The researchers said that, based on the results of their analysis of more than 4,700 heart patients, that physicians treating heart surgery patients should not only screen for depression prior to surgery, but that they should also pay closer attention to the long-term psychiatric care of patients deemed to be depressed.
"While many studies have shown that depression is just as important a cardiac risk factor as hypertension and smoking, there are still many in the field who do not fully appreciate this mind-body link," said Glen Xiong, M.D., who presented the results of the Duke study May 25, 2005, during the annual scientific sessions of the American Psychiatric Association in Atlanta.
"This under-appreciation may be because of the stigma associated with mental health issues," said Xiong, a resident in Duke's Medicine-Psychiatry program. "Many think that patients who have just had a heart attack are depressed and that with time, they'll get over it. Our study would indicate that these are the very patients who need to be followed more closely."
Their analysis of 4,794 heart surgery patients at Duke from 1999 to 2003 found that 5.1 percent of patients were taking SSRIs prior to surgery. When the researchers then checked survival rates four years later, they found that 75.1 percent of patients taking SSRIs were still alive, compared to 84.9 percent who weren't taking SSRIs.
"However, when we looked at the 30 days mortality following the operation, both groups were about the same," Xiong said. "It's only when patients get farther out from surgery that the mortality rates begin to increase among patients who were taking SSRIs prior to the heart surgery. We believe that this increase is due more to the underlying depression itself than medication use. It appears that for our study, SSRI usage serves as a marker for the depressed patients."
The researchers added that depression is associated with many physiological and psychosocial characteristics that likely explain why depressed patients tend to fare worse over time.
The researchers also found that those patients taking SSRIs were as a group significantly more often white than those who were not (85.8 percent vs. 76.2 percent) and female (43.9 percent vs. 29 percent). The SSRI group also was more likely to have diabetes, high blood pressure and increased cholesterol levels when compared to the non-SSRI group.
"We also know that depressed patients are less likely to take their medications, go to the doctor or rehab program regularly, eat healthy diets or stop smoking," Xiong continued. "It is precisely for these reasons we believe that these high-risk surgery patients need to receive appropriate treatment for depression."
"In our cohort of patients, only five percent were taking SSRIs, which we believe greatly under-represents the number of depressed heart patients," said Duke internist and psychiatrist Wei Jiang, M.D., Xiong's mentor and a senior member of the research team. "Nationally, it is believed that up to twenty percent of heart patients are depressed. This raises that concern that many depressed patients are being under-treated for their depression, and that we can save lives if we identify and treat depression appropriately."
"In many ways, this study raises more questions than it answers," Jiang continued. "It raises questions of how we treat depression in hearts disease – we need to see it as a long-term, chronic condition. I think we need to conduct longer-term studies to see if anti-depression medications and psychotherapy can influence the mortality rates for these patients."
Xiong added: "Just as importantly, we need to see if we should introduce a depression screening tool in our standard treatment for patients with heart disease. Should we be screening and monitoring for depression more regularly, like we do for hypertension and hypercholesterolemia?"
The study was supported by Duke's Department of Psychiatry and the Duke Clinical Research Institute.
Other members of the Duke team were Kristin Newby, M.D., Bob Clare, Linda Shaw, Peter Smith M.D., Kenneth Mahaffey, M.D., Chris O'Connor, M.D. and Ranga Krishnan, M.D.