Scientists have said that the increased risk of cardiovascular events for patients with coronary heart disease and symptoms of depression may be because of change in health behaviours, especially a lack of physical activity.

For a long time, depression has been recognized as a risk factor for the development of cardiovascular disease in healthy patients and for recurrent events in patients with established cardiovascular disease.

Despite the substantial body of evidence demonstrating a strong link between depression and cardiovascular disease, the explanation for this association remains unclear, according to background information in the article.

"Understanding how depression leads to cardiovascular events is necessary for developing interventions to decrease the excess cardiovascular morbidity [illness] and mortality [death] associated with depression," wrote the authors.

The study by Mary A. Whooley, M.D., of the VA Medical Center, San Francisco, and colleagues was conducted for determining why depressive symptoms are associated with an increased risk of cardiovascular events. The study included 1,017 outpatients with stable coronary heart disease followed-up for an average of 4.8 years.

Symptoms of depression were measured with a questionnaire, and various models were used to evaluate the extent to which the association of depressive symptoms with subsequent cardiovascular events (heart failure, heart attack, stroke, transient ischemic attack [a temporary cessation or reduction of blood supply to part of the brain], or death) were explained by disease severity at the beginning of the study and potential biological or behavioral factors.

It was found that participants with depressive symptoms had a 50 per cent greater risk of cardiovascular events: the age-adjusted annual rate of cardiovascular events was 10.0 percent among the 199 participants with depressive symptoms and 6.7 per cent among the 818 participants without depressive symptoms.

... contd.