A European study found that people who survive a heart attack may be at a higher risk of a second one if they are divorced.

Researchers from the Karolinska Institutet in Stockholm, Sweden, looked at 29,226 participants ages 40-76 one year after surviving their first heart attack.

The team recorded the marital status (married, unmarried, divorced, widowed), socioeconomic status (measured by disposable income) and educational level (nine years or less, 10-12 years, more than 12 years) of each participant, and then continued to follow them for an average of four years.

Divorced participants had an 18 percent greater risk of a recurrent event than married patients, while those in the highest household income quintile had a 35 percent lower risk of a second attack than those in the lowest quintile.

In addition, patients with more than 12 years of education had a 14 percent lower risk of a recurrent event than those with nine.