Heart bypass patients with supportive spouses are more than three times as likely to still be alive 15 years later than those who have never tied the knot, a study found.
They were also often more likely to live to tell the tale than those in bad marriages.
Women particularly benefit from having their husbandâ€™s shoulder to lean on, although male patients also do better if they are happy in their marriage.
The US researchers said there is something about a good marriage that â€˜gets under the skinâ€™ â€“ benefiting heart health to the same extent as quitting smoking, keeping trim and keeping a lid on high blood pressure.
She tracked the health of 225 men and women who had heart bypass surgery, a major operation in which surgeons take a vein from the patientâ€™s leg or chest to divert blood around a furred or blocked artery.
In triple or quadruple bypass surgery, three of four arteries are bypassed at the same time.
A year after the op, those who were married were asked to rate their satisfaction with their relationship.
Fifteen years later, 83 per cent of the happily wedded women were still alive, versus 28 per cent of those in unhappy marriages and 27 per cent of unmarried women.
The survival rate of contented husbands was also 83 per cent.Â But this time, the unhappily married fared significantly better than the bachelors.
Some sixty per cent of the men in less than happy marriages lived for at least 15 years after their op, compared with just 36 of those who had never married, the journal Health Psychology reports.
Researcher Kathleen King said: â€˜There is something in a good relationship that helps people stay on track.
â€˜Coronary bypass surgery was once seen as a miracle cure for heart disease.Â But now we know that for most patients, grafts are a temporary patch, even more susceptible to clogging and disease than native arteries.
â€˜So itâ€™s important to look at the conditions that allow some patients to beat the odds.â€™
Professor King, of the University of Rochester, New York State, said it is likely that caring and concerned spouses help by encouraging health behaviour such as stopping smoking or doing more exercise.
Loving and being loved back may also give people a powerful reason to â€˜stick around so they can stay in a relationship that they likeâ€™.
A previous British study found that those in a marriage marred by arguments are 34 per cent more likely to suffer from heart disease – including fatal heart attacks – than those in more tranquil relationships.
It is thought the strain of conflict with our nearest and dearest can damage the heart in a range of ways, from causing fluctuations in heart rate and blood pressure to interfering with blood clotting and the immune system.