Robust canonical correlations: A comparative study.

Several approaches for robust canonical correlation analysis will be presented and discussed. A first method is based on the definition of canonical correlation analysis as looking for linear combinations of two sets of variables having maximal (robust) correlation. A second method is based on alternating robust regressions. These methods axe discussed in detail and compared with the more traditional approach to robust canonical correlation via covariance matrix estimates. A simulation study compares the performance of the different estimators under several kinds of sampling schemes. Robustness is studied as well by breakdown plots.

Is It Possible to Simplify Risk Stratification Scores for Patients with ST-Segment Elevation Myocardial Infarction Undergoing Primary Angioplasty?

INTRODUCTION: There are several risk scores for stratification of patients with ST-segment elevation myocardial infarction (STEMI), the most widely used of which are the TIMI and GRACE scores. However, these are complex and require several variables. The aim of this study was to obtain a reduced model with fewer variables and similar predictive and discriminative ability. METHODS: We studied 607 patients (age 62 years, SD=13; 76% male) who were admitted with STEMI and underwent successful primary angioplasty. Our endpoints were all-cause in-hospital and 30-day mortality. Considering all variables from the TIMI and GRACE risk scores, multivariate logistic regression models were fitted to the data to identify the variables that best predicted death. RESULTS: Compared to the TIMI score, the GRACE score had better predictive and discriminative performance for in-hospital mortality, with similar results for 30-day mortality. After data modeling, the variables with highest predictive ability were age, serum creatinine, heart failure and the occurrence of cardiac arrest. The new predictive model was compared with the GRACE risk score, after internal validation using 10-fold cross validation. A similar discriminative performance was obtained and some improvement was achieved in estimates of probabilities of death (increased for patients who died and decreased for those who did not). CONCLUSION: It is possible to simplify risk stratification scores for STEMI and primary angioplasty using only four variables (age, serum creatinine, heart failure and cardiac arrest). This simplified model maintained a good predictive and discriminative performance for short-term mortality

Qualidade microbiol?gica e efeito das condi??es de congelamento e da incid?ncia de luz sobre os teores de retinol e capacidade antioxidante total do leite humano.

Programa de P?s-Gradua??o em Sa?de e Nutri??o. Escola de Nutri??o, Universidade Federal de Ouro Preto.Os Bancos de Leite Humano (BLH) s?o respons?veis pela capta??o, processamento e armazenamento em condi??es seguras do leite humano doado. Sabe-se que essas etapas de manipula??o do leite humano (LH) podem interferir na sua qualidade nutricional e funcional, no entanto, as evid?ncias cient?ficas ainda n?o s?o bem esclarecidas. Assim, o objetivo desse trabalho foi avaliar o efeito das condi??es de armazenamento (tempos/temperaturas de congelamento e efeito da incid?ncia de luz) sobre os teores de retinol e a capacidade antioxidante total (CAT) do LH, bem como a sua qualidade microbiol?gica. Na primeira etapa do estudo foi avaliado o efeito de diferentes tempos e temperaturas de congelamento sobre a CAT no leite humano cru (LHC) por dois m?todos in vitro (ABTS e DPPH). Na segunda etapa foi avaliado o impacto da luz, conferido pela utiliza??o de diferentes frascos de vidro (transparente, transparente recoberto por papel alum?nio e ?mbar) sobre os teores de retinol e a CAT no leite humano pasteurizado (LHP). A qualidade microbiol?gica do LHC doado pelas 10 doadoras que participaram do estudo foi avaliada por meio das seguintes an?lises realizadas em triplicata: contagens de Staphylococcus aureus, coliformes totais e termotolerantes, mes?filos aer?bios totais, e fungos e leveduras. Tamb?m foi aplicado um question?rio e um checklist para verificar a conformidade dos procedimentos de extra??o e armazenamento do leite adotados pelas doadoras. De acordo com a an?lise de ABTS, os n?veis de CAT aumentaram significativamente durante o tempo de armazenamento nas 3 temperaturas avaliadas, ao contr?rio da an?lise por DPPH em que os n?veis diminu?ram significativamente com o tempo de armazenamento nas 3 temperaturas, por?m as duas an?lises indicaram que as menores temperaturas preservaram mais a CAT. Com rela??o ao efeito da incid?ncia de luz por meio dos tr?s diferentes tipos de frascos avaliados, verificou-se que n?o houve interfer?ncia significativa por nenhum deles na CAT. J? em rela??o aos teores de retinol, verificou-se que os frascos ?mbar e transparente recoberto por papel alum?nio permitiram maior estabilidade do retinol contido no LH. De acordo com os resultados microbiol?gicos, verificou-se o crescimento de todos os microrganismos estudados nos leites de todas as doadoras e, em alguns casos, acima dos limites considerados seguros. Os resultados do checklist mostram que alguns procedimentos higi?nico-sanit?rios necess?rios n?o est?o sendo realizados de forma criteriosa, sendo importante a adequada orienta??o das m?es quanto a esses aspectos de higiene.The Human Milk Banks are responsible for the safe capture, processing and storage of donated human milk. It is known that these steps in the manipulation of human milk (HM) can interfere in its nutritional and functional quality, however, the scientific evidence is not yet clear. Thus, the objective of this work was to evaluate the effect of storage conditions (freezing times / temperatures and effect of light incidence) on retinol levels and total antioxidant capacity (TAC), as well as their microbiological quality. In the first stage of the study the effect of different times and freezing temperatures on TAC in raw human milk was evaluated by two in vitro methods (ABTS and DPPH). In the second stage, the impact of the light, verified by the use of different glass bottles (transparent, transparent covered by aluminum foil and amber) on retinol and TAC content in pasteurized human milk was evaluated. The microbiological quality of the raw human milk donated by the 10 donors participating in the study was evaluated by means of the following analyzes performed in triplicate: counts of Staphylococcus aureus, total and thermotolerant coliforms, total aerobic mesophiles, and fungi and yeasts. A questionnaire and a checklist were also applied to verify the conformity of the milk extraction and storage procedures adopted by the donors. According to the ABTS analysis, TAC levels increased significantly during the storage time at the 3 temperatures evaluated, unlike the DPPH analysis in which the levels decreased significantly with the storage time at the 3 temperatures, however the two analyzes indicated that the lower temperatures preserved the TAC more. Regarding the effect of light incidence through the three different types of flasks evaluated, it was verified that there was no significant interference by any of them in TAC. Regarding the retinol contents, it was verified that the amber and transparent bottles covered by aluminum foil allowed for a greater stability of the retinol contained in the HM. According to the microbiological results, the growth of all the microorganisms studied in the milk of all the donors was verified, and in some cases, above the limits considered safe. The results of the checklist show that some necessary hygienic-sanitary procedures are not being performed in a judicious way, being important the adequate orientation of the mothers regarding these aspects of hygiene

Utilidade do Strain Bidimensional por Speckle Tracking da Aurícula e Ventrículo Direito para Predizer Arritmias Tardias em Doentes Adultos com Tetralogia de Fallot Corrigida

OBJECTIVE: To determine whether right ventricular and/or atrial speckle tracking strain is associated with previous arrhythmic events in patients with repaired tetralogy of Fallot. METHODS AND RESULTS: We studied right ventricular and atrial strain in 100 consecutive patients with repaired tetralogy of Fallot referred for routine echocardiographic evaluation. Patients were divided into two groups, one with previous documentation of arrhythmias (n=26) and one without arrhythmias, in a median follow-up of 22 years. Patients with arrhythmias were older (p<0.001) and had surgical repair at an older age (p=0.001). They also had significantly reduced right ventricular strain (-14.7±5.5 vs. -16.9±4.0%, p=0.029) and right atrial strain (19.1±7.7% vs. 25.8±11.4%, p=0.001). Neither right ventricular nor right atrial strain were independent predictors of the presence of a history of documented arrhythmias, which was associated with age at correction and with the presence of residual defects. In a subanalysis after excluding 23 patients who had had more than one corrective surgery, right ventricular strain was an independent predictor of the presence of previous arrhythmic events (OR 1.19, 95% CI 1.02-1.38, p=0.025). Right atrial strain was also an independent predictor after adjustment (OR 0.93, 95% CI 0.87-0.99, p=0.029). The ideal cut-off for right ventricular strain was -15.3% and for right atrial strain 23.0%. CONCLUSIONS: Compared with conventional echocardiographic parameters, strain measures of the right heart are associated with the presence of arrhythmic events, and may be useful for risk stratification of patients with repaired tetralogy of Fallot, although a prospective study is required.info:eu-repo/semantics/publishedVersio

Adherence to Guidelines in the Treatment of Acute Coronary Syndromes: Progress Over Time

Introdução: O tratamento das Síndromes Coronárias Agudas (SCA) sofreu várias alterações muito rápidas nos últimos anos, traduzido nas múltiplas propostas de recomendações pelo ACC/AHA/ESC, baseados na evidência clínica. Avaliamos a implementação destas recomendações, comparando uma população de doentes de 2002, com uma população de 2005. Métodos: Estudo retrospectivo de 368 doentes admitidos em 2002 e 420 doentes admitidos em 2005 por SCA (com e sem elevação do segmento ST). Analisaram-se características clínicas e estratégias de tratamento. Resultados: Não se verificaram diferenças em termos de idade, sexo masculino, factores de risco para doença coronária ou história prévia de revascularização miocárdica. Verificou-se uma redução de doentes com antecedentes de enfarte do miocárdico e insuficiência renal e aumento da apresentação como enfarte com elevação do segmento ST. O tratamento com clopidogrel (6% versus 87%), bloqueador-beta(54% versus 79%), inibidores da enzima de conversão da angiotensina (72% versus 84%) e estatinas (78% versus 91%) aumentou (para todos p<0,001). Por outro lado, verificou-se um pequeno decréscimo na utilização de ácido acetilsalicílico (98% versus 95%, p=0,039) (com maior utilização de clopidogrel) e a ticlopidina deixou de ser utilizada (46% versus 0%, p<0,001). Os antagonistas dos receptores da glicoproteína IIb/IIIa não se alteraram significativamente (66% versus 67%, p=NS). Aumentaram as intervenções coronárias percutâneas (53% versus 67%, p<0,001). Não se verificou diferença em termos de mortalidade hospitalar (8,2% versus 6,4%) e aos 30 dias (9,0% versus. 8,6%), com redução ao 1ºano de seguimento (17,1% versus 11,7%, p=0,039). As estatinas e os bloqueadores beta são preditores independentes de mortalidade, com efeito de protecção. Conclusões: Entre 2002 e 2005, o tratamento das SCA melhorou significativamente de acordo com as recomendações existentes, traduzindo-se numa melhoria da mortalidade ao 1º ano de seguimento

Is Chronic Nitrate Therapy Associated with a Different Clinical Presentation of Acute Coronary Syndrome?

A terapêutica com nitratos pode induzir pré-condicionamento isquémico, com consequente aumento da tolerância a isquémia. No contexto de síndromes coronárias agudas (SCA), os nitratos podem condicionar uma diferente forma de apresentação, com maior protecção. Objectivos: Estudar numa população de doentes com SCA se a administração crónica prévia ao evento, de nitratos condiciona a forma de apresentação do SCA. Métodos: Estudo de 287 doentes (65 +- 13 anos, 66% sexo masculino) admitidos no nosso serviço por SCA (com e sem elevação do segmento ST) no primeiro semestre de 2005. Destes, 8% estavam sob terapêutica com nitratos prévia à admissão. Neste grupo 27% apresentaram-se como SCA com elevação do segmento ST e no grupo sem nitratos, este valor foi de 58% (p=0,005). Por análise univariada, a utilização de nitratos foi preditora da ocorrência preferencial de "SCA sem elevação do segmento ST" (OR 0,27, IC 95% 0,10-0,71, p=0,005). Após correcção para variáveis potencialmente influentes (idade, sexo, revascularização prévia, tabagismo) por análise multivariada de regressão logística, a terapêutica com nitratos foi preditora limiar da apresentação clínica "SCA sem elevação do segmento ST" (OR 0,37, IC 95% 0,13-1,04), p=0,059. Conclusão: A utilização prévia à ocorrência de SCA associou-se com um desvio da apresentação para a forma de SCA sem elevação do segmento ST. Este achado pode ser justificado pela hipótese de que os nitratos podem induzir um pré-condicionamento farmacológico, reduzindo a extensão transmural do enfarte

Does Admission NT-ProBNP Increase the Prognostic Accuracy of GRACE Risk Score in the Prediction of Short-Term Mortality After Acute Coronary Syndromes?

BACKGROUND: NT-proBNP has prognostic implications in heart failure. In acute coronary syndromes (ACS) setting, the prognostic significance of NT-proBNP is being sought. We studied short-term prognostic impact of admission NT-proBNP in patients admitted for ACS and in association with GRACE risk score (GRS). METHODS AND RESULTS: We studied 1035 patients admitted with ACS. Patients were divided in quartiles according to NT-proBNP levels on admission: Q1 <180 pg/ml; Q2 180-691 pg/ml; Q3 696-2664 pg/ml; Q4 2698-35 000 pg/ml. Groups were compared in terms of short-term all-cause mortality. Patients with higher NT-proBNP had worst GRS on admission. They also received less aggressive treatment. In-hospital mortality was 0.8%, 3.0%, 5.8% and 12.8% (P<0.001) and 30-day mortality 1.6%, 4.6%, 6.5% and 16.7% (P<0.001) respectively. In multivariate logistic regression analysis, NT-proBNP is an independent predictor of in-hospital (OR 2.35; 95% CI: 1.12-4.93, P=0.022) and 30-day mortality (OR 2.20; 95% CI: 1.17-4.12, P=0.014). However, NT-proBNP does not add any incremental benefit to GRS for prediction of outcome by ROC curve analysis. CONCLUSIONS: NT-proBNP is an independent predictor of in-hospital and 30-day mortality after ACS, independently of left ventricular function, but does not increase the prognostic accuracy of GRS.info:eu-repo/semantics/publishedVersio

Impact of Age on Treatment and Outcomes After Acute Myocardial Infarction, Particularly in Very Elderly Patients

INTRODUCTION: The elderly population admitted for acute myocardial infarction is increasing. This group is not well studied in international trials and is probably treated with a more conservative approach. OBJECTIVES: To evaluate the presentation and treatment of myocardial infarction according to age, particularly in very elderly patients. METHODS: We studied 1242 consecutive patients admitted with acute myocardial infarction, assessing in-hospital, 30-day and one-year mortality during follow-up for each age-group. Patients were divided into four groups according to age: <45 years (7.6%); 45-64 years (43.3%); 65-74 years (23.4%); and ≥75 years (25.7%). RESULTS: Elderly patients had a worse risk profile (except for smoking), more previous history of coronary disease and a worse profile on admission, with the exception of lipid profile, which was more favorable. With regard to treatment of the elderly, although less optimized than in other age-groups, it was significantly better compared to other registries, including for percutaneous coronary angioplasty. Both complications and mortality were worse in the older groups. In elderly patients (≥75 years), adjusted risk of mortality was 4.9-6.3 times higher (p<0.001) than patients in the reference age-group (45-64 years). In these patients, the independent predictors of death were left ventricular function and renal function, use of beta-blockers being a predictor of survival. CONCLUSIONS: Elderly patients represent a substantial proportion of the population admitted with myocardial infarction, and receive less evidenced-based therapy. Age is an independent predictor of short- and medium-term mortality

Impact of Obesity on Results after Primary Angioplasty in Patients with ST Segment Elevation Acute Myocardial Infarction

INTRODUCTION: Obesity is an important risk factor for the development of diabetes, hypertension, coronary disease, left ventricular dysfunction, stroke and cardiac arrhythmias. Paradoxically, previous studies in patients undergoing elective coronary angioplasty showed a reduction in hospital and long-term mortality in obese patients. The relation with body mass index (BMI) has been less studied in the context of primary angioplasty. OBJECTIVES: To evaluate the impact of obesity on the results of ST-segment elevation acute myocardial infarction treated by primary angioplasty. METHODS: This was a study of 464 consecutive patients with ST-segment elevation acute myocardial infarction undergoing primary angioplasty, 78% male, mean age 61 +/- 13 years. We assessed in-hospital, 30-day and one-year mortality according to BMI. Patients were divided into three groups according to BMI: normal--18-24.9 kg/m2 (n = 171); overweight--25-29.9 kg/m2 (n = 204); and obese-- > 30 kg/m2 (n = 89). RESULTS: Obese patients were younger (ANOVA, p < 0.001) and more frequently male (p = 0.014), with more hypertension (p = 0.001) and dyslipidemia (p = 0.006). There were no differences in the prevalence of diabetes, previous cardiac history, heart failure on admission, anterior location, multivessel disease, peak total CK or medication prescribed, except that obese patients received more beta-blockers (p = 0.049). In-hospital mortality was 9.9% for patients with normal BMI, 3.4% for overweight patients and 6.7% for obese patients (p = 0.038). Mortality at 30 days was 11 4.4% and 7.8% (p = 0.032) and at one year 12.9%, 4.9% and 9% (p = 0.023), respectively. On univariate analysis, overweight was the only BMI category with a protective effect; however, after multivariate logistic regression analysis, adjusted for confounding variables, none of the BMI categories could independently predict outcome. CONCLUSIONS: Overweight patients had a better prognosis after primary angioplasty for ST-segment elevation acute myocardial infarction compared with other BMI categories, but this was dependent on other potentially confounding variables