Cardiovascular Disease

Improving Chest Monitoring through Magnetic Resonance Angiogram Image Contrast Enhancement

Magnetic resonance angiography is a medical procedure used to offer an image of the blood vessels and organs of the body. Given the worldwide spread of cardiovascular diseases, more and more resources are invested in treating them. One of the most modern treatments involves the acquisition of images of the heart. Sometimes the contrast of these images is not satisfactory. Injecting invasive enhancement substances to obtain a better view of the cardiac route is not advisable. However, software algorithms can solve the problem. This study proposes and tests a local adaptive contrast-adjustment algorithm using the dual-tree complex wavelet transform. The method has been tested with medical data from a public database to allow comparisons to other methods. The selected algorithm further improved the contrast of images. The performances are given for evaluation, both visually (to help doctors make accurate diagnoses) and in parametric form (to show engineers which parts of the algorithm might need improvement). Compared to other contrast enhancement methods, the proposed wavelet algorithm shows good results and greater stability. Thus, we aim to avoid future pointless complications due to unnecessary contrast substances.

Canola produced under boreal climatic conditions in Newfoundland and Labrador have a unique lipid composition and expeller press extraction retained the composition for commercial use

The average fatty acid (FA) composition of canola oil is made up of 62% oleic acid (C18:1n9), 19% linoleic acid (C18:2n6), 9% linolenic acid (C18:3n3) and 7% saturated FA (SFA). We investigated whether boreal climate (7.5-17.2 °C) favorably altered the FA composition of canola. Results indicate that canola cultivated in boreal climatic conditions had approximately twice the levels of omega-3 FA (17-20%) compared to canola from other growing areas (9%). The presence of monoacetyldiacylglycerol (MAcDG), a unique class of triglyceride, is reported for the first time in canola cultivated in a boreal climate, and has the potential to reduce the risk of obesity and other health related diseases. We further demonstrated that a non-solvent based extraction method retained the novel lipid composition without reducing the quality of oil being produced. Our results contribute significantly to the understanding of lipid accumulation in the world's second most important oil crop when cultivated in a boreal or northern climate.

Treinamento aerobio e resistido, qualidade de vida e capacidade funcional de hipertensas

INTRODUÇÃO: Pacientes hipertensos podem apresentar comprometimento da qualidade de vida (QV) e da qualidade de vida relacionada à saúde (QVRS), tanto pela hipertensão arterial (HA), quanto pelos eventuais efeitos adversos do tratamento. Exercícios físicos, aeróbios e resistidos, melhoram a performance cardiorrespiratória e neuromuscular, mas há poucas evidências sobre seus efeitos na QV, QVRS e capacidade funcional (CF) em mulheres hipertensas. OBJETIVO: Avaliar e comparar os efeitos dos treinamentos aeróbio e resistido sobre a QV, QVRS e a capacidade funcional em hipertensas. MÉTODOS: Ensaio clínico randomizado, cego, com total de 18 sessões de exercícios. Foram incluídas mulheres hipertensas sob tratamento medicamentoso, não participantes de programas de exercícios, com 50 anos de idade ou mais, que não apresentaram arritmias e/ou alterações isquêmicas em teste ergométrico (protocolo de Bruce). A amostra foi randomizada como segue: grupo aeróbio (GA) (n = 21) e grupo resistido (GR) (n = 20). Intensidade GA: leve a moderada (Escala de Borg adaptada); GR: até 50-65% de 1 RM. Duas séries com 12 a 15 repetições. Antes e após a intervenção foram aplicados os questionários WHOQOL-bref (QV) e SF-36 (QVRS) e realizado o teste de caminhada de 6 minutos (TC6`) para avaliar a CF. Estatística: testes Shapiro-Wilk, t de Student, Fisher, U de Mann-Whitney e Wilcoxon. Nível de significância: p < 0,05. RESULTADOS: Os grupos eram inicialmente homogêneos nos aspectos clínicos, antropométricos, funcionais e sociodemográficos (p > 0,05). Após a intervenção houve melhora significativa em todos os domínios do WHOQOL-bref no GA e no GR houve melhora no domínio aspectos físicos. No SF-36, constatou-se melhora significativa em sete de oito domínios tanto no GA quanto no GR. Capacidade funcional: verificou-se melhora nos dois grupos (p < 0,001). CONCLUSÃO: Os dois tipos de treinamento melhoraram a QV e a CF e, dependendo dos objetivos estabelecidos, ambos podem ser eficazes.

[The association between Apolipoprotein E genotype and lipid profiles in healthy woman workers]

OBJECTIVES

Plasma lipid profiles and Apolipoprotein E (ApoE) are established risk factors for cardiovascular disease (CVD). The knowledge of lipid profile may estimate the potential victims of cardiovascular disease before its initiation and progression and offers the opportunity for primary prevention. The most common ApoE polymorphism has been found to influence plasma lipid concentrations and its correlation with CVD has been extensively investigated in the last decade.

METHODS

The ApoE polymorphism and its influence on plasma lipid were investigated in healthy woman workers. The information on confounding factors was obtained through a self-administered questionnaire and ApoE polymorphism was investigated using PCR.

RESULTS

The relative frequencies of alleles E2, E3 and E4 for the study population (n=305) were 0.127, 0.750 and 0.121, respectively. ApoE polymorphism was associated with variations in plasma HDL-cholesterol lipid profile. In order to estimate the independent effects of alleles E2 and E4, as compared with E3, on lipid profile, multiple regression was performed after adjustment for confounding variables such as age, BMI, blood pressure, education status, insulin, fasting glucose, HOMA-IR, menopause. ApoE2 had a negative association with HDL cholesterol and ApoE4 had a positive association with LDL cholesterol.

CONCLUSIONS

This study identified that the ApoE and CVD risk factors contribute to the lipid profiles, similar to other studies. The analysis including dietary intake and other gene in further studies may help to identify clear effects on lipid profiles as risk factor for CVD.

Examining gender equity in health policies in a low- (Peru), middle- (Colombia), and high- (Canada) income country in the Americas

Gender inequities in health prevail in most countries despite ongoing attempts to eliminate them. Assessment of gender-sensitive health policies can be used to identify country specific progress as well as gaps and issues that need to be addressed to meet health equity goals. This study selected and measured the existence of gender-sensitive health policies in a low- (Peru), middle- (Colombia), and high (Canada)-income country in the Americas. Investigators selected 10 of 20 gender-sensitive health policy indicators and found eight to be feasible to measure in all three countries, although the wording and scope varied. The results from this study inform policy makers and program planners who aim to develop, improve, implement, and monitor national gender-sensitive health policies. Future studies should assess the implementation of policy indicators within countries and assess their performance in increasing gender equity.

A multisite examination of sex differences in cardiac rehabilitation barriers by participation status

BACKGROUND

Despite its proven benefits and need, women are significantly less likely than men to participate in and complete cardiac rehabilitation (CR). The purpose of this study was to quantitatively investigate sex differences in CR barriers by participation status.

METHODS

Cardiac outpatients (1496, 430 female, 28.7%) of 97 cardiologists completed a mailed survey to discern CR participation. Respondents were asked to rate 19 CR barriers on a 5-point Likert scale.

RESULTS

Five hundred twenty-nine (43%) respondents self-reported participating in CR, with men being more likely to participate (p < 0.05). There was no significant sex difference in total number of CR barriers, but differences in individual barriers were found. For CR participants, t tests revealed significant sex differences in the perception of exercise as tiring or painful (p = 0.042) and work responsibilities (p = 0.013). For CR nonparticipants, women rated the following barriers as greater than men: transportation (p = 0.025), family responsibilities (p = 0.039), lack of CR awareness (p = 0.036), experiencing exercise as tiring or painful (p = 0.002), and comorbidities (p = 0.009).

CONCLUSIONS

Overall, women do not perceive greater barriers to CR participation than men, but the nature of their barriers differs, particularly among nonparticipants. Beliefs about the value of CR, awareness, and exercise parameters are all modifiable barriers that should be addressed among women.

Macrophage depletion suppresses sympathetic hyperinnervation following myocardial infarction

Myocardial infarction induces sympathetic axon sprouting adjacent to the necrotic region, and this has been implicated in the etiology of arrhythmias resulting in sudden cardiac death. Previous studies show that nerve growth factor (NGF) is essential for enhanced post-infarct sympathetic sprouting, but the cell types necessary to supply this neurotrophic protein are unknown. The objective of the present study was to determine whether macrophages, which are known to synthesize NGF, are necessary for post-infarct cardiac sympathetic sprouting. Ovariectomized female rats received left coronary artery ligation or sham operation, followed by intravenous injection of liposomes containing saline vehicle or clodronate, which kills macrophages. Sham-operated myocardium contained some sympathetic axons, few myofibroblasts and T cells and no CD-68-positive macrophages. In rats receiving saline liposomes through 7 days post-ligation, the posterolateral infarct border contained numerous myofibroblasts, macrophages and T cells, and sympathetic innervation was increased twofold. Treatment with clodronate liposomes reduced macrophage numbers by 69%, while myofibroblast area was reduced by 23% and T cell number was unaffected. Clodronate liposome treatment reduced sympathetic axon density to levels comparable to the uninfarcted heart. NGF protein content measured in western blots was reduced to 33% of that present in infarcts where rats received saline-containing liposomes. Tissue morphometry confirmed that NGF immunostaining was dramatically reduced, and this was attributable primarily to reduced macrophage content. These results show that macrophage destruction markedly reduces post-infarction levels of NGF and that the presence of elevated numbers of macrophages is obligatory for development of sympathetic hyperinnervation following myocardial infarction.

Degree and correlates of cardiac knowledge and awareness among cardiac inpatients

OBJECTIVE

To investigate the degree of CHD awareness as well as symptom, risk factor, and treatment knowledge in a broad sample of cardiac inpatients, and to examine its sociodemographic, clinical and psychosocial correlates.

METHODS

1308 CHD inpatients (351 [27.0%] female), recruited from 11 acute care sites in Ontario, participated in this cross-sectional study. Participants were provided with a survey which included a knowledge questionnaire among other measures, and clinical data were extracted from medical charts.

RESULTS

855 (68.8%) respondents cited heart disease as the leading cause of death in men, versus only 458 (37.0%) in women. Participants with less than high school education (p<.001), an annual family income less than $50,000CAD (p=.022), low functional capacity (p=.042), who were currently smoking (p=.022), who had no family history of heart disease (p<.001), and who had a perception of low personal control (p=.033) had significantly lower CHD knowledge.

CONCLUSIONS

Awareness of CHD is not optimal, especially among women, South Asians, and those of low socioeconomic status. CHD patients have a moderate level of disease knowledge overall, but greater education is needed.

PRACTICE IMPLICATIONS

Tailored educational approaches may be necessary for those of low socioeconomic status, particularly with regard to the nature of CHD, tests and treatments.

Sympathetic hyperinnervation and inflammatory cell NGF synthesis following myocardial infarction in rats

Sympathetic hyperinnervation occurs in human ventricular tissue after myocardial infarction and may contribute to arrhythmias. Aberrant sympathetic sprouting is associated with elevated nerve growth factor (NGF) in many contexts, including ventricular hyperinnervation. However, it is unclear whether cardiomyocytes or other cell types are responsible for increased NGF synthesis. In this study, left coronary arteries were ligated and ventricular tissue examined in rats 1-28 days post-infarction. Infarct and peri-infarct tissue was essentially devoid of sensory and parasympathetic nerves at all time points. However, areas of increased sympathetic nerve density were observed in the peri-infarct zone between post-ligation days 4-14. Hyperinnervation occurred in regions containing accumulations of macrophages and myofibroblasts. To assess whether these inflammatory cells synthesize NGF, sections were processed for NGF in situ hybridization and immunohistochemistry. Both macrophage1 antigen-positive macrophages and alpha-smooth muscle actin-immunoreactive myofibroblasts expressed NGF in areas where they were closely proximate to sympathetic nerves. To investigate whether NGF produced by peri-infarct cells induces sympathetic outgrowth, we co-cultured adult sympathetic ganglia with peri-infarct explants. Neurite outgrowth from sympathetic ganglia was significantly greater at post-ligation days 7-14 as compared to control tissue. Addition of an NGF function-blocking antibody prevented the increased neurite outgrowth induced by peri-infarct tissue. These findings provide evidence that inflammatory cell NGF synthesis plays a causal role in sympathetic hyperinnervation following myocardial infarction.

Cardiovascular disease in diabetes and the cardiometabolic syndrome: focus on minority women

Diabetes and the cardiometabolic syndrome (CMS) are evolving as global epidemics. In the United States, diabetes affects 20 million people, with 47 million afflicted with the CMS. These disorders have a higher propensity for women, particularly in minority populations with disproportionate increase in cardiovascular disease (CVD) morbidity and mortality. Despite the decline in CVD mortality rates in the general population over the past 35 years parallel to the advances in therapeutic interventions, these rates have increased in women with diabetes. Early preventive measures for CVD risk factor through behavioral and lifestyle modification, smoking cessation, and reduction in psychosocial stressors, as well as pharmacotherapy, are among the currently supported approaches to CVD risk reduction in this high-risk population. In this article, we discuss CVD in people with diabetes and the CMS, with emphasis on minority women, a particularly vulnerable population.

Weight change and mortality: the Nord-Trøndelag Health Study

OBJECTIVES

The prevalence of obesity is increasing. Overweight and obese people have increased mortality compared with normal weight people. We investigated the effect of weight change on mortality.

DESIGN

Prospective population study.

SETTING

We utilized data from two large population-based health studies conducted in 1984-86 and 1995-97 respectively. Cox proportional hazards models were used to calculate mortality rate ratios (RRs) with 95% confidence intervals (CIs) between people with a stable weight and people who lost or gained weight. Subjects. Totally 20,542 men and 23,712 women aged 20 years or more, without cardiovascular disease or diabetes at the first survey and without a history of cancer at the second survey were followed up on all-cause mortality for 5 years after the second survey.

RESULTS

We found no association between weight gain and mortality. People who lost weight had a higher total mortality rate compared with those who were weight stable [RR was 1.6 (95% CI: 1.4-1.8) in men and 1.7 (95% CI: 1.5-2.0) in women]. Similar associations were found for cardiovascular and noncardiovascular mortality. Additional analysis showed a linear increase in mortality rates across categories of weight loss for both men and women (P < 0.001). There was a statistically significant interaction between weight change and initial BMI, but only amongst men (P = 0.001).

CONCLUSIONS

Weight loss, but not weight gain, was associated with increased mortality amongst men and women. Although underlying undiagnosed disease is the most plausible explanation for this finding, the similar associations found for total mortality, cardiovascular mortality, and noncardiovascular mortality makes the causal pathway somewhat enigmatic.