Psychiatric Morbidity after Myocardial Infarction

Transcription

1 Quarterly Journal of Medicine, New Series LI, No. 201, pp , Winter 1982 Psychiatric Morbidity after Myocardial Infarction G. G. LLOYD and R. H. CAWLEY From King's College Hospital Medical School and Institute of Psychiatry, London S.E.5 Accepted 20 August 1981 SUMMARY Using a standardized interview, psychiatric morbidity was diagnosed in 35 out of 100 consecutive male patients one week after admission to hospital following a first acute myocardial infarction. Sixteen of these patients had been psychiatrically ill before the infarction and their psychiatric symptoms and social difficulties persisted throughout the 12 month period of observation. In contrast, patients whose psychiatric morbidity had been precipitated by the infarction tended to have transient symptoms and fewer problems of social adjustment. Measures of psychiatric morbidity one week after the attack did not predict subsequent mortality or difficulty in returning to work. Only a history of heavy smoking was significantly associated with mortality during the ensuing 12 months. Patients who regarded their illness as a loss or a threat had greater psychiatric morbidity than those who regarded it as an insignificant event. INTRODUCTION The importance of psychological factors in the aetiology of myocardial infarction has been claimed by many writers and there is accumulating evidence that stressful life events (1) and a characteristic pattern of behaviour (2, 3) play a part. Recently increasing attention has been paid to the emotional consequences of the illness. Psychological status after infarction has been reported to influence subsequent mortality (4 6) and rehabilitation, particularly return to work (7-9). In many countries extensive programmes of rehabilitation have been established, but such facilities are relatively uncommon in Britain where scepticism has been expressed regarding their efficacy (10, 11). In his original account of the illness Herrick (12) noted an absence of psychological disturbance. This contrasts sharply with the observations of later writers who have described considerable psychopathology, albeit of varying frequency. In the period immediately following infarction the reported frequency of psychological disturbance has ranged from 40 to 80 per cent (4, 13 16). These widely varying rates are due to several factors, including differences in selection of patients, time between infarct and assessment, and, particularly, the methods of assessment. Questionnaires examine only selected aspects of mental state whereas unstructured clinical interviews are subjective and lack standardization. The determinants of psychological reactions to illness are poorly understood. No consistent associations have been demonstrated between psychological reaction and measures of the severity of the illness and it Correspondence: G. G. Lloyd, Department of Psychological Medicine, Royal Infirmary, Edinburgh.

2 34 G. G. Lloyd and R. H. Cawley has been suggested that the personal meaning of the illness is of crucial importance in this respect (17). We report a prospective study in which psychiatric morbidity, social adjustment and attitudes to illness were measured in a series of men admitted to hospital after a first infarct and followed up four months and 12 months later. Our aims were to investigate the relationships between these variables and to examine their associations with the course of events during the year, with particular regard to the implications for programmes of rehabilitation. PATIENTS AND METHODS We studied a consecutive series of 100 men under 65 who had survived the first week after having been admitted to a coronary care unit following a first heart attack. No formal programme of rehabilitation was in progress during the course of the study. Each patient was interviewed on the seventh day after admission. Items in the personal and medical history were recorded in a standardized way, smoking habits were noted and the mental state examined using the Standardized Psychiatric Interview (18). This interview yields ratings of each of 11 symptoms during the previous week and 12 abnormalities observed at interview. (As all subjects had proven physical illness the questions on 'fatigue' were left out.) A total score obtained by doubling the scores for manifest abnormalities and adding them to the sum of symptom scores has been reported to correspond with overall clinical severity and this procedure was followed here. Where appropriate a psychiatric diagnosis was made according to the 8th Edition of the International Classification of Disease (19). Work, social, family, marital and sexual adjustment were assessed on the Scaled and Structured Interview for the Assessment of Maladjustment (SSIAM) (20, 21). Attitudes towards the illness were measured on an empirical basis. We asked patients to rate on a five-point scale, four statements pertaining to each of six different categories of meaning, namely, loss, threat, challenge, gain, punishment and insignificance. These attitude scales are available from the authors. Finally the physical severity of the infarction was measured by a coronary prognostic index (22) derived from data recorded independently on admission and a note was made of patients who had required electrical defibrillation or temporary cardiac pacing. Four months later the mental state examination and SSIAM were repeated, and a record was made of degree of recovery in terms of return to work, physical complications, smoking habits and the need for coronary arteriography or surgery. Personality measures, which will be reported separately, were also obtained at this time. These procedures were repeated 12 months after the initial illness. RESULTS 1. Numbers of patients, early treatment, follow-up ratios One hundred and five men with a definite diagnosis of a first acute myocardial infarction were admitted to the unit during the study period, November 1976 to January Five died during the first week and the remaining 100, who constituted the cohort for study, were interviewed at the end of the first week in hospital. Five patients had been successfully treated by D.C. cardioversion and four had a temporary pacemaker inserted for various degrees of heart block. The numbers of deaths and the survivors who were followed during the ensuing 12 months are shown in Table 1; 93 per cent of survivors were interviewed at four months and 92 per cent at 12 months.

3 TABLE 1. Deaths andfollow-up rates Psychiatric Morbidity after Myocardial Infarction 35 Time Patients Total Refused Total interviewed deaths follow-up untraced 1 week 100 * 4 months months *The five patients who died during the first week, among the 105 admitted to hospital during the study period, are omitted from further consideration. 2. Time to respond to symptoms Seventy patients sought medical attention within two hours of the onset of symptoms; the other 30 delayed longer, for over 24 hours in seven cases. A previous history of angina or the presence of another person suggesting medical contact were not significantly associated with earlier referral. Fifty patients initially considered their symptoms to be cardiac in origin and they had more often consulted within two hours than those who attributed their symptoms to non-cardiac causes (x 2 = 6-86; d.f. = \;p < 0-01). 3. Subsequent treatment and mortality Of the 100 patients who survived the first week, 11 died during the ensuing 12 months, all from cardiovascular causes. Ten patients underwent coronary arteriography, four had coronary artery bypass grafts and one had a permanent pacemaker inserted. There were no differences between the survivors and those who died with respect to the coronary prognostic index on admission or any of the demographic or psychological data collected at the interview at one week. The only distinguishing factor was the smoking history (23). Ten of the deaths occurred among the 56 men who had smoked at least 20 cigarettes daily up to the time of their infarct, and only one death among the other 42 who were non-smokers or lighter smokers. 4. Physical morbidity The Norris CPI scores ranged from 1-62 to with a mean of 5-18 (S.E. 0-23). Thirty patients reported having experienced angina before their infarct. Later, the proportion of patients who had experienced angina at some time increased to 53-5 per cent (46 of the 86 examined) at four months and 64-6 per cent (53 of the 82 examined at 12 months. Two patients survived a second infarct during the year. Patients who had experienced angina before the infarct had higher mean psychiatric morbidity scores at one week (12-30; S.E. 1-88) than patients who had not experienced angina (8-17; S.E. 0-77) (t = 2-2,1; p < 0-05). These differences were no longer evident at four and 12 months. 5. Psychiatric morbidity One week after admission 35 patients were identified as having significant psychiatric morbidity; they have been described more fully elsewhere (24). In 27 this morbidity was of moderate severity, in seven marked and in one severe. There were no sharp demarcations between these grades of severity nor between these patients and those not identified as 'cases'. As shown in Figs. 1 and 2 there was a wide variety of symptoms and observed abnormalities.

4 36 G. G. Lloyd andr. H. Cawley Somatic symptoms Sleep disturbance Hypnotics Irritability Impaired concentration Depression Anxiety Phobias Obsessions Oepersonalisatlon Patients without psychiatric morbidity Patients with psychiatric morbidity Reported symptoms FIG. 1. Mean scores for reported symptoms one week after myocardial infarction in patients with and without psychiatric morbidity. Depressed thoughts Patients without psychiatric morbidity Patients with psychiatric morbidity Manifest abnormalities at interview FIG. 2. Mean scores for manifest abnormalities one week after myocardial infarction in patients with and without psychiatric morbidity. Retrospective enquiries from the patient, relatives, general practitioner and relevant hospital notes made it clear that of these 35 patients, 16 had been psychiatrically ill at the time of their infarction (Group 1), while in 19 psychiatric morbidity had been precipitated by the heart attack (Group 2). Those without significant symptoms were designated Group 3. Patients in Group 1 had a much wider range of psychiatric diagnoses and were more likely to have experienced previous episodes of diagnosed psychiatric illness; four of them had been receiving psychiatric treatment up to the time of the infarction (24).

5 Psychiatric Morbidity after Myocardial Infarction 37 High psychiatric morbidity scores were observed in those who had experienced angina before infarction, there being no difference in the distribution of angina patients between Groups 1 and 2. There were no significant associations, either overall or within groups, between psychiatric morbidity scores and age, social class or the Norris C.P.I. T A B L E 2. Psychiatric morbidity scores Time Group 1 (n=16) Group 2 (n=19) Group 3 (w = 65) 1week 4 months 12 months Mean S.E Mean S.E Mean S.E There were wide differences in psychiatric morbidity scores at the second and third interviews as shown in Table 2. Patients in Group 1 continued to have high scores throughout the 12 month period whereas for patients in Group 2 symptoms were more transient so that by four months they had significantly lower scores than those in Group 1 (t = 2-57; p < 0-02). This difference was maintained at 12 months (t = 2-13; p < 0-05). The outcome in the three groups is shown in Figure 3. Group 1, psychiatric morbidity preceding myocardial infarction O Group 2, psychiatric morbidity precipitated by myocardial infarction A Group 3, no initial psychiatric morbidity 2. 1 week 4 months 12 months Time of interview after myocardial infarction FIG. 3. Evolution of psychiatric morbidity.

6 38 G. G. Lloyd andr. H. Cawley 6. Social Adjustment At one week there were significant correlations between high psychiatric scores and poor adjustment at work and in social (leisure) activities (Table 3). T A B L E 3. Correlations between psychiatric morbidity and scores on SSI A M at one week Spearman r p Work <0001 Social <0-03 Family Marriage Sex When the three groups were compared, Group 1 patients were found to have higher scores on all scales of the SSIAM and were significantly different from Group 2 on leisure (p < 0-02), family (p < 0-05) and marriage (p < 0-02) (Wilcoxon's Rank Sums Test). TABLE4. SSIAM scores at one week Work Social Family Marriage Sex Group 1 Group 2 Group ** 9-43* 8-71** p <005 **P < There were no significant changes in SSIAM scores within any of the three groups at later interviews. 7. Return to work Eighty four patients were working at the time of infarction. A significantly higher proportion of the group previously psychiatrically ill (Group 1) were not employed at the time (X 2 = 10-91;/? < 0-001). Sixty four per cent of those eligible to return to work did so by four months, the mean time taken to return being 9-3 weeks. Those who failed to resume work by four months could not be distinguished by their Norris scores or psychiatric morbidity scores at the initial assessment, neither did the proportions from Groups I and 2 differ (three of seven, and seven of 15 respectively). A smaller proportion (17 of 53) came from Group 3 but this difference does not reach statistical significance. Angina before the infarct was commoner in patients who had not returned to work. They had higher psychiatric scores at four months at which time they were also more likely to be diagnosed as having a psychiatric illness. (Table 5.) Eighty three per cent of those eligible had returned to work by 12 months and most of the others had retired with invalidity pensions.

7 Psychiatric Morbidity after Myocardial Infarction 39 TABLE 5. Comparison of patients who had returned to work by 4 months with those who had not returned Returned (n = 48) Not returned (n = 27) Norris score on admission Angina before admission Angina at 4 months Psych, score at 1 week Psych, score at 4 months Psych, diagnosis at 1 week Psych, diagnosis at 4 months 4-75 (S.E. 0 30) (S.E. 1 09) 6-42 (S.E. 1 07) (S.E. 0-50) (S.E. 1-56) (S.E. 1-79) X 2 --= 4-97;p<0-05 t = 2-58;p<0-02 = 4-27;/><0-05 f- 8. Attitudes To investigate associations which might be clinically relevant a score for each attitude was derived by adding the scores for individual items. T A B L E 6. Correlations between psychiatric morbidity and attitudes at initial interview Attitude Loss Challenge Threat Gain Punishment Insignificance Pearson r P <0 001 <0 001 <0 02 As shown in Table 6 there were significant positive correlations between psychiatric morbidity and the tendency to regard the illness as a loss or a threat. There was an inverse association between psychiatric morbidity and the tendency to view the illness as insignificant, an attitude resembling what some writers would call denial. Loss and threat were however highly correlated with one another (r = 0-742; p < 0-001) suggesting the items were measuring similar attitudes. When the effect of threat was partialled out, loss and psychiatric morbidity were still significantly correlated (r = 0-218; p < 0-03) but with its association with loss partialled out, threat no longer correlated significantly with psychiatric morbidity. Similarly insignificance is inversely correlated with threat (r = 0-353) and loss (r = 0-324) and its association with psychiatric morbidity disappeared when these variables were taken into consideration. No significant differences were found between the three patient groups for any attitude. DISCUSSION If acute medical intervention is to be effective after a heart attack the patient must present early. Many of the factors which determine arrival at hospital are outside the patient's influence but the decision to seek medical treatment is not. It is therefore noteworthy that 30 per cent delayed longer than two hours before deciding to see a doctor. Patients were more likely to consult early if they believed their symptoms were cardiac in origin. Greater public awareness of the commoner symptoms of ischaemic heart disease might be expected to lead to

8 40 G. G. Lloyd and R. H. Cawley earlier consultation. This however raises the prospect of inducing more consultations in those without heart disease. Appropriate measures for health education have the difficult assignment of achieving the maximum of early detection coupled with the minimum provocation of anxious introspection among those not affected. The 12 month mortality rates of 15 per cent of those admitted to the coronary care unit and 11 per cent of those surviving the first week are similar to those reported in other studies (25 27). For patients surviving the first week neither the original coronary prognostic index nor psychosocial measures predicted subsequent mortality. A history of heavy smoking did have a very strong predictive value, 10 of the 11 deaths occurring in patients who had smoked 20 or more cigarettes daily. We have provided a more complete profile of psychiatric symptoms after a myocardial infarction than previous reports, but have identified a lower prevalence of psychiatric morbidity. Our definition of psychiatric morbidity was based on the severity of symptoms which would warrant treatment by a general practitioner or psychiatrist in an outpatient clinic. In rating symptoms and manifest abnormalities according to defined criteria after a specific length of stay in hospital we are ensuring that our results can be compared with other groups of patients similarly assessed. Using the same interview method psychiatric illness was diagnosed in 30 per cent of patients attending a general practitioner's surgery (28), in 23 per cent of general medical inpatients (29) and in 31 per cent of patients with chronic renal failure on home dialysis (30). Our observations show that not all psychiatric symptoms can be regarded as a reaction to the cardiac illness because several patients were undoubtedly psychiatrically ill before the heart attack. These patients had considerable work, social and marital problems and their psychiatric symptoms were more likely to persist into the period after infarction. The relationship of these symptoms to the heart attack cannot be answered by this study. They may have been coincidental, on the other hand they may have played a causal role as Bianchi et al. have claimed (31). A third possibility is that they may have influenced the decision to seek medical treatment. In this case we would expect differences between the three groups in the time taken to decide on medical consultation but no such differences were found. Psychiatric symptoms precipitated by the infarction tended to be transient. The interview scores of these patients were similar to those with pre-existing psychiatric illness but, although a psychiatric diagnosis was made, the symptoms appeared to be an emotional reaction to the cardiac illness and to be an integral part of this. These patients improved with time without specific rehabilitation or psychiatric treatment especially if the physical course of the heart attack was uncomplicated and they were able to return to work. Sixty-four per cent of those eligible had returned to work by four months, this figure being almost identical to previous comparable British studies (9, 32, 33). Those who had not returned had significantly higher psychiatric scores at four months, in keeping with the observations of Nagle et al. (8) and Cay et al. (9) but differing from those of Mayou (34). Whether psychiatric symptoms delayed return to work could not be established. It was more likely in some cases that psychiatric symptoms resulted from their inability to resume working. Several patients who developed psychiatric morbidity for the first time by four months clearly fell into this category. Conflicting advice had been given about returning to work, employers' medical officers taking a more cautious attitude than hospital physicians and general practitioners. We found associations between psychiatric morbidity and the meaning of the illness as measured by the patients' attitudes, thus providing some support for the hypothesis that the meaning is important in determining the psychological reaction. Our findings could equally be interpreted as showing that attitudes to the illness are determined by the patient's mental state

9 Psychiatric Morbidity after Myocardial Infarction 41 at the time of assessment. Measurement of attitudes did not predict mortality or difficulty in returning to work. We did not find that mental state at one week influenced subsequent mortality, thus we did not confirm the observations of Hackett et al. (4) or Garrity and Klein (6). We did not specifically measure the psychological attribute of denial, which has been claimed to influence mortality, and our assessment was made at a later stage than the studies quoted. Had we interviewed patients earlier we might have found an association between mental state and mortality. However all five patients who died during the first week in hospital and who therefore did not enter the study, were severely ill physically and had high Norris scores. Implications for rehabilitation Controlled studies evaluating rehabilitation after myocardial infarction among British patients have shown little or no benefit (35, 36). The outcome of our patients indicates that most made a good recovery without special rehabilitation. Conventional medical management, including adequate advice about reduction of risk factors and resumption of previous activities, is sufficient in most cases. A poor outcome in psychological terms occurred in patients psychiatrically ill before the infarct. Cardiac rehabilitation is unlikely to help this group; they require specific psychiatric intervention which is not based on the assumption that the emotional symptoms are a consequence of the infarct. Stopping smoking is difficult for this group (23) whose emotional symptoms may perpetuate the habit. Patients with angina before the infarct and heavy manual workers have most difficulty returning to work. Several of the patients who developed significant psychiatric morbidity for the first time by four months after the attack had been prevented from returning to work by medical advice. At times contradictory advice had been given, occupational physicians generally taking a more conservative attitude than hospital doctors or general practitioners. Much psychological distress could perhaps be averted if the patient's functional capacity could be assessed in relation to his work at an early stage and alternative arrangements made if return to previous employment is not feasible. ACKNOWLEDGEMENTS We thank Dr. S. Oram and Dr. D. Jewitt for their help in planning this study which was supported by a grant from The Bethlem Royal and Maudsley Hospitals Research Fund. REFERENCES 1. Connolly J Life events before myocardial infarction. J Hum Stress 1976; 2: Rosenman RH, Brand RJ, Jenkins CD, Friedman M, Straus R, Wurm M Coronary heart disease in the Western Collaborative Group Study: final follow-up experience of 8j years. J Am Med Ass 1975; 233: Haynes SG, Feinleib M, Kannell WB The relationship of psychosocial factors to coronary heart disease in the Framingham study. III. Eight-year incidence of coronary heart disease. Am J Epidemiol 1980; 111: Hackett TP, Cassem NH, Wishnie HA The coronary care unit: an appraisal of its psychologic hazards. N Eng J Med 1968; 279: Bruhn JG, Paredes A, Adsett CA, Wolf S Psychological predictors of sudden death in myocardial infarction. J Psychosom Res 1974; 18: Garrity TF, Klein RF Emotional response and clinical severity as early determinants of six-month mortality after myocardial infarction. Heart Lung 1975; 4: Wynn A Unwarranted emotional distress in men with ischaemic heart disease. Med J Austral 1967; ii: Nagle R, Gangola R, Picton-Robinson I Factors influencing return to work after myocardial infarction. Lancet 1971; ii:

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