NEW YORK (Reuters Health) Mar 06 - Patients with coronary artery disease (CAD) may be at increased risk of death while using antidepressant drugs, according to results of an observational study reported at the American Psychosomatic Society in Denver.
However, "people with heart disease should definitely not stop taking their antidepressants, because we do not know if antidepressants were causing this (increased risk) or if it was due to some other characteristics of folks who are on antidepressants," presenter Dr. Lana L. Watkins told Reuters Health.
Their study was "a prospective evaluation of the contribution of anxiety and depression to the risk of sudden cardiac death in patients with coronary artery disease," the researcher noted.
Dr. Watkins and her colleagues at Duke University in Durham, North Carolina, monitored depressive symptoms and antidepressant use among 921 patients ages 29 to 90 years who were hospitalized for diagnostic coronary angiography. "All the patients had a history of or current CAD," she said.
Antidepressants were being used by 19.4% of subjects. Two thirds of the antidepressants were selective serotonin reuptake inhibitors (SSRIs).
During a mean of 3 years of follow-up, 21.4% of those taking antidepressants died, compared with 12.5% of those not on antidepressants. After adjusting for demographics, left ventricular ejection fraction, Beck Depression Inventory score, and comorbidities, antidepressant use remained an independent risk factor for mortality (hazard ratio 1.62, p = 0.029).
"We have to be clear about the fact that because this was not a placebo-controlled trial, it's possible that patients taking antidepressants had other factors (that could account for the increased risk), so our finding could be an epiphenomenon," Dr. Watkins emphasized.
For example, people on antidepressants may be sicker or more depressed, she explained, which in turn could lead to suppression of the immune system or an increase in cardiovascular risk factors such as hypertension, physical inactivity or alcohol or tobacco abuse.
"That is why it would be very premature for patients to stop taking their medications."
She does advise physicians to closely monitor their CAD patients who are taking antidepressants. Meanwhile, she and her associates are planning a more rigorous, placebo-controlled trial to tease apart the factors contributing to mortality risk in CAD patients.