If you often get nostalgic thinking about the joys you had when you were single, new research suggests that being married also has its merits. Researchers have found that unmarried heart patients face a higher risk of death.

Compared to married heart disease patients, being unmarried was associated with a higher risk of dying, said the study published in the Journal of the American Heart Association.

"I was somewhat surprised by the magnitude of the influence of being married has (on heart patients)," said lead researcher Arshed Quyyumi, Professor of Medicine at Emory University in Atlanta, US.

"Social support provided by marriage, and perhaps many other benefits of companionship, are important for people with heart disease," Quyyumi said.

The study of 6,051 patients (average age 63) undergoing cardiac catheterisation for coronary artery disease showed poor outcomes specifically among those who were divorced, separated, widowed or never married.

The researchers followed the patients for nearly four years.

The findings showed that compared to married patients, being unmarried was associated with 24 percent higher risk of death from any cause and 45 percent higher risk of death from cardiovascular disease.

And specifically, the risk of heart attack was 40 percent higher for those who were never married, the study said.