Psychosomatics 39:30-37, February 1998
© 1998 The Academy of Psychosomatic Medine
Perioperative Anxiety and Depression in Open-Heart Surgery
Guy Vingerhoets, Ph.D.
Received September 17, 1996; revised February 5, 1997; accepted March 18, 1997. From the Department of Psychiatry and Neuropsychology, University Gent, Belgium. Address reprint requests to Dr. Vingerhoets, Department of Psychiatry and Neuropsychology, University Hospital Gent 4K3, De Pintelaan 185, B–9000, Gent, Belgium.
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ABSTRACT
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Eighty patients completed state-anxiety and depression inventories on the day before, 7 days after, and 6 months after open-heart surgery. The patients with high, moderate, or low anticipatory anxiety still had relatively high, moderate, and low anxiety, respectively, in the postoperative period, supporting the linear relationship between preoperative and postoperative arousal. Omitting the items on somatic-vegetative complaints from the global depression score reveals that cardiac surgical patients do not experience significant postoperative changes in depression related to cognitive-affective symptoms. The preoperative assessment of emotional arousal significantly predicts the level of emotional distress after surgery.
Key Words: Open-Heart Surgery • Heart Surgery • Anxiety • Depression • Cardiac Surgery • Stress • Surgery
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INTRODUCTION
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Impending surgery is a stressful event that triggers specific emotional, cognitive, and physiological responses of a patient.1, 2 The amount of stress experienced is usually measured by the level of anxiety reported by the patient, and several studies have indeed shown increased anxiety scores in presurgical patients.3–5 The amount of reported anxiety depends on gender,6, 7 age,7, 8 and the motives for surgery.3 Extensive surgery or surgery with an uncertain outcome also produces more anxiety than surgery with relative little ambiguity about the course of events.7, 9, 10 Because open-heart surgery is an extensive operation with—at least for the individual patient—a relative uncertain outcome, studies on the experienced perioperative stress also found elevated anxiety scores in cardiac patients.11–15 Many presurgical patients also experience depressive symptoms that have been reported to increase after the operation.14, 16, 17 Unfortunately, the medical and paramedical staff of the surgery wards do not have the time, nor the training, to adequately deal with the patients' emotional distress. Recent research, however, indicates a negative relationship between preoperative psychological status and recovery, underlining the importance of emotional factors in medical treatment.18
The aim of this study is to offer a prospective view on the incidence and course of self-reported perioperative anxiety and depression. A better understanding of the kind and clinical course of perioperative stress in patient subgroups can improve the selection of patients who could benefit from appropriate treatment of psychological distress. The postoperative anxiety scores in patients with high, moderate, and low levels of preoperative anticipatory anxiety will be investigated to test the (curvi)linear hypothesis on the relation between preoperative and postoperative affective arousal.4, 19 It has been hypothesized by Janis19 that patients with either too high or too low preoperative anxiety will experience more emotional problems after surgery. Janis suggested that patients showing an average "normal" anticipating anxiety could most adequately do their "work of worrying" and experience fewer emotional disturbances after surgery.19 In contrast to this curvilinear relationship between preoperative and postoperative affective arousal, other self-report data describe the relation as linear, with high preoperative anxiety levels associated with the highest postoperative levels.4
A second question that will be addressed in this study concerns the effect of somatic items in depression inventories. Besides cognitive and affective symptoms, depression questionnaires frequently investigate somatic and vegetative symptoms associated with depression, such as weight loss, loss of appetite, insomnia, and fatigability. Medical patients, especially if they underwent invasive surgery, can have similar vegetative and somatic symptoms in the postoperative period that are unrelated to depression. Several studies have advocated the use of the nonsomatic items to differentiate between clinically depressed and nondepressed hospitalized patients with chronic medical illnesses.20–23 In this study, it will be evaluated whether the alleged increase in postoperative depression can be attributed to the increase of somatic complaints of the medically ill that are picked up by the somatic items of the depression questionnaire.
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METHODS
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All inpatients who were scheduled to have nonemergency cardiac surgery at the Center for Cardiac Surgery of the University Hospital Gent (Belgium) were considered for inclusion in the study, which was conducted in 1991–1994. Inclusion criteria were fluency in the testing language (Dutch) and the ability to complete the psychological questionnaires. During the collection phase, 130 patients gave informed consent. The patients were tested on the day before, 7 days after, and 6 months after surgery. The preoperative and early postoperative sessions were conducted while the patients were still in the hospital. Six months later, the patients were invited to the hospital for the follow-up assessment. Complete presurgery, postsugery, and follow-up measures for anxiety and depression were obtained in 80 subjects. Of the initial 130 patients, 21 refused 1 or both of the postoperative investigations, 7 were too ill to be tested, 10 could not be tested because of scheduling or transport problems, 10 returned incomplete inventories, and 2 patients had died. The group of 50 patients with incomplete data contained significantly more older, lower educated, and female patients. Because of this factor, the sample can no longer be considered as a random selection of Belgian patients undergoing cardiac surgery, although no significant differences between preoperative anxiety and depression scores were found between the groups with complete and incomplete data. The 80 patients included 13 women and 67 men, with a mean age of 58 years (standard deviation [SD]=8 years, range: 29–74) and an average educational level of 10 years (SD=3 years). The level of education measured in years of formal schooling of Belgian subjects is comparable to that of North American subjects. The skewed gender ratio (far more men than women) reflects the normal gender distribution in the population undergoing cardiac surgery. Sixty-four patients underwent coronary artery bypass graft surgery (CABG), 13 underwent valve replacement surgery, 2 were operated on both valves or a combination of valve surgery and bypass grafting, and 1 patient was operated on for the resection of an atrial tumor. No inhospital psychiatric complications were observed. Five patients exhibited postoperative delirium on the first postoperative day, but these problems were resolved before they were discharged from the intensive care unit and returned to their rooms in the hospital ward.
The only routinely prescribed psychopharmacological agent was a benzodiazepine on the night before surgery, that is, after the preoperative assessment took place. The cardiac medication of the CABG patients usually consisted of nitrate, calcium antagonists, and beta-blockers. The valve patients usually took angiotensin-converting enzyme inhibitors and anticoagulation preparates. Except for the beta-blockers, which have been associated with depressive reactions, these medications have no relevant effect on emotional behavior.
For the three assessments, the patients completed Dutch versions of the Spielberger State Anxiety Questionnaire24 and the Beck Depression Inventory (BDI).20 The state scale of the State-Trait Anxiety Inventory25 is used extensively in clinical research and has proved to be an adequate indicator of presurgical stress.26 State anxiety refers to relatively temporary states of unpleasant feelings of tension and apprehension accompanied by arousal of the autonomic nervous system. The BDI20 is a robust measure of self-reported depression and has been successfully used in research on patients undergoing cardiac surgery.27 The sum of the first 13 BDI items creates a cognitive-affective subscale for estimating depression in medically ill patients whose somatic and vegetative complaints might overestimate the severity of their depressions. The sum of the last eight BDI-items creates a subscale that measures somatic-performance complaints.20 Both the total depression score and the subscale scores were used in this study. Trait anxiety was only assessed in the preoperative session.24 Trait anxiety refers to more stable individual differences in anxiety disposition, which is the tendency to react anxiously in a threatening situation. The distinction between state anxiety and trait anxiety refers to the fact that anxious behavior develops not only as a function of the tendency to react anxiously to aversive stimuli but also as a result of situation-specific conditions.
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RESULTS
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The preoperative, postoperative, and follow-up anxiety and (total) depression scores are listed in Table 1. The women had higher trait-anxiety, state-anxiety, and depression scores in all assessments than did the men. This difference is only significant for the preoperative state anxiety score t(78)=2.12, P=0.04). Age and educational level show no significant correlation with the self-reported state-anxiety and depression scores. Compared with normative data,24 the average surgical patient reports elevated levels of state anxiety in all assessments. Considering state-anxiety scores>50 as clinically relevant and by using the revised whole-scale BDI cutoffs,20 the percentages of patients with clinically significant anxiety and depression are listed in Table 2.
A repeated measures analysis of variance (ANOVA) shows significant differences in state-anxiety scores over the 3 assessments, Hotelling's T2(2,78)=20.90, P<0.001. Most notably, there is a significant reduction in reported anxiety symptoms shortly after surgery. After 6 months, a further, but small, reduction in anxiety is noted. A stepwise multiple regression analysis indicates that the early postoperative state anxiety is best predicted by the patient's preoperative trait-anxiety and state-anxiety scores, explaining 40% of the variance. Preoperative trait anxiety and early postoperative depression entered the equation to explain 57% of the variance of the state-anxiety score at follow-up. The Pearson correlations between the trait-anxiety score and the pre-, post-, and follow-up state-anxiety scores are 0.59, 0.52, and 0.43, respectively (always P<0.001).
To evaluate the postoperative anxiety scores in the patients with different levels of preoperative anxiety, the patients were divided in three groups according to their preoperative state-anxiety score. The patients with a preoperative anxiety score higher than 1 standard deviation above the preoperative mean were considered patients with high anticipatory anxiety (n=13, mean preoperative state-anxiety score=63). The patients with preoperative anxiety scores below the preoperative mean minus 1 standard deviation were considered low anticipatory-anxiety patients (n=13, mean preoperative state-anxiety score=27). The patients with anxiety scores within the 1 standard deviation range were considered to have moderate anticipatory anxiety (n=54, mean preoperative state-anxiety score=45). Figure 1 shows that the patients with high, moderate, or low preoperative anxiety retained the same level of anxiety, respectively, in the early (7 days after) and later (6 months later) postoperative stages. A repeated measures ANOVA of the state-anxiety scores—with time of assessment as a within-subjects factor and the level of anticipatory anxiety (high, moderate, or low) as a between-subjects factor—revealed, besides the expected significant effects of assessment (Hotelling's T2[2,76]=16.48, P<0.001) and level of anticipatory anxiety (F[77]=53.81, P<0.001), a significant interaction effect (Hotelling's T2[4,154]=7.58, P<0.001).
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FIGURE 1. Perioperative state-anxiety inventory scores in patients with high (n=13), medium (n=54), and low (n=13) preoperative anxiety.
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A repeated measures ANOVA shows significant differences in total BDI depression scores over the 3 assessments, Hotelling's T2[2,78]=11.86, P<0.001. Post-hoc univariate F-tests show a significant increase in depression score shortly after surgery, F[1,79]=14.34, P<0.001. In Table 3, the total depression score is split in the cognitive-affective and the somatic-performance subscales for the 3 assessments. A repeated measures ANOVA for the cognitive-affective subscale shows no significant effect for time of assessment. A repeated measures ANOVA for the somatic-performance subscale shows significant differences between the assessments, Hotelling's T2[2,78]=29.28, P<0.001. There is a significant increase in somatic-performance complaints early after surgery (F[1,79]=27.42, P<0.001). At follow-up, the BDI somatic-performance score drops below preoperative levels (F(1,79)=28.46, P<0.001). Stepwise multiple regression analysis shows that the preoperative affective-cognitive depression score explains 35% of the variance of the early postoperative affective-cognitive depression score. The follow-up depression score is best predicted by the preoperative and early postoperative affective-cognitive depression scores, explaining 51% of its variance.
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DISCUSSION
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Bolstering and in agreement with previous research, the results show that surgical candidates report increased feelings of anxiety immediately before open-heart surgery. In a third of the patients, the preoperative level of anxiety is considered clinically relevant. On the seventh postoperative day, state anxiety has dropped significantly. The decrease is most prominent in patients with high preoperative anxiety levels. Six months after surgery, a further, albeit small, reduction in anxiety is noted. Although the level of reported anxiety is significantly decreased after surgery, the surgical patients experience elevated feelings of anxiety in both the early and later postoperative period compared with normative data.24 Between 10% and 20% of the patients show clinical levels of postoperative anxiety. It appears that the acute emotional arousal caused by the impending surgery is replaced by less vigorous but long-standing feelings of emotional discomfort after the operation. These feelings probably reflect an increased "worrying about one's health," the most frequently reported emotional complaint after cardiopulmonary bypass surgery.28 It can also be argued that because of the substantial dropout of the more vulnerable older, lower educated, and female patients, this study probably underestimates the proportion of patients with postoperative emotional distress.
The question can be raised if high, medium, low preoperative anxiety rates persist and yield high, medium, and low anxiety rates, respectively, in the postoperative period. The results of this study appear to confirm the linear hypothesis. This hypothesis refers to the state-trait theory of anxiety according to which the level of the subjective feelings of stress and tension is closely related to the patient's disposition to react anxiously in a life-threatening situation. Indeed, patients with high, moderate, or low anticipatory anxiety retained the same levels of anxiety in the postoperative period (Figure 1). While those patients with high anxiety had a significant drop in their anxiety following surgery, their scores can still be considered in the high range for anxiety. In addition, the preoperatively assessed trait anxiety contributes significantly to the prediction of the patients' postoperative state-anxiety levels, confirming the impact of anxiety disposition on perceived emotional stress. These results are in agreement with a prior study's finding that patients who were already emotionally at risk before cardiac surgery have the highest number of emotional problems 3–5 years after surgery.29 On the other hand, this study shows a significant interaction effect between anxiety group (high, moderate, or low preoperative anxiety) and time of assessment. The high anticipatory-anxiety patients show a considerable drop in anxiety immediately after surgery, followed by a slight increase at follow-up. The moderate anticipatory-anxiety patients show a steady decrease in anxiety over the entire postoperative period. The low anticipatory-anxiety patients show a small increase in self-reported anxiety in the postoperative period. The significant interaction effect can best be explained by the normal regression of extreme values, and the results do not confirm Janis's claims of a differential trend in postoperative anxiety levels between patients with normal and abnormal preoperative anxiety.
Previous research reported increased depressive symptoms after the operation.14, 16, 17 Speidel used the Hamilton Depression scale (Ham-D),30 an instrument for rating depressive symptomatology in adults based upon an interview. Smith et al.16 and Mattlar et al.17 based their results on the BDI, a self-report questionnaire that was also used in this study. Although these instruments, the Ham-D and BDI, use a different method to assess the level of depression, both scales include items that evaluate somatic and vegetative symptoms, such as weight loss, loss of appetite, insomnia, and fatigability, that are commonly found in depressive patients. Medical patients can have similar vegetative and somatic symptoms in the postoperative period that are not necessarily related to depression. The results of this study show that the early postoperative increase in reported depression is entirely attributable to an increase in the somatic complaints of the postsurgical patients. Omitting the somatic items from the BDI score reveals that cardiac surgical patients do not experience significant postoperative changes in depression related cognitive-affective symptoms. Although it can be argued that medical patients are more likely to translate feelings of depression into somatic complaints,27 cardiac surgery remains an invasive operation with justified postoperative somatic complaints. Similar remarks can be made about the research on patient depression after myocardial infarction. Somatic-performance BDI items cannot evaluate whether a positive response is caused by depression or by the physical status of the postsurgical patient, and these items should therefore be omitted in the interpretation of the depression score. Beck and Steer20 describe cognitive-affective subscale scores >10 as indicative of moderate depression. Applying this cutoff in this study reveals clinically relevant depression scores in 10% (n=8) of the preoperative patients and in 6.3% (n=5) on both postoperative assessments. Unfortunately, the use of cardiac medication was not systematically assessed and the contribution of beta-blockers on the depression score cannot be evaluated. Depression scores (cognitive-affective subscale) and state-anxiety scores are strongly correlated (r=0.52–0.69, always P<0.001), suggesting that a subgroup of patients show both high anxiety and depression scores and endure increased emotional distress in the perioperative period.
Recent research has shown that higher levels of preoperative state anxiety are associated with poorer outcome after cardiac surgery.18 My research indicates that patients with high preoperative emotional stress levels remain the most stressed group in the postoperative period and that psychometric assessment can identify patients at risk for clinical levels of postoperative anxiety and depression. The selected patients could benefit from psychological counseling aimed at reducing the patients' increased emotional arousal that was found to be an independent risk factor for increased mortality and morbidity in cardiovascular patients.31–33 Preventive counseling could possibly improve postoperative outcome in both medical and economic costs. These conclusions encourage further research on the assessment and treatment of psychological distress in cardiovascular patients.
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ACKNOWLEDGMENTS
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This research was supported by a grant (Grant No. 7–0034–91) from the "Actie Levenslijn" charity fund organized by the Vlaamse Televisie Maatschappij and coordinated by the National Fund for Scientific Research of the Belgian State. To complete the study, the author received an additional grant from the University Gent. The author thanks Dr. G. Van Nooten for allowing the author to study the patients that underwent surgery at the Center for Cardiac Surgery as well as all the patients who took part in the study.
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ABSTRACT
INTRODUCTION
