Background: Depression is common after acute myocardial infarction and is associated with an increased risk of mortality for at least 18 months. The prevalence and prognostic impact of depression in patients with unstable angina, who account for a substantial portion of acute coronary syndrome admissions, have not been examined.
Methods: Interviews were carried out in hospital with 430 patients with unstable angina who did not require coronary artery bypass surgery before hospital discharge. Depression was assessed using the 21-item self-report Beck Depression Inventory and was defined as a score of 10 or higher. The primary outcome was 1-year cardiac death or nonfatal myocardial infarction.
Results: The Beck Depression Inventory identified depression in 41.4% of patients. Depressed patients were more likely to experience cardiac death or nonfatal myocardial infarction than other patients (odds ratio, 4.68; 95% confidence interval, 1.94-11.27; P<.001). The impact of depression remained after controlling for other significant prognostic factors, including baseline electrocardiographic evidence of ischemia, left ventricular ejection fraction, and the number of diseased coronary vessels (adjusted odds ratio, 6.73; 95% confidence interval, 2.43-18.64; P<.001).
Conclusions: Depression is common following an episode of unstable angina and is associated with an increased risk of major cardiac events during the following year.