciona com novas tendências na área da saúde coletiva: incorporação de novos níveis hierárquicos de exposição, as iniqüidades e seus determinantes, a urbanização e seus efeitos e a avaliação de intervenções multi-setoriais. Nosso objetivo central é rever opções para a escolha da UC a ser investigada além de estratégias para a aferição de seus atributos físicos e sociais, utilizando a observação social sistemática (OSS). A combinação de dados originárias de dados administrativos, da vizinhança percebida, dos inquéritos populacionais e da OSS ainda necessita de maiores elaborações conceitual, metodológica e analítica. Entretanto, a compreensão da distribuição dos atributos físicos e sociais da UC permite compor níveis hierárquicos de complexidade relevantes para o entendimento da ocorrência dos eventos relacionados à saúde nas populações.<br>We understand that "where one lives makes a difference to health in addition to who you are", and that the effects of the place of residence or context unit (CU) on public health are due to the heterogeneity of the physical and social environment characteristics, in addition to the individual and aggregate attributes of the population nested in the CU. Those attributes, although intrinsically dependent on the individuals, are typically external to them and susceptible to intervention. Also, the UC's are understood as ecological units nested within successively larger communities. Depending on the study hypothesis, census-defined areas may be used as proxy for the CU. Alternatively, the CU may be defined by the individual's perception of his/her neighborhood. The renewed interest on the health effects of the CU are associated with new trends in public health, namely: new hierarchical levels of exposure beyond individual level characteristics, inequalities and social determinants of health, urbanization and the need to evaluate interventions not traditionally associated to public health. Our objective was, first, to review options while choosing the relevant CU and second, to review strategies to determine and quantify the characteristics of the CU using social systematic observation (SSO). The combination of census-defined data, information on the neighborhood defined by the local population, surveys and SSO still needs conceptual, methodological and analytical development. However, the distribution of the physical and social attributes of the CU will permit to incorporate other hierarchical level of complexity to better understand the incidence and prevalence of health related events in populations