Psychosomatics 45:414-418, October 2004
© 2004 The Academy of Psychosomatic Medicine
Assessment of Vital Exhaustion and Identification of Subjects at Increased Risk of Myocardial Infarction in General Practice
G.E. Schuitemaker, Ph.D.,
G.J. Dinant, M.D., Ph.D.,
G.A. van der Pol, and
A. Appels, Ph.D.
Received July 2, 2003; revision received Dec. 19, 2003; accepted Jan. 30, 2004. From the Department of General Practice and the Department of Medical Psychology, University of Maastricht; and the Research Institute for Extramural and Transmural Health Care, Maastricht, the Netherlands. Address reprint requests to Dr. Dinant, Department of General Practice, University of Maastricht, the Netherlands; geertjan.dinant{at}hag.unimaas.nl (e-mail).
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ABSTRACT
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Vital exhaustion, a state characterized by unusual fatigue, loss of energy, increased irritability, and feelings of demoralization, is one of the cardiovascular risk factors. The authors investigated whether vital exhaustion contributes to the identification of subjects at increased risk of myocardial infarction in general practice. In this prospective cohort study, vital exhaustion was assessed with the Maastricht Interview on Vital Exhaustion. Other cardiovascular risk factors established were age, gender, systolic and diastolic blood pressure, total cholesterol, body mass index, smoking habits, cardiovascular disease, and diabetes mellitus. A Cox regression analysis was used. The subjects were adults (41–66 years) in an average Dutch village population. Outcome measures were fatal and nonfatal myocardial infarction. At the univariate level, vital exhaustion doubled the risk of myocardial infarction. The effect of exhaustion was confounded by gender; women had higher exhaustion scores and a lower incidence of myocardial infarction. With control for gender, age, systolic blood pressure, total cholesterol, smoking habits, self-reported cardiovascular disease, and diabetes mellitus, vital exhaustion almost tripled the risk of myocardial infarction. Assessment of vital exhaustion contributes to the identification of subjects at increased risk of myocardial infarction in general practice.
Key Words: stress • primary care
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INTRODUCTION
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Prevention of cardiovascular disease, including myocardial infarction, is an important task for physicians, including general practitioners.1 Primarily, prevention requires the identification of risk factors. Generally recognized risk factors for myocardial infarction include older age, male gender, positive family history, smoking habits, hypertension, hypercholesterolemia, and diabetes mellitus.
Many patients feel exhausted after a myocardial infarction.2,3 Epidemiological studies investigating the precursors of myocardial infarction have shown that these feelings existed before the occurrence of myocardial infarction in the majority of patients.4 Appels labeled this state "vital exhaustion," a state characterized by unusual fatigue, loss of energy, increased irritability, and feelings of demoralization.5 This state reflects a breakdown of the adaptation to stress. This observation induced us to test whether an assessment of vital exhaustion could contribute to the identification of subjects at increased risk of myocardial infarction in general practice. This test was performed in the context of the so-called Mierlo Project.
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METHOD
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Design
The Mierlo Project was conducted among the adult population of the Dutch village of Mierlo, and the same population was used for this follow-up study. The Mierlo Project consisted of a selection procedure, immediately followed by two intervention studies, one in hypercholesterolemic subjects and one in subjects at risk of cardiovascular disease. The selection procedure consisted of a simple questionnaire mailed to inhabitants of the village who were ages 41 to 66 years.
The questionnaire consisted of the following six questions regarding the presence or awareness of risk factors for cardiovascular disease:
- Do you suffer from cardiovascular disease?
- Does your father or mother or any of your brothers or sisters suffer from a cardiovascular disease or a high cholesterol level?
- Do you suffer from diabetes?
- Do you suffer from hypertension?
- Is your weight in kilograms more than your length in centimeters minus 100?
- Do you smoke more than five cigarettes a day?
If one or more of the questions on the returned questionnaire had been answered yes (or undecided), the subject was invited for further examination at the selection center. The measurements taken at this visit included systolic and diastolic blood pressure (recorded twice, at the beginning and at the end of the visit, after which mean values were computed) and height and weight (used to calculate body mass index). In addition, smoking habits (numbers of cigarettes) were asked for, and a venous blood sample was taken for total cholesterol assay. Blood pressure and cholesterol measurements were performed according to the guidelines of the Dutch College of General Practitioners.6,7 The visits took place between May 1993 and May 1995.
At the visit, the subjects underwent the Maastricht Interview on Vital Exhaustion.8 The Maastricht Interview on Vital Exhaustion was administered by a trained practice nurse and a trained research nurse according to current standards. The interview consists of 23 questions asking about unusual fatigue, loss of energy, increased irritability, and feelings of demoralization, all scored as absent or present. Thus, the minimum score is 0, while the maximum score is 23. The duration of one interview was approximately 15 minutes. Cronbach's alpha for the Maastricht Interview on Vital Exhaustion was 0.89, indicating good reliability.
The cohort was followed for about 4 to 5 years. In the first year, the cohort followed the regular procedure of the Mierlo Project after the first visit. In subjects with a total cholesterol  7.0 mmol/liter at the first visit, two additional total cholesterol measurements were performed within a period of 2 months. No particular advice about eating habits or lifestyle was given during the visits. Subjects with a mean total cholesterol level of 7.0–9.9 mmol/liter in the three consecutive measurements entered a randomized clinical trial (those with total cholesterol 10 mmol/liter were excluded). The trial medication consisted of the cholesterol-lowering agent magnesium-pyridoxal-5'-phosphate-glutamate or placebo. Subjects with conditions interacting with the medication, such as other lipid-influencing medication, serious heart complaints (during the last 3 months), and diabetes mellitus, were excluded. The follow-up period was 1 year and involved three monthly visits to the general practitioner. More details about the design and results of the randomized clinical trial have been published elsewhere.9
Subjects with a modifiable risk level 8 participated in the descriptive study. The modifiable risk level is calculated by adding the modifiable risk factors of total cholesterol, diastolic blood pressure, systolic blood pressure, body mass index, exercise, and smoking habits, which are assigned a value depending on the severity of the risk (derived and adapted from the method by Anggard et al.10 Subjects visited their general practitioner every 3 months over a period of 1 year. Each visit involved an evaluation of their general condition in terms of cardiovascular disease: blood pressure and weight were determined, and smoking habits and physical activity were discussed. The duration of this study was 1 year.
Endpoint Definition and Statistical Analysis
The endpoint of the present study was myocardial infarction, which included the occurrence of nonfatal myocardial infarction and cardiac death. These were assessed in the period between January 1998 and October 1998 based on data from the general practitioner's patient records. Endpoint diagnoses were confirmed by a medical specialist. A myocardial infarction was diagnosed if at least two of the following three criteria were fulfilled: characteristic angina complaints for at least 15 minutes, characteristic ECG changes befitting a myocardial infarction, and increased cardiac enzymes established in the laboratory. Cardiac death was diagnosed if death occurred within 1 hour after the complaints began. If a person experienced more than one event, the first event was used as the endpoint.
Survival curves with myocardial infarction as the dependent variable were constructed for the vital exhaustion and nonvital exhaustion groups using the Cox regression model, with both direct and stepwise procedures. Subjects scoring 0–7 were labeled not vitally exhausted, while those scoring 8–23 were labeled vitally exhausted, according to the instructions.8 Covariates included age, gender, systolic blood pressure, diastolic blood pressure, total cholesterol, body mass index, smoking habits (yes/no), self-reported cardiovascular disease (question 1), and self-reported diabetes mellitus (question 3). Improvement of the model by the addition of vital exhaustion was tested by change of the –2 log likelihood (forward stepwise). Data were entered into SPSS, version 10.0. All p values were two-sided.
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RESULTS
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The screening questionnaire was sent to 3,276 subjects. A total of 3,061 questionnaires (93%) were returned. It was found that 455 subjects (15%) had not answered yes to any of the questions. The remaining 2,606 subjects were invited to visit the selection center. This invitation was declined by 146 subjects (6%). Seven subjects (0.2%) did not visit the selection center because they had moved out of Mierlo or had died between the start of the study and the assessments. Of those who visited the selection center, 19 (1%) had to be excluded because of language problems. This left a cohort of 2,433 subjects, of whom 167 participated in the randomized clinical trial and 458 in the descriptive study.
The median duration of follow-up was 50.8 months (SD=6.5), with a range of 2.0 to 62.7 months. During this period, 29 subjects suffered a nonfatal myocardial infarction; one subject died from myocardial infarction.
Table 1 shows the characteristics of the cohort at their entrance into the study. The table shows that male gender, age, total cholesterol, and systolic blood pressure increased the risk of myocardial infarction at the univariate level. Vital exhaustion just failed to reach the conventional level of statistical significance (RR=2.54; 95% confidence interval [CI]=0.97–6.64) because of the confounding effect of gender, with women having higher exhaustion scores and a smaller risk of myocardial infarction.
With control for gender, age, systolic blood pressure, total cholesterol, smoking habits, self-reported cardiovascular disease, and diabetes mellitus, the risk of vital exhaustion was found to be 2.91 (95% CI=1.07–7.92) (Table 2 and Figure 1). This confirms the hypothesis. The results of the stepwise procedure showed that a positive self-report of cardiovascular disease carried the highest risk of myocardial infarction. The model was significantly improved by the inclusion of systolic blood pressure and gender. Inclusion of vital exhaustion in the model led to a further improvement, as indicated by a significant change in the –2 log likelihood ratio (Table 3). No other factors were included in the model.
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TABLE 2. Multivariate Analysis of Risk Factors and Myocardial Infarction in 2,433 Subjects With and Without Vital Exhaustion
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FIGURE 1. Kaplan-Meyer Estimates of Time to the Occurrence of a Fatal or Nonfatal Myocardial Infarction in Subjects With and Without Vital Exhaustiona
aChanges in risk were attributable to the degree of vital exhaustion. Variables from Table 2 were included. P values and changes in risk were based on Cox proportional hazard analysis.
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TABLE 3. Multivariate Analysis of Changes in –2 Log Likelihood (forward stepwise) for Risk Factors and Myocardial Infarction in 2,433 Subjects With and Without Vital Exhaustion
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Because some subjects were participating in an intervention study, the analyses were repeated, including participation in the randomized clinical trial and the descriptive study as covariates. Results showed that the risk of vital exhaustion was not changed with control for participation in any of these intervention studies.
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DISCUSSION
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The results of a prospective study in a cohort of patients of a group practice showed that an assessment of vital exhaustion contributed to the identification of patients at increased risk of myocardial infarction. This result is consistent with earlier studies in which vital exhaustion was found to be predictive of cardiac events.2–5 As such, the present study showed that assessment of vital exhaustion contributed to the identification of subjects at increased risk of suffering a myocardial infarction within a period of at most 5 years.
The distinction between vital exhaustion and depression remains a subject of debate. Depression is also recognized as a predictor of myocardial infarction.11 We cannot answer the question of whether exhaustion is predictive of myocardial infarction because of its overlap with depression. However, a depressed mood, the key symptom of depression, is almost absent in exhausted subjects.12 Nearly all depressed patients feel exhausted. Of those who are exhausted, only 20% meet the DSM criteria for major depression. Cognitive distortions such as "I do not deserve to be loved" are usually absent in exhausted subjects.
The major limitation of the present study was the validity of the prescreening questionnaire. Subjects may have endorsed question 1, "Do you suffer from heart disease?" for different reasons. A negative answer to this question is no valid proof of the absence of cardiovascular disease. Also, no ECG recordings of the subjects were made, and therefore, no ECG evidence of ischemic heart disease was available. The presence of diabetes mellitus, too, was based upon self-report only.
Therefore, the present study does not prove that vital exhaustion is an independent risk factor of myocardial infarction because it cannot be ruled out that the feelings of loss of energy and general malaise were caused by existing heart disease in some subjects. However, the prevention of a recurrent cardiac event is as important as the prevention of a first myocardial infarction. Therefore, the results are meaningful for general practice, despite the fact that the design of the study was not really suitable to test an etiological hypothesis.
The Mierlo Project was designed as an intervention study. Control for participation in one of the interventions did not change the results. This might be caused by the fact that the randomized clinical trial did not change total cholesterol significantly9 and that the descriptive study did not influence the risk level to any notable degree. The effects of this descriptive study have not been evaluated. The lack of change might also be caused by the fact that no attempts were made to change the level of exhaustion.
This study among an average Western European village population demonstrates that exhaustion should be taken into account when evaluating an individual's risk of a first or second myocardial infarction.
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ACKNOWLEDGMENTS
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Supported by Steigerwald Arzneimittelwerk GmbH.
The authors thank Jan van den Boomen for his help in the data collection and Paula Pazo for her contribution to the data analysis.
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REFERENCES
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- Wood D, De Backer G, Faergeman O, Graham I, Mancia G, Pyörälä K: Prevention of coronary heart disease in clinical practice: recommendations of the Second Joint Task Force of European and Other Societies on Coronary Prevention. Eur Heart J 1998; 19:1434–1503[Free Full Text]
- Mendes de Leon CF, Kop WJ, de Swart HB, Bär FW, Appels A: Psychosocial characteristics and recurrent events after percutaneous transluminal coronary angioplasty. Am J Cardiol 1996; 77:252–255[CrossRef][Medline]
- Appels A, Kop W, Bär F, de Swart H, Mendes de Leon C: Vital exhaustion, extent of atherosclerosis, and the clinical course after successful percutaneous transluminal coronary angioplasty. Eur Heart J 1995; 16:1880–1885[Abstract/Free Full Text]
- Appels A, Mulder P: Excess fatigue as a precursor of myocardial infarction. Eur Heart J 1988; 9:758–764[Abstract/Free Full Text]
- Appels A: Psychological prodromata of myocardial infarction and sudden death. Psychother Psychosom 1980; 34:187–195[Medline]
- Walma EP, Grundmeijer HGLM, Thomas S, Prins A, van den Hoogen JPH, van der Laan JR: NHG-standaard Hypertensie (The DCGP Standard on Hypertension). Huisarts Wet 1997; 40:598–617 (translation available from: Nederlands Huisartsen Genootschap [Dutch College of General Practitioners], Lohmanlaan 103, 2536 XD Utrecht)
- Van Binsbergen JJ, Brouwer A, Van Drenth BB, Haverkort AFM, Prins A, Van der Weijden T: NHG-Standaard: Cholesterol (The DCGP Standard on Hypertension). Huisarts Wet 1991; 34:551–557 (translation available from: Nederlands Huisartsen Genootschap [Dutch College of General Practitioners], Lohmanlaan 103, 2536 XD Utrecht)
- Meesters C, Appels A: An interview to measure vital exhaustion, II: reliability and validity of the interview and correlations of vital exhaustion with personality characteristics. Psychol Health 1996; 11:573–581
- Schuitemaker GE, van der Pol GA, Aretz CPM, Dinant GJ: A placebo-controlled, double-blind, randomized trial of magnesium-pyridoxal-5'-phosphate-glutamate for hypercholesterolemia and other clinical-chemical risk factors of cardiovascular disease in a primary care setting. Eur J Clin Pharmacol 2001; 56:857–863[CrossRef][Medline]
- Anggard EE, Land JM, Lenihan CJ, Packard CJ, Percy MJ, Ritchie LD, Shepherd J: Prevention of cardiovascular disease in general practice: a proposed model. Br Med J 1986; 293:177–180
- Frasure-Smith N, Lesperance F, Talajic M: Depression and 18-month prognosis after myocardial infarction. Circulation 1995; 91:999–1005[Abstract/Free Full Text]
- van Diest R, Appels A: Vital exhaustion and depression: a conceptual study. J Psychosom Res 1991; 35:535–544[CrossRef][Medline]
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ABSTRACT
INTRODUCTION
