Even after controlling for such factors as age, degree of heart disease and severity of depression, the Duke University Medical Center researchers found that heart patients taking antidepressant medications had a 55% higher risk of dying.
Previously, Duke researchers reported that the presence of depression is an important risk factor for heart patients. This new finding of the risk from antidepressants raises issues about the optimal way to treat depression in cardiac patients, the researchers said.
According to Duke team leader Dr Lana Watkins, the researchers believe their findings add further support for the potential role of non-pharmocological approaches to treating depression in reducing the risk of death in depressed heart patients. She advised physicians caring for heart patients who are taking antidepressants to monitor patients closely.
“We were surprised since antidepressants, particularly the newer class of antidepressants known as selective serotonin reuptake inhibitors (SSRI), have been generally considered safe,” Dr Watkins said. “However, even after taking into account many patient variables, as well as the type of antidepressant, the risk still remained. So there is something important going on here that we don’t fully understand.”
Dr Watkins added that the design of the study prevents definitive conclusions regarding the effects of antidepressant drugs. In the current observational study, patients were not randomized to receive an antidepressant or a placebo drug, therefore characteristics of the patients, such as greater likelihood for their depression or their medical condition to worsen, may be responsible for the effects. Randomized placebo-controlled trials are therefore needed to confirm the Duke findings.
In April, Duke investigators will begin enrolling depressed patients in a randomized trial testing the abilities of exercise and SSRIs to impact such physiological markers of coronary artery disease as platelet aggregation, heart rate variability and baroreflex sensitivity, or the ability of blood vessel walls to respond appropriately to changes in blood pressure.