PTSD predicts doubled risk of CHD in middle-aged veterans

Atlanta, GA - In a study of middle-aged male twins who were Vietnam-era veterans, those who had posttraumatic stress disorder (PTSD) were twice as likely to develop coronary heart disease within the next decade compared with their brothers who were free of PTSD—independent of traditional risk factors for CHD ^[1].

The study, which used myocardial perfusion imaging as well as clinical events to determine the incidence of CHD, was published online June 25, 2013 in the Journal of the American College of Cardiology .

"This is the first study to use objective measuring of ischemic heart disease to confirm that PTSD is a risk factor for heart disease," Dr Viola Vaccarino (Emory University, Atlanta, GA), told heartwire .

In the twins with PTSD, "we did find that smoking behavior, [lack of] physical activity, drinking more alcohol—the behavioral lifestyle factors—were more [common], as expected, but we did not find [increases in] the other risk factors such as high blood pressure and lipid profile," which was "unexpected," she added.

Counseling patients with PTSD to control traditional risk factors as well as improving adverse lifestyle behaviors "would be a good place to start" to prevent heart disease, she noted. Since stress may play a role, "it would be useful for people with PTSD try to control their symptoms, possibly with medication . . . meditation, breathing exercises, [and] regular physical activity . . . which may seem obvious but are very important measures."

Does PTSD really up heart disease risk?

Although many studies have reported a link between PTSD and the development of CHD, the results have been inconsistent, and many studies were cross-sectional or based on self reports, the authors write.

They sought to clarify this relationship by using an objective measure of CHD in a population of veterans.

They conducted a prospective study of 562 male twins—340 identical twins and 222 fraternal twins—from the Vietnam Era Twin Registry who had replied to a survey asking about PTSD and depression in 1992 (baseline) and who did not report having cardiovascular disease then.

At baseline, the participants had a mean age of 42.6 years, and 137 individuals had PTSD. All participants had been active in the military; about half had served in the Vietnam War, and about 98% were white.

After a mean follow-up of 13 years, the participants underwent myocardial perfusion imaging with positive emission tomography (PET) ^[13]N] ammonia at rest and after pharmacologic stress (with adenosine). They also reported whether they had symptomatic CHD—MI, overnight hospitalization for CHD, a revascularization procedure—or a stroke or transient ischemic attack.

A total of 69 twins developed CHD during follow-up. The incidence of CHD was more than double in the twins with PTSD compared with those without PTSD (22.6% vs 8.9%). The association remained robust—odds ratio 2.1 (95% CI 1.1-3.9)—after adjustment for sociodemographic factors, service in Southeast Asia, lifestyle, other CHD risk factors, major depression, and other psychiatric diagnoses.

Compared with their twin brothers with no PTSD, those with PTSD had a higher stress total severity score, denoting the presence of more perfusion defects, and a significantly lower coronary flow reserve, a measure of microvascular function.

Thus, the increased risk of CHD in the twins with PTSD was confirmed by quantitative measures of coronary perfusion and myocardial blood flow and not explained away by CHD risk factors, adverse health behaviors, or familial risk factors, Vaccarino summarized.

The etiology remains to be unraveled, she added. Individuals with PTSD experience an arousal response—increased heart rate, blood pressure, and stress hormones—when they are exposed to reminders of the trauma in their everyday life. "It could be that this repeated exposure . . . may have a cumulative adverse effect . . . [that could lead to] a greater risk for acute ischemia or arrhythmia," she speculated.

Important study, "powerful" cardiac imaging results

In an accompanying editorial ^[2], Dr Stephen Sidney (Kaiser Permanente Northern California Division of Research, Oakland) writes that this study adds further support for a potential causal association between PTSD and coronary disease.

"The Vaccarino study is particularly important because of the powerful association of PTSD with impaired myocardial coronary perfusion assessed by PET imaging," he writes. Clinicians need to be aware of this increased risk of CHD in patients with PTSD. "Our consciousness should be raised to the importance of obtaining a history of exposures that are associated with PTSD risk and to perform or refer patients for screening, diagnosis, and treatment, when appropriate."

Heartwire from Medscape © 2013 

Cite this: PTSD predicts doubled risk of CHD in middle-aged veterans - Medscape - Jun 28, 2013.