Across all age groups, subjects with stable CAD who suffer angina attacks are characterized by lower HRQoL than healthy individuals [3]. The QoL of such CAD patients is 15–30% lower than that of healthy individuals of identical age, and is also lower than that of subjects with arterial hypertension or DM only [12]. Conversely, patients with CAD and concomitant diseases such as DM or chronic obstructive pulmonary disease (COPD) are characterized by significantly lower HRQoL than CAD patients without concomitant health problems [13]. In general, it is accepted that the degree of advancement of CAD (in terms of progressive atherosclerotic changes) is correlated with decreased HRQoL. However, certain studies, carried out using select questionnaires commonly used to measure the HRQoL of CAD patients, did not demonstrate such a strong relationship. Thus, it seems that poor physical functioning, most often caused by angina symptoms (mainly pain and breathlessness) is not the only determinant of HRQoL in CAD.

In CAD patients, similar to those with hypertension, women reported worse general HRQoL than that observed in men [14, 15]. It is well known that women experience coronary heart disease in a different way to that experienced by men. Presentations of cardiac pain for women can include vague signs and symptoms such as extreme fatigue, discomfort in the shoulder blades, and shortness of breath. Women have a higher prevalence of functional disability and a lower prevalence of obstructive coronary heart disease (as evidenced by coronary angiography) than men [16]. The paradoxical sex difference in which women have a lower prevalence of anatomical CAD but worsening symptoms, ischemia and outcomes appears to be linked to a sex-specific pathophysiology of coronary reactivity, and includes microvascular dysfunction, which is more prevalent in women [17]. Compared with men, the reduction in the perception of HRQoL may even reach 10–20% in women [18]. Nevertheless, differences have not been found between men and women with CAD in terms of self-rated health, which has been reported by both sexes as being “average”. However, more female patients than male patients feel that their everyday activities are negatively affected by CAD symptoms. Also, more female patients than male patients feel that these restrictions in everyday activity resulting from CAD have increased in the past 6 months [2]. Poor self-rated health and negative attitudes concerning illness lead to decreased HRQoL in psychological and physical dimensions. It has been reported that depression symptoms have a greater impact on the HRQoL of women with post-myocardial infarction compared with men 1 year after a cardiac incident.

Poorer self-rated health status not only has scientific value, but also has important clinical utility because it plays a part in the prognosis of women with CAD. Data from the WISE study confirmed that women with suspected myocardial ischemia who rated their health as “poor” (hazard ratio (HR): 2.1) or “fair” (HR: 2.0) experienced significantly shorter times to major CVD events compared with women who rated their health as “excellent” or “very good”. In the WISE study, self-rated health predicted major CVD events independently of demographic factors, CVD risk factors, and angiography-defined disease severity [19].

Westin et al. [14] studied 400 subjects with CAD coronary after their first cardiac incident. They found that the HRQoL of women 1 month after the cardiac incident (i.e., measuring general health, anxiety, depression, self-esteem, sexual health, arrhythmia) as well as 1 year later (i.e., measuring general health, anxiety, depression) was lower than in men. Additionally, 19–45% of those studied recorded worsening HRQoL after 1 year. Careful attention should be paid to the significantly worsened HRQoL of women with CAD if undertaking the secondary prevention of SA.

Several theories have arisen concerning the sex-dependent differences in HRQoL in CAD patients and the general population. van Jaarsveld et al. [20] discovered that lower HRQoL in women suffering from CAD was explained by their greater sensitivity to changes in HRQoL resulting from increased restrictions in physical and social activity, which brought about heightened levels of stress and frustration. That finding suggested that psychological distress and role pressure were characteristic of women with CAD. A lower level of education was an additional factor negatively influencing the HRQoL of women with CAD. In the WISE study, in which the primary endpoint was evaluation of the independent contribution of socioeconomic factors on the estimation of time to cardiovascular death or myocardial infarction (MI), 819 women were enrolled and referred for clinically indicated coronary angiography. With respect to socioeconomic factors, income remained a significant predictor of cardiovascular death or MI in risk-adjusted models that controlled for angiographic coronary disease, chest-pain symptoms, and cardiac risk factors [21]. It was suggested that QoL would be more strongly associated with social support among women than in men with CAD.

Younger (i.e., aged < 55 years) male and female subjects with CAD report significantly lower self-rated health than their older counterparts. This could be because coronary disease restricts younger people from fulfilling their (usually active) professional and social roles. Advanced age is usually accompanied by less physical activity. Hence, minimal cardiac pain after percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) are tolerated better by older patients as opposed to more physically active younger patients. Older individuals (especially women after menopause) have less knowledge about CAD and, compared with younger individuals, take less active interest in their own health, which may influence HRQoL [22].

Atypical cardiac pain experienced by women also leads to misunderstanding of the warning signs and symptoms of MI or exacerbation of stable ischemic heart disease. Moreover, women do not recognize the threat of CAD (even if there is a significant family history) and delay seeking healthcare for signs of acute MI [16].

As in other CVDs, stark differences in HRQoL can be found between subjects with CAD and their families. Men with CAD often exaggerate the restrictions placed on them by their illness, and have a tendency to reduce their level of family and social activities. Also, family members often do not recognize the health problems of individuals with CAD. Conversely, healthy men who are partners of women with CAD tend to overstate the everyday functional restrictions of their partners. They exhibit overprotective behavior, often looking to restrict the activity of women who, as a result, feel even more “sick”.

An additional factor is the psychological state and manner in which patients interpret changes to their health status. Patients who are accommodating and approach life in an optimistic manner rate their symptoms as less burdensome than do pessimistic patients, even during anginal pain [23]. An optimistic outlook (“positive affect”) is associated with significantly higher HRQoL in patients subjected to different invasive procedures for treating CAD (e.g., CABG, PCI) [24]. Such an attitude is also derived from patient compliance with recommendations for therapy stated by the attending physician, as well as the patient’s opinion of treatment effectiveness. On the other hand, Pelle et al. reported that CAD patients with a lack of positive affect (“anhedonia”) reported poorer health status and higher levels of somatic and cognitive symptoms. Somatic and cognitive symptoms differed as a function of anhedonia over time, but health status did not [25]. In another study published recently, > 1,700 participants were observed for < 10 years [26]. In this large prospective, population-based survey, positive affect (defined as the experience of pleasurable emotions such as joy, happiness, excitement, enthusiasm) was associated with a reduced risk of incident CAD independent of negative affects (depressive symptoms, hostility, anxiety). That finding underlined the protective effects of positive affect on physical health and the prognosis.

More advanced stages of chronic CAD often lead to an increased risk of MI, which is accompanied by heightened emotional stress. However, after a few months, most post-MI patients return to a stable psychological state and optimal physical functioning [27]. In ≈25–30% of such patients, a constant feeling of uneasiness concerning their health remains and/or depression develops, leading to decreased HRQoL. It has been demonstrated that the negative influence of MI on HRQoL more frequently affects younger patients (< 55 years old) and may even last < 2 years after the incident.

In the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO-I) Angiographic study, it was confirmed that, 2 years after MI, left ventricular ejection fraction (LVEF) correlated well with post-MI HRQoL (i.e., the lower the LVEF, the lower the HRQoL) [28]. Carrying out psychological tests and observing patients after MI allows the future course of coronary disease to be predicted. Choosing appropriate treatment (including lifestyle management) improves the prognosis and allows for a quicker return to normal activity. Schweikert et al. analyzed data from the Monitoring Trends and Determinants in Cardiovascular Disease (MONICA)/Cooperative Health Research in the Region of Augsburg (KORA) Myocardial Infarction Registry in Augsburg, Germany. That registry contains ≈2,950 patients, and they confirmed that MI survivors had a significant reduction in HRQoL (measured with the EQ-5D VAS questionnaire) compared with the general population [29]. In this study, the main predictors of lower HRQoL were older age, DM, obesity, current smoking, and experience of re-infarction. Having a heart attack at a young age (45–54 years) was particularly devastating for HRQoL: in young survivors, MI decreased HRQoL to the level of QoL observed in the general population 20 years later [29].

Symptoms of depression and anxiety are important factors influencing HRQoL in CAD. It is estimated that among patients with stable CAD, 25–45% at some point require pharmacological therapy for depression [30]. This group is even greater among post-MI patients and those with CHF. Long-term clinical studies have confirmed that individuals with CVD also suffering from depression have a 3.5-fold greater risk of death 18-months after MI than individuals without depression. Newer data further describe the influence of depression which presents after acute coronary syndrome (ACS) or during hospitalization due to ACS. In such cases, depression not only progressively decreases HRQoL, but also increases the risk of cardiovascular death < 5 years after an acute cardiovascular event [31].

Hospitalization due to coronary disease is another factor associated with reduced HRQoL in certain patients. It has also been found that individuals with a reduced level of social support (material or emotional) more often present with depression and an increased level of aggression 1 month after angiographic diagnostic testing. This relationship exists irrespective of sex, age, and degree of CAD advancement.

Another study in a random group of 250 patients with CAD measuring HRQoL the Cardiac Health Profile (CHP) and the EQ-VAS questionnaires found cognitive dysfunction to be the strongest determinant of HRQoL [32]. Cognitive dysfunction (measured in terms of memory, ability to learn, and concentration) explained 43% of differences in these questionnaires and influenced HRQoL to a greater extent than a breakdown in physical and psychological wellbeing [32]. Moreover, the degree of cognitive dysfunction was independent of the CCS class presented by the patients.

Data obtained from the Translational Research Investigating Underlying Disparities in Recovery from Acute Myocardial Infarction: Patients’ Health Status (TRIUMPH) Registry in the USA have shown that cognitive impairment without dementia (CIND) occurs in > 50% of older adult survivors of acute MI [33]. Moreover, in older CAD patients (mean age, 73 years), CIND was associated with less invasive care, less referral and participation in cardiac rehabilitation, and worse riskadjusted 1-year survival.