Depression Can Be Deadly After Bypass
More Depressed Patients Die After Bypass Surgery Than Non-Depressed
Aug. 21, 2003 -- Heart patients who suffer from depression immediately before or after coronary artery bypass surgery face an increased risk of early death, Duke University researchers report.
Depressed patients followed for an average of five years after the bypass surgery were twice as likely to die as patients who were not depressed in the largest and longest study of its kind.
Although researchers did not measure the impact of treating depression on outcomes, they suggest that screening for it before and after surgery could improve patient outcome. Their findings are published in the Aug. 23 issue of the journal The Lancet.
"Despite our advances in surgical and medical management of patients after coronary artery bypass surgery, depression is an important independent predictor of death after surgery and should be carefully monitored and treated if necessary," researcher and clinical psychologist James Blumenthal, PhD, says in a news release. "We believe that psychological assessment before and after surgery could be a low-cost and relatively easy way of potentially saving lives."
Blumenthal and colleagues examined the medical records of roughly 800 bypass surgery patients treated at Duke University Medical Center who filled out psychological questionnaires immediately before surgery and six months later. Thirty-eight percent met the clinical definition for depression before surgery, with 12% experiencing moderate to severe symptoms.
There were 122 deaths during a follow-up. Death occurred in about 10% of those who were not depressed before or after bypass surgery, compared with 19% for those who were persistently depressed.
For those patients with mild depression and whose depression symptoms remained after bypass surgery, the rates of death were similar to those who had had depression classified as moderate to severe.
"We don't exactly know how depression influences mortality, but there are many possible explanations," study researcher Heather S. Lett tells WebMD. "Depressed patients may be less likely to follow the health advice of their doctors when told to do things like give up smoking or exercise. And there is a link between depression and risk factors for cardiovascular disease like hypertension and diabetes."
Lett says it is not clear from the Duke study if treating depression improves survival among heart patients. The largest study ever to look at that issue, reported by researchers from Washington University and the Mayo Clinic two months ago, found that treatment of depression did not improvement survival. In the Enhancing Recovery in Coronary Heart Disease Patients Study (ENRICHD), survival among depressed heart attack patients who received treatment for depression was no better than those who did not.
The lead researcher of that study, Robert M. Carney, PhD, says he was surprised and disappointed by the findings but still believes treatment of depression in patients with heart disease can improve survival.
"We know that depression is associated with a higher risk for death and cardiac complications. It stands to reason that treatment can lower this risk," Carney tells WebMD. "But clearly one benefit that we can be certain of at this point is that a depressed patient's quality of life will be very much improved with treatment. And that is more than enough justification for screening cardiac patients."