Patients with heart disease who are subsequently diagnosed with depression are twice as likely to develop heart failure, US researchers claim.
Previous studies have shown that depression is a clinically significant risk factor for developing heart disease, especially for men and women aged between 25 and 50.
This latest study focused on the impact of depression following hospitalisation for coronary artery disease (CAD) and involved 13,708 patients with an average age of 64.
The patients had all suffered a heart attack but did not have a diagnosis of heart failure or depression.
The patients were then followed for 5.6 years for any signs of heart failure and depression.
Overall, the researchers found that 1,377 patients went on to be diagnosed with depression, and 674 patients developed heart failure.
Among those diagnosed with depression, 695 patients reported taking medicines to control their symptoms.
Patients with depression were found to be twice as likely to develop heart failure as patients who were not depressed.
But patients who were taking antidepressants for their depression had the same risk of developing heart failure as patients who were not taking medication for their depression.
The researchers suggest that depressed patients have poorer medication adherence, which may explain why they are more likely to develop heart failure.
But they add that depression is also associated with heart rate variability and elevated inflammatory levels.
Lead researcher Dr Heidi May, from the Intermountain Medical Centre in Utah, said: 'Our data suggests that depression is an important and emerging risk factor for heart failure among patients with coronary heart disease.
'Interestingly, when we stratified patients with depression by whether they received antidepressant medication or not, the incidence of heart failure didn't change.'
This finding may indicate that antidepressants may not be able to alter the physical or behavioural risks associated with depression and heart failure, despite a potential improvement in depressive symptoms, she said.
Comment below and tell us what you think