Psychological and social factors in coronary heart disease

Abstract

More than six decades of empirical research have shown that psychosocial risk factors like low socio-economic status, lack of social support, stress at work and family life, depression, anxiety, and hostility contribute both to the risk of developing coronary heart disease (CHD) and the worsening of clinical course and prognosis in patients with CHD. These factors may act as barriers to treatment adherence and efforts to improve life-style in patients and populations. In addition, distinct psychobiological mechanisms have been identified, which are directly involved into the pathogenesis of CHD. In clinical practice, psychosocial risk factors should be assessed by clinical interview or standardized questionnaires, and relevance with respect to quality of life and medical outcome should be discussed with the patient. In case of elevated risk, multimodal, behavioural intervention, integrating counselling for psychosocial risk factors and coping with illness, should be prescribed. In case of clinically significant symptoms of depression and anxiety, patients should be referred for psychotherapy, and/or medication according to established standards (especially selective serotonin reuptake inhibitors (SSRIs)) should be prescribed. Psychotherapy and SSRIs appear to be safe and effective with respect to emotional disturbances; however, a definite beneficial effect on cardiac end-points has not been documented.

Key words::

• Anxiety
• behaviour
• coronary disease
• depression
• hostility
• life-style
• medication adherence
• social class
• social support
• stress (psychological)

Key messages

• Low socio-economic status, lack of social support, stress at work and family life, depression, anxiety, and hostility contribute both to the risk of developing coronary heart disease (CHD) and the worsening of clinical course and prognosis in patients with CHD.

• Psychosocial risk factors may act as barriers to treatment adherence and efforts to improve life-style in patients and populations. In addition, distinct psychobiological mechanisms have been identified, which are directly involved into the pathogenesis of CHD.

• Psychosocial risk factors should be assessed by clinical interview or standardized questionnaires, and relevance with the patient in respect to quality of life and medical outcome should be discussed. In case of elevated risk, multimodal, behavioural intervention, integrating counselling for psychosocial risk factors and coping with illness, should be prescribed.

• In case of clinically significant symptoms of depression and anxiety, patients should be referred for psychotherapy, and/or medication should be prescribed.

Introduction

Modern approaches to primary and secondary prevention of cardiovascular disease (CVD) stress the importance of assessing ‘total risk’ (1) in order to predict the incidence and the course of CVD better than by just taking single risk factors (e.g. serum cholesterol) into account. ‘Standard risk factors’ for CVD include older age, male gender, smoking, abnormal lipids, hypertension, and diabetes. However, after more than six decades of empirical research in the field of psychocardiology, most of which was done in coronary heart disease (CHD), there is convincing evidence that certain psychosocial factors contribute to the risk of CVD, even after statistical control for the effects of standard risk factors. Thus, leaving psychosocial risk factors unrecognized may lead to insufficient preventive and therapeutic efforts and further increase CVD burden. This narrative review will briefly summarize the most important findings and display possible biobehavioural mechanisms. Furthermore, several national and international guidelines on CVD primary and secondary prevention have incorporated recommendations on the management of psychosocial risk factors (1,2), which will also be summarized.

Psychosocial factors in the course and development of CHD

Several psychosocial factors influence both the risk of developing CHD and the worsening of clinical course and prognosis in patients with CHD. The following psychosocial factors have been identified (Table I):

Table I. Psychosocial risk factors in coronary heart disease.

Low socio-economic status

Lack of social support and social isolation

Stress at work and in family life

Depression

Anxiety

Hostility and anger

Type D (distressed) personality

Low socio-economic status

Multiple large prospective studies have shown that men and women with low socio-economic status (SES), defined as low education, low income, holding a low-status job, or living in a poor residential area, have an increased all-cause as well as CHD mortality risk (relative risk (RR) ∼ 1.3–2.0) (3–7). Even in young adults, modest inverse associations between some traditional risk factors and the SES of their parents have been observed (8).

Stress at work and in family life

According to a recent systematic review, there is moderate evidence that work-related stress, e.g. high psychological demands, lack of social support, and iso-strain are risk factors for incident CVD in men (odds ration (OR) ∼ 1.5) (9,10). Studies involving women were too few to draw firm conclusions (9).

But also conflicts, crises, and long-term stressful conditions in family life have been shown to increase CHD risk (hazard ration (HR) ∼ 2.7–4.0), especially in women (RR ∼ 2.9–4.0) (11,12).

Social isolation and low social support

Social support may act as a buffer towards chronic stress and enhance coping with illness. Recent systematic reviews confirm that people who are isolated or disconnected from others are at increased risk of dying prematurely from CHD. Similarly lack of social support leads to decreased survival and poorer prognosis among people with clinical manifestations of CHD (RR ∼ 1.5–3.0) (13,14).

Depression

Several systematic reviews and meta-analyses have shown that clinical depression and depressive symptoms predict incident CHD (RR ∼ 1.6) (15,16) and worsen its prognosis (OR ∼ 2.2–2.4) (17,18). In patients after myocardial infarction, a dose-response relationship between the severity of depression and worse outcome could be observed, with a 3-fold mortality rate in those most affected by depressive symptoms (19). Perceived social support seems to counteract the adverse effect of depression (20), whereas lack of support was found to reinforce its adverse effects (21). In older studies, enhanced risk in patients with depression may also in part have been due to adverse effects of tricyclic antidepressants (22,23).

Anxiety

Recent large epidemiological studies indicate that panic attacks increase the risk of incident cardiovascular events (HR ∼ 1.7–4.2) (24,25). I addition, generalized anxiety, phobic anxiety, and panic attacks may worsen the course of established CHD (OR ∼ 1.01–2.0) (26–28). But other studies have been inconclusive with regard to the direction, magnitude, and prognostic significance of anxiety. For example, a recent post-hoc analysis of a large prospective cohort study found lower all-cause mortality in anxious CHD patients (HR ∼ 0.7) (29). A higher mortality could only be observed in post-myocardial infarction (MI) patients with reduced systolic left ventricular function (HR ∼ 1.3), suggesting antipodal effects of anxiety on different subgroups of CHD patients (29). Nevertheless, two recent meta-analyses confirmed that anxiety as such is an independent risk factor for incident CHD (HR ∼ 1.3) (30) and for adverse events following myocardial infarction (OR ∼ 1.5–1.7) (31). However, so far no such meta-analytic evidence exists for anxiety observed in patients with chronic CHD (e.g. those with stable angina, post-percutaneous coronary intervention (PCI)/coronary artery bypass graft (CABG) patients or post-MI patients assessed more than 3 months after MI).

Hostility and anger

Hostility is nowadays considered to be the ‘pathogenic core’ of the former ‘Type A’ behaviour pattern. Hostility is a personality trait that is characterized by extensive experience of mistrust, rage, and anger, and the tendency to engage in aggressive, maladaptive social relationships. A recent meta-analysis has confirmed that anger-proneness and hostility are associated with an increased risk for cardiovascular events in both healthy and CHD populations (HR ∼ 1.2) (32). However, this effect is smaller than the one observed for anxiety and in particular for depression.

Type D personality

In contrast to depressive symptoms, which often occur in episodes, the so called ‘Type D (= distressed) personality’ involves an enduring tendency to experience a broader spectrum of negative emotions (negative affectivity, e.g. depressiveness, anxiousness, feeling tense, or annoyed) and to inhibit self-expression in relation to others (social inhibition). The Type D personality has been shown to predict poor prognosis in patients with CHD (OR ∼ 2.4–8.9), even after adjustment for isolated depressive symptoms, stress, and anger (33–36). From a clinical perspective, the Type D personality is close to the concept of dysthymic disorder according to the International Classification of Disease (ICD)-10, although studies on its diagnostic classification are lacking.

Clustering of psychosocial risk factors and biobehavioural mechanisms

In most situations, psychosocial risk factors do not occur in isolation from one another but tend to cluster in the same individuals and groups. For example, both women and men of lower SES and/or chronic stress are more likely to be depressed, hostile, and socially isolated (37,38).

Mechanisms that link psychosocial factors to increased CVD risk include unhealthy life-style (more frequent smoking, unhealthy food, and less physical exercise), increased health care utilization, and low adherence to behaviour change recommendations or cardiac medications (4,6,39–41). In addition, persons and patients with psychosocial risk factors such as depression and/or chronic stress show alterations in autonomic function (including reduced heart rate variability) in the hypothalamic pituitary axis and other endocrine markers (including insulin resistance), which affect haemostatic and inflammatory processes, and endothelial function (38,40). The neuroendocrine changes can also induce a state of heightened physiologic responsivity to acute stress, which interacts with chronic stressors and causes more adverse events (Figure 1).

Figure 1. Pathophysiologic mechanisms by which chronic stress and affective disorders promote atherosclerosis. From reference (40) with permission.

ANS = autonomic nervous system; SNS = sympathetic nervous system; HPA = hypothalamic–pituitary–adrenal.

Consequences for health care in patients and persons at risk for CHD

The tendency of psychosocial risk factors and biobehavioural mechanisms to cluster in the same individuals and groups has important implications for strategies to modify risk and improve quality of life. For example, as persons with high levels of negative affect are more likely to smoke, partly due to an antidepressant-like effect of cigarette smoke (42), attempts to help them quit smoking might be more successful if they include elements designed to reduce hostility and depression. Similarly, attempts to reduce the CHD risk in the socially disadvantaged might be more effective by incorporating training in skills that will reduce negative feelings and increase access to positive, supportive social ties as well as self-efficacy. In other words, behavioural interventions that reduce levels of psychosocial risk factors are likely to have broad benefits in terms of enabling people to be more successful in modifying unhealthy life-styles and reducing biological consequences of stress.

Assessment of psychosocial risk factors in clinical practice

The assessment of psychosocial factors in patients and persons with CHD risk factors is crucial as a means to stratify future preventive efforts according to the individual risk profile of the patient. Standardized measurements for depression, anxiety, hostility, SES, social support, or psychosocial stress are available in many languages and countries (43). Alternatively, a preliminary assessment of psychosocial factors can be made within the physicians’ clinical interview. For that purpose, European and national guidelines on CVD prevention recommend the following core questions for the assessment of psychosocial risk factors (1,2):

• Do you have no more than mandatory education? Are you a manual worker? (low SES)

• Do you lack control over how to meet the demands at work? Is your reward inappropriate for your effort? Do you have serious problems with your spouse? (work and family stress)

• Are you living alone? Do you lack a close confidant? Do you lack any person to help you in case of illness? (social isolation and lack of social support)

• Do you feel down, depressed, and hopeless? Have you lost interest and pleasure in life? (depression)

• Do you frequently feel angry over little things? Do you often feel annoyed about habits other people have? (hostility and anger)

A ‘yes’ in one or more questions indicates elevated risk, and relevance of psychosocial factors with respect to quality of life and medical outcome should be discussed with the patient.

Current guidelines do not include questions regarding symptoms of anxiety; however, increasing evidence on the impact of anxiety on CHD justifies additional screening for anxiety. Suitable questions on symptoms of anxiety can be derived from standardized instruments based on the Diagnostic Statistical Manual - fourth revision (DSM-IV) or ICD-10 criteria (such as the PHQ-4) (44). Questions like ‘Do you frequently feel nervous, anxious, or on edge?’, ‘Are you frequently unable to stop or control worrying?’ allow core symptoms of clinically relevant anxiety to be assessed. After positive initial screening, more specific questions regarding anxiety related to cardiac disease are mandatory (e.g. fear of getting an MI, panic attacks presenting with chest pain or palpitations, or phobic avoidance behaviour).

Although the Type D personality is usually measured by a self-rating questionnaire (i.e. the DS-14) (33), the underlying clinical phenomena (e.g. depressiveness, anxiousness, feeling tense, or annoyed) in combination with social inhibition (i.e. problems getting in contact with others and expressing oneself) can be assessed by interview. Suitable questions in clinical practice are: ‘In general, do you often feel anxious, irritable, or depressed?’ (with ‘yes’ indicating negative affectivity) and ‘Do you often share your thoughts and feelings with other people?’ (with ‘no’ indicating social inhibition).

Evidence for psychosocial risk factor modification programmes

Repetitive meta-analyses and systematic reviews have shown that several therapeutic and preventive intervention methods are available that counteract psychosocial stress and promote healthy behaviours. These interventions are likely to have beneficial effects on physiological risk factors and distress (45). Two recent meta-analyses and a more recent randomized controlled trial (RCT) have also shown their potential to prevent the progression of clinical CHD (45–47), especially in patients who achieved their proximal behavioural goals (45,48). In addition, there is evidence that intervention programmes should be individualized based on individual risk constellations and include gender-specific aspects (47,49).

Specific interventions to reduce depression, anxiety and distress

Several recent RCTs have specifically targeted depression in CHD patients. Coronary patients with clinically significant depression can safely and effectively be treated with psychotherapy (50–52) or selective serotonin reuptake inhibitors (SSRIs) (51,53). The marked improvement in quality of life achieved by these treatments justifies their routine use in depressed patients with CHD. In addition, a recent RCT has shown that telephone-delivered collaborative care for treatment of depression after by-pass surgery resulted in improved health-related quality of life, physical functioning, and mood symptoms (54).

Although a definite beneficial effect on cardiac end-points has not been documented, secondary analyses of a large multicentre RCT to decrease depressive feelings and improve social support in patients after MI found beneficial cardiovascular effects in white men (55), in patients who responded to antidepressant treatment (56), and in patients receiving a combination of cognitive-behavioural individual therapy and group training (57). In this study, the combined intervention was associated with a significant 33% reduction in cardiac events, while either individual or group therapy alone could not significantly reduce events (57). Results from other, non-randomized studies indicate that also SSRIs may have the potential to improve CHD prognosis in patients with (58) and without (59) previously documented CHD; however, one RCT in patients after MI failed to show such an effect (60).

Regarding anxiety, several psychosocial or multimodal intervention studies in patients with CHD have measured anxiety as a secondary outcome; however, results have been inconclusive. A recent meta-analysis by (45) has shown only small, insignificant effects compared to controls (r −0.11 versus −0.03). Hence, until now, only very few studies specifically targeted anxiety in CHD patients. For example, one RCT on a nurse-led, home-based intervention for patients after by-pass surgery has shown beneficial effects on anxiety, but the sample was too small, and the follow-up period was too short to demonstrate impact on cardiac events (61). While awaiting conclusive results that treating depression or anxiety will alter CHD prognosis, a prudent approach at present is to offer patients with clinically significant depression or anxiety treatment with psychotherapy and antidepressant/anxiolytic medication, especially SSRIs.

In addition to the treatment of mood symptoms, there are several other approaches to psychosocial intervention that have proved to be useful. Stress management programmes have repeatedly been shown to improve not only subjective well-being but also risk factor levels and CHD outcomes (45,46). In hostile CHD patients, a group-based hostility control intervention may lead not only to decreases in behaviourally assessed hostility levels but also decreased depression, resting heart rate, and cardiovascular reactivity to mental stress, as well as increased social support and satisfaction with life (62,63). For women with CHD, specific behavioural group treatments may be useful for reducing distress (46,49,64). Recently, a RCT from Sweden has shown that a group-based stress reduction programme for women with CHD may prolong lives independently of other prognostic factors (47).

Until now, few studies have focused on psychosocial risk beyond the individual perspective; however, results seem promising and merit further research. For example, work reorganizations aimed at improving autonomy and increasing control at work may result in improved social support and reduction in physiological stress responses. Hence, work stress reduction in managers and supervisors may have beneficial health effects not only on the target individuals but also improve perceived social support in their subordinates (65).

Conclusions

As there is convincing evidence that psychosocial risk factors contribute both to the risk of developing CHD and the worsening of the clinical course of CHD, preventive and therapeutic efforts should include strategies to identify and manage psychosocial risk factors in patients and populations. In clinical practice, psychosocial risk factors should be assessed by clinical interview or standardized questionnaires, relevance with respect to quality of life and medical outcome should be discussed with the patient, and appropriate interventions should be initiated. Specifically, multimodal, behavioural interventions, integrating counselling for psychosocial risk factors and coping with illness, have been shown to promote a healthy life-style, enhance quality of life, and improve cardiac prognosis. In case of clinically significant symptoms of depression and anxiety, patients should be referred to a specialist for psychotherapy, and/or psychotropic medication (especially SSRIs) according to established principles should be prescribed. Psychotherapy and SSRIs appear to be safe and effective with respect to emotional disturbances; however, a definite beneficial effect on cardiac end-points has not been documented.

But the feasibility of systematic screening for psychosocial risk factors and referral to adequate interventions in clinical routine remains a matter of uncertainty. Further education and training of physicians, and cardiologists in particular, how to screen and motivate patients for psychosocial treatment is clearly necessary. For that reason, special training courses have been developed in some countries, which are now available for cardiologists and other health care professionals (66). In addition, political and financial factors impeding the implementation of such preventive efforts, e.g. budget restraints regarding the physician-patient consultation process, have to be addressed (1).

Declaration of interest: The author states no conflict of interest and has received no payment in the preparation of this manuscript.