You survived a heart attack. Now what about the depression?

Heart attack patients with prolonged depression or anxiety are at a higher risk of death. That's the finding of research published today in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC).

"Temporary mood swings, if they are not too frequent or dramatic, are a normal part of life," said study author Dr. Erik Olsson, of Uppsala University, Sweden. "Feeling a little depressed after a heart attack might even be a good thing if it makes you withdraw a bit and get some rest. Emotional states help us regulate our behaviours."

"On the other hand, chronic emotional distress makes it harder to adopt the lifestyle changes that improve prognosis after a heart attack," he continued. "These include quitting smoking, being physically active, eating healthily, reducing stress, and taking prescribed medications."

Previous research has shown that emotional distress, such as depression and anxiety, affects prognosis after a heart attack. This was the first study to examine prognosis according to the duration of distress. The study included 57,602 patients from the national SWEDEHEART registers who survived at least one year after a first heart attack. Emotional distress (including depression and anxiety) was measured at 2 and 12 months after the heart attack. Patients were then followed-up for a median of 4.3 years.

The study shows that persistent emotional distress over 1 year impacts on prognosis, whereas short-term distress does not. Compared to those with no emotional distress, patients who felt depressed or anxious at both time points were 46 percent and 54 percent more likely to die from cardiovascular and non-cardiovascular causes, respectively, during follow-up. Patients who felt distressed only at 2 months were not at increased risk.

More than 20 percent of patients fell into the category of persistent emotional distress. Previous research shows that this state is mainly linked with sociodemographic, rather than clinical, factors.2 For example being younger, female, born abroad, and unemployed (versus employed or retired).

"It appears that the Matthew effect3 also applies to cardiac rehabilitation, whereby those who have continue to benefit whereas those without do not," said Dr. Olsson. "Better resources in life including education and cognitive ability enable us to handle difficult patches, while a good job with a good salary gives us more control over our circumstances. This is not the case for people with a tougher life—we know for example that immigrants who have fled from difficult situations are less likely to get the right treatment."

Most cardiac rehabilitation clinics offer some kind of counselling and Dr. Olsson said this could be a good opportunity for people with continual feelings of anxiety or depression to get help.

Some 15 percent of participants felt anxious or depressed at 2 months but then recovered. "These are likely to be people with a higher socioeconomic status who have good coping mechanisms," said Dr. Olsson.

To recover from the initial emotional reaction to a heart attack, he said: "Try to keep doing your usual activities, at least the positive ones. Some patients begin to avoid exercise and sex because they are afraid of triggering another event, but most things that feel risky are not. If you're in a low mood you may expect less enjoyment from socialising, but then find it is more pleasurable than you predicted. If you haven't been depressed or anxious before, at least not very often, don't worry about it. It is likely a normal reaction to a life-threatening event which is also partly biological."

Dr. Olsson noted that 10 percent of patients in the study felt distressed only at 12 months, and they were 46 percent more likely to die from non-cardiovascular causes during follow-up. "This distress is unlikely to be related to the heart attack," he said. "These patients resemble those with persistent distress in terms of education, marital status, and employment, and may be another fragile group."