Washington, DC - Long-term anxiety was an independent predictor of MI among men participating in the Normative Aging Study, none of whom had coronary disease or diabetes at baseline, new research suggests [1]. According to the study authors, a range of anxiety characteristics independently and prospectively predicted MI, even after they controlled not only for major CVD risk factors but also for other psychosocial factors.

In an interview with heartwire, lead author on the study, Dr Biing-Jiun Shen (University of Southern California, Los Angeles), pointed out that other psychosocial factors have been linked to heart disease in the past: so-called "type-A" personality was the hot topic in the 1970s, hostility was the research focus in the 1980s, and depression has increasingly been recognized as a CVD risk factor over the past 15 to 20 years, he notes. "It turns out—once we parse out the effects from depression, type-A personality, anger, and hostility—anxiety remained significant in predicting heart disease," Shen told heartwire. "That suggests that it is not because anxious people tend to be more depressed or angrier: anxiety is a risk factor over and above what can be explained by these other psychosocial factors."

Their study appears online January 7, 2008 in the Journal of the American College of Cardiology.

Shen et al's study assessed psychasthenia (excessive doubts, obsessive thinking, irrational compulsions), social introversion, phobia, and manifest anxiety in 735 men, whose mean age was 60. After adjustment for fasting glucose, body-mass index, HDL, systolic blood pressure, age, education, and marital status, men with higher anxiety as defined by the any of the four anxiety characteristics or all four in combination were significantly more likely to have an MI over the roughly 12 years of follow-up. Anxiety characteristics remained significant even after other psychosocial factors previously linked to CVD were controlled for.

The authors conclude that "anxiety-prone dispositions" may signal a higher risk of MI in older men, potentially opening a new avenue for preventive medicine. "Moderately elevated anxiety is associated with a modest risk of MI, and severe anxiety represents an MI risk that may warrant clinical attention," they write. To heartwire, however, Shen stressed that the study offers no insights into whether treating anxiety could help prevent subsequent CVD—a topic that needs to be addressed in the future.

Shen et al hypothesize that if anxiety is indeed a unique, independent risk factor for MI, it might help explain findings from earlier studies that have linked MI to other psychosocial risk factors such as depression or hostility, although they also acknowledge that different psychosocial factors are interrelated and may boost cardiovascular risk in a reciprocal fashion.

Shen also emphasized that their study looked only at older men—other psychosocial conditions might play a more important role in women or at different stages of life. Whether all of these psychosocial factors have a single root cause, or how they interact, is also "the million-dollar question" and something his group is continuing to investigate.

Shen hopes his paper will serve as a reminder to cardiologists and other physicians to be on the lookout for psychological conditions or dispositions that may be contributing factors in the development of cardiovascular disease. Cardiologists, he says, are getting the message about depression. "We want to increase awareness that anxiety, particularly chronic pervasive anxiety . . . is also an important risk factor, especially in older males."