In this analysis of 1022 men and women with stable CVD, we found that PTSD was a strong and independent predictor of greater symptom burden, greater functional limitation, and worse quality of life. In contrast, 2 objective measures of cardiac function, ejection fraction and inducible ischemia, were not significantly associated with cardiovascular health status. These findings demonstrate that the association of PTSD with worse cardiovascular health status is not just due to greater medical comorbidity in patients with PTSD.
Previous studies have demonstrated an association between PTSD and self-reported health status,11-15,30,31
but it has been unclear whether this association is independent of objective measures of physical health. Our results build on these prior studies by examining the relative impact of PTSD and comorbid physical illness on health status. Determining the independent contributions of PTSD and comorbid medical disorders has been challenging for many reasons. First, most studies use self-reported history to define presence or absence of comorbid physical diseases, and such measures may be subject to diagnostic inaccuracies or reporting bias. Second, focusing on the role of comorbid physical illness requires health status measures that reflect the symptoms and functional limitations specific to that disease. Yet, validated disease-specific health status measures are available for only a limited number of physical illnesses. Lastly, no studies of PTSD and health status have examined the severity of physical illness or objective measures of disease-specific function, both of which may be important determinants of health status.
The availability of a validated, CVD-specific health status questionnaire and the detailed measures of CVD severity and cardiac function in the Heart and Soul Study allowed us to address these challenges. Of the 3 cardiac function measures examined, only exercise capacity, which has been used to validate the SAQ, was a significant predictor of health status.25
This is consistent with our prior finding that another psychiatric factor, level of depressive symptoms, was a more important determinant of function and quality of life in patients with CVD than expensive physiologic measures of cardiac function.16
In addition to their value as predictors of patient-centered health status outcomes, psychosocial factors are also strongly associated with cardiac events and mortality.32-34
In the INTERHEART study of 29 432 patients across 52 countries, psychosocial factors accounted for more than 30% of attributable risk of myocardial infarction.34
However, despite their importance, psychosocial factors are often overlooked in primary care and specialist medical practice, and mental health conditions such as PTSD may not be adequately diagnosed and treated in patients with chronic physical illness.35
Though PTSD symptoms are often chronic, trials of both behavioral and pharmacologic therapies have demonstrated that treating PTSD can improve patients’ function and quality of life.36-38
Indeed, our results suggest a dose response between PTSD and cardiovascular health status because participants with prior PTSD had health status outcomes that were intermediate between those with never and current PTSD. Though our sample size is too small to draw definitive conclusions about remitted PTSD, the cardiovascular status of this group deserves further study.
Posttraumatic stress disorder may affect cardiovascular health status through several pathways. Posttraumatic stress disorder is associated with biologic changes, including altered inflammation and sympathetic nervous system activity, which may adversely affect the cardiovascular system.39,40
In addition, patients with PTSD may have differences in health behaviors, such as smoking and physical activity, that could worsen health status by increasing symptoms and decreasing function.41
Therefore, PTSD may act both directly and indirectly to worsen cardiovascular health status.
Our findings should be interpreted in light of several limitations. First, this study included mostly older men, and our results may not generalize to other populations. Second, we focused on CVD because it is the leading cause of death in the world, and several recent studies have found that patients with PTSD have significantly increased risks of developing and dying of CVD.3,7,8,42
However, our findings about the relative influence of PTSD on health status may not extend to patients with other comorbid physical illnesses. Third, though CDIS yields diagnoses of current, past, or no PTSD, we could not determine the exact duration of PTSD symptoms nor could we evaluate the association of severity of PTSD symptoms with health status. In addition, our relatively small number of participants with past PTSD prevented us from fully exploring the association of remitted PTSD and health status. Finally, because our results are cross-sectional, we cannot determine whether the association between PTSD and worse health status is causal.
In summary, we found that PTSD was significantly associated with worse cardiovascular health status, independent of objective measures of cardiac function and comorbid depression. In contrast, 2 measures of cardiac function were not significantly associated with health status. Further study is needed to determine whether treating PTSD symptoms can improve function and quality of life in patients with heart disease.