Dr Ferketich said: "The level of psychological distress among the healthy population is estimated to be 2.8%. But, we found that in our study over 4.1% with coronary heart disease and 6.4% with MI had psychological distress. And for those with congestive heart failure the figure was as high as one in 10."
She said that the increased level among those with CHD was not statistically significant, but for those who had MI it was double that of the healthy population and triple for those with heart failure. In each disease category the level of distress was higher if the illness had been diagnosed within the last 12 months.
"Because of the way the NHIS conducts its survey we know that our study group is representative of the general population in the USA with heart disease," she said. "This means there are over one million in the USA with a history of CHD, MI or CHF experiencing psychological distress."
There was a higher proportion of females, individuals with less than a high school education, Hispanics and non-Hispanic black people, the obese, non-drinkers, current smokers, the sedentary and individuals with hypertension or diabetes among heart disease patients with elevated distress levels.
"It's hard to know why, but we typically see this in research," said Dr Ferketich. "It may be that there are additional sources of stress in individuals in these groups."
The findings suggested that psychological distress was a significant co-morbidity (associated condition) of cardiovascular disease, according to co-author Dr Binkley.
"All the symptoms of psychological distress measured on the K6 sadness, nervousness, restlessness, hopelessness, worthlessness and the feeling that everything is an effort are more prevalent among respondents with one or more of the heart diseases. So, we are not talking here about an unequal distribution of one or two particular symptoms.
Contact: Margaret Willson
European Society of Cardiology