The Impact of Cardiac Rehabilitation on the Level of Anxiety and Symptoms of Depression in Patients after Coronary Revascularization

Cardiovascular disease (CVD) is one of the most important causes of morbidity and mortality in Europe and the US [1, 2]. It looks similar in the case of Poland [3]. There is also a large variability between different European countries. In highly developed countries, incidence has remained stable or has slightly decreased in recent years. However, in developing countries, incidence is increasing continuously. CVDs are also an important reason for hospitalization and the development of disability, causing depletion in the labor market [2]. Among cardiovascular diseases, ischemic heart disease is the most important cause of almost 20% of deaths. Ischemic heart disease (IHD), and especially coronary artery disease (CAD) is a dynamic process initiated by the formation of atherosclerotic plaques within the coronary arteries, causing systematic reduction of their lumens, and giving rise to episodes caused by rupture of these plaques and the formation of an acute thrombotic event. It may cause complete occlusion and myocardial necrosis. Due to the different pathogenesis and clinical manifestations, coronary artery disease can be divided into acute coronary syndromes (ACS) and chronic coronary syndromes (CCS) [4].

There are many risk factors for coronary artery disease, both nonmodifiable, such as age, gender, or genetics, and reversible, including hypertension, lipid disorders, diabetes, and smoking [5]. Low socioeconomic status and a wide range of emotional events and mental disorders, including depression, anxiety symptoms, and acute or chronic stress are also important risk factors for CVD. Stressful situations, both in professional and personal life, can directly contribute to the release of acute coronary syndrome. These can include very different factors, including strong negative emotions or exposure to disasters [6]. The risk of a heart attack increases by 21 times in the first 24 hours after the death of a loved one and decreases gradually over the following days [7]. Panic and anxiety attacks also increase the risk of acute coronary syndrome [8]. Anxiety itself is an independent risk factor for cardiac events and cardiac mortality after acute myocardial infarction [9, 10, 11].

Depressive disorders have many implications in the course of IHD. On the one hand, depression can be treated as a risk factor that significantly increases the possibility of a heart attack. On the other hand, the co-occurrence of depression intensifies the course of cardiovascular diseases [12]. In patients who have had a myocardial infarction, the co-occurrence of depression significantly impairs the results of treatment and increases the risk of repeated cardiovascular incidents [13]. In their meta-analysis, Nicholson et al. showed that patients with depression suffering from IHD have a 60% higher risk of dying from cardiologic causes compared to the general population of patients with IHD [14].

IHD treatment is a comprehensive process covering pharmacological methods, intravascular revascularization, coronary artery bypass surgery (CABG) and nonpharmacological methods, including comprehensive cardiac rehabilitation (CR) [15, 16]. Recently, revascularization procedures, both endovascular and surgical, have become very important methods of treatment. They are performed both in the treatment of acute coronary syndromes and in chronic coronary syndromes. Revascularization procedures should be part of a comprehensive secondary prevention strategy aimed at modifying risk factors and introducing lasting changes in patients’ lifestyles. Cardiac rehabilitation is an integral part of this procedure. It usually includes physical training, treatments conducive to risk factor modification, education, and psychological support [5]. It improves quality of life, reduces distal mortality, and reduces the frequency of hospitalization [15, 17].

The aim of the study was to assess the impact of three weeks of stationary cardiac rehabilitation on the level of anxiety and symptoms of depression in patients with coronary heart disease after interventional cardiology or surgical coronary revascularization.

The eligibility criterion for participation in the study was the condition after recent acute coronary syndrome – myocardial infarction treated interventionally with primary coronary angioplasty, or after urgent coronary artery bypass surgery. Participants underwent early cardiac rehabilitation in stationary conditions. Patients were in the day ward at the Center for Early Cardiac Rehabilitation in Łódź. They participated in 3-week rehabilitation stays. Based on the medical documentation, basic information was obtained regarding the participants’ past medical history, including the presence of comorbidities, and anthropometric data regarding place of residence, education, and any addictions.

All qualified were tested twice: at the beginning (first or second day) and at the end (discharge date) of rehabilitation using the Beck Depression Inventory (BDI) [18, 19, 20], as well as the Spielberger’s State-Trait Anxiety Inventory (STAI) [21, 22]. BDI is used to assess the occurrence of depressive symptoms. It is a tool used in the diagnosis of depression or for monitoring the effectiveness of treatment for depression. This test consists of 21 questions that relate to the main symptoms of depression. The patient fills in the answer sheet by himself, choosing one of 4 variants, which are scored from 0 to 3 points. The final score is calculated using the sum of all points, where a score of 0–10 means no depression, 11–27 means moderate depression, and 28 or more means severe depression [22].

The State-Trait Anxiety Inventory (STAI), developed by C.D. Spielberger, aims to measure the level of anxiety as a feature and as a condition. It consists of two scales, each containing 20 statements. The first, STAI-X1, is used to study anxiety state, and the second, STAI-X2, checks for anxiety features. The respondent has to decide on a scale of 1 to 4 how a given sentence matches his current state. We read the results using the appropriate key, which gives two separate solutions for STAI-X1 and STAI-X2. Raw performance norms range from 20 points, which means low anxiety, to a maximum of 80 points. After the initial analysis, the results can also be given in stens (standard ten score). A score of 1 to 4 sten means low anxiety, 5 to 6 medium, and 7 to 10 high anxiety [23].

In the statistical analysis, the Shapiro-Wilk test was used to assess the normalcy of distribution of obtained results. In the case of a distribution close to normal, the Student’s t-test was used to assess the significance of differences between the studied variables. For non-normal distribution, nonparametric ANOVA, Kruskal-Wallis rank test, Mann-Whitney and Wilcoxon tests were used. The results are presented as the mean and standard deviation and the median with min/ max values. To show the presence of correlation between these, the Spearman rank correlation test was used.

Written conscious informed consent was obtained from all the participants. The study was performed in agreement with the ethical guidelines of the 1975 Declaration of Helsinki. The consent of the local bioethics commission was obtained for the research. All authors declare no conflicts of interest.

The study involved a randomly selected group of 40 patients, including 18 women and 22 men with coronary artery disease, after revascularization treatment. The participants’ age was on average 70.75 years, and ranged from 49–85 years. The reason for admission to cardiac rehabilitation for 67.5% (27 patients) was for interventional treatment of myocardial infarction, and in 32.5% (13 patients) it was urgent CABG. In terms of education, 15% were characterized by primary education, 40% upper secondary education, 27.5% at postsecondary level and, finally, 17% of patients had a university education. Only 3 patients (7.5%) had no additional diseases. Most of the respondents (37 participants, or 92.5%), were characterized by the coexistence of diseases in addition to coronary artery disease. Of these, 30% had one additional disease, 62.5% 2 to 3, and 7.5% had over 3 comorbidities. The most common comorbidities were hypertension – 27 participants (67.5%) – and heart failure – 24 participants (60.0%). The distribution of the individual accompanying diseases is shown in Figure 1.

Figure 1

Patients prior to the commencement of cardiac rehabilitation were characterized by varying levels of symptoms of depression assessed on a Beck scale, as well as anxiety assessed by the STAI form, treated as both a condition (STAI-X1) and features (STAI-X2).The level of depression averaged 14.55 ± 6.47 points. Before rehabilitation, a total of 26 patients (65%) obtained a BDI score above 11, of which 2 patients had above 27 points, for severe depression. In contrast, 14 patients (35%) were assessed as free from depression. At the end of the rehabilitation, none of the assessed persons was included in the group of severe depression, and only 9 persons (22.5%) obtained a result above 11 points. The average Beck scale result was statistically significantly higher in women compared to men and was 17.94 ± 7.07 vs 11.78 ± 4.40, respectively; p <0.05. The average score for the entire group of patients was 8.28 ± 5.26 and was statistically significantly lower than the baseline p <0.001. Similar differences occurred in the group of women 17.94 ± 7.07 vs 10.56 ± 5.90 at p <0.001 and men 11.78 ± 4.40 vs 6.41 ± 3.88 at p <0.001. These data are presented in Table 1. The Beck scale result before and after rehabilitation did not correlate with age or duration of the disease, as well as with the presence of additional diseases, including diabetes and heart failure, and smoking. It did not differ significantly depending on the reason for the rehabilitation.

In the case of the STAI form assessing the level of anxiety, both as a condition and trait, no differences were observed depending on sex (Fig. 2), age, duration of the disease, or other assessed parameters. Persons before rehabilitation were characterized by medium and low levels of anxiety both as a condition and as a trait. It was STAI-X1 – 31.80 ± 7.24 and STAI-X2 – 35.98 ± 8.29, respectively. At the end of the rehabilitation period, it was statistically significantly reduced to STAI-X1: 26.40 ± 6.30 and STAI-X2: 29.80 ± 6.57 at p <0.001. Also in relation to separate groups of men and women, similar signifi cant changes were noted; they are listed in Table 1. Low levels of anxiety were found in 29 patients, and 11 patients had moderate anxiety. Values on the STAI-X1 scale, both at the beginning and at the end of rehabilitation, varied significantly depending on the number of comorbidities. It was the lowest in the group of patients with one comorbid disease (p <0.05) (Fig. 3). There was a strong positive correlation between anxiety assessed as a condition and as a trait, both at the beginning (R = 0.88; p <0.001) and at the end of rehabilitation (R = 0.86; p <0.001). The results are shown in Figure 4. The level of anxiety strongly correlated positively with the presence of depressive symptoms. This happened at the beginning – for anxiety as a condition (R = 0.76, p <0.001) and features (R = 0.70; p <0.001), respectively, and at the end of rehabilitation – for anxiety as a condition (R = 0.76; p <0.001) and features (R = 0.70; p <0.001). After the rehabilitation, the level of anxiety as a trait also positively correlated with the age of the patients (R = 0.36; p <0.05), which indicates its severity increasing with age.

Figure 2

Figure 3

Figure 4

Treatment of coronary heart disease is a long-term process that covers almost all of life after diagnosis. Its main goal is to extend the patient’s life, and an important role is also to improve the quality of life of patients. It has been proven that increased levels of anxiety and depression significantly affect both therapeutic goals. Revascularization treatment results in both life extension and reduction of IHD symptoms. Nonetheless, revascularization alone may exacerbate the symptoms of depression, compared to pre-CABG, or may not improve symptoms of pre-existing disorders [23, 24, 25].

Szczepańska-Gieracha et al. [26] reports that among 50 subjects after CABG, the average level of intensity of depression symptoms on the Beck scale before the rehabilitation was 14.4±7.8. Women were characterized by a higher level of depression. At the end of the rehabilitation period, the severity of symptoms assessed in BDI statistically significantly decreased. This was analogous to the results of our own research, in which at the end of rehabilitation the severity of depression symptoms significantly decreased in each of the assessed subgroups, also regardless of gender. In our study, the level of BDI did not depend on the cause of cardiac rehabilitation, that is, CABG surgery and interventional treatment of ACS. The STAI severity of anxiety was similar. Persons starting rehabilitation were characterized by an analogous level of anxiety both as a condition and features, as in the study by Szczepańska-Gieracha et al. It also strongly correlated positively with the level of depression. The use of typical early cardiac rehabilitation resulted in a significant reduction of these disorders. Moreover, a positive correlation between the severity of anxiety and the age of patients was revealed, which would suggest an increase in the level of anxiety with age. It was also confirmed that the level of anxiety as a condition is the lowest in Figure patients with only one comorbid disease and increases with their increasing number.

Zhang et al. [27] in a prospective study compared the effect of intensive rehabilitation on various aspects of life of patients after coronary revascularization, including anxiety and depression, using the Hospital Anxiety and Depression Scale (HADS). After six months of follow-up, persons undergoing cardiac rehabilitation had significantly fewer symptoms of depression and anxiety compared to baseline. In addition, the decrease in anxiety and depression was significantly greater in these persons compared to the group who had not undergone cardiac rehabilitation. What’s more, reducing depression and anxiety had a positive impact on the overall quality of life in these persons. Other reports emphasize that cardiac rehabilitation that reduces depression symptoms and anxiety levels has a positive effect on patients’ attitudes towards further treatment and further life plans and professional activity [28]. Slightly different results 4were . obtained by Dragunajtys-Sudoł, who examined the impact of 24-day cardiac rehabilitation in the conditions of a sanatorium, using the questionnaire Scale for Assessment of Psychological Rehabilitation Effects (SOPER) [29]. Although after 24 days of rehabilitation, the severity of anxiety, similar to our own study, has decreased significantly, however, the attitude of the subjects towards therapy and towards work and life goals has deteriorated. These results were different from those obtained by Zhang et al., which can be partly explained by the time of inclusion in CR. In the case of Dragunajtys-Sudoł, there were patients undergoing rehabilitation only 6 months after coronary revascularization, they had not been rehabilitated before, unlike in Zhang et al. and in the authors’ own study. This may indicate the need to include persons as soon as possible after coronary interventions into the cardiac rehabilitation program; this brings about the best results. This approach is confirmed by a report by Dudek et al. regarding patients undergoing elective coronary artery surgery [30]. Among these patients, assessed on the day before the PCI procedure, the baseline level of BDI depression symptoms was 13.3±8.0, and the value above 11 points was found in 48% of them. One month after surgery, there was a significant improvement, with a reduction of BDI to 9.5 ± 8.0 (p<0.01), and the percentage of patients with a depression score decreased to 29%.Unfortunately, in further follow-up after 6 and 12 months, the BDI again rose to near baseline. In addition, in some patients who did not have symptoms of depression in the first determination, the BDI value increased significantly, enabling its diagnosis. Also in our study we found a high percentage of patients with a BDI score indicating depressive disorders covering 65% of patients, which at the end of rehabilitation decreased significantly to 22.5%. There are two main differences between the work of Dudek et al. and own research. Patients in the analysis by Dudek et al. were stable and underwent elective coronary revascularization, while our patients underwent PCI due to acute myocardial infarction or underwent urgent CABG. This may explain a higher proportion of patients with depression symptoms, although the average BDI score was similar at study entry 14.55±4.47 vs 13.3±8.0. In both cases, after about a month (in our case after the end of CR), the BDI index significantly decreased. Further observation brought a renewed increase, which we could not observe in our patients. The important difference is that our patients were subjected to CR, and in the Dudek et al. study they were not. So perhaps the fact that the symptoms of depression increase again and appear in patients who are initially free of them, may be associated with a lack of CR. This thesis may be too far-reaching, and therefore it requires further investigation. Richards et al. [31] point to the need to implement or intensify psychological intervention during rehabilitation after treatment of ACS. In her opinion, this translates into improved treatment efficiency and reduces depressive symptoms. The beneficial effect of CR is also described in the case of other cardiovascular diseases treated surgically and also affects older patients. Völler et al. [32] demonstrated a significant reduction in depressive symptoms and anxiety levels as a result of cardiac rehabilitation in patients with aortic stenosis, both after classical aortic valve replacement surgery and after intravascular intervention (TAVI). He indicates that the elderly – the primary subjects of TAVI – significantly benefit from cardiac rehabilitation in reducing depression symptoms and anxiety levels.

On the basis of the above-mentioned observations and our own research results, it can be concluded that cardiac rehabilitation, especially that which also includes psychological intervention, contributes to a significant reduction in the level of anxiety and depression symptoms. The earliest possible implementation of these interventions can be expected to be most effective and to contribute to reducing important risk factors for coronary reoccurrence and hospitalization and thus cardiovascular mortality. It also contributes to the reduction of care costs, including for the elderly. The precise clarification of all aspects of the impact of CR on care costs and prevalence due to anxiety disorders and depression requires further investigation.