Is mental stress bad for your heart if you have post-heart attack depression?

This study included heart attack patients and investigated whether those with post-heart attack depression are more likely to develop reduced heart blood flow (ischemia) from mental-stress. 

Coronary artery disease refers to when blood vessels that supply the heart muscle with blood and oxygen (coronary arteries) become blocked. When a coronary artery becomes completely blocked, a heart attack occurs and can cause death of part of the heart muscle.

About 20% of patients that survive a heart attack develop depression. These patients are more likely to have worse outcomes and have a recurrent heart attack compared to heart attack patients that do not develop depression.  

One possible reason for this is that depressed patients are more susceptible to mental stress, which is associated with doubling the risk of heart events (such as a heart attack) and death in stable coronary artery disease patients. 

This study investigated whether patients with post-heart attack depression are likely to develop reduced coronary artery blood flow to the heart (heart ischemia) from mental stress. Mental stress (e.g. from public speaking) was compared with physical stress (exercise) to see whether it is mental stress that causes heart ischemia in depressed post-heart attack patients.  

Patients were aged <60 years who had a heart attack in the previous 6 months. There were 49 males and 49 females in the study. Patients were examined to see if they had symptoms of depression.

Ischemia was measured using a type of imaging scan, called single-photon emission computed tomography (SPECT). Patients underwent three SPECT imaging scans, one with rest, one with mental stress (public speaking task) and one with physical stress (e.g. running on a treadmill).

The study found that depressive symptoms were significantly associated with ischemia from mental stress, with those with more symptoms experiencing higher levels of mental stress-induced ischemia. All depressive symptoms, such as sleep and appetite disturbance, or feelings of sadness and pessimism were associated with increased ischemia. Depressive symptoms were not associated with physical stress-induced ischemia. 

The study concluded that higher levels of depression among post-heart attack patients is associated with a higher risk of developing heart ischemia from mental stress, increasing the risk of recurrent heart attack. 

The study only included a small number of patients, which means that it is not known how accurate the data is. 

If you or someone you know have had a heart attack and subsequently developed symptoms of depression, talk to a doctor about ways to manage and treat depression in order to increase your chances of a better outcome.