Best practice for prevention and treatment of cardiovascular disease through an equity lens : a review

Background Despite declining rates of cardiovascular disease (CVD) mortality in developed countries, lower socioeconomic groups continue to experience a greater burden of the disease. There are now many evidence-based treatments and prevention strategies for the management of CVD and it is essential that their impact on the more disadvantaged group is understood if socioeconomic inequalities in CVD are to be reduced.

Aims To determine whether key interventions for CVD prevention and treatment are effective among lower socioeconomic groups, to describe barriers to their effectiveness and the potential or actual impact of these interventions on the socioeconomic gradient in CVD.

Methods Interventions were selected from four stages of the CVD continuum. These included smoking reduction strategies, absolute risk assessment, cardiac rehabilitation, secondary prevention medications, and heart failure self-management programmes. Electronic searches were conducted using terms for each intervention combined with terms for socioeconomic status (SES).

Results Only limited evidence was found for the effectiveness of the selected interventions among lower SES groups and there was little exploration of socioeconomic-related barriers to their uptake. Some broad themes and key messages were identified. In the majority of findings examined, it was clear that the underlying material, social and environmental factors associated with disadvantage are a significant barrier to the effectiveness of interventions.

Conclusion Opportunities to reduce socioeconomic inequalities occur at all stages of the CVD continuum. Despite this, current treatment and prevention strategies may be contributing to the widening socioeconomic-CVD gradient. Further research into the impact of best-practice interventions for CVD upon lower SES groups is required.

Inequalities in cardiovascular disease mortality : the role of behavioural, physiological and social risk factors

Background While the relationship between socio-economic disadvantage and cardiovascular disease (CVD) is well established, the role that traditional cardiovascular risk factors play in this association remains unclear. The authors examined the association between education attainment and CVD mortality and the extent to which behavioural, social and physiological factors explained this relationship.

Methods Adults (n=38 355) aged 40–69 years living in Melbourne, Australia were recruited in 1990–1994. Subjects with baseline CVD risk factor data ascertained through questionnaire and physical measurement were followed for an average of 9.4 years with CVD deaths verified by review of medical records and autopsy reports.

Results CVD mortality was higher for those with primary education only, compared with those who had completed tertiary education, with an HR of 1.66 (95% CI 1.10 to 2.49) after adjustment for age, country of birth and gender. Those from the lowest educated group had a more adverse cardiovascular risk factor profile compared with the highest educated group, and adjustment for these risk factors reduced the HR to 1.18 (95% CI 0.78 to 1.77). In analysis of individual risk factors, smoking and waist circumference explained most of the difference in CVD mortality between the highest and lowest education groups.

Conclusions Most of the excess CVD mortality in lower socio-economic groups can be explained by known risk factors, particularly smoking and overweight. While targeting cardiovascular risk factors should not divert efforts from addressing the underlying determinants of health inequalities, it is essential that known risk factors are addressed effectively among lower socio-economic groups.

Which interventions offer best value for money in primary prevention of cardiovascular disease?

Background
Despite many decades of declining mortality rates in the Western world, cardiovascular disease remains the leading cause of death worldwide. In this research we evaluate the optimal mix of lifestyle, pharmaceutical and population-wide interventions for primary prevention of cardiovascular disease.

Methods and Findings
In a discrete time Markov model we simulate the ischaemic heart disease and stroke outcomes and cost impacts of intervention over the lifetime of all Australian men and women, aged 35 to 84 years, who have never experienced a heart disease or stroke event. Best value for money is achieved by mandating moderate limits on salt in the manufacture of bread, margarine and cereal. A combination of diuretic, calcium channel blocker, ACE inhibitor and low-cost statin, for everyone with at least 5% five-year risk of cardiovascular disease, is also cost-effective, but lifestyle interventions aiming to change risky dietary and exercise behaviours are extremely poor value for money and have little population health benefit.

Conclusions
There is huge potential for improving efficiency in cardiovascular disease prevention in Australia. A tougher approach from Government to mandating limits on salt in processed foods and reducing excessive statin prices, and a shift away from lifestyle counselling to more efficient absolute risk-based prescription of preventive drugs, could cut health care costs while improving population health.

Comorbidity of cardiovascular disease, diabetes and chronic kidney disease in Australia

This is the first report of a projected series regarding the comorbidity of cardiovascular disease (CVD), diabetes and chronic kidney disease (CKD) in Australia. Comorbidity refers to any two or more of these diseases that occur in one person at the same time. The questions to be answered in this report include: 1. How many Australians have comorbidity of CVD, diabetes and CKD? 2. What is the proportion of hospitalisations with these comorbidities? 3. How much do these comorbidities contribute to deaths? 4. What is the magnitude of comorbidity in the context of each individual disease? 5. Are there differences in the distribution of these comorbidities among age groups and sexes?

Age at quitting smoking as a predictor of risk of cardiovascular disease incidence independent of smoking status, time since quitting and pack-years

Background: Risk prediction for CVD events has been shown to vary according to current smoking status, pack-years smoked over a lifetime, time since quitting and age at quitting. The latter two are closely and inversely related. It is not known whether the age at which one quits smoking is an additional important predictor of CVD events. The aim of this study was to determine whether the risk of CVD events varied according to age at quitting after taking into account current smoking status, lifetime pack-years smoked and time since quitting.
Findings. We used the Cox proportional hazards model to evaluate the risk of developing a first CVD event for a cohort of participants in the Framingham Offspring Heart Study who attended the fourth examination between ages 30 and 74 years and were free of CVD. Those who quit before the median age of 37 years had a risk of CVD incidence similar to those who were never smokers. The incorporation of age at quitting in the smoking variable resulted in better prediction than the model which had a simple current smoker/non-smoker measure and the one that incorporated both time since quitting and pack-years. These models demonstrated good discrimination, calibration and global fit. The risk among those quitting more than 5 years prior to the baseline exam and those whose age at quitting was prior to 44 years was similar to the risk among never smokers. However, the risk among those quitting less than 5 years prior to the baseline exam and those who continued to smoke until 44 years of age (or beyond) was two and a half times higher than that of never smokers.
Conclusions: Age at quitting improves the prediction of risk of CVD incidence even after other smoking measures are taken into account. The clinical benefit of adding age at quitting to the model with other smoking measures may be greater than the associated costs. Thus, age at quitting should be considered in addition to smoking status, time since quitting and pack-years when counselling individuals about their cardiovascular risk.

Framingham risk prediction equations for incidence of cardiovascular disease using detailed measures for smoking

Current prediction models for risk of cardiovascular disease (CVD) incidence incorporate smoking as a dichotomous yes/no measure. However, the risk of CVD associated with smoking also varies with the intensity and duration of smoking and there is a strong association between time since quitting and the risk of disease onset. This study aims to develop improved risk prediction equations for CVD incidence incorporating intensity and duration of smoking and time since quitting. The risk of developing a first CVD event was evaluated using a Cox’s model for participants in the Framingham offspring cohort who attended the fourth examination (1988–92) between the ages of 30 and 74 years and were free of CVD (n=3751). The full models based on the smoking variables and other risk factors, and reduced models based on the smoking variables and non-laboratory risk factors demonstrated good discrimination, calibration and global fit. The incorporation of both time since quitting among past smokers and pack-years among current smokers resulted in better predictive performance as compared to a dichotomous current/non-smoker measure and a current/quitter/never smoker measure. Compared to never smokers, the risk of CVD incidence increased with pack-years. Risk among those quitting more than five years prior to the baseline exam and within five years prior to the baseline exam were similar and twice as high as that of never smokers. A CVD risk equation incorporating the effects of pack-years and time since quitting provides an improved tool to quantify risk and guide preventive care.

Co-morbid cardiovascular disease and depression : sequence of disease onset is linked to mental but not physical self-rated health. Results from a cross-sectional, population-based study

Purpose: Self-rated health has been linked to important health and survival outcomes in individuals with co-morbid depression and cardiovascular disease (CVD). It is not clear how the timing of depression onset relative to CVD onset affects this relationship. We aimed to first identify the prevalence of major depressive disorder (MDD) preceding CVD and secondly determine whether sequence of disease onset is associated with mental and physical self-rated health. Methods: This study utilised cross-sectional, populationbased data from 224 respondents of the 2007 Australian National Survey of Mental Health and Wellbeing (NSMHWB). Participants were those diagnosed with MDD and reported ever having a heart/circulatory condition over their lifetime. Age of onset was reported for each condition. Logistic regression was used to explore differences in self-rated mental and physical health for those reporting pre-cardiac and post-cardiac depression. Results: The proportion of individuals in whom MDD preceded CVD was 80.36% (CI: 72.57-88.15). One-fifth (19.64%, CI: 11.85-27.42) reported MDD onset at the time of, or following, CVD. After controlling for covariates, the final model demonstrated that those reporting post-cardiac depression were significantly less likely to report poor selfrated mental health (OR:0.36, CI: 0.14-0.93) than those with pre-existing depression. No significant differences were found in self-rated physical health between groups (OR:0.90 CI: 0.38-2.14). Conclusions: MDD is most common prior to the onset of CVD. Further, there is an association between pre-morbid MDD and poorer self-rated mental health. To our knowledge, this is the first time this has been demonstrated in a national, population-based survey. As self-rated health has been shown to predict important outcomes such as survival, we recommend that those with MDD be identified as vulnerable to CVD onset and poorer health outcomes

Age-specific trends in cardiovascular mortality rates in Australia between 1980 and 2005

Aim: Recent analyses suggest the decline in coronary heart disease (CHD) mortality rates is slowing in younger age groups in countries such as the UK and US. We aimed to assess recent mortality rate trends in all circulatory disease and its subtypes in Australia.

Methods: Annual all circulatory, CHD, and cerebrovascular disease mortality rates between 1980 and 2005 for Australia were analysed. Data were stratified by sex and ten-year age group (age 35 to 85+). The annual rate of change and significant changes in trends were identified using joinpoint Poisson regression.

Results: Age standardised all circulatory disease mortality rates continue to decline in Australia, falling from 441 per 100,000 in 1980 to 145 per 100,000 in 2005 for males and from 264 per 100,000 to 96 per 100,000 for females. The rate of decline from both CHD and cerebrovascular disease appears to be stable or accelerating for individuals aged 55 years and over. However, the decline in young men and women aged 35-54 years is slowing for CHD and cerebrovascular disease mortality alike (except cerebrovascular disease mortality in males aged 35-44). For females aged 35-44 and 45-54 there has been no change in the cerebrovascular mortality rate since 1993 and 1999, respectively.

Conclusions: In Australia, whilst in older adults the decline in cardiovascular mortality rates is generally accelerating, in younger adults it appears to be slowing. It will be important to identify the causes of these trends.

Co-morbid depression is associated with poor work outcomes in persons with cardiovascular disease (CVD) : a large, nationally representative survey in the Australian population

Background: Co-morbid major depressive disorder (MDD) and cardiovascular disease (CVD) is associated with poor clinical and psychological outcomes. However, the full extent of the burden of, and interaction between, this co-morbidity on important vocational outcomes remains less clear, particularly at the population level. We examine the association of co-morbid MDD with work outcomes in persons with and without CVD.

Methods. This study utilised cross-sectional, population-based data from the 2007 Australian National Survey of Mental Health and Wellbeing (n = 8841) to compare work outcomes of individuals with diagnostically-defined MDD and CVD, MDD but not CVD, CVD but not MDD, with a reference group of "healthy" Australians. Workforce participation was defined as being in full- or part-time employment. Work functioning was measured using a WHO Disability Assessment Schedule item. Absenteeism was assessed using the 'days out of role' item.

Results: Of the four groups, those with co-morbid MDD and CVD were least likely to report workforce participation (adj OR:0.4, 95% CI: 0.3-0.6). Those with MDD only (adj OR:0.8, 95% CI:0.7-0.9) and CVD only (adj OR:0.8, 95% CI: 0.6-0.9) also reported significantly reduced odds of participation. Employed individuals with co-morbid MDD and CVD were 8 times as likely to experience impairments in work functioning (adj OR:8.1, 95% CI: 3.8- 17.3) compared with the reference group. MDD was associated with a four-fold increase in impaired functioning. Further, individuals with co-morbid MDD and CVD reported greatest likelihood of workplace absenteeism (adj. OR:3.0, 95% CI: 1.4-6.6). Simultaneous exposure to MDD and CVD conferred an even greater likelihood of poorer work functioning.

Conclusions: Co-morbid MDD and CVD is associated with significantly poorer work outcomes. Specifically, the effects of these conditions on work functioning are synergistic. The development of specialised treatment programs for those with co-morbid MDD and CVD is required.

The health-related quality of life burden of co-morbid cardiovascular disease and major depressive disorder in Australia : findings from a population-based, cross-sectional study

Purpose Health-related quality of life (HRQOL) can be significantly impaired by the presence of chronic conditions such as cardiovascular disease (CVD) and major depressive disorder (MDD). The aim of this paper was to (1) identify differences in HRQOL between individuals with CVD, MDD, or both, compared to a healthy reference group, (2) establish whether the influence of co-morbid MDD and CVD on HRQOL is additive or synergistic and (3) determine the way in which depression severity interacts with CVD to influence overall HRQOL.

Methods Population-based data from the 2007 Australian National Survey of Mental Health and Well-being (NSMHWB) (n = 8841) were used to compare HRQOL of individuals with MDD and CVD, MDD but not CVD, CVD but not MDD, with a healthy reference group. HRQOL was measured using the Assessment of Quality of Life (AQOL). MDD was identified using the Composite International Diagnostic Interview (CIDI 3.0).

Results Of all four groups, individuals with co-morbid CVD and depression reported the greatest deficits in AQOL utility scores (Coef: −0.32, 95% CI: −0.40, −0.23), after adjusting for covariates. Those with MDD only (Coef: −0.27, 95% CI: −0.30, −0.24) and CVD only (Coef: −0.08, 95% CI: −0.11, −0.05) also reported reduced AQOL utility scores. Second, the influence of MDD and CVD on HRQOL was shown to be additive, rather than synergistic. Third, a significant dose–response relationship was observed between depression severity and HRQOL. However, CVD and depression severity appeared to act independently of each other in impacting HRQOL.

Conclusions HRQOL is greatly impaired in individuals with co-morbid MDD and CVD; these conditions appear to influence HRQOL in an additive fashion. HRQOL alters with depression severity, therefore treating depression and improving HRQOL is of clinical importance.

Age-specific trends in cardiovascular mortality rates in the Netherlands between 1980 and 2009

Recent analyses suggest the decline in coronary heart disease mortality rates is slowing in younger age groups in countries such as the US and the UK. This work aimed to analyse recent trends in cardiovascular mortality rates in the Netherlands. Analysis was of annual all circulatory, ischaemic heart disease (IHD), and cerebrovascular disease mortality rates between 1980 and 2009 for the Netherlands. Data were stratified by sex and 10-year age group (age 35–85+). The annual rate of change and significant changes in the trend were identified using joinpoint Poisson regression. For almost all age and sex groups examined the rate of IHD and cerebrovascular disease mortality in the Netherlands has more than halved between 1980 and 2009. The decline in mortality from both IHD and cerebrovascular disease is continuing for all ages and sex groups, with anacceleration in the decline apparent from the late 1990s/early 2000s. The decline in age-specific all circulatory, coronary heart disease and cerebrovascular disease mortality rates continues for all age and sex groups in the Netherlands.

Cultural understanding of health and adjustment to cardiovascular disease among the Greek elderly

The onset of chronic illness is a major lef event that presents serious challenges for the individual at a micro and macro level. The way in which adaptation to such illness occurs is closely related to cultural and linguistic factors that are an integral part of personal identity. This study presents the health beliefs of elderly Greek Australians and they way in which they understand health and disease. The process by which this population conceptualizes CVD and seeks medical care is discussed in the context of their specific cultural views and attitudes towards illness.