The purpose of this article is to highlight some particularly salient psychosocial factors that have been independently associated with coronary heart disease (CHD) but to do so with a focus on the older adult in the secondary prevention setting. Although accumulating evidence supports important relationships between psychosocial factors and CHD, the issue to be addressed in this article is whether such relationships hold true in the older adult and whether rehabilitation and secondary prevention interventions are effective in addressing these factors. As much as possible, current recommendations (related to psychosocial issues) from worldwide Clinical Practice Guidelines are highlighted. This article is not intended to be a systematic review; indeed, such reviews have been done with respect to the individual risk factors discussed here. The reader is directed to the meta-analysis by van Melle et al1 with regard to the prognostic impact of depression on post-myocardial infarction (MI) morbidity and mortality and also to the review by Bunker et al2 regarding the relationship between social isolation and CHD onset and prognosis.

Contributors to CHD in older adults include biological, psychological, social, and spiritual factors. Although commonly understood risk factors such as smoking, sedentary behavior, dyslipidemia, hypertension, and diabetes contribute to the pathogenesis of CHD, psychosocial factors are also important influences. Nomand et al3 found that biomedical risk factors explained only 33% of the variability in 30-day mortality after MI in older adults; 67% of the variability remained unexplained, even after accounting for severity of disease on admission. In 2003, Stuart-Shor et al4 published a comprehensive review of the literature regarding psychosocial factors and cardiovascular disease (CVD) in the elderly. They reported that (a) although there is emerging evidence of a relationship between CVD and psychosocial factors in the elderly, the data specific to older persons are limited, and (b) the physical limitations that often accompany aging predispose older adults to a decreased quality of life, an increased risk of depression, and relatively more difficulty engaging in lifestyle modification.

Social Support and Social Isolation

As the conceptual and empirical study of the broad term social support has advanced, it is important to distinguish among the concepts of social support, social integration, and social networks. Social integration refers to the presence or absence (social isolation) of social ties or relationships. Social network refers to the structure of one's relationships and has been described as either small and dense, or large and broad. Social support refers to the functions or provisions given by one's social relationships such as emotional concern, instrumental assistance, or information.

Lack of social support is associated with increased cardiovascular risk.5,6 In a recent systematic overview, Mookadam and Arthur6 found social isolation or lack of social support network to be associated with increased cardiovascular mortality and morbidity with an odds ratio of 2 to 3. This excess morbidity and mortality is independent of known predictors of cardiac mortality in both the short-term (up to 6 months) and long-term (up to 6 years) post-MI periods. Although the literature is conflicting, on balance it appears that the relationship between social isolation and CVD mortality is nonlinear with a 2- to 3-fold excess mortality in the most isolated groups and little or no variation in those with moderate to high levels of social support. This finding implies that deficiency beyond a certain threshold is deleterious to health. Incremental gains in social networks do not enhance health or well-being measurably. Therefore, it is important to assess, and if possible, satisfy the minimal threshold in the most vulnerable isolated group. Older adults are more likely to fall into this vulnerable group.

Although there is a vast literature about social support, social isolation, and CHD, there are few studies specifically examining the impact of social networks on older persons with heart disease. Hildingh et al7 conducted a descriptive study of the social networks and need for social support of 128 participants (68% male, 32% female; age range 65-94) following a first MI. Social networks were assessed by a 12-item questionnaire assessing the structural properties of participants' social relationships (eg, "The persons in my social network know each other through me"). The social support measure included 9 items related to emotional support, instrumental aid, and informational support (eg, "I have an increased need for somebody to turn to when I am in trouble"). The results showed that the participants, even the oldest ones, had an available social network and that its members provided adequate emotional support. These older adults had social networks that were characterized as dense, not widely dispersed, and with strong relationship ties; characteristics that are typical of elders' social networks. Men reported more support from their wives (67%) than women from their husbands (34%).

Sorkin et al8 extended the work on social isolation in older cardiac patients by examining the concepts of loneliness and lack of companionship as possible predictors of "a coronary condition." The association between low social integration, or social isolation, and CHD has often been attributed to the deleterious effects of loneliness; however, loneliness per se has seldom been the focus of CHD research. Loneliness theorists9 have conceptualized 2 types of underlying deficits: (a) lack of emotional support (lack of intimacy) and (b) lack of companionship (lack of a sense of belonging), thus leading to either emotional loneliness or social loneliness.

Sorkin et al8 recruited 180 community-dwelling adults ranging in age from 58 to 90 (mean age = 70.5; SD = 6.9). Most participants (64%) were widowed, divorced, or single and 46% lived alone. Participants' baseline health status was self-reported and most (85%) judged their health to be good or excellent. Key predictor variables were loneliness, emotional support, and companionship. The outcome of interest was "heart condition status," which was determined by a medical examination and was recorded dichotomously as either "no heart condition" or "heart condition." Examples of heart conditions were dysrhythmia, valve abnormality, or blood pressure abnormality. Data were also collected on possible mediators such as: physiologic factors (eg, serum cholesterol, high-density lipoprotein, weight), health behaviors (eg, smoking, sedentary lifestyle, poor dietary habits), affective states (eg, depression and mood), and demographic characteristics.

Greater loneliness was found to be associated with an increased probability of having a heart condition, as were low levels of both emotional support and companionship. For every unit increase in level of loneliness, there was a 3-fold increase in the odds of being diagnosed with a heart condition. Conversely, for every unit increase in perceived availability of emotional support, there was a 97% decrease in the odds of having a heart condition. These results have important implications for nursing assessment and intervention, which will be discussed later in this article.

Depression

Depression has emerged as a risk factor for CHD10,11 and has been clearly shown to predict mortality following MI; even minor depressive symptoms may be a marker for risk.12,13 Depression may confer risk through increased sympathetic tone, decreased heart rate variability,14 or mechanisms which increase blood coagulation.15 Risk for CHD may also be mediated by behavioral choices such as reduced compliance with treatment recommendations; for example, depression is associated with reduced participation in cardiac rehabilitation.16

Once again, there are limited data on the relationship between depression and CHD that are specific to the older adult. Having said that, the ongoing Cardiovascular Health Study17 is providing important information about cardiovascular risk factors in Americans aged 65 and older. Ariyo et al18 examined depressive symptoms and risk of CHD in a Cardiovascular Health Study cohort of 4,493 participants who were free of CVD at study entry. Depression was assessed, using the Center for Epidemiological Studies Depression Scale (CES-D),19 at baseline and then annually for an average of 6 years.19 CES-D scores >=8 are recognized as "at risk of clinical depression." All morbid events after the baseline visit were classified as incident events. Mortality was ascertained using death codes according to the International Classification of Disease.

Approximately 50% of participants had at least one CES-D score >=8 over the 6 years of follow-up, although the cumulative mean scores were closer to 5. Thus, depression was not highly prevalent in these older adults but those who more likely to be depressed were less educated, had lower incomes, had a history of diabetes, had higher body mass index, or were smokers.

For every 5-unit increase in cumulative mean depression scores, there was a 15% increase in risk of developing CHD (after adjustment for traditional demographic and CHD risk factors) and a 16% increased risk of death. When cumulative mean depression scores were grouped (ie, scores of 0-4, 5-9, 10-14, 15+), those with the highest scores had a 40% increased risk of CHD and a 60% increased risk of death.

Some authors have suggested that physicians underrecognize depressive symptoms in older adults, and thus, such patients are underdiagnosed and undertreated.20 The findings from the above Cardiovascular Health Study cohort highlight the importance of assessment and screening for depression as part of our effort to reduce risk of CHD and death in older persons, particularly those who have small social networks or low social support.

Given the clearly established relationship between social isolation, depression, and CHD, various investigators have conducted studies aimed at ameliorating social isolation and/or depression in the hopes of affecting morbidity and mortality. Perhaps the most noteworthy of these studies is the Enhancing Recovery in Coronary Heart Disease Patients (ENRICHD) Randomized Trial.21 The ENRICHD trial randomized 1,084 women and 1,397 men (mean age = 61 years) with depression, low social support, or both to receive individual cognitive-behavioral psychotherapy, often supplemented with group therapy. In addition, the antidepressant sertraline, a selective serotonin reuptake inhibitor, was prescribed when necessary. Treatment resulted in significant but modest improvements in depression and social support. Despite measurable treatment benefits among depressed or socially isolated individuals, the 4-year survival curves showed no difference between intervention and control with respect to recurrent MI or death. When currently accumulated evidence is evaluated in totality, it is not yet clear whether psychosocial interventions in patients with CHD can be expected to have a significant impact on secondary prevention outcomes.

Differences Between Men and Women

Any examination of psychosocial factors and CHD must consider the possibility of sex and/or gender differences. In the case of depression, social isolation, and social support, the most frequently examined factor for which sex and gender differences have been explored is depression.

The point prevalence of major depression is documented to range from 15% to 25% in patients with coronary artery disease. In the Ontario Cardiac Rehabilitation Pilot Project,22 for example, the prevalence of depression at entry to cardiac rehabilitation was 17.9% (801/4,477 patients). Several authors have reported higher rates of depression in women than in men, especially after MI.13,22,23 Recently, Todaro et al24 reported on the current and lifetime prevalence of depressive disorders in men (n = 75) and women (n = 35) who were enrolled in cardiac rehabilitation. They found that a greater proportion of female versus male participants met diagnostic criteria for a depressive disorder during their lifetime (42.9%, n = 15 vs 18.7%, n = 14; P = .01). Likewise, there was a higher prevalence of current depressive disorder in female cardiac rehabilitation participants compared with males (28.6%, n = 10 vs 9.3%, n = 7; P = .02).

In terms of the consequences of depression in cardiac patients, Frasure-Smith et al25 found that depression after MI was a risk factor for 1-year mortality in both men and women; however, women were twice as likely to report post-MI symptoms of depression as men.

Sex differences have been reported in terms of psychosocial adjustment following MI. Brezinka and Kittel26 reviewed 9 studies comparing psychosocial adjustment after MI and 6 studies related to post-coronary artery bypass graft surgery or percutaneous coronary interventions in men and women. Eight of the 9 post-MI studies suggested that women do not cope as well psychosocially as men; they scored higher on psychosomatic symptoms, anxiety, and depression. The 6 studies comparing psychosocial adjustment after coronary artery bypass graft or percutaneous coronary intervention were inconclusive. As evidence accumulates, it appears that post-MI female patients represent a high-risk cardiac rehabilitation group for depression as an outcome of their cardiac event and that rehabilitative and secondary prevention interventions need to be adjusted accordingly.

With regard to social support and social isolation, the relationship between widowhood and excess mortality is striking, especially in the first year of living alone,27 and the size of one's social network has been found to be inversely related to mortality, independent of risk factors for heart disease.28 Women are more likely to be widows at the time of their cardiac event, and thus, may be at higher risk during the first year of recovery and rehabilitation. Additionally, persons who are depressed and have heart disease are a group that reportedly has poor social support networks.29 Lack of social support and depression are interrelated in a complex manner. In the (approximately) 20% of patients post-MI who are mildly to moderately depressed, a strong social support network ameliorates the effects of depression on cardiac mortality.6

In 2003, Davidson et al30 conducted a review of published studies on the experiences and rehabilitative needs of older women with heart disease. In their review of over 120 publications, they determined that women experience greater disability than men, are at higher risk of psychosocial distress, and have a greater need for social support, particularly, instrumental support.

Taken together, this evidence raises important considerations for cardiac rehabilitation and secondary prevention. First, systematic efforts to assess for depression, anxiety, and social isolation should be implemented for all patients, but special attention to women may be necessary. Distressed individuals should receive appropriate referral and treatment, and will likely need a higher level of monitoring to ensure adherence to their treatment or rehabilitation program. Peer support has been found to be a useful adjunct to the multifactorial rehabilitation interventions that are typically offered to cardiac patients. A facilitated peer support group for women with heart disease may provide an environment that enhances recovery,31 however, much more research that focuses on female cardiac populations is necessary before strong recommendations can be made.

Discussion and Implications

It is clear that depression, social isolation, and its possible derivatives, emotional loneliness and social loneliness, affect risk for, and recovery from, CHD in older adults. Research evidence related specifically to older adults remains sparse, however, widespread recognition of the impact of the changing population demographic is spurring new research in this important area. National guidelines for cardiac rehabilitation and secondary prevention in several countries have made recommendations related to psychosocial issues and are beginning to address them in the context of the older cardiac patient.

The Agency for Health Care Policy and Research32 in the United States made the following recommendation related to cardiac rehabilitation and psychological well-being: "exercise training is recommended to enhance measures of psychological functioning, particularly as a component of multifactorial cardiac rehabilitation." The Agency for Health Care Policy and Research statement regarding older adults is:

Elderly coronary patients have exercise trainability comparable to that of younger patients participating in similar exercise rehabilitation. Elderly female and male patients show comparable improvement. Referral to and participation in exercise rehabilitation is less frequent at elderly age, especially for elderly females. No complications or adverse outcomes of exercise training at elderly age were described in any study. Elderly patients of both genders should be strongly encouraged to participate in exercise-based cardiac rehabilitation.

These statements are consistent with recommendations made by the Heart Research Center, Victoria, Australia in their Best Practice Guidelines for Cardiac Rehabilitation and Secondary Prevention,33 and the Canadian Guidelines for Cardiac Rehabilitation and Cardiovascular Disease Prevention.34

In their Guidelines for the Management of Patients with Acute Myocardial Infarction,35 the American College of Cardiology and the American Heart Association stated "The psychological status of the patient should be evaluated, including inquiries regarding symptoms of depression, anxiety, or sleep disorders and the social support environment." The American Association of Cardiovascular and Pulmonary Rehabilitation statement on Core Components of Cardiac Rehabilitation/Secondary Prevention Programs36 recommends formal evaluation of psychological distress and identifies specific intervention strategies, including stress management, education, attention to need for social support, and referral to appropriate professionals for treatment of moderate to high levels of anxiety or depression. Such recommendations are also made in the Canadian Guidelines for Cardiac Rehabilitation and Cardiovascular Disease Prevention34 and the Best Practices Evidence Guide for Cardiac Rehabilitation37 produced by the New Zealand Guidelines Group. Although various international guidelines make clear statements about exercise and the older adult, the recommendations for psychological assessment and intervention are much more generic.

Fortunately, there is emerging research evidence to provide some direction for interventions that target psychosocial issues in older cardiac patients. Lavie and Milani38 found that both the prevalence and severity of depression dropped in older patients (mean age = 71 +/- 4 years) who took part in a 12-week exercise and education program after a major cardiac event.

Stewart et al39 tested the effect of a 12-week support intervention for post-MI patients and their spouses. Three types of support were provided: emotional, information, and affirmation. Participants reported positive effects of the intervention on coping, outlook, confidence, and spousal relationship.

Hildingh and Fridlund40 found that the type of patient who attended peer support groups after a cardiac event reported more health problems than nonattenders and scored higher on several dimensions of social support. Based on the work of Hildingh and Fridlund,40 one might speculate that a prerequisite for benefit from peer support groups is the availability of, and prior use of, social support networks in other aspects of life.

Several decades of research have shown a consistent relationship between social support, social isolation, and CVD; similarly, large amounts of evidence are accumulating regarding the relationship between depression and CVD. The challenge remains to plan and evaluate interventions which target either the contributing factors or the possible mediators of these relationships.

Both primary and secondary prevention of CVD require individual commitment to a healthy lifestyle and a high degree of involvement in self-management. Secondary prevention in the older adult provides a unique opportunity for nurses. Nurses are optimally positioned to facilitate management of the complex needs of older adults due to nurses' expertise in communication, their ability to understand and integrate biopsychosocial issues, and their skill in exploring sensitive topics related to emotions and support. Given the current state of evidence, nurses must take up the call to address these issues clinically with older adults and, where possible, should contribute to new research regarding ways to reduce or eliminate the negative sequelae associated with emotions and CVD.

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