Association between depression and development of coronary artery disease: pathophysiologic and diagnostic implications

Depression and coronary artery disease (CAD) are both extremely prevalent diseases. In addition, compromised quality of life and life expectancy are characteristics of both situations. There are several conditions that aggravate depression and facilitate the development of CAD, as well as provoke a worse prognosis in patients with already established CAD: inferior adherence to medical orientations (medications and life style modifications), greater platelet activation and aggregation, endothelial dysfunction, and impaired autonomic dysfunction (lowered heart rate variability). Recent literature has shown that depression alone is becoming an independent risk factor for cardiac events both in primary and secondary prevention. As the diagnosis of depression in patients with heart disease is difficult, due to similarities of symptoms, the health professional should perform a careful evaluation to differentiate the clinical signs of depression from those related with general heart diseases. After a myocardial infarction, depression is an independent risk factor for mortality. Successful therapy of depression has been shown to improve patients' quality of life and cardiovascular outcome. However, multicentric clinical trials are needed to support this inference. A practical liaison between qualified professionals is necessary for the better management of depressed patients with excess risk in developing CAD. Accordingly, pathophysiological and clinical implications between depression and CAD are discussed in this article.