A surprising new study showed that marriage is an unexpected factor affecting the survival rate of people suffering from heart attacks.

A family can get you through a lot of rough times — including a heart attack.

The massive study analyzed just under 1 million patients, of which 25,287 had a previous heart attack, 168,431 had high blood pressure, 53,055 had high cholesterol, and 68,098 had type 2 diabetes mellitus. For the purpose of the study, participants were defined as single, married, divorced, or widowed and followed up until 2013 for mortality.

Immediately, an intriguing correlation emerged: married patients were 14% more likely than single patients to survive a heart attack. Similar figures stood for patients who also had high cholesterol, high blood pressure, or diabetes. Although the importance of having a spouse for support has been suggested in previous studies, this is by far the largest of its kind.

Dr Paul Carter, lead author of the study said:

“Marriage, and having a spouse at home, is likely to offer emotional and physical support on a number of levels ranging from encouraging patients to live healthier lifestyles, helping them to cope with the condition and helping them to comply to their medical treatments. Our findings suggest that marriage is one way that patients can receive support to successfully control their risk factors for heart disease, and ultimately survive with them.”

Similarly, people who were divorced seem to fare worse than the average.

“The nature of a relationship is important and there is a lot of evidence that stress and stressful life events, such as divorce, are linked to heart disease,” added Dr Carter. “With this in mind, we also found that divorced patients with high blood pressure or a previous heart attack had lower survival rates than married patients with the same condition.”

This raises an interesting question — is it something specific to heart attacks, or does it carry out to all serious illnesses? Previous studies have indicated that marriage (or a serious relationship) also raises the odds of cancer survival, so it seems quite safe to say that having a person to rely on can make a big difference.

However, it’s unclear exactly how this support manifests itself. It could be the mental aspect that does all the difference, or it could be that married people are more likely to stick to a healthy regimen and avoid risk factors.

The findings were presented at the ESC Cardio conference and have not yet been peer reviewed.