Depression is an established risk factor for acute coronary syndrome (ACS), nonetheless the mechanisms underlying this association are still unclear and literature disagrees on the role played by anxiety. Moreover, most of the studies included subjects with a long lasting history of heart disease or recurrent depressive episodes that could bias the results.

We performed serial assessments of anxiety, depression and new cardiac events in a cohort of never-depressed patients in the two years after their first ACS.

Clarify the role of anxiety and depression in predicting new cardiac events.

Two hundred and fifty-one consecutive patients completed the two-years follow-up. The presence of depression was evaluated with the Primary Care Evaluation of Mental Disorders (PRIME-MD) and its severity with the Hospital Anxiety and Depression Scale (HADS). Evaluations were collected at baseline, when GRACE-score was calculated, and at 1, 2, 4, 6, 9, 12 and 24-months follow-ups.

Forty-two patients (16.7%) developed a second cardiac event and, of these, eighteen (42.9%) had a previous depressive episode. At Cox Regression, controlling for confounding clinical variables (e.g. GRACE-score), developing a first-ever depressive episode was a significant risk factor (OR=2.38; 95%CI=1.11–5.14; P=0.027) whereas baseline anxiety was protective (OR=0.56; 95%CI=0.38–0.81; P=0.002). The latter, moreover, moderated the effect of incident depression on new cardiac events.

Our results confirm the well-established detrimental effect of depression on cardiac prognosis and suggest clinicians to keep in mind anxious symptoms when facing a patient at his/her first ACS.