heart disease and stress

The impact of stress on physical health has been fairly well documented, with emerging research detailing possible pathways or mechanisms of action. Such research has a tremendous impact on disease prevention strategies and best practices in healthcare. One of the areas revealing the strongest connection between stress and physical health is cardiology, with a strong correlation between environmental, psychological, and psychosocial stress and the etiology or exacerbation of heart disease. The following five articles provide an overview of recent research into the link between stress and cardiovascular disease.

Cohen, B.E., Edmondson, D. & Kronish, I.M. (2015). State of the art review. American Journal of Hypertension 28(11): 1295-1302. Stress contributes to the etiology of cardiovascular disease, even in patients who had previously shown no other risk factors. Chronic stress—whether exposure to daily life stressors over time or the chronic stress associated with posttraumatic stress disorder—may be particularly damaging to heart health. Stress increases risk for heart disease and also results in poorer patient prognosis.

Possible mechanisms whereby psychological health impacts physiological health include autonomic nervous system and immune system activity, hemodynamics, and the hypothalamic-pituitary-adrenal axis: providing insight into the physiological links between mental states and cardiovascular health. In a systematic review of literature published in the American Journal of Hypertension, Cohen, Edmondson & Kornish (2015) showcase recent research on the connection between mental health in general and cardiovascular disease.

Both epidemiological studies and smaller-scale empirical research have “firmly established a connection” between cardiovascular health and specific mental health states linked to stress including depression, anxiety, and post-traumatic stress disorder. The authors summarize the findings from epidemiological and clinical studies detailing the specific physiological factors and biological mechanisms underlying the stress responses, detailing them for each of the relevant mental health conditions. The authors also provide details related to study methodology and research design to offer suggestions for future research on the relationship between stress and heart disease.

Generally, issues like blood pressure and inflammatory responses are particularly indicated as stress-related causal factors in heart disease. In fact, research shows that exposure to systematic daily stressors also increases the mortality rate from heart disease. Daily stressors have been shown to be causes of cardiovascular disease in general, and also associated with the risk factors that may lead to cardiovascular disease. According to the authors, there is an even stronger correlation between posttraumatic stress disorder and cardiovascular disease. The development of acute myocardial ischemia is of particular note.

Dimsdale, J.E. (2008). Psychological stress and cardiovascular disease. Journal of the American College of Cardiology 51(13): DOI: 10.1016/j.jacc.2007.12.024 The relationships between stress, heart health and cardiovascular disease are complex. Research can reveal the different impacts of acute versus chronic stress, with potentially different physiological responses to both of these types of stress. Some research also elucidates the connection between experiencing a stressful life event and specific heart-related issues.

There may in fact be different pathophysiological responses involved in acute stressors such as living through a sudden disaster versus chronic exposure to stress such as work-related stress. How stress directly affects the heart is an important area of research, too, shedding light on things like how stress adversely affects homeostasis or the central nervous system, which then in turn leads to cardiovascular disease. Effective stress management is therefore considered a critical component of heart health, with implications for healthcare practice.

In “Psychological Stress and Cardiovascular Disease,” Dimsdale (2008) provides a systematic review of literature on the relationship between stress and cardiovascular disease. According to Dimsdale (2008), there have been over forty thousand individual studies focusing on stress and heart disease: a strong indicator of the relevance of the issue for healthcare in general. Some of the studies point to direct correlations between heart health and “myocardial infarction, myocardial ischemia, and wall motion abnormalities,” according to Dimsdale (2008, p. 1237).

As research becomes more sophisticated in terms of isolating or pinpointing specific pathophysiological responses and mechanisms, it will become more possible for future researchers to identify either the best pharmacological or psychological treatment interventions that can improve coping mechanisms or reduce the impact that stress has on physiological pathways. The author also differentiates between acute and chronic stress.

As Dimsdale (2008) points out, effective coping strategies, genetics, and individual differences can all be mitigating factors that build resilience in persons who have been exposed to stressful events or who experience regular stressors. The author also points out research design and methodological issues that helps to clarify the causal relationships, and to suggest improvements to research reliability and validity. Johnson, J.V. & Hall, E.M. (2011). Job strain, work place social support, and cardiovascular disease: a cross-sectional study of a random sample of the Swedish working population.

American Journal of Public Health 78(10): 1336-1342. Some studies on the connection between heart disease and stress use experimental designs to show how specific types of stress impact physiological changes correlated with heart disease. Stress is a relatively generic term that should be qualified better in good research designs. For example, not all people react to the same situations in the same way. Some people perceive a situation as being stressful, a situation that others would not find stressful and vice-versa.

It is important to classify the types of stressors and individual responses to those stressors. Locus of control has been implicated as a stressor in the workplace, with social support systems being identified as a mitigating factor. In “Job Strain, Work Place Social Support, and Cardiovascular Disease,” Johnson & Hall (2011) use a cross-sectional research design to demonstrate the relationships between workplace environmental factors and cardiovascular disease prevalence.

The authors randomly selected over thirteen thousand subjects in Sweden, and used self-report measures to determine the workplace factors such as psychosocial support, psychosocial work-related demands, locus of control in the workplace, status or power, and perceived supervisory support. Prevalence ratios were assessed based on the Swedish Central Bureau of Statistics Survey of Living Conditions, which provides a systematic classification and coding design that can be used to determine heart disease prevalence. The authors also adjusted for age and other confounding variables.

The results showed that blue collar males were especially susceptible to stress-related heart disease, with low social or supervisory support and low perceived control particularly relevant issues. The findings show how specific social and psychological conditions can be precursors to stress, which in turn precipitates heart disease. Lavie, C.J., Menezes, A.R., de Schutter, A., et al. (2016). Impact of cardiac rehabilitation and exercise training on psychological risk factors and subsequent prognosis in patients with cardiovascular disease. Canadian Journal of Cardiology 32(10): S365-S373.

When it comes to research on stress and cardiovascular disease, one of the most important driving purposes in research is to generate a reliable body of evidence that can be used in preventative care and nursing practice. It is important to have on hand a series of published reports indicating which specific lifestyle factors improve resilience or which mitigate the stress responses, thereby improving cardiovascular health and reducing morbidity and mortality rates. One of the most well-known and clinically established variables in mitigating stress and promoting heart health is exercise.

In fact, exercise can be used as an intervention for persons who already have cardiovascular disease, to improve prognosis. Whether exercise works directly on heart health pathways, or more indirectly on first improving psychological wellbeing and then subsequently improving cardiovascular health, remains to be seen. In “Impact of Cardiac Rehabilitation and Exercise Training on Psychological Risk Factors and Subsequent Prognosis in Patients with Cardiovascular Disease,” the researchers evaluate several psychological risk factors associated with cardiovascular disease.

The authors also assess cardiac rehabilitation and exercise training programs for their therapeutic benefits in patients with cardiovascular disease, as many of these programs have been shown to be especially effective for promoting cardiovascular fitness. Furthermore, exercise training programs have been shown to reduce risk factors linked with heart disease such as lipids, glucose levels, blood pressure, and inflammation. Meta-analyses of the research have revealed a strong connection between exercise and reduced morbidity and mortality rates of cardiovascular disease, according to Lavie, Manezes, de Schutter, et al., 2016).

This study is another review of literature on the connection between stress and heart disease, focusing exclusively on the potential for exercise regimes to reduce risk factors, improve resilience, and promote better prognosis in patients who already have been diagnosed with cardiovascular disease. Steptoe, A. & Kivimaki, M. (2013). Stress and cardiovascular disease. Annual Review of Public Health 34(2013): 337-354. Research on stress and heart disease can focus on any number of disease pathways including those linked to the inflammatory response, the autonomic immune responses, and hormonal system responses.

Studies have shown that even single exposures to stressful events can trigger a cardiac event in some individuals, but not others, requiring further investigation into the risk factors that make some people more susceptible than others to developing cardiovascular disease. It is important to isolate the physiological mechanisms involved in cardiovascular disease before jumping to conclusions about the ways stress impacts cardiovascular health in general.

While the relationship between stress and cardiovascular health is practically indisputable, less is known about how the relationship works and what intervening variables are most important. In “Stress and Cardiovascular Disease,” Steptoe & Kivimaki offer an overview of literature for the Annual Review of Public Health. Unique in this study is a focus on the “hypothalamic–pituitary–adrenocortical and sympatho–adrenomedullary axes,” p. 337). These axes refer to factors like the release of stress-related hormones like cortisol.

The researchers identify types of psychological stress, including both acute and chronic types, and discuss related concerns like inflammation, hemostasis, and the immune system as regulatory mechanisms helping the body to cope with stress. Coping with stress is essential for helping to reduce coronary strain, and also to reduce the strain placed on other physiological systems. One of the main findings in this study is that chronic work-related or personal life-related stressors leads to an almost fifty percent increase in coronary heart disease, albeit with some methodological concerns.

Long-term, chronic stress is also associated with higher mortality rates due.