Patients battling depression after a heart attack may be much more likely to suffer a stroke, according to new research presented at ACC.22, the American College of Cardiology’s 71st Annual Scientific Session.

The team behind the analysis tracked nearly 500,000 patients who suffered a heart attack between 2015 and 2021. Approximately 51,000 patients, 10.5% of the total cohort, had a diagnosis of depression following their heart attack.

All data came from the TriNetX database, and the patients all had similar backgrounds and demographics.

“The only difference between these two cohorts is that one has depression,” lead author Frank H. Annie, PhD, a research scientist in the department of cardiology at Charleston Area Medical Center in Charleston, West Virginia, said in a statement. “There could be a multitude of depression-related factors that are leading to these outcomes. What we’re seeing in this data is very troubling, and we need to dig deeper to understand the causes and effects.”

Overall, Annie et al. found, 12% of patients with a diagnosis of depression suffered a stroke. Among patients with no diagnosis of depression, the stroke rate was 8.3%.

The authors noted that depression’s impact on a heart attack survivor’s stroke risk could be explained in a number of ways. For instance, depressed patients may be less likely to attend medical appointments and take prescribed medications, they wrote. Also, depression can impact a person’s sleep habits or make it harder for them to exercise and maintain a healthy diet.

Looking closer at the data, men were more likely to have a diagnosis of depression following a heart attack than women. Also, hypertension, diabetes, coronary artery disease, heart failure and chronic obstructive pulmonary disease were all more common among patients with a diagnosis of depression.