Impact of depression on sex differences in outcome after myocardial infarction

Women have an unexplained worse outcome after myocardial infarction (MI) compared with men in many studies. Depressive symptoms predict adverse post-MI outcomes and are more prevalent among women than men. We examined whether depressive symptoms contribute to women's worse outcomes after MI.

In a prospective multicenter study (PREMIER), 2411 (807 women) MI patients were enrolled. Depressive symptoms were assessed with the Patient Health Questionnaire. Outcomes included 1-year rehospitalization, presence of angina using the Seattle Angina Questionnaire, and 2-year mortality. Multivariable analyses were used to evaluate the association between sex and these outcomes, adjusting for clinical characteristics. The depressive symptoms score was added to the models to evaluate whether it attenuated the association between sex and outcomes. Depressive symptoms were more prevalent in women compared with men (29% versus 18.8%, P<0.001). After adjusting for demographic factors, comorbidities, and MI severity, women had a mildly higher risk of rehospitalization (hazard ratio, 1.20; 95% CI, 1.04 to 1.40), angina (odds ratio, 1.32; 95% CI, 1.00 to 1.75), and mortality (hazard ratio, 1.27; 95% CI, 0.98 to 1.64). After adding depressive symptoms to the multivariable models, the relationship further declined toward the null, particularly for rehospitalization (hazard ratio, 1.14; 95% CI, 0.98 to 1.34) and angina (odds ratio, 1.22; 95% CI, 0.91 to 1.63), whereas there was little change in the estimate for mortality (hazard ratio, 1.24; 95% CI, 0.95 to 1.62). Depressive symptoms were significantly associated with each of the study outcomes with a similar magnitude of effect in both women and men.

A higher prevalence of depressive symptoms in women modestly contributes to their higher rates of rehospitalization and angina compared with men but not mortality after MI. Our results support the recent recommendations of improving recognition of depressive symptoms after MI.