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THURSDAY, Aug. 21, 2003 (HealthDayNews) -- People who are depressed before and after cardiac bypass operations are twice as likely to die within five years of the surgery as people who are not depressed, claims new research.
While other studies have noted this phenomenon, the latest study is the largest and longest to date.
"This study really puts depression on the map as a risk factor that needs to be considered by physicians," says lead researcher James Blumenthal, a professor of medical psychology at Duke University.
Blumenthal and his colleagues studied 817 people who had bypass surgery, first asking them to fill out a questionnaire before their surgery evaluating depression and then asking them to complete the questionnaire again after six months.
According to the study, which appears in the Aug. 23 issue of The Lancet, 310 people had some form of depression. After 12 years of follow-up, 122 people had died.
Of those who died, 10 percent had never been depressed, compared with 19 percent who were persistently depressed.
There have never been studies that look at treating depression before and after bypass surgery, Blumenthal notes. "We don't know whether treating patients for depression would make a difference in their outcome," he says, "but that would be important for future studies to determine."
While the reasons for the link between depression and death are not clear, Blumenthal says that depressed patients are less likely to take their medication and less likely to exercise. These behavorial factors might contribute to their increased risk, he says.
"There are also physiological differences between people that are depressed and people that aren't depressed," Blumenthal says. "For example, people who are depressed have greater stickiness in their blood, which increases clotting." They also have a greater variability in their heart rate, he adds.
Doctors need to pay attention to depression, as well as other factors considered in people undergoing bypass surgery, Blumenthal says.
And patients need to recognize the physical, not just the psychological, consequences of depression, he says.
"If you have symptoms of depression, you should discuss this with your physician in the same way you would talk about chest pain or other cardiac risk factors," he advises. While physicians may be more aware of the importance of recognizing depression, it's up to patients to help their doctors understand how they're feeling, Blumenthal says.
Richard Sloan, a professor of medical psychology at Columbia University, says the findings are not surprising.
"There is a growing and substantial literature showing that depression is associated with an increased risk of adverse cardiovascular events," he says.
However, "this study is far and away the most comprehensive study of depression among patients undergoing bypass surgery," he adds. "It's a very solid finding."
"Screening for depression ought to be routine for patients undergoing heart surgery because, as this study points out, depression doubles the risk of death after surgery, even with all the improvements in technique," Sloan says.
More information
To learn more about bypass surgery, visit the American Heart Association. The National Institute of Mental Health can help explain depression.
