抗うつ薬は心血管転帰を改善する (Abstract 1178-111)

A new study found that screening for and treating depression could help to reduce the risk of heart disease in patients with moderate to severe depression.

Researchers at the Intermountain Medical Center Heart Institute in Salt Lake City analyzed the health records and rates of death, coronary artery disease and stroke of more than 26,000 patients treated in the statewide network of health centers over a three-year period. Patients completed a nine-question depression-screening questionnaire, which assessed such factors as mood, sleep and appetite, to determine their level of depressive symptoms. Based on the questionnaires, researchers identified 5,311 patients as having moderate to severe depression and 21,517 patients as having no to mild depression.

The study, which was presented March 15 at the American College of Cardiology's 64th Annual Scientific Session in San Diego, found patients with moderate to severe depression who took antidepressants alone had a lower risk of death, coronary artery disease and stroke than patients with moderate to severe depression who did not take antidepressant or statin medications. Taking statins alone or in combination with antidepressants was not associated with a significant risk reduction in this group of patients.

"What I take away from this study is that screening and treatment of depressive symptoms should be a high priority," said Heidi May, Ph.D., M.S.P.H., a cardiovascular epidemiologist at the Intermountain Medical Center Heart Institute, Salt Lake City, and the study's lead author. "Antidepressants were not associated with a reduced cardiovascular risk in people with little or no depression, but in moderately to severely depressed people, antidepressants were shown to significantly improve cardiovascular outcomes."

Depression is a known risk factor for cardiovascular disease. Previous studies assessing the impact of antidepressants on this risk have had mixed results, with some suggesting antidepressants have a positive effect and others suggesting a negative effect. This is the first study to assess the relative effects of the simultaneous use of antidepressants and cholesterol-lowering drugs among patients with varying levels of depressive symptoms.

Patients with moderate to severe depression who were taking antidepressants alone had a 53 percent lower risk of dying, developing coronary artery disease or having a stroke during the three-year follow-up period as compared to patients with moderate to severe depression who were not taking antidepressants or statins. Moderately to severely depressed patients taking antidepressants alone appeared to also fare better than those taking statins alone or a combination of statins and antidepressants, although these relationships were not directly analyzed.

"We thought we'd see an additive effect—that taking both medications would lower the risk more than either drug alone—but we found that in the more depressed people, the antidepressant really was what made the biggest difference," May said. "Focus is usually placed more on traditional cardiovascular risk factors and unfortunately, depression is often overlooked. This study adds to the evidence that, when used properly, antidepressants can improve cardiovascular outcomes among those with depressive symptoms."

The researchers excluded from the analysis patients with known cardiovascular disease such as heart failure, coronary artery disease, or a previous heart attack or stroke. They also excluded those who were already taking antidepressants when they completed the questionnaire.

Although the study did not directly investigate how antidepressants might improve cardiovascular health, May said the link could be related to behavioral changes.

"Antidepressants might have relevant physiological benefits, but I also think that improving a person's mood can contribute to a cascade of behavioral changes that improve cardiovascular health," May said. "For example, people who are having depressive symptoms may not be as inclined to exercise, practice good health habits or comply with health advice. Using an antidepressant to reduce depressive symptoms might also help people better take care of their heart health." 

The analysis accounted for standard cardiovascular risk factors such as diabetes, smoking and hypertension. However, because the study only included information that was available in patients' health records, the researchers were unable to account for other factors such as level of physical activity, changes in habits or non-drug mental health treatment such as psychotherapy. May said future studies could help to further refine understanding of the relationships between depression, antidepressants and cardiovascular health.

Findings from another study presented at ACC.15 also add to the evidence that depression may influence cardiovascular outcomes, prompting authors to call on cardiologists to pay closer attention to depression when managing patients with heart disease.

Researchers at Care Institute of Medical Sciences in India found depression to be independently associated with a greater chance of cardiovascular death and lower quality of life (e.g., overall well-being, emotional stability, physical activity). In fact, depressed patients had nearly double the risk of dying over the three-year study period compared with those who are not depressed. Being readmitted to the hospital or needing repeated angioplasty to open blocked arteries was unaffected by depression status. All told, 40 percent of 1,648 subjects studied had depression.

Keyur Parikh, M.D., and his colleagues say this study, while limited to India, is among the first to examine the relationship between depression and hospitalization, revascularization and death. Based on the results, clinicians have introduced yoga and cognitive behavioral therapy into ongoing cardiac rehab programs and plan to evaluate whether this might improve outcomes.