In this issue of the Journal of Cardiopulmonary Rehabilitation, Sharp and colleagues1 report the results of a psychosocial training program for health professionals engaged in cardiac rehabilitation in Glasgow, UK. Results showed that a 2 1/2-day training program was effective in improving participants' knowledge of psychosocial issues and cognitive behavior therapy techniques and suggested that "enhancing cardiac care staffs' awareness of such [psychosocial] risk factors and equipping key staff groups with skills to effectively manage recognized problems will potentially improve rates of morbidity and mortality." The authors should be commended for their efforts to conduct research in a clinical setting and to increase awareness and knowledge of the importance of psychosocial factors in cardiac patients. The study was not without several methodological shortcomings that are worth mentioning: In the absence of a control group, it is impossible to attribute changes to the intervention. A key outcome measure was participant knowledge, which was assessed by a 70-item ad hoc Individual Statement Questionnaire tailored to assess the main learning outcomes of the study. Before training, participants obtained an average score of 42.4, which increased to 48.3 after training and to 47.4 at 3 months follow-up. Although this improvement may be statistically significant, the practical significance of answering 60% of the items correctly at baseline to 69% correctly after training is uncertain. Although their knowledge may have increased, previous exposure to the test and familiarity with the items also may have contributed to their higher scores. Although the authors noted that the nonsignificant decline in Individual Statement Questionnaire scores at follow-up suggests that "knowledge gains were maintained after 3 months," it would seem that participants will need to continue to learn about psychosocial risk factors through readings or by attending additional workshops to achieve higher scores. It also would be important to know if psychosocial risk factors were more likely to be identified by cardiac rehabilitation staff, if referral rates for mental health services increased, or if adherence to important behavioral risk factors-smoking cessation, exercise adherence, and medication compliance-improved. That is, increased knowledge is valuable, but how that knowledge is used to enhance patient care is what matters most.
Sharp et al note that the importance of psychosocial risk factors is "increasingly well-recognized" and cite a recent review by Rozanski and colleagues2 that referenced more than 100 empirical studies since their previous review in 19993 documenting the relationship of stress and cardiac events. Among a host of psychosocial factors (eg, anxiety, job stress, low social support), the evidence for the importance of depression is particularly compelling. Clinical depression is associated with a 2- to 4-fold greater risk in post-myocardial infarction (MI) patients,4 and work from a number of institutions, including our own, has shown that increased depressive symptoms is also a significant risk factor in patients who have undergone coronary bypass surgery5 and who have heart failure.6 Depression does not seem to be simply a surrogate marker for compromised cardiac function because the risk is independent of various indices of disease severity, including left ventricular ejection fraction and B-type natriuretic peptide. Furthermore, examination of the prognostic significance of depression compared with the more traditional risk factors of increased blood pressure, hyperlipidemia, and smoking indicates that depression may have even more importance compared with the traditional risk factors that are almost universally accepted by the medical community (see Figure 1). The INTERHEART study,7 a case-control study that assessed 8 traditional coronary heart disease (CHD) risk factors along with an index of psychosocial stress in a sample of 12,461 acute post-MI patients and 14,637 matched controls from 52 countries, yielded similar results: the odds ratios and population-attributable risk for acute MI were highly significant and comparable with those noted for other major CHD risk factors.
What is surprising is that these data may have a very limited impact on physician attitudes and medical practice. For example, a July 4th ABC news report that announced the death of Ken Lay, the former chief executive officer of Enron, of an apparent MI asked rhetorically, "Did the stress do it?" (http://abcnews.go.com/Health/story?id=2156836&page=1). The medical community is divided on this issue. Despite the accumulated evidence documenting the relationship of stress and various CHD outcomes (eg, Rozanski et al2,3), there is no consensus among physicians as to the prognostic value of psychosocial risk factors. Providing cardiac rehabilitation specialists with knowledge is important, but there is no guarantee that knowledge will affect attitudes and beliefs, much less clinical practice.
There are a number of obstacles to the widespread acceptance of psychosocial factors as being important risk factors in CHD patients. Stress can be difficult to define, and there is no general consensus as to how to objectively measure it; unlike blood pressure, lipids, and cardiac function, there is neither a "gold standard" for measurement nor established cutoff values to guide treatment decisions. In addition, methods to modify psychosocial factors, including both pharmacological and behavioral approaches, are still being developed and evaluated. Difficulties in modifying psychosocial risk factors should not be underestimated. For example, several highly publicized clinical trials yielded essentially negative results. In the M-HART trial,10 1,376 male and female patients with a recent MI were randomly assigned to 12 months of a psychosocial intervention or usual care. Twelve-month follow-up data indicated that the intervention did not reduce rates of all-cause mortality. Furthermore, there was a trend in which women who received the intervention were actually at greater risk for cardiac and all cause-mortality compared with those who received usual care only. Similarly, Jones and West11 randomized 2,328 patients with a recent acute MI to usual care or seven 2-hour sessions of a psychosocial intervention that included group and individual psychotherapy, relaxation training, and stress management. Twelve-month follow-up data revealed that the intervention did not significantly reduce depression, nor did it decrease the risk for mortality or re-infarction. Because the behavioral interventions did not reduce stress or improve psychosocial functioning, it is not be surprising that patient survival was not improved. The ENRICHD trial,12 which examined the effects of cognitive behavior therapy on post-MI patients with depression or low perceived social support, reported only modest reductions of depression compared with usual care, and the treatment had no measurable impact on clinical outcomes. Thus, although psychosocial interventions may reduce stress and improve quality of life, which are important in their own right, at this time, there is very limited evidence to suggest that reducing stress can reduce morbidity and mortality in cardiac patients.
One reason for the limited evidence is simply that there has been a paucity of research in the area, especially relative to the number of drug trials that have been conducted. Research using psychosocial interventions presents a number of logistical challenges, particularly with respect to standardizing an intervention that can be delivered effectively and inexpensively to large numbers of patients in a randomized controlled trial across multiple clinical sites. Rozanski et al2 suggested that before large-scale, multicenter randomized trials are implemented, smaller-scale studies using intermediate end points can be used to provide important insights into the potential benefits of psychosocial treatments. For example, it was recently reported that stress reduction may favorably alter biomarkers of risk, such as increased heart rate variability and improved vascular function.13 More research studies evaluating the effects of interventions on psychosocial risk factors in CHD patients are desperately needed and should be a high priority in the future.
A final suggestion by Sharp et al that deserves comment is the notion that psychosocial training is important to equip cardiac physicians with the skills to recognize and manage psychosocial risk factors. Although this may be a worthwhile goal, it is not clear that physicians have the time or desire to become skilled at assessing and treating psychosocial risk factors, nor is this something that we should necessarily expect or even want physicians to do. Expertise in psychosocial assessment and interventions requires considerable training. Would we want to train psychologists to perform physical examinations, intensive care nurses to perform exercise stress testing, or physiotherapists to perform nutritional counseling? Cardiac rehabilitation programs have trained physicians, exercise physiologists, and nutritionists/dietitians who provide these specialized services.
Indeed, what makes cardiac rehabilitation so special is that it involves a multidisciplinary team of professionals who bring their own unique training and expertise to the care of CHD patients. Educating cardiac rehabilitation staff about the importance of psychosocial risk factors is valuable, but we do not need to aspire to train physicians and other cardiac rehabilitation staff to become psychologists. Rather, we should become more familiar with each staff member's areas of expertise, respect and appreciate their respective skills and unique contributions, recognize the limits of our own training and expertise, and develop better methods for optimally integrating these different perspectives and treatment modalities into the assessment and treatment of the whole.
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