The role of reducing intakes of saturated fat in the prevention of cardiovascular disease : where does the evidence stand in 2010?

Current dietary recommendations advise reducing the intake of saturated fatty acids (SFAs) to reduce coronary heart disease (CHD) risk, but recent findings question the role of SFAs. This expert panel reviewed the evidence and reached the following conclusions: the evidence from epidemiologic, clinical, and mechanistic studies is consistent in finding that the risk of CHD is reduced when SFAs are replaced with polyunsaturated fatty acids (PUFAs). In populations who consume a Western diet, the replacement of 1% of energy from SFAs with PUFAs lowers LDL cholesterol and is likely to produce a reduction in CHD incidence of >2–3%. No clear benefit of substituting carbohydrates for SFAs has been shown, although there might be a benefit if the carbohydrate is unrefined and has a low glycemic index. Insufficient evidence exists to judge the effect on CHD risk of replacing SFAs with MUFAs. No clear association between SFA intake relative to refined carbohydrates and the risk of insulin resistance and diabetes has been shown. The effect of diet on a single biomarker is insufficient evidence to assess CHD risk. The combination of multiple biomarkers and the use of clinical endpoints could help substantiate the effects on CHD. Furthermore, the effect of particular foods on CHD cannot be predicted solely by their content of total SFAs because individual SFAs may have different cardiovascular effects and major SFA food sources contain other constituents that could influence CHD risk. Research is needed to clarify the role of SFAs compared with specific forms of carbohydrates in CHD risk and to compare specific foods with appropriate alternatives.

A pilot study evaluating multiple risk factor interventions by community pharmacists to prevent cardiovascular disease : The PAART CVD pilot project

Background: There is insufficient evidence for the efficacy of comprehensive multiple risk factor interventions by pharmacists in the primary prevention of cardiovascular disease (CVD). Given the proven benefits of pharmacist interventions for individual risk factors, it is essential that evidence for a comprehensive approach to care be generated so that pharmacists remain key members of the health care team for individuals at risk of initial onset of CVD. Objective: To establish the feasibility of an intervention delivered by community pharmacists to reduce the risk of primary onset of CVD.
Methods: A single-cohort intervention study was undertaken in 2008-2009. Twelve community pharmacists from 10 pharmacies who were trained to provide lifestyle and medicine management support to reduce CVD risk recruited 70 at-risk participants aged 50-74 years who were free from diabetes or CVD. Participants received a baseline assessment to establish CVD risk and health behaviors. An assessment report provided to patients and pharmacists was used to collaboratively establish treatment goals and, over 5 sessions, implement treatment strategies. Follow-up assessment at 6 months measured changes in baseline parameters. The primary outcome was the average change to overall 5-year risk of CVD onset.
Results: Sixty-seven participants were included in the analysis. The mean participant age was 60 years and 73% were female. We observed a 25% (95% CI 17 to 33) proportional risk reduction in overall CVD risk. Significant reductions also occurred in mean blood pressure (-11/-5 mm Hg) and waist circumference (-1.3 cm), with trends toward improvement for most other observed risk factors.
Conclusions: Findings support previous evidence of positive cardiovascular health outcomes following pharmacist intervention in other patient groups; we recommend generating randomized controlled trial evidence for a primary prevention population.

Blockade of 5-HT2A receptors suppresses hyperthermic but not cardiovascular responses to psychosocial stress in rats

The aim of this study was to determine whether 5-HT2A receptors mediate cardiovascular and thermogenic responses to acute psychological stresses. For this purpose, adult male Wistar hooded rats instrumented for telemetric recordings of either electrocardiogram (ECG) (n=12) or arterial pressure (n=12) were subjected, on different days, to four 15-min episodes of social defeat. Prior to stress, animals received s.c. injection of the selective 5-HT2A receptor antagonist SR-46349B (trans-4-((3Z)3-[(2-dimethylaminoethyl)oxyimino]-3-(2-fluorophenyl)propen-1-yl)-phenol, hemifumarate) (at doses of 0.3, 1.0 and 3.0 mg/kg) or vehicle. The drug had no effect on basal heart rate or heart rate variability indexes, arterial pressure, and core body temperature. Social defeat elicited significant and substantial tachycardic (347±7 to 500±7 bpm), pressor (77±4 to 97±4 mm Hg) and hyperthermic (37.0±0.3 to 38.5±0.1 °C) responses. Blockade of 5-HT2A receptors, at all doses of the antagonist, completely prevented stress-induced hyperthermia. In contrast, stress-induced cardiovascular responses were not affected by the blockade (except small reduction of tachycardia by the highest dose of the drug). We conclude that in rats, 5-HT2A receptors mediate stress-induced hyperthermic responses, but are not involved in the genesis of stress-induced rises in heart rate or arterial pressure, and do not participate in cardiovascular control at rest.

3D fibrous structures as cardiovascular implants

Medical textiles are a highly specialised stream of technical textiles industry with a growing range of applications. A significant advancement has been achieved in surgical products or biomedical textiles (implantable/non-implantable) with the advent of 3D textile manufacturing techniques. Cardiovascular soft tissue implants (vascular grafts) have been a field of interest over decades for use of innovative 3D tubular structures in treatment of cardiovascular diseases. In the field of soft tissue implants, knitted and woven tubular structures are being used for large diameter blood vessel replacements. Advent of electrospinning and tissue engineering techniques has been able to provide promising answers to small diameter vascular grafts. The aim of this review is to outline the approaches in vascular graft development utilising different 3D tubular structure forming techniques. The emphasis is on vascular graft development techniques that can help improve treatment efficacy in future.

Improving the cost-effectiveness of cardiovascular disease prevention in Australia : a modelling study

Background : Cardiovascular disease is the leading cause of death worldwide. Like many countries, Australia is currently changing its guidelines for cardiovascular disease prevention from drug treatment for everyone with 'high blood pressure' or 'high cholesterol', to prevention based on a patient's absolute risk. In this research, we model cost-effectiveness of cardiovascular disease prevention with blood pressure and lipid drugs in Australia under three different scenarios: (1) the true current practice in Australia; (2) prevention as intended under the current guidelines; and (3) prevention according to proposed absolute risk levels. We consider the implications of changing to absolute risk-based cardiovascular disease prevention, for the health of the Australian people and for Government health sector expenditure over the long term.

Methods : We evaluate cost-effectiveness of statins, diuretics, ACE inhibitors, calcium channel blockers and beta-blockers, for Australian men and women, aged 35 to 84 years, who have never experienced a heart disease or stroke event. Epidemiological changes and health care costs are simulated by age and sex in a discrete time Markov model, to determine total impacts on population health and health sector costs over the lifetime, from which we derive cost-effectiveness ratios in 2008 Australian dollars per quality-adjusted life year.

Results : Cardiovascular disease prevention based on absolute risk is more cost-effective than prevention under the current guidelines based on single risk factor thresholds, and is more cost-effective than the current practice, which does not follow current clinical guidelines. Recommending blood pressure-lowering drugs to everyone with at least 5% absolute risk and statin drugs to everyone with at least 10% absolute risk, can achieve current levels of population health, while saving $5.4 billion for the Australian Government over the lifetime of the population. But savings could be as high as $7.1 billion if Australia could match the cheaper price of statin drugs in New Zealand.

Conclusions : Changing to absolute risk-based cardiovascular disease prevention is highly recommended for reducing health sector spending, but the Australian Government must also consider measures to reduce the cost of statin drugs, over and above the legislated price cuts of November 2010.

Potential of pharmacists to help reduce the burden of poorly managed cardiovascular risk

Introduction: Rural areas require better use of existing health professionals to ensure capacity to deliver improved cardiovascular outcomes. Community pharmacists (CPs) are accessible to most communities and can potentially undertake expanded roles in prevention of cardiovascular disease (CVD).

Objective: This study aims to establish frequency of contact with general practitioners (GPs) and CPs by patients at high risk of CVD or with inadequately controlled CVD risk factors.

Design, setting and participants: Population survey using randomly selected individuals from the Wimmera region electoral roll and incorporating a physical health check and self-administered health questionnaire. Overall, 1500 were invited to participate.

Results: The participation rate was 51% when ineligible individuals were excluded. Nine out of 10 participants visited one or both types of practitioner in the previous 12 months. Substantially more participants visited GPs compared with CPs (88.5% versus 66.8%). With the exception of excess alcohol intake, the median number of opportunities to intervene for every inadequately controlled CVD risk factor and among high risk patient groups at least doubled for the professions combined when compared with GP visits alone.

Conclusion: Opportunities exist to intervene more frequently with target groups by engaging CPs more effectively but would require a significant attitude shift towards CPs. Mechanisms for greater pharmacist integration into primary care teams should be investigated.

Population-level changes to promote cardiovascular health

Background: Cardiovascular diseases (CVD) cause 1.8 million premature (<75 years) death annually in Europe. The majority of these deaths are preventable with the most efficient and cost-effective approach being on the population level. The aim of this position paper is to assist authorities in selecting the most adequate management strategies to prevent CVD.

Design and Methods: Experts reviewed and summarized the published evidence on the major modifiable CVD risk factors: food, physical inactivity, smoking, and alcohol. Population-based preventive strategies focus on fiscal measures (e.g. taxation), national and regional policies (e.g. smoke-free legislation), and environmental changes (e.g. availability of alcohol).

Results: Food is a complex area, but several strategies can be effective in increasing fruit and vegetables and lowering intake of salt, saturated fat, trans-fats, and free sugars. Tobacco and alcohol can be regulated mainly by fiscal measures and national policies, but local availability also plays a role. Changes in national policies and the built environment will integrate physical activity into daily life.

Conclusion: Societal changes and commercial influences have led to the present unhealthy environment, in which default option in life style increases CVD risk. A challenge for both central and local authorities is, therefore, to ensure healthier defaults. This position paper summarizes the evidence and recommends a number of structural strategies at international, national, and regional levels that in combination can substantially reduce CVD.

Cardiovascular risk factors and psychological distress in Australian farming communities

Objective:  To examine the prevalence of cardiovascular disease (CVD) risk factors, psychological distress and associations between physical and mental health parameters within a cohort of the Australian farming community.

Design:  Cross-sectional descriptive study.

Setting:  Farming communities across Australia.

Participants:  Data of men (n = 957) and women (n = 835) farmers from 97 locations across Australia were stratified into categories based on National Cholesterol Education Program guidelines.

Main outcome measure(s):  Prevalence of and interrelationship between overweight, obesity, dyslipidaemia, hypertension, diabetes risk and psychological distress.

Results:  There was a higher prevalence of overweight (42.5%, 95% confidence interval (CI), 34.2–50.8), obesity (21.8%, 95% CI, 18.3–25.3), abdominal adiposity (38.4% 95% CI, 24.5–52.5), hypertension (54.0%, 95% CI, 34.4–73.5) and diabetes risk (25.3%, 95% CI, 17.7–36.7) in the farming cohort compared with national data. There was also a positive significant association between the prevalence of psychological distress and obesity, abdominal adiposity, body fat percentage and metabolic syndrome in older (age ≥ 50 years) participants.

Conclusions:  This study group of farming men and women exhibited an increased prevalence of CVD risk factors and co-morbidities. The findings indicate a positive association between psychological distress and risk for developing CVD, particularly in the older farmers. If the younger cohort were to maintain elevated rates of psychological distress, then it is foreseeable that the next generation of farmers could experience poorer physical health than their predecessors.

Five-year change in cardiovascular risk factors according to education level : the Australian diabetes, obesity and lifestyle (AusDiab) study

Background: Lower socioeconomic status (SES) is strongly associated with a higher prevalence of major cardiovascular risk factors, but few studies have examined changes in these risk factors over time according to SES. We aimed to determine whether SES is a predictor of the change in cardiovascular risk factor levels in a contemporary Australian adult cohort

Methods: Participants in the population-based AusDiab study aged 25+ years who attended both baseline and 5-year follow-up examinations (n=5 954) were categorised according to their level of education at baseline. Cardiovascular risk factor data at both time points were ascertained through questionnaire and physical measurement. Analysis was stratified by gender.

Results: The mean levels of systolic blood pressure, total cholesterol and the prevalence of smoking decreased between the two time points across all educational categories. Increases were also seen in mean BMI and the prevalence of diabetes. For blood pressure, the smallest decrease was seen among men with lower education (age-adjusted difference from higher education 2.8 mmHg, 95% CI 1.0 to 4.6). For total cholesterol, the decrease was greatest among women with lower education (age-adjusted difference from higher education 0.11 mmol/l, 95% CI 0.19 to 0.02). Among those "not at risk" at baseline for each risk factor, women with lower education were more likely than those with higher education to progress to being "at risk" for BMI (age-adjusted odds ratio 1.60, 95% CI 1.09 to 2.35).

Conclusion: Educational gradients narrowed for total cholesterol in women, but widened for systolic blood pressure in men and remained static for other risk factors. Lower education was also associated with an earlier onset of overweight or obesity in women. Given current socioeconomic gradients in risk factors levels, these findings suggest that social inequalities in CVD will persist and may even widen in the future.

Incidence of cardiovascular risk factors by education level 2000-2005 : the Australian diabetes, obesity and lifestyle (AusDiab) cohort study

Lower socioeconomic status (SES) is associated with a higher prevalence of major risk factors for cardiovascular disease (CVD). However, few longitudinal studies have examined the association between SES and CVD risk factors over time. We aimed to determine whether SES, using education as a proxy, is associated with the onset of CVD risk factors over 5 years in an Australian adult cohort study.

Participants in the Australian Diabetes, Obesity and Lifestyle study (AusDiab) study aged 25 years and over who attended both baseline and 5-year follow-up examinations (n=5 967) were categorised according to educational attainment. Cardiovascular risk factor data at both time points were ascertained through questionnaire and physical measurement.

Women with lower education had a greater risk of progressing from normal weight to overweight or obesity than those with higher education (age-adjusted OR 1.57, 95% CI 1.06-2.31). Both men and women with lower education were more likely to develop diabetes (age-adjusted OR from higher education 1.75, 95% CI 1.14-2.71 and 3.01, 95% CI 1.26-7.20, respectively). A lower level of education was associated with a greater number of risk factors accumulated over time in women (OR of progressing from having two or less risk factors at baseline to three or more at follow up, 2.04, 95% 1.32-3.14).

In this Australian population-based study, lower educational attainment was associated with an increased risk of developing both individual and total CVD risk factors over a 5-year period. These findings suggest that SES inequalities in CVD will persist into the future.

Suboptimal management of cardiovascular risk factors in coronary heart disease patients in primary care occurs particularly in women

Background:  Patients with established coronary heart disease (CHD) are at the highest risk of further events. Despite proven therapies, secondary prevention is often suboptimal. General practitioners (GPs) are in an ideal position to improve secondary prevention.

Aim:  To contrast management of cardiovascular risk factors in patients with established CHD in primary care to those in clinical guidelines and according to gender.

Methods:  GPs throughout Australia were approached to participate in a programme incorporating a disease management software (mdCare) program. Participating practitioners (1258 GPs) recruited individual patients whose cardiovascular risk factor levels were measured.

Results:  The mdCare programme included 12 509 patients (58% male) diagnosed with CHD. Their mean age was 71.7 years (intra-quartile range 66–78) for men and 74 years (intra-quartile range 68–80) for women. Low-density-lipoprotein cholesterol was above target levels in 69% (2032) of women compared with 58% (2487) in men (P < 0.0001). There was also a higher proportion of women with total cholesterol above target levels (76%, 3592) compared with men (57%, 3787) (P < 0.0001). In patients who were prescribed lipid-lowering medication, 53% (2504) of men and 72% (2285) of women continued to have a total cholesterol higher than recommended target levels (P < 0.0001). Overall, over half (52%, 6538) had at least five cardiovascular risk factors (55% (2914) in women and 50% (3624) in men, P < 0.0001).

Conclusion:  This study found less intensive management of cardiovascular risk factors in CHD patients, particularly among women, despite equivalent cardiovascular risk. This study has shown that these patients have multiple risk factors where gender also plays a role.

Accuracy of national mortality codes in identifying adjudicated cardiovascular deaths

Objective: This study investigated the sensitivity and specificity of the national mortality codes in identifying cardiovascular disease (CVD) deaths and documents methods of verification.

Methods: A 12-year retrospective case ascertainment of all ICD-coded CVD deaths was performed for deaths between 1990 and 2002 in the Melbourne Collaborative Cohort Study, comprising 41,528 subjects. Categories of non-CVD codes were also examined. Stratified samples of 750 deaths were adjudicated from a total of 2,230 deaths. Expert panels of cardiologists and neurologists adjudicated deaths.

Results: Of the 750 deaths adjudicated, 582 were verified as CVD [392 coronary heart disease (CHD) and 92 stroke] and 168 non-CVD. Estimated sensitivity and specificity of national mortality codes for identifying specific causes of death were: CHD 74.2% (95% CI: 69.8–78.5%) and 97.6% (96.0–99.2%), respectively; myocardial infarction 59.9% (50.9–69.0%) and 94.2% (92.4–96.0%), respectively; haemorrhagic stroke 58.9% (46.0–71.7%) and 99.8% (99.4–100.0%), respectively and; ischaemic stroke 38.7% (20.5–56.9%) and 99.9% (99.6–100.0%), respectively. Misclassification was most common for deaths with primary ICD codes for endocrine-metabolic and genito-urinary diseases.

Conclusions: National mortality coding under-estimated the true proportion of CHD and stroke deaths in the cohort by 13.6% and 50.8%, respectively.